Document:

EXHIBIT 10.12

                                OPTION AND ASSET
                           PURCHASE AND SALE AGREEMENT

     THIS AGREEMENT (this "Agreement"), dated as of February 28, 2005, is
entered into by and between Thornton Drilling Company, a Colorado corporation
with a mailing address of P.O. Box 811, Pocola, Oklahoma 74902 (hereinafter
called "Buyer"), and SPA Drilling, L.P., a limited partnership organized under
the laws of the State of Texas, with a mailing address of P.O. Box 6747,
Abilene, Texas (hereinafter called "Seller"),

                                   WITNESSETH:

     That Seller desires to sell to Buyer and Buyer desires to purchase from
Seller, on the terms set forth in this Agreement, those certain assets
identified in Exhibits "A" and "B" attached hereto and made a part hereof.
Accordingly, Seller and Buyer agree as follows:

1.   SALE AND PURCHASE OF ASSETS

     1.1 Assets To Be Sold. Seller shall sell, transfer and assign to Buyer, and
Buyer shall purchase and receive, all right, title and interest in and to the
following described assets hereinafter collectively referred to as the Assets,"
to-wit:

          1.1.1 The personal property, machinery and equipment described on
     Exhibit "A" attached hereto and made a part hereof.

          1.1.2 Those certain agreements described in Exhibit "B" attached
     hereto and made a part hereof

     1.2 Assets Excluded. The Assets do not include:

          1.2.1 Cash, accounts receivable and work in progress associated with
     the agreements described in Exhibit "B" attached hereto and made a part
     hereof and relating to operations prior to the Effective Date of Sale, and
     prepaid items.

     1.3 Conveyancing Instruments. The Assets to be conveyed by Seller to Buyer
pursuant to Section 1.1 shall be conveyed "as is" with the express conditions
and limitations noted in Section 4.1. The Assets to be transferred to Buyer
pursuant to Section 1.1 shall be transferred pursuant to a form of sale and
assignment as provided in Sections 6.1.3 and 6.2.6.

2.   PURCHASE PRICE

     2.1. Price. As consideration for the sale of the Assets, Buyer shall pay to
Seller or its designee, Nineteen Million Six Hundred Thousand United States
dollars ($19,600,000.00) (the "Purchase Price"), as follows:

          2.1.1 Upon signing this Agreement, Buyer shall pay to Seller the sum
     of Five Hundred Thousand Dollars ($500,000.00), which shall be an option
     fee, by wire transfer,

     in immediately available funds, to a bank account to be designated by
     Seller. In the event this transaction is closed, said option fee shall be
     credited against the purchase price of the Assets.

          2.1.2 Balance shall be paid at Closing by wire transfer, in
     immediately available funds, to a bank account to be designated by Seller.

          2.1.3 The payment provided for in Section 2.1.1 shall be considered an
     option fee. Accordingly, either Buyer or Seller may recede from this
     Agreement at any time prior to Closing by giving written notice of such
     action to the other party prior to Closing. Should Buyer recede from this
     Agreement, then Buyer shall forfeit the option fee to Seller and Buyer
     shall have no other liability whatsoever to Seller for receding from this
     Agreement. Should Seller recede from this Agreement, then Seller shall,
     with the written notice of Seller's receding from the Agreement, return the
     option fee to Buyer and pay to Buyer the additional sum of $500,000.00, and
     Seller shall have no other liability whatsoever to Buyer for receding from
     this Agreement.

          2.1.4 Notwithstanding the provisions of Section 2.1.3, (i) Seller may
     recede from this Agreement without liability to Buyer for return of Buyer's
     option fee or payment of an additional $500,000 if Seller recedes because
     Buyer has materially breached this Agreement, and (ii) Buyer may recede
     from this Agreement and be entitled to the return of its option fee if
     Buyer recedes because Seller has materially breached this Agreement or
     because Seller has, pursuant to the provisions of Section 5.2, 5.3 and/or
     Section 8.2, withdrawn or deleted from the Assets having a value equal to
     or greater than $3,000,000.

     After the Effective Date of Sale, Seller will pay only that portion of
invoices received with respect to any of the agreements described in attached
Exhibit "B" that are applicable to work performed or material received in the
period prior to the Effective Date of Sale; other charges and invoices under
said agreements will be returned to the vendor for rebilling to Buyer.
Similarly, after the Effective Date of Sale, Buyer will pay only that portion of
invoices received with respect to any of the agreements described in attached
Exhibit "B" that are applicable to work performed or material received in the
period subsequent to the Effective Date of Sale; other charges and invoices
under said agreements will be returned to the vendor for rebilIing to Seller.

     2.2 Assumption of Liabilities. Buyer shall assume and be responsible for
all obligations of Seller accruing after the Effective Date of Sale under the
agreements listed in Exhibit B hereto (except that lease rentals shall be
prorated as of the Effective Date of Sale, and any obligation associated with an
agreement listed in Exhibit B shall be assumed only to the extent that the
material or service with respect to which such payment is due is received by
Buyer after the Effective Date of Sale).

     2.3 Non-Competition and Non-Solicitation. In consideration of the Purchase
Price, Seller and the partners in Seller (said partners being signatory parties
hereto), agree that, for a period of two (2) years commencing on the Closing
Date, neither Seller nor any of the partners in Seller shall:

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          (a)  engage in any way, directly or indirectly, in the business of
               drilling, completing or workover of oil and gas wells within a
               200 mile radius of the city limits of Abilene, Texas;

          (b)  solicit or assist in soliciting, directly or indirectly, any
               current, future or former customer of the Seller or Buyer,
               wherever situated, in connection with their needs for drilling,
               competition, workover or related rigs; or

          (c)  induce, advise or counsel any employee or agent, of the Buyer to
               leave the employ of the Buyer, solicit or employ the services of
               employees or agents of the Buyer, or otherwise interfere with the
               relationship between the Buyer and its employees or agents.

     2.4 Effective Date of Sale. The Effective Date of Sale of the Assets
described in Section 1.1 shall be at the close of business by Seller on April
29, 2005.

     2.5 Closing. The Closing of the transactions contemplated herein and the
transfer of the Assets shall occur on April 29, 2005, at Seller's office at
10:00 A.M. local time, or such other date, time and place as Seller and Buyer
may agree in writing.

     2.6 Purchase Price Allocation. The Purchase Price shall be allocated in
accordance with Exhibit C hereto. Seller and Buyer further agree to file all tax
returns or reports, including, without limitation, IRS From 8594, for their
respective taxable years in which the Closing occurs and to reflect the
allocation of the Purchase Price described in Exhibit C on any such tax returns
or reports and agree not to take any position inconsistent therewith before any
governmental authority or in the course of any tax audit, tax review or tax
litigation matter relating thereto.

3.   TAXES

     3.1 Payment of Taxes. All ad valorem, property and other similar forms of
taxes, which have been paid by Seller or which have accrued on or before the
Effective Date of Sale, shall be prorated between Seller and Buyer as of the
Effective Date of Sale. Buyer shall be responsible for all sales, use and
similar taxes arising out of the sale of the Assets, but not any income taxes
for which Seller and its partners are liable as a consequence of the Sale. At
the Closing, Buyer shall pay Seller all state and local sales or use taxes
applicable to that portion of the Assets which is tangible personal property,
and Seller shall remit such amount to the appropriate taxing authority in
accordance with applicable law. Buyer shall hold harmless and shall indemnify
Seller for any sales or use taxes assessed against Seller by any taxing
authority in respect to this sale, including the amounts of any penalties,
interest and attorneys' fee.

     Should this purchase and sale constitute an isolated or occasional sale and
not be subject to sales or use tax with any of the taxing authorities having
jurisdiction over this transaction, no sales tax will be collected by Seller
from Buyer at the date of Closing. Seller agrees to cooperate with Buyer in
demonstrating that the requirements for an isolated or occasional sale or any
other sales tax exemption have been met.

                                       3

4.   REPRESENTATIONS AND WARRANTIES

     4.1 Seller's Representations and Warranties. Seller represents and warrants
to Buyer:

          4.1.1 Seller is a limited partnership duly organized and validly
     existing, in good standing, under the laws of the State of Texas. Seller
     has the power and authority to own the Assets and to carry on its business
     as now conducted and to enter into and to carry out the terms of this
     Agreement.

          4.1.2 Spud, Inc., a Texas corporation and the general partner of
     Seller, and EFO OILERS, L.P., BRH 2002, L.P. and Jim D. Mayfield, the only
     limited partners of Seller, are the only persons having partnership
     interests in Seller.

          4.1.3 The execution and delivery of this Agreement and the
     consummation of the transactions contemplated hereby have been duly
     authorized and Seller is not subject to any charter, by-law, lien or
     encumbrance of any kind, agreement, instrument, order or decree of any
     court or governmental body which would prevent consummation of the
     transactions contemplated by this Agreement.

          4.1.4 Seller will at the Closing be the owner of 100% of the right,
     title and interest in the Assets, and the transfer of the Assets to Buyer
     pursuant to this Agreement will vest in Buyer all right, title and interest
     in and to all of the Assets, free and clear of all security interests,
     mortgages, liens, tax liens, leases and other encumbrances.

          4.1.5 Seller has made available to Buyer for inspection and copying
     all books and records maintained by or on behalf of Seller concerning the
     Assets and, to the best of Seller's knowledge, none of the information so
     made available contains or will contain any untrue statement of a material
     factor omits or will omit to state a material fact necessary to make the
     statements contained therein not misleading.

          4.1.6 No employee of Seller has or will on the date of Closing have
     any contract of employment with Seller.

          4.1.7 With respect to each of the agreements described in Exhibit "B"
     attached hereto and made a part hereof: (a) each has been duly authorized,
     executed and delivered by Seller; (b) each is in full force and effect; (c)
     neither Seller nor, to the knowledge of Seller, any other party to such
     agreements (i) is, or as a result of the transactions contemplated herein
     will be, in breach of or default, or with the lapse of time or the giving
     of notice, or both, would be in breach or default, with respect to any of
     its obligations thereunder; or (ii) has given or threatened to give notice
     of any default under or inquiry into any possible default under, or action
     to alter, terminate, rescind or procure a judicial reformation of any such
     agreement; and (d) Seller ,does not anticipate that any other party to any
     such agreement will be in breach of or default under or repudiate any of
     its obligations thereunder.

                                       4

          4.1.8 There are no preferential purchase rights, consents and
     approvals required to be obtained for the transfer of the Assets to Buyer.

          4.1.9 There is no claim, demand, filing, cause of action,
     administrative proceeding, lawsuit or other litigation pending or
     threatened that could now or hereafter materially affect the ownership,
     operation or value of any of the Assets.

          4.1.10 The Assets have been used by. Seller in compliance with all
     laws, orders, regulations, rules and ordinances issued or promulgated by
     all governmental authorities having jurisdiction with respect to the
     Assets, including, but not limited to, laws, regulations and ordinances
     relating to environmental protection, health and safety; and all necessary
     governmental certificates, consents, permits, licenses or other
     authorizations with regard to the ownership or operation of the Assets have
     been obtained and Seller has received no notices of violations in respect
     of such licenses, permits or authorizations.

EXCEPT AS EXPRESSLY PROVIDED IN THIS AGREEMENT, THE ASSETS DESCRIBED ON EXHIBIT
"A" ARE TO BE SOLD "AS IS," AND SELLER MAKES NO WARRANTY, EXPRESS OR IMPLIED IN
FACT OR BY LAW, WHETHER OF OPERATING CONDITION, SAFETY, COMPLIANCE WITH
GOVERNMENT REGULATIONS, MERCHANTABILITY, FITNESS FOR ANY PARTICULAR PURPOSES,
CONDITION OR OTHERWISE, CONCERNING ANY OF SAID ASSETS. ALL PERSONAL PROPERTY,
MACHINERY AND EQUIPMENT ARE TO BE CONVEYED BY SELLER AND ACCEPTED BY BUYER
PRECISELY AND ONLY "AS IS, WHERE IS." SELLER DOES NOT WARRANT THE ASSETS FREE
FROM REDHIBITORY VICES OR DEFECTS.

     4.2 Buyer's Representations and Warranties. Buyer represents and warrants:

          4.2.1 Buyer is a corporation duly organized and validly existing, in
     good standing, under the laws of the State of Colorado and has the power
     and authority to own its property and to carry on its business as now
     conducted and to enter into and to carry out the terms of this Agreement.

          4.2.2 The execution and delivery of this Agreement and the
     consummation of the transactions contemplated hereby have been duly
     authorized and Buyer is not subject to any charter, by-law, lien or
     encumbrance of any kind, agreement, instrument, order or decree of any
     court or governmental body which would prevent consummation of the actions
     contemplated by this Agreement.

          4.2.3 Buyer shall comply with all applicable laws, ordinances, rules
     and regulations and shall promptly obtain and maintain all permits required
     by public authorities in connection with the Assets purchased.

          4.2.4 Buyer acknowledges that the Assets have been used for oil and
     gas drilling operations and related oilfield operations and possibly the
     storage and

                                       5

     disposal of waste materials incidental to or occurring in connection with
     such operations, and Buyer has entered into this Asset Sale Agreement on
     the basis of Buyer's own investigation of the physical condition of the
     Assets. Buyer is acquiring the Assets precisely and only in an "as is and
     where is" condition.

5.   ADDITIONAL COVENANTS

     5.1 Seller shall afford to Buyer, and/or Buyer's designated
representatives, reasonable access to the Assets, from the date hereof until the
Closing, for the purpose of inspecting the Assets and conducting such tests
thereon (at the expense of Buyer) as Buyer may deem necessary to satisfy itself
as to the condition of the Assets.

     5.2 Asset Title Review. From the date hereof until the Closing, "Seller
shall make available to Buyer without express or implied warranty of any kind
regarding the accuracy of such information, copies of information in Seller's
possession regarding Seller's title to the Assets. Buyer shall review the
information at Seller's office Buyer specifically agrees that any conclusions
made from any examination done or caused to be done shall result from its own
independent review and judgment only. In the event of a title defect which would
prevent Buyer from enjoyment of the Assets in the same manner enjoyed by Seller
immediately prior to the date of this agreement, Buyer shall notify Seller of
such. defect within fifteen (15) days after discovery. If Seller and Buyer
cannot agree on resolution of such defect, Seller shall elect (a) to cure the
defect at its own expense, (b) to delete the property with such defect from the
sale and to reduce the Purchase Price by the amount allocated to such property
on Exhibit C, or (c) to cancel the sale and refund Buyer's $500,000.00 deposit
without interest.

     5.3 Operations Prior to Closing. After the date of this Agreement and prior
to the Closing, Seller shall use and maintain the Assets in substantially the
same manner in which they have been used and maintained prior to this Agreement.
Unless Seller and Buyer otherwise agree, Seller shall not enter into any
agreement or transaction in relation to the Assets except such as are entered
into in the ordinary course of business consistent with past practices. Seller
shall not be obligated for any expenditures for purposes other than normal
day-to-day operations between the execution of this Agreement and the Closing
thereon. In the event that an expenditure for other purposes is proposed,
contemplated, or necessary to maintain a property included in the Assets in the
condition such property is as of the date of this Agreement, Seller shall elect
(a) to make such expenditure to maintain such property in such condition, (b) to
delete the property from the sale and to reduce the Purchase Price by the amount
allocated to such property on Exhibit C, or (c) to cancel the sale and refund
Buyer's $500,000.00 deposit amount without interest. Except as contemplated in
the preceding sentence or unless Buyer and Seller otherwise agree, Seller shall
not materially alter the Assets (other than the use of supplies and consumables)
or remove any improvements, equipment or property which comprise the Assets
(other than the use of supplies and consumables) with the exception of
individual Assets (i) involving a fair market value of less than Two Thousand
Dollars ($2,000.00) and (ii) sold or transferred to unaffiliated third parties
or disposed of or consumed in the ordinary course of business. Seller shall
promptly notify Buyer of any material matter affecting the Assets known to
Seller which arises from the date of this Agreement to the date of Closing.

                                       6

     5.4 Force Majeure. In the event any Assets is damaged by fire or other
calamity before Closing, Seller may repair the damage at its cost or, at its
sole option, either reduce the purchase price by the cost of the damage or
withdraw the damaged asset from the sale and reduce the purchase price by the
undamaged value thereof Should Buyer and Seller not agree as to the amount of
such price reduction, and if Buyer is not in default hereunder, this Agreement
will be terminated and Seller shall promptly after such termination return to
Buyer the amount specified in Section 2.1.1 without interest.

6.   CONDITIONS PRECEDENT TO CLOSING

     6.1 Seller's Condition Precedent. The obligations of Seller to consummate
the transactions contemplated by this Agreement are subject to each of the
following conditions:

          6.1.1 Buyer shall have performed and complied with aft, terms of this
     Agreement required to be performed or complied with by Buyer prior to
     Closing.

          6.1.2 No action or proceeding by or before any governmental authority
     shall have been instituted or threatened (and not subsequently dismissed,
     settled or otherwise terminated) which might restrain, prohibit or
     invalidate any of the transactions contemplated by this Agreement.

          6.1.3 Seller and Buyer shall have executed a bilateral form of
     assignment whereby Seller transfers all right, title and interest in the
     Assets to Buyer, and Buyer assumes the obligations and liabilities pursuant
     to Section 2.2 hereof.

     6.2 Buyer's Conditions Precedent. The. obligations of Buyer to consummate
the transactions contemplated by this Agreement are subject to each of the
following conditions:

          6.2.1 The representations and warranties by Seller set forth in this
     Agreement shall be true and correct in all material respects at and as of
     the Closing as though made at and as of the Closing; and Seller shall have
     performed and complied with all terms of this Agreement required to be
     performed or complied with by Seller prior to Closing.

          6.2.2 No action or proceeding by or before any. governmental authority
     shall have been instituted or threatened (and not subsequently dismissed,
     settled or otherwise terminated) which might restrain, prohibit or
     invalidate any of the transactions contemplated by this Agreement.

          6.2.3 Since the date of this Agreement, there shall have been no
     material adverse changes in the condition of any of the Assets, except
     normal depreciation of equipment through ordinary wear and tear.

          6.2.4 All consents and approvals required to be obtained for the
     transfer of the Assets to Buyer shall have been obtained, and all
     preferential purchase rights arising in connection with the transfer of the
     Assets to Buyer shall have been waived or shall have expired.

                                       7

          6.2.5 Buyer shall be reasonably satisfied with the results of its due
     diligence review of the Assets provided for in Sections 5.1, 5.2 and 8.2.

          6.2.6 Seller and Buyer will have, executed a bilateral form of
     assignment whereby Seller transfers all right, title and interest in the
     Assets to Buyer, and Buyer assumes the obligations and liabilities pursuant
     to Section 2.2 hereof.

7.   CROSS-INDEMNIFICATION

     7.1 Buyer agrees to indemnify and hold Seller harmless from and against any
and all liability, loss, cost and expense (including, without limitation, court
costs and reasonable attorneys' fees) that are attributable to the Assets
conveyed to Buyer and are attributable to periods of time after the Effective
Date of Sale (including, but not limited to, any liability resulting from the
condition of the Assets arising after the Effective Date of Sale under any
federal, state or local statute, regulation, rule, ordinance or order relating
to the environment or health and safety) or that are attributable to a breach by
Buyer of any of its surviving representations and warranties hereunder.

     7.2 Seller agrees to indemnify and hold Buyer harmless from and against any
and all liability, loss, cost and expense (including, without limitation, court
costs and reasonable attorneys' fees) that are attributable to the Assets
conveyed to Buyer and are attributable to periods of time on or before the
Effective Date of Sale (including, but not limited to, any liability resulting
from the condition of the Assets as of the Effective Date of Sale under any
federal, state or local statute, regulations, rule, ordinance or order relating
to the environment or health and safety) or that are attributable to a breach by
Seller of any of its surviving representations and warranties hereunder.

     7.3 Each party does not assume, and hereby disclaims any liability or
obligation in respect of, any matter against which a party is obligated to
indemnify the other party under the terms of this Agreement.

8.   MISCELLANEOUS

     8.1 Payment of Expenses and Fees. Buyer and Seller shall each bear their
own costs and expenses, including but not limited to attorney's fees incurred in
connection with the transactions contemplated in this Agreement; provided,
however, Buyer shall pay all recording fees or transfer taxes in connection with
the recording of any instrument of transfer of Assets from Seller to Buyer
hereunder.

     8.2 Environmental Review. Promptly after signing this Agreement, Buyer
and/or its representatives may have access to environmental data in Seller's
files for the Assets to be sold herein. Buyer and/or its representatives shall
review the information at Seller's office. Buyer specifically acknowledges that
such access is given as an accommodation only, that Seller makes no
representations whatsoever as to the accuracy completeness or reliability of any
such environmental information so or otherwise disclosed to or obtained by Buyer
and that Buyer

                                       8

relies and depends on and uses any and all such environmental information
exclusively and entirely at its own risk and without any recourse whatsoever.
Seller shall use reasonable efforts to arrange for the performance of any
additional environmental testing at Buyer's expense which Buyer may reasonably
request, and Seller and Buyer shall cooperate to ensure that such testing is
performed on an expedited basis before Closing. If it is determined by Closing
that any of the Assets has been materially contaminated (with "materially
contaminated" being defined as the violation of applicable Federal or State laws
or regulations or common law principles, with respect to environmental
conditions, to the extent that prosecution, if instituted, would likely result
in a penalty, fine or damage payment which are material when compared with the
value of the affected property), Seller shall elect either (a) to correct or to
make arrangements for the correction of such contamination, (b) to delete the
Asset from this sale and reduce the Purchase Price by the amount allocated to
such Asset on Exhibit C, or (c) to cancel the entire sale and refund Buyer's
$500,000.00 option fee without interest. Buyer shall cooperate with Seller's
reasonable corrective work, and any operations unreasonably interfering with the
corrective work shall cease until correction is completed.

     8.3 Books and Records. With the exception of books of account, tax returns
and correspondence relating thereto, Seller's proprietary, technical or
interpretive information and any documents of overall significance to Seller's
business, Seller shall deliver to Buyer promptly after Closing copies of any
materials, contract and agreement files which may exist in Seller's files and
which relate to the Assets. Buyer shall preserve such records for a period of
six years after the date of Closing or such longer periods as may be required by
law or agreement relating to such documents and during such period shall make
the same available for examination (or for the making of copies or extracts), if
necessary for a lawful purpose, by Seller at reasonable times so not to
interfere with Buyer's business. If Buyer desires to destroy any such materials
prior to the end of such period, Buyer shall give Seller notice of such desire
and may destroy such materials unless Seller requests that such materials not be
destroyed, in which case such materials' shall be retained by Buyer or
retransferred to Seller.

     8.4 Entire Agreement. This Agreement constitutes the entire agreement
between Seller and Buyer with respect to the transactions contemplated herein,
and supersedes all prior oral or written agreements, commitments, understandings
or information otherwise furnished by Seller to Buyer with respect to such
matters. No amendment shall be binding unless in writing and signed by
representatives of both parties. Headings used in this Agreement are only for
convenience of reference and shall not be used to define the meaning of any
provision. This Agreement is for the benefit of Seller and Buyer only and not
for the benefit of third parties.

     8.5 Notices. All notices and consents to be given hereunder shall be in
writing and shall be deemed to have been duly given if delivered personally,
telexed with receipt acknowledged, mailed by registered mail, or delivered by a
recognized commercial courier to the party at the address set forth on the first
page of this Agreement or such other address as any party shall have designated
by ten days' notice to the other party.

     8.6 Governing Law. This Agreement shall be governed by the law of the State
of Texas without regard to rules concerning conflicts of law.

                                       9

     8.7 All representations and warranties made by Seller and Buyer under this
Agreement shall remain in full force and effect, and shall survive the
execution, delivery and performance of this Agreement, for a period of two years
from the Closing.

     8.8 Assignment. Buyer may assign its rights and obligations under this
Agreement to an entity in which Buyer or an affiliate of Buyer owns in excess of
80% of the equity interests without the consent of Seller.

     IN WITNESS WHEREOF, each party hereto has executed this agreement in the
presence of the indicated witnesses, to be effective as of the Effective Date.

                                   SPA DRILLING, L.P.

                                   By: Spud, Inc., a Texas corporation
                                       General Partner of SPA Drilling, L.P

                                   By: /s/ BEN HOLMES
                                       -----------------------------------------
                                   Name: Ben Holmes
                                   Title: President

                                   Date: 2-28-05

                                   EFO OILERS, L.P., a Texas limited partnership
                                      Limited Partner of SPA Drilling, L.P.

                                   By: EFO Holdings, L.P.
                                   Its: General Partner

                                   By: EFO GenPar, Inc., a Texas corporation
                                   Its: General Partner

                                   By: /s/ G. LARRY WALLACE
                                       -----------------------------------------
                                   Name: G. Larry Wallace
                                   Its: President

                                   Date: 2-25-05

                                       10

                                   BRH 2002, L.P., a Texas limited partnership
                                      Limited Partner of SPA Drilling, L.P.

                                   By: SHK Inc., a Texas corporation
                                   Its: General Partner

                                   By: /s/ BEN HOLMES
                                       -----------------------------------------
                                   Name: Ben Holmes
                                   Its: President

                                   Date: 2-28-05

                                   /s/ JIM D. MAYFIELD
                                   ---------------------------------------------
                                       Jim D. Mayfield
                                       Limited Partner of SPA Drilling, L.P.

                                   Date: 2-28-05

                                   THORNTON DRILLING COMPANY

                                   /s/ RICHARD THORNTON
                                   ---------------------------------------------
                                   By: Richard Thornton
                                   Its: President

                                   Date: 2-28-05

                                       11

                                 AMENDMENT NO. 1
                                       TO
                           PURCHASE AND SALE AGREEMENT

     AMENDMENT NO. 1 (the "AMENDMENT") dated as of March 31, 2005 to the
Purchase and Sale Agreement (the "PURCHASE AGREEMENT") dated February 28, 2005
between Thornton Drilling Company, a Delaware corporation (and, as of the date
of the Purchase Agreement, a Colorado corporation) ("BUYER") and SPA Drilling
L.P., a Texas limited partnership.

                                   WITNESSETH

     WHEREAS, the parties hereto desire to amend the Purchase Agreement in
certain respects;

     WHEREAS, capitalized terms not otherwise defined herein shall have the
meanings given to them in the Purchase Agreement;

     NOW, THEREFORE, the parties hereto agree as follows:

     Section 1. Amendment to Section 1.3 of Purchase Agreement. Section 1.3 of
the Purchase Agreement is hereby amended by adding the letter "(a)" before the
current words thereof and inserting a new clause (b) thereto as follows:

     "(b) Seller and Buyer agree to execute and deliver such other documents,
certificates, agreements and other writings and to take such other actions as
may be necessary or desirable in order to consummate or implement expeditiously
the transactions contemplated by this Agreement and to vest in Buyer good and
marketable title to the Assets."

     Section 2. Amendment to Section 2.4 of Purchase Agreement. Section 2.4 of
the Purchase Agreement is hereby amended in its entirety by substituting the
following:

     "2.4 The Effective Date of Sale of the Assets described in Section 1.1
shall be at the close of business by Seller on March 31, 2005."

     Section 3. Amendment to Section 4.1 of Purchase Agreement. Section 4.1 of
the Purchase Agreement is hereby amended by adding the following Section 4.1.11:

     "4.1.11 The conveyance of the Assets by Seller constitutes the sale of the
entire operating assets of a business or of a separate division, branch, or
identifiable segment of a business and is an occasional sale under Section
151.304 of the Texas Tax Code and the rules promulgated thereunder."

     Section 4. Amendment to Section 8.3 of Purchase Agreement. Section 8.3 of
the Purchase Agreement is hereby amended by adding the letter "(a)" before the
current words thereof and inserting a new clause (b) thereto as follows:

     "(b) Notwithstanding anything in this Agreement to the contrary, on and
after the Closing Date, Seller will afford promptly to Buyer and its agents
reasonable access to its books

of account, tax returns, financial and other records (including, without
limitation, accountant's work papers and all items referenced in Section 8.3(a)
to the extent not delivered to Buyer promptly after Closing), information,
employees, consultants and auditors to the extent necessary or useful for Buyer
in connection with any audit, investigation, dispute or litigation or any other
reasonable business purpose relating to the business of the Buyer (after giving
effect to the purchase of the Assets); provided that any such access by Buyer
shall not unreasonably interfere with the conduct of the business of Seller.
Buyer shall hold, and shall use its best efforts to cause its officers,
directors, employees, accountants, counsel, consultants, advisors and agents to
hold, in confidence, unless compelled to disclose by judicial or administrative
process or by other requirements of law, all confidential documents and
information concerning the business of the Seller as it exists after the
Closing, except to the extent that such information can be shown to have been
(i) previously known on a nonconfidential basis by Buyer, (ii) in the public
domain through no fault of Buyer or (iii) later lawfully acquired by Buyer from
third parties. The obligation of Buyer to hold any such information in
confidence shall be satisfied if they exercise the same care with respect to
such information as they would take to preserve the confidentiality of their own
similar information. Without limiting the generality of the foregoing, Seller
shall make available to Buyer any employees or consultants necessary or useful
to the preparation of historical audited financial statements relating to the
Assets and shall use its best efforts to cause such employees or consultants to
deliver to the Buyer's auditors all certifications, attestations and
representations deemed necessary or useful for the completion of such historical
audits."

     Section 5. Governing Law. This Amendment shall be governed by the law of
the State of Texas, without regard to rules concerning conflicts of law rules.

     Section 6. Counterparts; Effectiveness. This Amendment may be signed in any
number of counterparts, each of which shall be an original, with the same effect
as if the signatures thereto and hereto were upon the same instrument. This
Amendment shall become effective when each party hereto shall have received a
counterpart hereof signed by the other party hereto. Until and unless each party
has received a counterpart hereof signed by the other party hereto, this
Amendment shall have no effect and no party shall have any right or obligation
hereunder (whether by virtue of any other oral or written agreement or other
communication).

                                       2

     IN WITNESS WHEREOF, the parties hereto have caused this Amendment No. 1 to
be duly executed as of the day and year first above written.

                                   SPA DRILLING, L.P.

                                   By: Spud, Inc., a Texas corporation,
                                          General Partner of SPA Drilling, L.P.

                                   By: /s/ BEN HOLMES
                                       -----------------------------------------
                                       Name: Ben Holmes
                                       Title: President

                                   EFO OILERS, L.P., a Texas limited partnership

                                      Limited Partner of SPA Drilling, L.P.

                                   By: EFO Holdings, L.P.
                                   Its: General Partner

                                   By: EFO GenPar, Inc., a Texas corporation
                                   Its: General Partner

                                   By: /s/ G. LARRY WALLACE
                                       -----------------------------------------
                                       Name: G. Larry Wallace
                                       Title: President

                                   BRH 2002, L.P., a Texas limited partnership

                                      Limited Partner of SPA Drilling, L.P.

                                   By: SHK Inc., a Texas corporation
                                   Its: General Partner

                                   By: /s/ BEN HOLMES
                                       -----------------------------------------
                                       Name: Ben Holmes
                                       Title: President

                                       3

                                   JIM D. MAYFIELD

                                   /s/ JIM D. MAYFIELD
                                   ---------------------------------------------
                                   Limited Partner of SPA Drilling, L.P.

                                   THORNTON DRILLING COMPANY

                                   By: /s/ RICHARD THORNTON
                                       -----------------------------------------
                                       Name: Richard Thornton
                                       Title: President

                                       4

                       ASSIGNMENT AND ASSUMPTION AGREEMENT

     THIS ASSIGNMENT AND ASSUMPTION AGREEMENT (this "ASSIGNMENT") is made and
entered into as of this 31st day of March, 2005, by and among Thornton Drilling
Company, a Delaware corporation ("TDC"), and Union Drilling Texas, LP, a Texas
limited partnership ("UDT").

                                   WITNESSETH:

     WHEREAS, TDC, as purchaser, and SPA Drilling, L.P., a Texas limited
partnership ("SPA"), as seller, entered into that certain Option and Asset
Purchase and Sale Agreement dated February 28, 2005 (as amended, the "PURCHASE
AGREEMENT");

     WHEREAS, Union Drilling, Inc. has acquired all of the outstanding stock of
TDC and has formed UDT to take title to and hold the assets and agreements
described in the Purchase Agreement;

     WHEREAS, Union Drilling, Inc. is an affiliate of TDC and owns in excess
of 80% of the equity interests in UDT and the general partner of UDT;

     WHEREAS, this Assignment is pursuant to the right of TDC contained in
Section 8.8 of the Purchase Agreement to assign its rights under the Purchase
Agreement.

     NOW, THEREFORE, in consideration of the foregoing and the mutual agreements
contained herein, and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, and intending to be legally bound,
TDC and UDT hereby agree as follows:

     TDC hereby assigns and sets over to UDT all of the rights and obligations
of TDC under and with respect to the Purchase Agreement.

     UDT hereby accepts the above and foregoing assignment, assumes all of the
obligations of TDC under the Purchase Agreement and agrees to perform any and
all of the obligations of TDC thereunder, all effective as of the 31st day of
March 2005.

THORNTON DRILLING COMPANY,            UNION DRILLING TEXAS, LP,

a Delaware corporation                a Texas limited partnership.
                                         By: Union Drilling Texas GP, LLC

By: /s/ RICHARD THORNTON                 By: /s/ CHRISTOPHER STRONG
    -------------------------------          -----------------------------------
    Name:                                    Christopher Strong, President
    Title:Exhibit 10.13

================================================================================

                            ASSET PURCHASE AGREEMENT

                            DATED AS OF MAY 31, 2005

                                     BETWEEN

                              C AND L SERVICES, LP

                                    AS SELLER

                                       AND

                            UNION DRILLING TEXAS, LP

                                    AS BUYER

================================================================================

                            ASSET PURCHASE AGREEMENT

          THIS ASSET PURCHASE AGREEMENT is made and entered into as of May 31,
2005, between C AND L SERVICES, LP, a Texas limited partnership ("Seller"), and
UNION DRILLING TEXAS, LP, a Texas limited partnership ("Buyer").

                                   WITNESSETH:

          WHEREAS, Buyer desires to purchase the Assets (as hereinafter defined)
from Seller; and

          WHEREAS, Seller desires to sell the Assets to Buyer in exchange for
the payment by Buyer of the Purchase Price (as hereinafter defined);

          NOW, THEREFORE, for and in consideration of the mutual benefits
derived and to be derived herefrom by each party, Seller and Buyer agree as
follows:

                                    ARTICLE I

                                   DEFINITIONS

               1.01 Basic Definitions. In addition to the terms defined in the
          introductory paragraph of this Agreement, for purposes hereof, the
          following terms shall have the meanings set forth in this Article I,
          unless the context otherwise requires:

          "Affiliate" means, as to the person specified, any person controlling,
controlled by or under common control with such person, with the concept of
control in such context meaning the possession, directly or indirectly, of the
power to direct or cause to direct or cause the direction of the management
policies of another, whether through the ownership of voting securities, by
contract, or otherwise.

          "Agreement" means this Asset Purchase Agreement and all schedules and
exhibits attached hereto.

          "Assets" has the meaning specified in Section 2.01.

          "Best Efforts" means a party's best efforts in accordance with
reasonable commercial practice.

          "Business Day" means a day on which national banks are generally open
for the transaction of business in Pittsburgh, Pennsylvania.

          "Buyer" has the meaning specified in the preamble.

          "Closing" means the consummation of the sale and purchase of the
Assets as contemplated by this Agreement which shall take place on the Closing
Date.

          "Closing Date" has the meaning specified in Section 9.01.

          "Code" means the Internal Revenue Code of 1986, as amended, and any
successor thereto.

          "Governmental Entity" means any court or tribunal in any jurisdiction
(domestic or foreign) or any public, governmental commission, board, bureau or
other authority or instrumentality (domestic or foreign).

          "Purchase Price" means the consideration specified in Section 3.01 to
be paid by Buyer to Seller in connection with the sale of the Assets by Seller
to Buyer under the terms of this Agreement.

          "Rig Lien" means the security interest of Community Bank of Cleburne
in certain of the Assets, securing a debt of Seller in the approximate principal
amount of $1.4 million, and any related UCC financing statements filed by
Community Bank of Cleburne.

          "Seller" has the meaning specified in the preamble.

               1.02 Additional Definitions. Other terms are elsewhere defined in
          this Agreement and shall, for purposes of this Agreement, have the
          meanings so specified unless the context otherwise requires. The
          definitions given to the terms herein shall be applicable to both the
          singular and plural forms of such terms as the context requires.

                                   ARTICLE II

                           PURCHASE AND SALE OF ASSETS

               2.01 Assets to be Purchased. Upon the terms and subject to the
          conditions set forth in this Agreement, at the Closing, Seller agrees
          to sell, assign, transfer, deliver and convey to Buyer, and Buyer
          agrees to purchase, the following (collectively, the "Assets"):

          (a)  the two land drilling rigs described on Schedule 2.01(a),
               together with all of such drilling rigs' engines, machinery, and
               fittings, and the drilling equipment, blowout preventers,
               handling tools, spare parts, supplies, tubulars and pipe
               described on Schedule 2.01(a) (collectively, the "Rigs");

          (b)  the following tangible and intangible assets used or held for use
               in connection with the ownership, maintenance and operation of
               the Assets, to the extent assignable by law and Seller or its
               Affiliates have the right to assign and transfer such assets:

               (i)  all records to be delivered to Buyer pursuant to Section
                    2.04; and

               (ii) the certificates, licenses, permits, consents, operating
                    authorities, orders, exemptions, franchises, approvals,
                    registrations and other

                                       2

                    authorizations and applications therefor specifically
                    associated with the maintenance and operation of the Assets
                    ("Permits"); and

               (iii) all warranties relating to the Assets providing benefits to
                    the owner of the Assets.

          Notwithstanding the foregoing, if any drill pipe is replaced or
          substituted pursuant to Section 8.09, the Assets shall include such
          replacement or substituted drill pipe and not the drill pipe replaced.

               2.02 Risk and Expense. Seller shall bear the risks inherent in
          the ownership of the Assets until the Closing Date. Seller shall
          maintain in full force and effect the insurance policies currently
          covering the Assets through the Closing Date. Should either of the
          Rigs sustain damage in excess of $1,000,000 before the Closing Date,
          this Agreement shall immediately terminate. Should either of the Rigs
          suffer any damage that constitutes less than $1,000,000 between the
          date hereof and the Closing, Sellers shall at the Closing pay over to
          Buyer any insurance proceeds received by Sellers with respect to such
          damage, together with an amount equal to any insurance deductible or
          coinsurance amount applied against such damages.

               2.03 Nonassumption of Liabilities. Buyer does not assume and
          shall in no event be liable for any liabilities, debts or obligations
          of Seller, whether accrued, absolute, matured, contingent or
          otherwise, including, without limitation, (a) any foreign, federal,
          state, county, or local taxes, including, without limitation, excise
          taxes, or documentary transfer taxes, which in each case arise from
          the ownership of the Assets on or prior to the Closing Date or from
          the consummation of the transactions contemplated by this Agreement;
          (b) any obligations or liabilities arising from any Environmental Laws
          (as hereinafter defined) or hazardous substances, or any other
          obligations or liabilities of any type relating to ownership or
          operation of any property either directly or indirectly by Seller or
          the ownership or operation of any business, property or assets
          utilized by Seller arising prior to or on the Closing Date; (c) any
          obligations or liabilities whatsoever which may be imposed upon Buyer
          as a successor to Seller either directly or indirectly or otherwise by
          any Environmental Laws; (d) any obligations or liabilities arising out
          of, relating to, or in connection with any action, suit, proceeding,
          or investigation pending or threatened against Seller or any of its
          shareholders, officers, directors, employees, or agents; (e) any labor
          or employment-related claims, obligations, or liabilities which accrue
          or arise from events occurring prior to, on or after the Closing Date,
          including, but not limited to, any claim of obligation or liability
          relating to wages, employee benefits, severance pay, workers'
          compensation, including insurance premiums, unemployment insurance,
          breach of employment contract, wrongful discharge, employment
          discrimination, or unfair labor practice; (f) any claims, obligations,
          or liabilities arising under or relating to any alleged violation of
          the Worker Adjustment and Retraining Notification Act of 1988, as
          amended; (g) any liabilities for fees or expenses incident to the
          preparation of this Agreement or the consummation of the transactions
          contemplated hereby

                                       3

          (including, without limitation, counsel, accountant's or finder's fees
          of Seller); or (h) trade payables or expenses, debt, contracts,
          agreements, leases or other obligations of Seller.

               2.04 Delivery of Records.

          (a)  Buyer shall be entitled to the records physically located on the
               Rigs or at the location thereof on the Closing Date and relevant
               to the Rigs.

          (b)  As promptly following the Closing as practicable, Seller shall
               deliver or cause to be delivered to Buyer at such location as
               mutually agreed, copies of any technical or operational manuals
               or maintenance records related to the Assets.

          (c)  Seller shall be entitled to retain all originals of its
               corporate, financial, accounting, legal, tax and audit records,
               subject to Buyer's rights of inspection as set forth in Section
               8.02.

                                  ARTICLE III

                                 PURCHASE PRICE

               3.01 Consideration for Assets. As consideration for the sale by
          Seller to Buyer of the Assets, Buyer shall pay to Seller the sum of
          Eight Million and No/100 Dollars ($8,000,000.00) in United States
          currency, subject to Section 8.09 (the "Purchase Price").

                                   ARTICLE IV

                      REPRESENTATIONS, WARRANTIES OF SELLER

          Seller represents and warrants to and agrees with Buyer that, as of
the date hereof and as of the Closing Date:

               4.01 Organization and Qualification. Seller is a limited
          partnership duly organized, validly existing, and in good standing
          under the laws of Texas, has the full power and authority, to own,
          operate and lease its property and to carry on its business as now
          conducted, and is duly qualified and is in good standing in each
          jurisdictions in which the character of its properties and assets
          currently owned or leased or the nature of its business transactions
          makes such qualification necessary.

               4.02 Due Execution. The execution, delivery and performance of
          this Agreement by Seller and the consummation of the transactions
          contemplated hereby have been duly authorized by all requisite
          corporate action including the approval by the general and limited
          partners of Seller. This Agreement and all other agreements and
          written obligations entered into or undertaken in connection with the
          transactions contemplated hereby constitute the valid and legally
          binding

                                       4

          obligations of Seller enforceable against Seller in accordance with
          their respective terms.

               4.03 Legal Power and Authority. Seller has full power and
          authority to enter into this Agreement and to perform all acts and to
          do all things required on its part to be performed in connection with
          this Agreement and the transactions contemplated hereby, and has
          granted full power and authority to its appropriate officers to take
          all actions, to do all things and to make, execute and deliver all
          documents as may be necessary or required in order to effectuate and
          consummate the transactions contemplated hereby.

               4.04 No Conflicts. The execution, delivery and performance by
          Seller of this Agreement and the other documents, instruments and
          agreements contemplated hereby and the consummation of the transaction
          contemplated hereby and thereby will not (a) conflict with or result
          in a breach of any provisions of the organizational documents of
          Seller, (b) result in a material default or the creation of any lien
          or encumbrance or give rise to any right of termination, cancellation
          or acceleration under any of the terms, conditions or provisions of
          any note, bond, mortgage, indenture, license, lease or other agreement
          to which Seller is a party or by which it or the Assets may be bound
          or affected, or (c) violate any order, writ, injunction, judgment,
          decree, statute, rule or regulation applicable to Seller or any of its
          properties or assets.

               4.05 Litigation. There are no material suits, actions,
          proceedings or governmental investigations or inquiries pending or, to
          Seller's knowledge, threatened against Seller or the Assets that
          reasonably may be expected to have a materially adverse effect on the
          sale by Seller of the Assets.

               4.06 Brokers. Seller has incurred no obligation or liability,
          contingent or otherwise, for brokers' or finders' fees with respect to
          the matters provided for in this Agreement.

               4.07 Title to and Condition of Assets. On the date of this
          Agreement, Seller lawfully owns and is lawfully possessed of good,
          valid, and indefeasible title to the Assets. At the Closing, Seller
          shall lawfully own and be lawfully possessed of, and shall sell,
          transfer and assign to Buyer, good, valid, and indefeasible title to
          the Assets, free and clear of any and all mortgages, security
          interests, liens, claims, debts, charges, or other encumbrances of any
          kind. Seller agrees to warrant and defend the title to, and possession
          of, the Assets for the benefit of Buyer against the claims and demands
          of all persons claiming an interest in the Assets as of the Closing
          Date, regardless of when any such claims or demands may be asserted.
          Seller has not received any written notice from any governmental
          agency, board, bureau, body, department or authority of any federal,
          state, municipal or foreign jurisdiction, to the effect that any of
          the Assets is in violation of any applicable ordinance, regulation or
          building, zoning, environmental or other law in respect thereof, the
          violation of which will have a material adverse effect on the
          ownership or use of any of such Assets.

                                       5

               4.08 Insurance. Seller has in place insurance policies of the
          types and in coverage amount sufficient to fully insure any damage or
          casualty loss which may arise between the date hereof and Closing with
          respect to any of the Assets. Seller has previously delivered to Buyer
          a true and complete list of all deductible and retention amount
          applicable to the Assets under such policies. Seller does not know of
          any threatened termination of or material alteration of coverage under
          any of such policies. All premiums payable under all such policies
          have teen timely paid and Seller has otherwise complied fully with the
          terms and conditions of all such policies.

               4.09 Compliance with Laws. Seller has substantially complied
          with, and is in substantial compliance with, all federal, state, local
          and foreign statutes, laws, ordinances, regulations, rules, permits,
          judgments, orders or decrees applicable to the Assets, and there does
          not exist, to the best of Seller's knowledge, any basis for any claim
          of default under or violation of any such statute, law, ordinance,
          regulation, rule, judgment, order or decree with respect to the
          Assets.

               4.10 No Untrue Statement. In or in connection with the making of
          this Agreement, together with the various schedules and exhibits
          hereto, Seller has not made any untrue statements of a material fact
          or omitted to state a material fact necessary in order to make the
          statements made by it herein not misleading.

               4.11 Sales Tax Exemption. To the knowledge and belief of Seller,
          the conveyance of the Assets by Seller is an occasional sale under
          Section 151.304 of the Texas Tax Code and the rules promulgated
          thereunder and is thus exempt from the imposition of the Texas sales
          tax.

                                   ARTICLE V

                     REPRESENTATIONS AND WARRANTIES OF BUYER

          Buyer represents and warrants to and agrees with Seller that, as of
the date hereof and as of the Closing Date:

               5.01 Organization and Qualification. Buyer is a limited
          partnership duly organized, validly existing, and in good standing
          under the laws of Texas, has the full power and authority, to own,
          operate and lease its property and to carry on its business as now
          conducted, and is duly qualified and is in good standing in each
          jurisdiction in which the character of its properties and assets
          currently owned or leased or the nature of its business transactions
          makes such qualification necessary.

               5.02 Due Execution. The execution, delivery and performance of
          this Agreement by Buyer and the consummation of the transactions
          contemplated hereby have been duly authorized by all requisite
          corporate action including the approval by its Board of Directors.
          This Agreement and all other agreements and written obligations
          entered into or undertaken in connection with the transactions

                                       6

          contemplated hereby constitute the valid and legally binding
          obligations of Buyer enforceable against Buyer in accordance with
          their respective terms.

               5.03 Legal Power and Authority. Buyer has full power and
          authority to enter into this Agreement and to perform all acts and to
          do all things required on its part to be performed in connection with
          this Agreement and the transactions contemplated hereby, and has
          granted full power and authority to its appropriate officers to take
          all actions, to do all things and to make, execute and deliver all
          documents as may be necessary or required in order to effectuate and
          consummate the transactions contemplated hereby.

               5.04 No Conflicts. The execution, delivery and performance by
          Buyer of this Agreement and the other documents, instruments and
          agreements contemplated herein will not (a) conflict with or result in
          a breach of any provision of the organizational documents of Buyer,
          (b) result in a material default or the creation of any lien or
          encumbrance or give rise to any right of termination, cancellation, or
          acceleration under any of the terms, conditions or provisions of any
          material note, bond, mortgage, indenture, license or other agreement
          to which Buyer is a party or by which it or any of its properties
          assets or may be bound or affected, or (c) violate any order, writ,
          injunction, judgment, decree, statute, rule or regulation applicable
          to Buyer or any of its respective properties or assets.

               5.05 Litigation. There are no material suits, actions,
          proceedings or governmental investigations or inquiries pending or, to
          Buyer's knowledge, threatened against Buyer or its properties, assets,
          operations or businesses that reasonably may be expected to have a
          materially adverse effect on the purchase by Buyer of the Assets.

               5.06 Brokers. Buyer has incurred no obligation or liability,
          contingent or otherwise, for brokers' or finders' fees with respect to
          the matters provided for in this Agreement.

                                   ARTICLE VI

                       CONDITIONS TO OBLIGATIONS OF SELLER

          The obligations of Seller to consummate the transactions contemplated
herein are subject, at the option of Seller, to the fulfillment, on or prior to
the Closing Date, of each of the following conditions:

               6.01 Representations and Warranties. Each of the representations
          and warranties of Buyer herein contained shall be true and correct
          (disregarding all references to materiality contained therein) in all
          material respects on the Closing Date.

               6.02 Performance. Buyer shall have performed all material
          obligations, covenants, and agreements hereunder and shall have
          complied with all material

                                       7

          covenants and conditions contained in this Agreement to be performed
          or complied with by Buyer at or prior to the Closing.

               6.03 Legal Prohibition. No provision of any applicable law or
          regulation and no judgment, injunction, order or decree shall prohibit
          the consummation of the Closing.

                                   ARTICLE VII

                       CONDITIONS TO OBLIGATIONS OF BUYER

          The obligations of Buyer to consummate the transactions contemplated
herein are subject, at the option of Buyer, to the fulfillment on or prior to
the Closing Date of each of the following conditions:

               7.01 Representations and Warranties. Each of the representations
          and warranties of Seller herein contained shall be true and correct
          (disregarding all references to materiality contained therein) in all
          material respects on the Closing Date.

               7.02 Performance. Seller shall have performed all material
          obligations, covenants and agreements hereunder and shall have
          complied with all material covenants and conditions contained in this
          Agreement to be performed or complied with by Seller at or prior to
          the Closing.

               7.03 Legal Prohibition. No provision of any applicable law or
          regulation and no judgment, injunction, order or decree shall prohibit
          the consummation of the Closing.

               7.04 Release of Lien. The Rig Lien shall have been released and
          terminated.

               7.05 Board Approval. The board of directors of Union Drilling,
          Inc., the indirect parent corporation of Buyer, shall have approved
          the execution and performance of this Agreement by Buyer.

                                  ARTICLE VIII

                     COVENANTS AND AGREEMENTS OF THE PARTIES
                BEFORE, RELATING TO AND SUBSEQUENT TO THE CLOSING

          Seller and Buyer hereby covenant and agree as follows:

               8.01 Expenses. Except as may be otherwise provided in this
          Agreement, Seller and Buyer shall pay and discharge, or cause to be
          paid and discharged, their own expenses incurred in connection with
          the preparation, authorization, execution, and performance of this
          Agreement and the transactions contemplated

                                       8

          herein, including, without limitation, inspection fees and fees and
          expenses of counsel, accountants and consultants.

               8.02 Access; Books and Records. Seller shall provide the
          officers, employees and attorneys of Buyer reasonable access, during
          normal business hours upon Buyer's reasonable prior notice to Seller,
          to the Assets and the records of Seller specifically relating thereto.
          Seller shall cooperate fully with such representatives of Buyer in
          connection with such review. If and to the extent necessary to comply
          with any disclosure requirements under the Securities Act of 1933 or
          the Securities Exchange Act of 1934, or any rules or regulations
          thereunder, or for any other reasonable business purpose, Buyer shall
          have the right, at its own expense, at any time or from time to time
          within three (3) years after the Closing Date during reasonable
          business hours upon reasonable notice to Seller to inspect, and make
          copies of or extracts from, any of the records of Seller relating to
          the business of Seller or the Assets and which are not provided to
          Buyer (the "Retained Records"). Without limiting the generality of the
          foregoing, Seller shall make available to Buyer any employees or
          consultants necessary or useful to the preparation of historical
          audited financial statements relating to the Assets and shall use its
          best efforts to cause such employees or consultants to deliver to the
          Buyer's auditors all certifications, attestations and representations
          deemed necessary or useful for the completion of such historical
          audits. None of the Retained Records in the possession of Seller shall
          be destroyed prior to three (3) years after the Closing Date without
          the consent of Buyer, unless first reproduced by microfilm or any
          other similar process. In the event that during such period Seller
          wishes to destroy any of the Retained Records at any time or from time
          to time after the Closing Date, Seller shall give not less than sixty
          (60) days notice to Buyer and Buyer shall have the right, at its own
          expense, during reasonable business hours to remove such records and
          keep possession of the same.

               8.03 Preservation of Assets. From the date hereof and until the
          Closing Date, Seller shall use its Best Efforts to preserve, maintain
          and protect the Assets.

               8.04 Notices of Certain Events. Until the Closing, Seller will
          promptly notify Buyer of any action, suit, proceeding, claim or
          investigation which is overtly threatened or commenced against Seller
          which is not fully insured against (except standard deductible or
          self-retention amounts) and which relates to or affects the Assets or
          this Agreement or the transactions contemplated hereby, and Buyer will
          promptly notify Seller of any action, suit, proceeding, claim or
          investigation which is overtly threatened or commenced against Buyer
          which is not fully insured against (except standard deductible or
          self-retention amounts) and which relates to and materially and
          adversely affects Buyer or its business or affects this Agreement or
          the transactions contemplated hereby. Seller further agrees to
          promptly notify Buyer of (i) any notice or other communication from
          any governmental or regulatory agency or authority in connection with
          the transactions contemplated by this Agreement; (ii) any notice or
          other communication from any person or entity alleging that the
          consent of such person or entity is or may be required in connection
          with the transactions contemplated by this Agreement; and (iii) the

                                       9

          damage or destruction by fire or other casualty of any Asset or part
          thereof or in the event that any Asset or part thereof becomes the
          subject of any proceeding or, to the knowledge of any Seller,
          threatened proceeding for the taking thereof or any part thereof or of
          any right relating thereto by condemnation, eminent domain or other
          similar governmental action.

               8.05 Actions with Respect to Closing. Seller will use its Best
          Efforts to obtain the satisfaction of the conditions to Closing
          applicable to Seller set forth in Article VII as soon as practicable.
          Buyer will use its Best Efforts to obtain the satisfaction of the
          conditions to Closing applicable to Buyer set forth in Article VI as
          soon as practicable.

               8.06 Public Statements. Neither the Buyer nor Seller, nor any of
          their respective Affiliates, shall make any news release or other
          announcement concerning the transactions contemplated hereby without
          first obtaining approval from each party hereto; except that Buyer may
          disclose the transactions contemplated hereby in connection any
          offering of its securities or as otherwise may be required by law.

               8.07 Continued Effectiveness of Representations and Warranties.
          Seller and Buyer shall each use its Best Efforts to cause the
          representations and warranties made by it herein to continue to be
          true and correct on and as of the Closing Date as if made on and as of
          the Closing Date.

               8.08 Removal of Assets. Seller agrees to allow Buyer up to ten
          days after the Closing Date to remove the Rigs and any associated
          Assets from the current drill sites in Johnson County, Texas, unless
          Buyer shall have entered into a new drilling contract with the
          operator of such drill site.

               8.09 Drill Pipe Inspection. As promptly as practicable after the
          execution of this Agreement, Seller shall retain a reputable firm to
          inspect the 10,000 feet of 4 1/2 inch drill pipe included in the
          Assets to verify its rating as double white band pipe (API RP7G
          specifications). If the inspection is not completed prior to the
          Closing, Buyer shall hold back $150,000 of the Purchase Price until
          such time as the inspection is satisfactorily completed and the pipe
          is available to Buyer. In the event that the results of the inspection
          preclude Seller from being able to deliver 10,000 feet of 4 1/2 double
          white band rated pipe to Buyer, Seller may elect to either substitute
          10,000 feet of similarly rated 5 inch pipe or forfeit the $150,000
          holdback and conclude the sale without the 4 1/2 inch drill pipe.

                                   ARTICLE IX

                                     CLOSING

               9.01 Time and Place of Closing. Subject to the satisfaction by
          Seller and Buyer of the conditions set forth in Articles VII and VI,
          respectively, the Closing

                                       10

          of the transactions contemplated by this Agreement shall take place on
          June 2, 2005, at such place and time as the parties may agree. The
          date on which the Closing takes place is herein referred to as the
          "Closing Date."

               9.02 Actions of Seller at the Closing. At the Closing, Seller
          shall:

          (a)  deliver to Buyer a duly executed Bill of Sale and General
               Instrument of Assignment of the Assets (the "Bill of Sale") in
               the form of Exhibit A, dated as of the Closing Date;

          (b)  deliver to Buyer possession of the Assets at the current drill
               sites Johnson County, Texas;

          (c)  deliver to Buyer any and all other affidavits, certificates,
               documents, or agreements required by any federal, state, or local
               governmental or administrative body or authority necessary to
               pass title to the Assets to Buyer, together with such operation
               manuals, engineering drawings and specifications, technical
               documentation and copies of certificates pertaining to the Assets
               as Seller may possess;

          (d)  execute such other documents and instruments, and take such other
               actions, as may be necessary to carry out Seller's obligations
               under this Agreement.

               9.03 Actions of Buyer at Closing. At the Closing, and subject to
          Section 8.09, Buyer shall deliver to Seller the Purchase Price, by
          wire transfer to the account or accounts designated in writing by
          Seller. It is understood that a portion of the Purchase Price
          sufficient to obtain the release of the Rig Lien ($1,435,223.42 if the
          Closing occurs on June 2, 2005) will be paid by Buyer on Seller's
          behalf directly to Community Bank of Cleburne, as provided in the
          payoff letter previously delivered by Community Bank of Cleburne.

               9.04 Passage of Title; Delivery of Assets. Title to the Assets
          will pass from Seller to Buyer at the Closing, subject to Section
          8.09.

               9.05 Further Assurances. Subject to the terms and provisions of
          this Agreement, from time to time subsequent to the Closing Date, each
          party agrees to use reasonable efforts to execute and deliver, at the
          reasonable request of the other party, such additional documents and
          instruments as may, in the reasonable opinion of the requesting party,
          be reasonably required to carry out the intents and purposes of this
          Agreement and the transactions contemplated hereby.

                                    ARTICLE X

                                      TAXES

               10.01 Income Taxes. Seller shall assume responsibility for, and
          shall bear and pay, all income taxes, and other similar taxes on gross
          income, net income, or

                                       11

          gross receipts (including any applicable interest or penalties)
          incurred or imposed by any United States or foreign taxing authority
          with respect to the operation of the Assets prior to Closing.

               10.02 Sales Taxes. Buyer shall assume responsibility for, and
          shall bear and pay, all state and local sales and use taxes (including
          any applicable interest or penalties) incurred or imposed with respect
          to the sale by Seller to Buyer of the Assets pursuant to this
          Agreement.

               10.03 Tax Indemnities. Seller agrees to indemnify and hold
          harmless Buyer and its successors and assigns from and against any and
          all claims, demands, assessments, deficiencies, liabilities, costs,
          and expenses (including reasonable attorneys' fees and other costs and
          expenses of Buyer incident to the defense of same) that are caused by,
          arise out of, or result from any liability for the payment of federal,
          state or local taxes (including applicable penalties and interest)
          attributable to the operation of the Assets prior to the Closing for
          which the responsibility for payment has been allocated to Seller
          pursuant to the preceding provisions of this Article X.

                                   ARTICLE XI

                                 INDEMNIFICATION

               11.01 Indemnification by Seller. In addition to the other
          indemnities given by Seller to Buyer in this Agreement, Seller shall
          indemnify and hold harmless Buyer and its successors and assigns from
          and against any and all claims, demands, losses, damages, liabilities,
          costs, expenses, and deficiencies (including, without limitation,
          reasonable attorneys' fees and other costs and expenses of Buyer
          incident to the defense of any claim that results in litigation, or
          the settlement of any claim, or the enforcement by Buyer or the
          provisions of this Section 11.01) caused by, arising out of, or
          resulting from, and to pay Buyer any sum that Buyer pays or becomes
          obligated to pay on account of, (a) the ownership of the Assets by
          Seller prior to the Closing Date, (b) the use and/or operation of the
          Assets prior to the Closing Date, (c) any breach or default in the
          performance by Seller of any covenant or agreement of Seller contained
          in this Agreement or in any other instrument delivered by or on behalf
          of Seller pursuant hereto, (d) any breach of a warranty or an
          inaccurate or erroneous representation made by Seller herein or in any
          other instrument delivered by or on behalf of Seller pursuant hereto,
          or (e) any and all actions, suits, proceedings, claims, demands or
          judgments incident to any of the foregoing. If any person shall assert
          a claim against Buyer or its affiliates that, if successful, might
          result in a breach or default by Seller under this Agreement, Buyer
          shall give Seller prompt written notice thereof, and Seller shall have
          the right to participate in the defense thereof and to be represented,
          at the sole expense of Seller, by counsel selected by it. No such
          claim, demand, or other matter shall be compromised or settled by
          Seller or Buyer in any manner that might adversely affect the interest
          of the other party without the prior written consent of such other
          party (which consent shall not be unreasonably withheld).

                                       12

               11.02 Indemnification by Buyer. In addition to the other
          indemnities given by Buyer to Seller in this Agreement, Buyer shall
          indemnify and hold harmless Seller and its successors and assigns from
          and against any and all claims, demands, losses, damages, liabilities,
          costs, expenses, and deficiencies (including, without limitation,
          reasonable attorneys' fees and other costs and expenses of Seller
          incident to the defense of any claim that results in litigation, or
          the settlement of any claim, or the enforcement by Seller or the
          provisions of this Section 11.02) caused by, arising out of, or
          resulting from, and to pay Seller any sum that Seller pays or becomes
          obligated to pay on account of, (a) the ownership of the Assets by
          Buyer from and after the Closing Date, (b) the use and/or operation of
          the Assets from and after the Closing Date, (c) any breach or default
          in the performance by Buyer of any covenant or agreement of Buyer
          contained in this Agreement or in any other instrument delivered by or
          on behalf of Buyer pursuant hereto, (d) any breach of a warranty or an
          inaccurate or erroneous representation made by Buyer herein or in any
          other instrument delivered by or on behalf of Buyer pursuant hereto,
          or (e) any and all actions, suits, proceedings, claims, demands or
          judgments incident to any of the foregoing. If any person shall assert
          a claim against Seller or its affiliates that, if successful, might
          result in a breach or default by Buyer under this Agreement, Seller
          shall give Buyer prompt written notice thereof, and Buyer shall have
          the right to participate in the defense thereof and to be represented,
          at the sole expense of Buyer, by counsel selected by it. No such
          claim, demand, or other matter shall be compromised or settled by
          Buyer or Seller in any manner that might adversely affect the interest
          of the other party without the prior written consent of such other
          party (which consent shall not be unreasonably withheld).

                                   ARTICLE XII

                                   TERMINATION

               12.01 Termination. This Agreement may be terminated and the
          transactions contemplated hereby may be abandoned at any time prior to
          the Closing:

          (a)  by mutual written consent of Buyer and Seller;

          (b)  by Buyer, if

               (i)  the Closing shall not have occurred by June 7, 2005
                    (provided that the right to terminate this Agreement under
                    this clause (i) shall not be available to Buyer if Buyer's
                    failure to fulfill any of its obligations under this
                    Agreement or its misrepresentation or breach of warranty
                    hereunder has been the cause thereof); or

               (ii) there has been a material breach by Seller of any covenant
                    or agreement, or a material inaccuracy of any representation
                    or warranty of Seller, contained in this Agreement which has
                    rendered the satisfaction of any condition to the
                    obligations of

                                       13

                    Buyer impossible and such breach or inaccuracy has not been
                    cured by Seller within five (5) Business Days after Seller's
                    receipt of notice thereof from Buyer, or waived by Buyer.

          (c)  by Seller, if

               (i)  the Closing shall not have occurred by June 7, 2005
                    (provided that the right to terminate this Agreement under
                    this clause (i) shall not be available to Seller if Seller's
                    failure to fulfill any of its obligations under this
                    Agreement or its misrepresentation or breach of warranty
                    hereunder has been the cause thereof); or

               (ii) there has been a material breach by Buyer of any covenant or
                    agreement, or a material inaccuracy of any representation or
                    warranty of Buyer, contained in this Agreement which has
                    rendered the satisfaction of any condition to the
                    obligations of Seller impossible and such breach or
                    inaccuracy has not been cured by Buyer within five (5)
                    Business Days after Buyer's receipt of notice thereof from
                    Seller, or waived by Seller.

          (d)  By Buyer or Seller pursuant to Section 2.02.

               12.02 Effect of Termination. In the event of the termination of
          this Agreement pursuant to Section 12.01 by Buyer or Seller, written
          notice thereof shall forthwith be given to the other party specifying
          the provision hereof pursuant to which such termination is made, and
          this Agreement shall become void and have no effect, and there shall
          be no liability hereunder on the part of Buyer or Seller or any of
          their respective directors, officers, employees, stockholders or
          representatives; provided that nothing contained in this Section 12.02
          shall relieve any party from liability for damages actually incurred
          (excluding consequential damages) for breach of any covenant or
          agreement, or for the inaccuracy of any representation or warranty,
          contained herein.

                                  ARTICLE XIII

                            MISCELLANEOUS PROVISIONS

               13.01 Notices. All notices required or permitted to be given
          hereunder shall be in writing and shall be delivered personally, or
          sent by reputable overnight courier, or mailed by certified or
          registered United States Mail with postage prepaid, or sent by
          telecopy (provided such telecopy is confirmed by mail in the manner
          previously described), addressed to the appropriate party at the
          address for such party shown below or at such other address as such
          party shall have theretofore designated by written notice delivered to
          the party giving such notice:

     If to Seller:

          C and L Services, LP

                                       14

          2005 South Main St.
          Cleburne, Texas 76031
          Attn: Cody Jones and Larry Durham
          Telephone No.: (817) 641-5600
          Telecopy No.: (817) 641-6500

     If to Buyer:

          Union Drilling Texas, LP
          South Pittsburgh Technology Park
          3117 Washington Pike
          Bridgeville, Pennsylvania 15017
          Attn: Christopher Strong
          Telephone No.: (412) 257-9390
          Telecopy No.:(412) 257-9392

          Any notice given in accordance herewith shall be deemed to have been
given when delivered to the addressee in person or transmitted by telecopy, or
one (1) day after such notice has been delivered to a reputable overnight
courier, or five (5) days after such notice has been deposited in the United
States Mail, as the case may be, Seller or Buyer may change the address to which
such communications are to be directed by giving written notice to the other
parties in the manner provided in this Section 13.01.

               13.02 Entire Agreement. This Agreement, the documents,
          instruments and agreements to be executed pursuant hereto, the
          schedules and exhibits hereto, and the documents referred to herein,
          constitute the entire agreement between the parties hereto pertaining
          to the subject matter hereof and supersede all prior agreements,
          understandings, negotiations and discussions, whether oral or written,
          of the parties pertaining to the subject matter hereof.

               13.03 Successors and Assigns. This agreement shall be binding
          upon and inure to the benefit of the parties hereto and their
          respective successors and assigns. Buyer may assign its rights
          hereunder only to an Affiliate or subsidiary of Buyer.

               13.04 Amendment. This Agreement may be amended only by an
          instrument in writing executed by all of the parties hereto.

               13.05 Waiver. Any of the terms, covenants, representations,
          warranties or conditions hereof may be waived only by a written
          instrument executed by or on behalf of the party hereto waiving
          compliance. The failure of any party at any time or times to require
          performance of any provision hereof shall in no manner affect the
          right of such party at a later time to enforce the performance of such
          provisions. No waiver by any party of any condition, or of any breach
          of any term, covenant, representation, or warranty contained in this
          Agreement, in any one or more instances, shall be deemed to be or
          construed as a further or continuing waiver of any such condition or
          breach, or a waiver of any other condition or of any breach of any
          other term, covenant, representation or warranty.

                                       15

               13.06 Captions. The captions in this Agreement are for
          convenience only and shall not be considered a part of or affect the
          construction or interpretation of any provision of this Agreement.

               13.07 No Third-Party Beneficiaries. Nothing in this Agreement
          shall entitle any party other than Buyer and Seller to any claim,
          cause of action, remedy, or right of any kind.

               13.08 Governing Law. This Agreement shall be governed by the laws
          of the State of Texas, without regard to conflicts of law principles.

               13.09 Severability. If any term or other provision of this
          Agreement is invalid, illegal, or incapable of being enforced by any
          rule of law or public policy, all other conditions and provisions of
          this Agreement shall nevertheless remain in full force and effect so
          long as the economic or legal substance of the transactions
          contemplated hereby is not affected in any adverse manner to any
          party. Upon such determination that any term or other provision is
          invalid, illegal, or incapable of being enforced, the parties hereto
          shall negotiate in good faith to modify this Agreement so as to effect
          the original intent of the parties as closely as possible in an
          acceptable manner to the end that the transactions contemplated hereby
          are fulfilled to the extent possible.

               13.10 Execution Counterparts. This Agreement may be executed in
          any number of counterparts, and each such counterpart hereof shall be
          deemed to be an original instrument, but all such counterparts
          together shall constitute for all purposes one agreement.

                                       16

          IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the date first above written.

                                       SELLER:
                                       C AND L SERVICES, LP

                                       By /s/ CODY JONES
                                          --------------------------------------
                                       Name: Cody Jones
                                       Title: President

                                       BUYER:
                                       UNION DRILLING TEXAS, LP, by
                                       UNION DRILLING TEXAS GP, LLC, its General
                                       Partner

                                       By /s/ CHRISTOPHER STRONG
                                          --------------------------------------
                                       Christopher Strong, President

                                       17

                         INDEX TO SCHEDULES AND EXHIBITS

Schedule
Number     Description
--------   -----------
2.01(a)    Assets

Exhibits
--------
Exhibit A  Form of Bill of Sale

                                       18

                                Schedule 2.01(a)

                                     Assets

NATIONAL 80B

NATIONAL 80B Single Drum Drawworks, 1,000-HP, LEBUS Grooved f/1-1/4" Drilling
Line, FOSTER Make-Up & Breakout Catheads, Overrunning Clutch, Air Driller's
Console Controls, Unitized PARMAC 22" Hydromatic Brakes, Crown-O-Matic

2-Engine Compound w/Single Pedestal Pump Drive, (2) CAT D-379 Diesel Engines,
NATIONAL 245-125 Torque Converters, QUINCY 390 Air Compressor MAST/SUBSTRUCTURE

DSI 131'H x 18'6"W Cantilever Mast, 500,000# SHL, IDEAL 6-Sheave Pin Type Crown
Block, (2) Crown Stands

16'H Box on Box Substructure, V-Door, Steps, Safety Rails, Built-In Parts Room,
Locker Room, Air Volume Tank, Air Lines

MUD PUMPS

BOMCO F-800 Triplex Mud Pump, Forged Steel Fluid End w/Quick Change Valve Cover
& Quick Change Cylinder Head Caps, Pulsation Dampener, Shear Relief Valve,
Charging Pump, Master Skidded, p/b CAT D-398 Diesel Engine

BOMCO F-800 Triplex Mud Pump, Forged Steel Fluid End w/Quick Change Valve Cover
& Quick Change Cylinder Head Caps, Pulsation Dampener, Shear Relief Valve,
Charging Pump, Skidded, Compound Driven

ROTATING/TRAVELING EQUIPMENT

250-Ton Block/Hook Combination
300-Ton Swivel
OILWELL 20-1/2" X 53" Rotary Table
5-1/4" x 46'L Hex Kelly
Kelly Drive Bushing

                                       19

WELL CONTROL EQUIPMENT

SHAFFER LA-70, 11" 5,000# Double Blowout Preventer
WSI 11" 5,000# Annular Blowout Preventer
KOOMEY 4-Station Closing Unit
3" Choke Manifold, Skidded

RIG HOUSES

8'W x 28'L Top Doghouse, Skidded, w/Lockers, SATELLITE Automatic Driller, MARTIN
DECKER Type-D Weight Indicator, 4-Pin Drilling Recorder, Heater
10'W x 20'L Parts/Tool House, Skidded

GENERATORS/UTILITY HOUSE

(2) MECALTE 325-KW Generator Sets, Each p/b CAT D-3406B DITA Diesel Engines,
Skidded
Screw Air Compressor
Motor Control Center/Receptacle Outlets
Voltage Panel f/Trailers
All Above Mounted in 10'W x 30'L Utility House, w/Fluorescent Lights, Skidded

MUD SYSTEM

750-Barrel Mud System, 2-Tank, Mud Agitators in Each Tank, Mud Flow Troughs,
Internal & External Plumbing, (4) 5" x 6" Centrifugal Pumps p/b Electric Motors,
Skidded

MCM Dual Screen Shale Shaker
Desander w/(2) 10" Cones
Desilter w/(10) 5" Cones

                                       20

WATER/FUEL TANK/LUBESTER

10,000-Gallon Fuel Tank, Skidded
Lubester, Skidded, with Suncoast Bulk tanks mounted on skid

HANDLING TOOLS

BJ Type B Rotary Tongs, 4" - 10-3/4"
Drill Pipe Slips, Drill Collar Slips, Safety Clamp
INGERSOLL RAND 4,000# Capacity Air Hoist

AUXILIARY EQUIPMENT

Rotary Hose
15,000' Capacity Wireline Unit
7,500' of 1-1/4" Drilling Line, Spool, Stand
42"H x 60'L 2-Section Catwalk
4-Sets (8) Pipe Racks

DRILL PIPE/DRILL COLLARS

10,000' 5" Drill Pipe, Double White Band
(20) 7" Spiral Drill Collars

                                       21

IDECO 750

IDECO 750 Single Drum Drawworks, 1,000-HP, LEBUS Grooved f/1-1/8" Drilling Line,
FOSTER Make-Up & Breakout Catheads, Overrunning Clutch, Air Driller's Console
Controls, Crown-O-Matic, Unitized PARMAC 22" Hydromatic Brakes

2-Engine Compound w/Single Pedestal Pump Drive, (2) CAT D-379 Diesel Engines,
NATIONAL 245-125 Torque Converters

MAST/SUBSTRUCTURE

Branham 131'H x 18'6"W Cantilever Mast, 550,000# GNC, 5-Sheave Pin Type Crown
Block, (1) Crown Stands

16'H Box on Box Substructure, V-Door, Steps, Safety Rails, Air Volume Tank, Air
Lines

MUD PUMPS

BOMCO F-800 Triplex Mud Pump, Forged Steel Fluid End w/Quick Change Valve Cover
& Quick Change Cylinder Head Caps, Pulsation Dampener, Shear Relief Valve,
Charging Pump, Master Skidded, p/b CAT D-398 Diesel Engine

BOMCO F-800 Triplex Mud Pump, Forged Steel Fluid End w/Quick Change Valve Cover
& Quick Change Cylinder Head Caps, Pulsation Dampener, Shear Relief Valve,
Charging Pump, Skidded, Compound Driven

ROTATING/TRAVELING EQUIPMENT

300-Ton Traveling Block
200-Ton Hook
300-Ton Swivel
IDECO 23" X 54" Rotary Table
4-1/4" x 44'L Square Kelly
Kelly Drive Bushing

                                       22

WELL CONTROL EQUIPMENT

SHAFFER LA-5000, 11" 5,000# Double Blowout Preventer
HYDRIL 12" 3,000# Annular Blowout Preventer
KOOMEY 5-Station Closing Unit
3" Choke Manifold, Skidded

RIG HOUSE

8'W x 32'L Top Doghouse, Skidded, w/Lockers, SATELLITE Automatic Driller, MARTIN
DECKER Type-D Weight Indicator, 4-Pin Drilling Recorder, Heater

GENERATORS/UTILITY HOUSE

(2) MECALTE 325-KW Generator Sets, Each p/b CAT D-3406B DITA Diesel Engines,
Skidded
Screw Air Compressor
Motor Control Center/Receptacle Outlets
Voltage Panel f/Trailers
All Above Mounted in 10'W x 30'L Utility House, w/Fluorescent Lights, Skidded

MUD SYSTEM

750-Barrel Mud System, 2-Tank, Mud Agitators in Each Tank, Mud Flow Troughs,
Internal & External Plumbing, (4) 5" x 6" Centrifugal Pumps p/b Electric Motors,
Skidded
MCM Dual Screen Shale Shaker
Desander w/(2) 10" Cones
Desilter w/(10) 5" Cones

WATER/FUEL TANK/LUBESTER

500-Barrel Water Tank, Skidded
Lubester, Skidded, with Suncoast Bulk tanks mounted on Skid

                                       23

HANDLING TOOLS

BJ Type D Rotary Tongs, 4" - 10-3/4"
Drill Pipe Slips, Drill Collar Slips, Safety Clamp
INGERSOLL RAND 4,000# Capacity Air Hoist

AUXILIARY EQUIPMENT

Rotary Hose
15,000' Capacity Wireline Unit
7,500' of 1-1/8" Drilling Line, Spool, Stand
42"H x 60'L 2-Section Catwalk
2-Sets (4) Pipe Racks

DRILL PIPE/DRILL COLLARS

10,000' 4-1/2" Drill Pipe, Grades E & S135
(20) 6" Spiral Drill Collars

                                       24

Exhibit A

                              Form of Bill of Sale

                       GENERAL BILL OF SALE AND ASSIGNMENT

          GENERAL BILL OF SALE AND ASSIGNMENT, effective as of 12:01 a.m. on
June 2, 2005, from C AND L SERVICES, LP, a Texas limited partnership ("Seller"),
to UNION DRILLING TEXAS, LP, a Texas limited partnership ("Buyer").

                                    RECITALS

          1. Seller is executing and delivering this General Bill of Sale and
Assignment to Buyer for the purpose of selling, assigning, transferring, and
delivering to, and vesting in, the Buyer all right, title and interest of the
Seller in and to the "Assets" (as defined in the Asset Purchase Agreement dated
as of May 31, 2005, by and between Seller and Buyer).

                                    AGREEMENT

          Section 1. In consideration of the premises and of other good and
valuable consideration, receipt of which is hereby acknowledged, Seller by these
presents does sell, assign, transfer, and deliver to, and vest in Buyer, its
successors and assigns forever, good and marketable title and all of Seller's
right, title, and interest, legal and equitable, in and to each and every one of
the Assets.

          TO HAVE AND TO HOLD all of the Assets unto Buyer, its successors and
assigns forever; and Seller does for itself, and its successors and assigns,
covenant and agree with Buyer to WARRANT AND DEFEND the title of the aforesaid
Assets against all and every person and persons whomsoever.

          Section 2. Seller hereby constitutes and appoints Buyer, its
successors and assigns the true and lawful attorney and attorneys of Seller with
full power of substitution in its

                                       25

name and stead, but on behalf and for the benefit of Buyer, its successors and
assigns, to demand and receive any and all of the Assets sold, transferred and
assigned to Buyer this instrument and to give receipts and releases for and in
respect of the same or any part thereof, to endorse any claim or right of any
kind in respect thereof and to do all acts and things in relation to the Assets,
which Buyer, its successors and assigns may deem desirable, Seller hereby
declaring that the foregoing powers are coupled with an interest and are not
revocable and shall not be revoked by Seller or its successors or assigns for
any reason whatsoever.

          Section 3. Seller, for itself, its successors and assigns, hereby
covenants and agrees that, at any time and from time to time forthwith upon the
written request of Buyer, Seller will, at its expense, do, execute, acknowledge,
and deliver or cause to be done, executed, acknowledged, or delivered, all and
every such further acts, deeds, assignments, transfers, conveyances, powers of
attorney, and assurances as may be reasonably required by Buyer in order to
sell, assign, transfer, and convey to, and vest in, Buyer, its successors and
assigns, or to aid and assist Buyer in reducing to possession and use any or all
of the Assets assigned to Buyer.

          Section 4. Nothing herein expressed or implied is intended or shall be
construed to confer upon or give to any person or entity, other than Seller and
Buyer, and their respective successors and assigns, any rights or remedies by
reason of this General Bill of Sale and Assignment.

          Section 5. This General Bill of Sale and Assignment is executed by,
and shall be binding upon, Seller, its successors and assigns, for the uses and
purposes above set forth and referred to, as of the effective date thereof.

                                       26

          IN WITNESS WHEREOF, Seller has caused this General Bill of Sale and
Assignment to be signed as of the date set forth above.

                                       C AND L SERVICES, LP

                                       By: /s/ CODY JONES
                                           -------------------------------------
                                       Name: Cody Jones
                                       Title: President

                                       27

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