QuickLinks
 -- Click here to rapidly navigate through this document
  



 
 

EXHIBIT 4.15    
  


 
 

PROMISSORY NOTE
  (Floating Rate)    




	$6,000,000.00	 	March 29, 2002





        For value received, PIONEER DRILLING SERVICES, LTD., a Texas limited partnership (formerly known as Pioneer
Drilling Co., Ltd.), as principal ("Borrower"), promises to pay to the order of THE FROST NATIONAL
BANK, a national banking association ("Lender") at P.O. Box 1600, San Antonio, Texas 78296, or at such other address as
Lender shall from time to time specify in writing, the principal sum of SIX MILLION AND 00/100 DOLLARS ($6,000,000.00), or so much thereof as may be advanced pursuant to the terms of that certain Loan
Agreement (herein so called) dated March 30, 2001, as amended, in legal and lawful money of the United States of America, with interest on the outstanding principal from the date advanced until
paid at the rate set out below. Interest shall be computed on a per annum basis of a year of 360 days and for the actual number of days elapsed, unless such calculation would result in a rate
greater than the highest rate permitted by applicable law, in which case interest shall be computed on a per annum basis of a year of 365 days or 366 days in a leap year, as the case may
be. 


        1.    Payment Terms. Interest only shall be due and payable monthly as it accrues on the last day of each and every calendar
month, beginning April 30, 2002 and continuing regularly and monthly thereafter until September 29, 2002, when the entire amount hereof, principal and interest then remaining unpaid,
shall be then due and payable; interest being calculated on the unpaid principal each day principal is outstanding and all payments made credited to any collection costs and late charges, to the
discharge of the interest accrued and to the reduction of the principal, in such order as Lender shall determine. 


        2.    Late Charge. If a payment is made 10 days or more late, Borrower will be charged, in addition to interest, a
delinquency charge of (i) 5% of the unpaid portion of the regularly scheduled payment, or (ii) $250.00, whichever is less. Additionally, upon maturity of this Note, if the outstanding
principal balance (plus all accrued but unpaid interest) is not paid within 10 days of the maturity date, Borrower will be charged a delinquency charge of (i) 5% of the sum of the
outstanding principal balance (plus all accrued but unpaid interest), or (ii) $250.00, whichever is less. Borrower agrees with Lender that the charges set forth herein are reasonable
compensation to Lender for the handling of such late payments. 


        3.    Interest Rate. Interest on the outstanding and unpaid principal balance hereof shall be computed at a per annum rate equal
to the lesser of (a) a rate equal to the Prime Rate of Lender, plus one percent (1%) per annum, with said rate to be adjusted to reflect any change in said Prime Rate at the time of any such
change or (b) the highest rate permitted by applicable law, but in no event shall interest contracted for, charged or received hereunder plus any other charges in connection herewith which
constitute interest exceed the maximum interest permitted by applicable law, said rate to be effective prior to maturity (however such maturity is brought about). The "Prime Rate" shall mean the prime
rate of interest charged by Lender as established from time to time. The Prime Rate is a reference rate and does not necessarily represent the lowest or best rate actually charged to any customer. 


        4.    Default Rate. Matured unpaid principal and interest shall bear interest from date of maturity until
paid at (a) the highest rate permitted by applicable law, or (b) if no such maximum rate is established by applicable law, at the rate stated above plus five percent (5%) per annum. 


1





 



        5.    Prepayment. Borrower reserves the right to prepay, prior to maturity, all or any part of the principal of this Note
without penalty. Any prepayments shall be applied first to accrued interest and then to principal. Borrower will provide written notice to the holder of this Note of any such prepayment of all or any
part of the principal at the time thereof. All payments and prepayments of principal or interest on this Note shall be made in lawful money of the United States of America in immediately available
funds, at the address of Lender indicated above, or such other place as the holder of this Note shall designate in writing to Borrower. All partial prepayments of principal shall be applied to the
last installments payable in their inverse order of maturity. 


        6.    Default. It is expressly provided that upon default in the punctual payment of this Note or any part hereof, principal or
interest, as the same shall become due and payable, or upon the occurrence of an event of default specified in any of the other Loan Documents (as defined below) and such default continues after the
giving of written notice to Borrower and the passage of the applicable cure period as provided in the Loan Agreement, the holder of this Note may, at its option, without further notice or demand,
(i) declare the outstanding principal balance of and accrued but unpaid interest on this Note at once due and payable, (ii) refuse to advance any additional amounts under this Note,
(iii) foreclose all liens securing payment hereof, (iv) pursue any and all other rights, remedies and recourses available to the holder hereof, including but not limited to any such
rights, remedies or recourses under the Loan Documents, at law or in equity, or (v) pursue any combination of the foregoing; and in the event default is made in the prompt payment of this Note
when due or declared due, and the same is placed in the hands of an attorney for collection, or suit is brought on same, or the same is collected through probate, bankruptcy or other judicial
proceedings, then the Borrower agrees and promises to pay all costs of collection, including reasonable attorney's fees. 


        7.    Joint and Several Liability; Waiver. Each maker, signer, surety and endorser hereof, as well as all heirs, successors and
legal representatives of said parties, shall be directly and primarily, jointly and severally, liable for the payment of all indebtedness hereunder. Lender may release or modify the obligations of any
of the foregoing persons or entities, or guarantors hereof, in connection with this loan without affecting the obligations of the others. All such persons or entities expressly waive presentment and
demand for payment, notice of default, notice of intent to accelerate maturity, notice of acceleration of maturity, protest, notice of protest, notice of dishonor, and all other notices and demands
for which waiver is not prohibited by law, and diligence in the collection hereof; and agree to all renewals, extensions, indulgences, partial payments, releases or exchanges of collateral, or taking
of additional collateral, with or without notice, before or after maturity. No delay or omission of Lender in exercising any right hereunder shall be a waiver of such right or any other right under
this Note. 


        8.    No Usury Intended; Usury Savings Clause. In no event shall interest contracted for, charged or received hereunder, plus
any other charges in connection herewith which constitute interest, exceed the maximum interest permitted by applicable law. The amounts of such interest or other charges previously paid to the holder
of the Note in excess of the amounts permitted by applicable law shall be applied by the holder of the Note to reduce the principal of the indebtedness evidenced by the Note, or, at the option of the
holder of the Note, be refunded. To the extent permitted by applicable law, determination of the legal maximum amount of interest shall at all times be made by amortizing, prorating, allocating and
spreading in equal parts during the period of the full stated term of the loan and indebtedness, all interest at any time contracted for, charged or received from the Borrower hereof in connection
with the loan and indebtedness evidenced hereby, so that the actual rate of interest on account of such indebtedness is uniform throughout the term hereof. 


2





 



        9.    Security. This Note has been executed and delivered pursuant to the Loan Agreement, and is secured by, inter alia, that
certain Security Agreement dated March 30, 2001, executed by and between Pioneer Drilling Co., Ltd. and Lender, as amended, covering certain collateral as more particularly described
therein. This Note, the Loan Agreement and all other documents evidencing, securing, governing, guaranteeing and/or pertaining to this Note, including but not limited to those documents described
above, are hereinafter collectively referred to as the "Loan Documents." The holder of this Note is entitled to the benefits and security provided in
the Loan Documents. 


        10.  Texas Finance Code. In no event shall Chapter 346 of the Texas Finance Code (which regulates certain revolving loan
accounts and revolving tri-party accounts) apply to this Note. To the extent that Chapter 303 of the Texas Finance Code is applicable to this Note, the "weekly ceiling" specified in such
article is the applicable ceiling; provided that, if any applicable law permits greater interest, the law permitting the greatest interest shall apply. 


        11.  Governing Law, Venue. This Note is being executed and delivered, and is intended to be performed in the State of Texas.
Except to the extent that the laws of the United States may apply to the terms hereof, the substantive laws of the State of Texas shall govern the validity, construction, enforcement and
interpretation of this Note. In the event of a dispute involving this Note or any other instruments executed in connection herewith, the undersigned irrevocably agrees that venue for such dispute
shall lie in any court of competent jurisdiction in Bexar County, Texas. 


        12.  Purpose of Loan. Borrower agrees that no advances under this Note shall be used for personal, family or household
purposes, and that all advances hereunder shall be used solely for business, commercial, investment, or other similar purposes. 


        13.  Captions. The captions in this Note are inserted for convenience only and are not to be used to limit the terms herein. 


        14.  Financial Information. Borrower agrees to promptly furnish such financial information and statements, including financial
statements in a format acceptable to Lender, lists of assets and liabilities, agings of receivables and payables, inventory schedules, budgets, forecasts, tax returns, and other reports with respect
to Borrower's financial condition and business operations as Lender may request from time to time. This provision shall not alter the obligation of Borrower to deliver to Lender any other financial
statements or reports pursuant to the terms of any other loan documents executed in connection with this Note. 


        15.  Renewal and Extension. This Note is given in renewal and extension, but not extinguishment, of all amounts left owing and
unpaid on that certain promissory note dated March 30, 2001 executed and delivered by Pioneer Drilling Co., Ltd. and payable to the order of Lender in the original principal face amount
of $12,000,000.00. 



	 	 	BORROWER:
	

 	
 	
PIONEER DRILLING SERVICES, LTD., a Texas limited partnership (formerly known as Pioneer Drilling Co., Ltd.)
	

 	
 	

By:	
 	

PDC Mgmt. Co., a Texas corporation, General Partner
	

 	
 	

By:	
 	


	 	 	 	 	Printed Name:

	 	 	 	 	Title:





3









QuickLinks



EXHIBIT 4.15


PROMISSORY NOTE (Floating Rate)