FORM 10-K405

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549

               Annual Report Pursuant to Section 13 or 15(d) of
                      the Securities Exchange Act of 1934

For the fiscal year ended December 31, 1997

Commission File Number 0-16331

                        DYCO OIL AND GAS PROGRAM 1986-X
                            (A LIMITED PARTNERSHIP)
            (Exact name of registrant as specified in its charter)

           Minnesota                       41-1565819
(State or other jurisdiction of          (I.R.S. Employer
incorporation or organization)        Identification Number)

         Samson Plaza
   Two West Second Street
        Tulsa, Oklahoma                       74103
     (Address of principal                  (Zip Code)
      executive offices)

Registrant's telephone number, including area code: (918) 583-1791

Securities registered pursuant to Section 12(b) of the Act:  None.

Securities registered pursuant to Section 12(g) of the Act:
      Units of limited partnership interest

      Indicate by check mark  whether the  registrant  (1) has filed all reports
required to be filed by Section 13 or 15(d) of the  Securities  Exchange  Act of
1934  during  the  preceding  12 months  (or for such  shorter  period  that the
registrant was required to file such  reports),  and (2) has been subject to the
filing requirements for the past 90 days. Yes [X] No [ ]

      Indicate by check mark if disclosure of  delinquent  filers  pursuant to
Item  405  of  Regulation  S-K  is  not  contained  herein,  and  will  not be
contained,  to the best of  registrant's  knowledge,  in  definitive  proxy or
information  statements  incorporated  by  reference  in Part III of this Form
10-K405 or any amendment to this Form 10-K405.  [X]

      The units of  limited  partnership  are not  publicly  traded,  therefore,
registrant cannot compute the aggregate market value of the voting units held by
non-affiliates of the registrant.

      DOCUMENTS INCORPORATED BY REFERENCE:  None.





<PAGE>




                                 FORM 10-K405

                        DYCO OIL AND GAS PROGRAM 1986-X
                       (a Minnesota limited partnership)


                               TABLE OF CONTENTS


PART I.......................................................................3
      ITEM 1.     BUSINESS...................................................3
      ITEM 2.     PROPERTIES.................................................7
      ITEM 3.     LEGAL PROCEEDINGS.........................................11
      ITEM 4.     SUBMISSION OF MATTERS TO A VOTE OF LIMITED PARTNERS.......11
PART II.....................................................................11
      ITEM 5.     MARKET FOR THE REGISTRANT'S LIMITED PARTNERSHIP UNITS
                  AND RELATED LIMITED PARTNER MATTERS.......................11
      ITEM 6.     SELECTED FINANCIAL DATA...................................13
      ITEM 7.     MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                  CONDITION AND RESULTS OF OPERATIONS.......................14
      ITEM 8.     FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA...............19
      ITEM 9.     CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON
                  ACCOUNTING AND FINANCIAL DISCLOSURE.......................30
PART III....................................................................30
      ITEM 10.    DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT........30
      ITEM 11.    EXECUTIVE COMPENSATION....................................31
      ITEM 12.    SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND
                  MANAGEMENT................................................35
      ITEM 13.    CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS............35
PART IV.....................................................................37
      ITEM 14.    EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS
                  ON FORM 8-K...............................................37
      SIGNATURES............................................................39





                                       2
<PAGE>



PART I


ITEM 1.  BUSINESS

      General

      The Dyco Oil and Gas Program 1986-X Limited Partnership (the "Program") is
a Minnesota  limited  partnership  engaged in the production of oil and gas. The
Program  commenced  operations  on December 12, 1986 with the primary  financial
objective of investing its limited  partners'  subscriptions  in the drilling of
oil  and gas  prospects  and  then  distributing  to its  limited  partners  all
available  cash flow from the Program's  on-going  production  operations.  Dyco
Petroleum Corporation ("Dyco") serves as the General Partner of the Program. See
"Item 2. Properties" for a description of the Program's reserves and properties.

      The  limited   partnership   agreement   for  the  Program  (the  "Program
Agreement")  provides  that limited  partners are  allocated  99% of all Program
costs and revenues and Dyco, as General Partner,  is allocated 1% of all Program
costs and  revenues.  Included in such costs is the Program's  reimbursement  to
Dyco of the Program's proportionate share of Dyco's geological, engineering, and
general and administrative expenses.

      Dyco  currently  serves as General  Partner  of 32  limited  partnerships,
including the Program.  Dyco is a wholly-owned  subsidiary of Samson  Investment
Company.  Samson  Investment  Company  and its various  corporate  subsidiaries,
including Dyco, (collectively,  the "Samson Companies") are primarily engaged in
the production and  development of and  exploration for oil and gas reserves and
the acquisition and operation of producing properties. At December 31, 1997, the
Samson  Companies  owned  interests  in  approximately  13,000 oil and gas wells
located  in 19  states  of the  United  States  and  the  countries  of  Canada,
Venezuela,  and Russia.  At December 31,  1997,  the Samson  Companies  operated
approximately 2,500 oil and gas wells located in 15 states of the United States,
as well as Canada, Venezuela, and Russia.

      As a limited  partnership,  the Program  has no  officers,  directors,  or
employees.  It relies  instead  on the  personnel  of Dyco and the other  Samson
Companies.  As of March 1, 1998, the Samson Companies employed approximately 820
persons.  No employees  are covered by  collective  bargaining  agreements,  and
management believes that the Samson Companies provide a sound employee relations
environment. For information regarding the executive officers of Dyco, see "Item
10. Directors and Executive Officers of the Registrant."

      Dyco's  and the  Program's  principal  place of  business  is located at
Samson Plaza, Two West Second Street, Tulsa, Oklahoma


                                       3
<PAGE>



74103, and their telephone number is (918) 583-1791 or (800) 283-1791.


      Funding

      Although the Program  Agreement  permits the Program to incur  borrowings,
the Program's  operations and expenses are currently funded out of the Program's
revenues from oil and gas sales. Dyco may, but is not required to, advance funds
to  the  Program  for  the  same  purposes  for  which  Program  borrowings  are
authorized.


      Principal Products Produced and Services Rendered

      The Program's sole business is the  development  and production of oil and
gas with a  concentration  on gas.  The  Program  does  not  hold  any  patents,
trademarks,  licenses,  or  concessions  and is not a  party  to any  government
contracts.  The  Program  has no backlog of orders and does not  participate  in
research and development  activities.  The Program is not presently encountering
shortages of oilfield tubular goods, compressors,  production material, or other
equipment.


      Oil, Gas, and Environmental Control Regulations

      Regulation  of Production  Operations -- The  production of oil and gas is
subject to  extensive  federal and state laws and  regulations  governing a wide
variety of matters, including the drilling and spacing of wells, allowable rates
of  production,  prevention  of  waste  and  pollution,  and  protection  of the
environment.  In  addition  to the direct  costs  borne in  complying  with such
regulations,  operations and revenues may be impacted to the extent that certain
regulations limit oil and gas production to below economic levels.

      Regulation  of Sales and  Transportation  of Oil and Gas -- Sales of crude
oil and  condensate are made by the Program at market prices and are not subject
to price controls. The sale of gas may be subject to both federal and state laws
and  regulations.  The provisions of these laws and  regulations are complex and
affect all who  produce,  resell,  transport,  or purchase  gas,  including  the
Program.  Although  virtually all of the Program's gas production is not subject
to  price  regulation,   other  regulations   affect  the  availability  of  gas
transportation services and the ability of gas consumers to continue to purchase
or use gas at current levels. Accordingly,  such regulations may have a material
effect  on the  Program's  operations  and  projections  of  future  oil and gas
production and revenues.

      Future  Legislation --  Legislation  affecting the oil and gas industry is
under constant review for amendment or expansion.


                                       4
<PAGE>



Because  such laws and  regulations  are  frequently  amended or  reinterpreted,
management  is unable to  predict  what  additional  energy  legislation  may be
proposed or enacted or the future cost and impact of complying  with existing or
future regulations.

      Regulation of the  Environment -- The Program's  operations are subject to
numerous laws and  regulations  governing  the  discharge of materials  into the
environment or otherwise relating to environmental  protection.  Compliance with
such  laws  and  regulations,   together  with  any  penalties   resulting  from
noncompliance,  may increase the cost of the Program's  operations or may affect
the  Program's  ability  to  timely  complete  existing  or  future  activities.
Management  anticipates  that various local,  state,  and federal  environmental
control agencies will have an increasing impact on oil and gas operations.


      Significant Customers

      Purchases  of gas by El Paso  Energy  Marketing  Company  ("El  Paso") and
Transok, Inc. accounted for approximately 85.4% and 11.9%, respectively,  of the
Program's oil and gas revenues  during the year ended  December 31, 1997. In the
event of  interruption  of  purchases  by  these  significant  customers  or the
cessation or material change in availability  of open-access  transportation  by
the Program's  pipeline  transporters,  the Program may encounter  difficulty in
marketing  its  gas  and  in  maintaining  historic  sales  levels.  Alternative
purchasers or transporters may not be readily available.

      The Program's  principal  customers for crude oil  production are refiners
and other companies which have pipeline facilities near the producing properties
of the Program. In the event pipeline facilities are not conveniently  available
to  production  areas,  crude oil is usually  trucked by  purchasers  to storage
facilities.


      Competition and Marketing

      The  domestic  oil and gas  industry is highly  competitive,  with a large
number of companies and  individuals  engaged in the exploration and development
of oil and gas properties.  The ability of the Program to produce and market oil
and gas profitably depends on a number of factors that are beyond the control of
the Program.  These factors include worldwide political instability  (especially
in oil-producing regions), United Nations export embargoes, the supply and price
of foreign  imports of oil and gas, the level of consumer  product demand (which
can be heavily  influenced  by weather  patterns),  government  regulations  and
taxes,  the price and  availability of alternative  fuels,  the overall economic
environment,  and the availability and capacity of transportation and processing
facilities. The effect


                                       5
<PAGE>



of these  factors on future oil and gas industry  trends  cannot be accurately
predicted or anticipated.

      The most important variable affecting the Program's revenues is the prices
received  for  the  sale  of oil  and  gas.  Predicting  future  prices  is very
difficult.  Concerning  past trends,  average yearly  wellhead gas prices in the
United States have been volatile for a number of years.  For the past ten years,
such  average  prices have  generally  been in the $1.40 to $2.40 per Mcf range,
significantly  below prices  received in the early 1980s.  Average gas prices in
the latter part of 1996 and parts of 1997,  however,  were somewhat  higher than
those yearly  averages.  Gas prices are  currently in the middle  portion of the
10-year average price range described above.

      Substantially  all of the  Program's  gas  reserves  are being sold on the
"spot  market."  Prices on the spot  market  are  subject to wide  seasonal  and
regional pricing  fluctuations due to the highly  competitive nature of the spot
market. In addition,  such spot market sales are generally  short-term in nature
and are dependent  upon the  obtaining of  transportation  services  provided by
pipelines.  Spot prices for the Program's gas decreased from approximately $3.57
per Mcf at December  31,  1996 to  approximately  $2.32 per Mcf at December  31,
1997.  Such prices  were on an MMBTU  basis and differ from the prices  actually
received  by  the  Program  due  to  transportation  and  marketing  costs,  BTU
adjustments, and regional price and quality differences.

      For the past ten years,  average  oil prices  have  generally  been in the
$16.00 to $24.00 per barrel range.  Due to global  consumption and supply trends
over the last several  months,  as well as expectations of at least a short-term
slowdown in Asian energy  demand,  oil prices have  recently  been in the mid to
lower  portions of this  pricing  range,  and in early 1998 dropped to as low as
$12.00 per barrel. It is not known whether this trend will continue.  Prices for
the Program's oil decreased from approximately $23.75 per barrel at December 31,
1996 to approximately $16.25 per barrel at December 31, 1997.

      Future prices for both oil and gas will likely be different  from (and may
be lower  than) the prices in effect on  December  31,  1997.  Primarily  due to
heating  season  demand,  year-end  prices in many past years have  tended to be
higher, and in some cases  significantly  higher,  than the yearly average price
actually received by the Program for at least the following year.  Management is
unable to predict  whether  future oil and gas prices will (i)  stabilize,  (ii)
increase, or (iii) decrease.


      Insurance Coverage

      The Program is subject to all of the risks  inherent in the  exploration
for and production of oil and gas, including blowouts,  pollution,  fires, and
other casualties.  The Program


                                       6
<PAGE>



maintains  insurance  coverage as is  customary  for  entities of a similar size
engaged in operations similar to that of the Program,  but losses can occur from
uninsurable risks or in amounts in excess of existing  insurance  coverage.  The
occurrence  of an event  which is not fully  covered by  insurance  could have a
material  adverse  effect on the  Program's  financial  position  and results of
operations.


ITEM 2.  PROPERTIES

      Well Statistics

      The  following  table sets forth the  numbers of gross and net  productive
wells of the Program as of December 31, 1997.

                              Well Statistics(1)

                            As of December 31, 1997

                  Gross productive wells(2):
                     Oil                                 -
                     Gas                                 8
                                                      ----
                        Total                            8

                  Net productive wells(3):
                     Oil                                 -
                     Gas                              1.21
                                                      ----
                        Total                         1.21

----------
(1)   The designation of a well as an oil well or gas well is made by Dyco based
      on the relative amount of oil and gas reserves for the well. Regardless of
      a well's oil or gas designation,  it may produce oil, gas, or both oil and
      gas.
(2)   As used  throughout  this Annual  Report on Form 10-K  ("Annual  Report"),
      "Gross  Well" refers to a well in which a working  interest is owned.  The
      number  of gross  wells is the  total  number  of wells in which a working
      interest is owned.
(3)   As used throughout this Annual Report, "Net Well" refers to the sum of the
      fractional  working  interests  owned in gross wells.  For example,  a 15%
      working interest in a well represents one Gross Well, but 0.15 Net Well.


      Drilling Activities

      The  Program  participated  in no drilling  activities  for the year ended
December 31, 1997.





                                       7
<PAGE>



      Oil and Gas Production, Revenue, and Price History

      The following table sets forth certain historical  information  concerning
the oil  (including  condensates)  and  gas  production,  net of all  royalties,
overriding royalties, and other third party interests, of the Program,  revenues
attributable to such production, and certain price and cost information.

                              Net Production Data

                                                Year Ended December 31,
                                          ----------------------------------
                                            1997          1996        1995
                                          --------      --------    --------

Production:
   Oil (Bbls)(1)                               305           307         398
   Gas (Mcf)(2)                             80,262        87,534      94,215

Oil and gas sales:
   Oil                                    $  6,060      $  5,915    $  6,685
   Gas                                     186,238       185,703     127,800
                                           -------       -------     -------
      Total                               $192,298      $191,618    $134,485
                                           =======       =======     =======

Total direct operating expenses(3)        $ 57,433      $ 64,580    $ 67,844
                                           =======       =======     =======

Direct operating expenses as a
   percentage of oil and gas
   sales                                     29.9%         33.7%       50.4%

Average sales price:
   Per barrel of oil                        $19.87        $19.27      $16.80
   Per Mcf of gas                             2.32          2.12        1.36

Direct operating expenses per
   equivalent Mcf of gas(4)                 $  .70        $  .72      $  .70

----------

(1)   As used throughout this Annual Report, "Bbls" refers to barrels of 42 U.S.
      gallons and  represents  the basic unit for  measuring  the  production of
      crude oil and condensate oil.
(2)   As used  throughout  this Annual  Report,  "Mcf" refers to volume of 1,000
      cubic feet under  prescribed  conditions of pressure and  temperature  and
      represents the basic unit for measuring the production of gas.
(3)   Includes lease operating  expenses and production  taxes.
(4)   Oil production  is converted  to gas  equivalents  at  the rate of six Mcf
      per  barrel,  representing  the estimated  relative energy  content of gas
      and oil, which rate  is not  necessarily  indicative of  the  relationship
      of oil and gas prices.  The


                                       8
<PAGE>



      respective prices of oil and gas are affected by market and other  factors
      in addition to relative energy content.


      Proved Reserves and Net Present Value

      The following table sets forth the Program's  estimated proved oil and gas
reserves and net present value  therefrom as of December 31, 1997.  The schedule
of  quantities of proved oil and gas reserves was prepared by Dyco in accordance
with the rules prescribed by the Securities and Exchange Commission (the "SEC").
As used  throughout  this  Annual  Report,  "proved  reserves"  refers  to those
estimated  quantities of crude oil, gas, and gas liquids  which  geological  and
engineering  data  demonstrate  with  reasonable  certainty to be recoverable in
future  years from known oil and gas  reservoirs  under  existing  economic  and
operating conditions.

      Net present  value  represents  estimated  future gross cash flow from the
production and sale of proved reserves,  net of estimated oil and gas production
costs (including  production  taxes, ad valorem taxes, and operating  expenses),
and estimated future development costs, discounted at 10% per annum. Net present
value  attributable to the Program's proved reserves was calculated on the basis
of current costs and prices at December 31, 1997. Such prices were not escalated
except in  certain  circumstances  where  escalations  were  fixed  and  readily
determinable in accordance with applicable contract provisions.  The prices used
by Dyco in  calculating  the net present  value  attributable  to the  Program's
proved  reserves  do not  necessarily  reflect  market  prices  for  oil and gas
production  subsequent to December 31, 1997. Year-end prices have generally been
higher than prices during the rest of the year.  There can be no assurance  that
the prices used in  calculating  the net present value of the  Program's  proved
reserves at December 31, 1997 will actually be realized for such production.

      The process of  estimating  oil and gas  reserves  is  complex,  requiring
significant  subjective  decisions in the  evaluation  of available  geological,
engineering,  and  economic  data  for  each  reservoir.  The  data  for a given
reservoir may change substantially over time as a result of, among other things,
additional development activity, production history, and viability of production
under varying economic conditions;  consequently, it is reasonably possible that
material  revisions to existing reserve  estimates may occur in the near future.
Although  every  reasonable  effort has been made to ensure  that these  reserve
estimates represent the most accurate assessment  possible,  the significance of
the  subjective  decisions  required and variances in available data for various
reservoirs  make these  estimates  generally  less precise than other  estimates
presented in connection with financial statement disclosures.





                                       9
<PAGE>



                              Proved Reserves and
                               Net Present Value
                             From Proved Reserves

                            As of December 31, 1997

            Estimated proved reserves:
               Gas (Mcf)                                  405,846
               Oil and liquids (Bbls)                       1,294

            Net present value
               (discounted at 10% per annum)             $446,732


      No estimates  of the proved  reserves of the Program  comparable  to those
included  herein have been included in reports to any federal  agency other than
the SEC.  Additional  information  relating to the Program's  proved reserves is
contained in Note 4 to the Program's financial statements, included in Item 8 of
this Annual Report.


      Significant Properties

      As of December 31, 1997,  the  Program's  properties  consisted of 8 gross
(1.21 net)  productive  wells.  The Program  owns an interest in one  additional
well. Affiliates of the Program operate 8 (89%) of its wells. As of December 31,
1997, the Program had estimated  total proved reserves of 405,846 Mcf of gas and
1,294  barrels of oil,  with a present  value  (discounted  at 10% per annum) of
estimated  future net cash flow of $446,732.  All of the Program's  reserves are
located in the Anadarko Basin of western Oklahoma and the Texas panhandle, which
is an established oil and gas producing basin.


      Title to Oil and Gas Properties

      Management believes that the Program has satisfactory title to its oil and
gas properties. Record title to substantially all of the Program's properties is
held by Dyco as nominee.

      Title  to the  Program's  properties  is  subject  to  customary  royalty,
overriding  royalty,   carried,   working,   and  other  similar  interests  and
contractual  arrangements  customary in the oil and gas  industry,  to liens for
current taxes not yet due, and to other  encumbrances.  Management believes that
such burdens do not materially detract from the value of such properties or from
the Program's  interest  therein or materially  interfere  with their use in the
operation of the Program's business.




                                       10
<PAGE>




ITEM 3.  LEGAL PROCEEDINGS

      To the knowledge of the management of Dyco and the Program,  neither Dyco,
the Program,  nor the Program's  properties are subject to any  litigation,  the
results  of which  would  have a  material  effect  on the  Program's  or Dyco's
financial condition or operations.


ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF LIMITED PARTNERS

      There were no matters  submitted to a vote of the limited  partners during
1997.


PART II

ITEM 5.  MARKET FOR THE REGISTRANT'S LIMITED PARTNERSHIP UNITS AND RELATED
         LIMITED PARTNER MATTERS

      The Program does not have an  established  trading market for its units of
limited  partnership  interest  ("Units").  Pursuant to the terms of the Program
Agreement, Dyco, as General Partner, is obligated to annually issue a repurchase
offer which is based on the  estimated  future net revenues  from the  Program's
reserves and is calculated pursuant to the terms of the Program Agreement.  Such
repurchase offer is recalculated  monthly in order to reflect cash distributions
made to the limited partners and extraordinary  events. The following table sets
forth,  for the  periods  indicated,  Dyco's  repurchase  offer per Unit and the
amount of the Program's  cash  distributions  per Unit for the same period.  For
purposes of this Annual Report,  a Unit  represents an initial  subscription  of
$5,000 to the Program.

                                    Repurchase            Cash
                                       Price          Distributions
                                    ----------        -------------

      1996:
         First Quarter                 $ 88                $ -
         Second Quarter                  63                 25
         Third Quarter                   90                  -
         Fourth Quarter                  50                 40

      1997:
         First Quarter                 $ 50                $ -
         Second Quarter                  50                  -
         Third Quarter                  162                  -
         Fourth Quarter                 137                 25

      1998:
         First Quarter                 $117                $20




                                       11
<PAGE>




      The Program  has 2,021 Units  outstanding  and  approximately  634 limited
partners of record.




                                       12
<PAGE>



ITEM 6.  SELECTED FINANCIAL DATA

                             Selected Financial Data

     The following table presents selected financial data for the Program.  This
data should be read in conjunction with the financial statements of the Program,
and the respective notes thereto,  included elsewhere in this Annual Report. See
"Item 8. Financial Statements and Supplementary Data."
<TABLE>
<CAPTION>

                                                                   December 31,
                                          --------------------------------------------------------------
                                            1997          1996         1995          1994         1993
                                          --------      --------     --------      --------     --------

<S>                                       <C>           <C>          <C>           <C>          <C>
Summary of Operations:
   Oil and gas sales                      $192,298      $191,618     $134,485      $179,004     $224,982
   Total revenues                          193,485       192,842      135,166       180,070      225,702

   Lease operating expenses                 43,348        50,808       58,323        48,015       47,258
   Production taxes                         14,085        13,772        9,521        13,061       16,094
   General and administrative
      expenses                              22,280        21,766       21,713        20,194       24,641
   Depreciation, depletion, and
      amortization of oil and gas
      properties                            16,518         6,950       17,395        32,455       39,452

   Net income                               97,254        99,546       28,214        66,345       98,257
      per Unit                               48.12         49.26        13.96         32.83        48.62
   Cash distributions                       50,525       131,365       40,420       111,155      141,470
      per Unit                                  25            65           20            55           70

Summary Balance Sheet Data:
   Total assets                            149,325       133,084      140,704       142,576      187,225
   Partners' capital                       141,273        94,544      126,363       138,569      183,379
</TABLE>



                                       13
<PAGE>




ITEM 7.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
         OF OPERATIONS

      Use of Forward-Looking Statements and Estimates

      This Annual Report contains certain forward-looking  statements. The words
"anticipate,"  "believe,"  "expect,"  "plan," "intend,"  "estimate,"  "project,"
"could," "may," and similar expressions are intended to identify forward-looking
statements.  Such statements reflect  management's current views with respect to
future  events and  financial  performance.  This Annual  Report  also  includes
certain information which is, or is based upon, estimates and assumptions.  Such
estimates and assumptions  are  management's  efforts to accurately  reflect the
condition and operation of the Program.

      Use of  forward-looking  statements and estimates and assumptions  involve
risks and uncertainties which include, but are not limited to, the volatility of
oil and gas prices, the uncertainty of reserve  information,  the operating risk
associated with oil and gas properties  (including the risk of personal  injury,
death, property damage, damage to the well or producing reservoir, environmental
contamination,  and other  operating  risks),  the  prospect of changing tax and
regulatory laws, the availability and capacity of processing and  transportation
facilities,  the  general  economic  climate,  the  supply  and price of foreign
imports of oil and gas, the level of consumer product demand,  and the price and
availability  of  alternative  fuels.  Should  one or more  of  these  risks  or
uncertainties  occur  or  should  estimates  or  underlying   assumptions  prove
incorrect,  actual  conditions or results may vary materially and adversely from
those stated, anticipated, believed, estimated, or otherwise indicated.


      General Discussion

      The following  general  discussion  should be read in conjunction with the
analysis of results of operations  provided below.  The most important  variable
affecting the Program's  revenues is the prices received for the sale of oil and
gas. Predicting future prices is very difficult. Concerning past trends, average
yearly  wellhead gas prices in the United States have been volatile for a number
of years. For the past ten years, such average prices have generally been in the
$1.40 to $2.40 per Mcf range,  significantly  below prices received in the early
1980s.  Average gas prices in the latter part of 1996 and parts of 1997 however,
were somewhat higher than those yearly averages. Gas prices are currently in the
middle portion of the 10-year average price range described above.

     Substantially all of the Program's gas reserves are being sold on the "spot
market." Prices on the spot market are subject


                                       14
<PAGE>



to wide seasonal and regional pricing fluctuations due to the highly competitive
nature of the spot  market.  In addition,  such spot market sales are  generally
short-term  in nature and are  dependent  upon the  obtaining of  transportation
services provided by pipelines. Spot prices for the Program's gas decreased from
approximately  $3.57 per Mcf at December 31, 1996 to approximately $2.32 per Mcf
at  December  31,  1997.  Such prices were on an MMBTU basis and differ from the
prices  actually  received by the Program due to  transportation  and  marketing
costs, BTU adjustments, and regional price and quality differences.

      For the past ten years,  average  oil prices  have  generally  been in the
$16.00 to $24.00 per barrel range.  Due to global  consumption and supply trends
over the last several  months as well as  expectations  of at least a short-term
slowdown in Asian energy  demand,  oil prices have  recently  been in the mid to
lower  portions of this  pricing  range,  and in early 1998 dropped to as low as
$12.00 per barrel. It is not known whether this trend will continue.  Prices for
the Program's oil decreased from approximately $23.75 per barrel at December 31,
1996 to approximately $16.25 per barrel at December 31, 1997.

      Future prices for both oil and gas will likely be different  from (and may
be lower  than) the prices in effect on  December  31,  1997.  Primarily  due to
heating  season  demand,  year-end  prices in many past years have  tended to be
higher, and in some cases  significantly  higher,  than the yearly average price
actually received by the Program for at least the following year.  Management is
unable to predict  whether  future oil and gas prices will (i)  stabilize,  (ii)
increase, or (iii) decrease.


      Results of Operations

                     Year Ended December 31, 1997 Compared
                        to Year Ended December 31, 1996
                     -------------------------------------

      Total oil and gas sales remained  relatively  constant in 1997 as compared
to 1996.  An increase  of  approximately  $16,000  related to an increase in the
average  price  of  gas  sold  was   substantially   offset  by  a  decrease  of
approximately  $15,000 related to a decrease in volumes of gas sold.  Volumes of
oil and gas sold  decreased  2 barrels and 7,272 Mcf,  respectively,  in 1997 as
compared to 1996.  Average oil and gas prices increased to $19.87 per barrel and
$2.32 per Mcf,  respectively,  in 1997 from $19.27 per barrel and $2.12 per Mcf,
respectively, in 1996.

      Oil and gas production  expenses  (including lease operating  expenses and
production  taxes)  decreased  $7,147 (11.1%) in 1997 as compared to 1996.  This
decrease resulted primarily from (i) the decrease in volumes of gas sold in 1997
and (ii) the sale of one high-cost  well in 1997. As a percentage of oil and gas
sales, these expenses decreased to 29.9% in 1997 from 33.7% in


                                       15
<PAGE>



1996. This percentage  decrease was primarily due to the decrease in oil and gas
production expenses discussed above.

      Depreciation,  depletion,  and  amortization  of oil  and  gas  properties
increased  $9,568 (137.7%) in 1997 as compared to 1996.  This increase  resulted
primarily from (i) a decrease in the oil and gas prices used in the valuation of
reserves  at December  31,  1997 as  compared  to  December  31, 1996 and (ii) a
$28,000  recompletion  in 1997 which  increased  the  capital  costs  subject to
amortization.  As a percentage of oil and gas sales,  this expense  increased to
8.6% in 1997 as compared to 3.6% in 1996. This percentage increase was primarily
due  to  the  dollar  increase  in  depreciation,  depletion,  and  amortization
discussed above.

      General  and  administrative  expenses  increased  $514  (2.4%) in 1997 as
compared to 1996.  As a percentage of oil and gas sales,  this expense  remained
relatively constant at 11.6% in 1997 as compared to 11.4% in 1996.


                     Year Ended December 31, 1996 Compared
                        to Year Ended December 31, 1995
                     -------------------------------------

      Total oil and gas sales increased  $57,133 (42.5%) for 1996 as compared to
1995. Of this increase,  approximately $72,000 was related to an increase in the
average price of gas sold,  which amount was  partially  offset by a decrease of
approximately  $14,000 related to a decrease in volumes of gas sold.  Volumes of
oil and gas sold decreased 91 barrels and 6,681 Mcf,  respectively,  for 1996 as
compared to 1995.  The decrease in volumes of oil sold was primarily a result of
normal  declines in production  due to diminished oil reserves on several wells.
Average  oil and gas  prices  increased  to $19.27 per barrel and $2.12 per Mcf,
respectively,  for 1996 from $16.80 per barrel and $1.36 per Mcf,  respectively,
for 1995.

      Oil and gas production  expenses  (including lease operating  expenses and
production  taxes)  decreased  $3,264 (4.8%) for 1996 as compared to 1995.  This
decrease was primarily due to workover  charges incurred on one well during 1995
in order to improve the  recovery of reserves.  As a  percentage  of oil and gas
sales,  these  expenses  decreased  to 33.7% for 1996 from 50.4% for 1995.  This
percentage  decrease was primarily due to the increases in the average prices of
oil and gas sold during 1996.

      Depreciation,  depletion,  and  amortization  of oil  and  gas  properties
decreased  $10,445  (60.0%)  for 1996 as  compared to 1995.  This  decrease  was
primarily due to upward  revisions of previous oil and gas reserve  estimates at
December 31, 1996. As a percentage of oil and gas sales,  this expense decreased
to 3.6% for 1996 from 12.9% for 1995. This percentage decrease was primarily due
to the dollar decrease in depreciation, depletion,


                                       16
<PAGE>



and amortization  discussed above and the increases in the average prices of oil
and gas sold during 1996.

      General and administrative  expenses remained relatively constant for 1996
as  compared  to 1995.  As a  percentage  of oil and gas sales,  these  expenses
decreased to 11.4% for 1996 from 16.1% for 1995.  This  percentage  decrease was
primarily due to the increases in the average  prices of oil and gas sold during
1996.


      Liquidity and Capital Resources

      Net  proceeds  from  operations  less  necessary   operating  capital  are
distributed to the limited  partners on a quarterly  basis.  See "Item 5. Market
for the  Registrant's  Limited  Partnership  Units and Related  Limited  Partner
Matters."  The net proceeds  from  production  are not  reinvested in productive
assets, except to the extent that producing wells are improved, or where methods
are employed to permit more efficient recovery of reserves, thereby resulting in
a positive economic impact.  Assuming  production levels for 1997, the Program's
proved  reserve  quantities at December 31, 1997 would have  remaining  lives of
approximately  5.1  years  for gas  reserves  and 4.2  years  for oil  reserves.
However,  since the Program's  reserve estimates are based on oil and gas prices
at December 31, 1997, it is possible that a significant  decrease in oil and gas
prices from  December  31, 1997  levels  will  reduce  such  reserves  and their
corresponding life-span.

      The Program's  available capital from the limited partners'  subscriptions
has been spent on oil and gas drilling activities and there should be no further
material capital resource commitments in the future.  Occasional expenditures by
the Program for well completions or workovers,  however, may reduce or eliminate
cash available for a particular  quarterly cash  distribution.  During 1997, the
Program invested approximately $28,000 in a recompletion on one well in order to
improve  the  recovery  of  reserves.   The   recompletion   was   unsuccessful.
Subsequently,  the well was sold for salvage value of approximately  $8,300. The
unsuccessful  recompletion  expenses incurred by the Program adversely  impacted
the Program's cash flows during 1997. The Program has no debt commitments.  Cash
for operational purposes will be provided by current oil and gas production.

      There can be no  assurance as to the amount of the  Program's  future cash
distributions.   The  Program's  ability  to  make  cash  distributions  depends
primarily  upon the level of  available  cash flow  generated  by the  Program's
operating  activities,  which will be affected (either positively or negatively)
by many factors  beyond the control of the Program,  including  the price of and
demand for oil and gas and other market and economic conditions.  Even if prices
and costs remain stable, the amount of cash


                                       17
<PAGE>



available for distributions  will decline over time (as the volume of production
from  producing   properties  declines)  since  the  Program  is  not  replacing
production through acquisitions of producing properties and drilling.


      Inflation and Changing Prices

      Prices obtained for oil and gas production  depend upon numerous  factors,
including the extent of domestic and foreign production, foreign imports of oil,
market  demand,  domestic  and  foreign  economic  conditions  in  general,  and
governmental  regulations  and tax laws.  The general  level of inflation in the
economy did not have a material effect on the operations of the Program in 1997.
Oil and gas prices have  fluctuated  during recent years and generally  have not
followed the same pattern as inflation. See "Item 2.
Properties - Oil and Gas Production, Revenue, and Price History."


      Year 2000 Computer Issues

      Dyco has reviewed its  computer  systems and hardware to locate  potential
operational  problems  associated  with the year 2000. Such review will continue
until all potential  problems are located and  resolved.  Dyco believes that all
year-2000  problems  in its  computer  system have been or will be resolved in a
timely  manner and have not caused and will not cause either (i)  disruption  of
the Program's  operations or (ii) a material  effect on the Program's  financial
condition or results of operations.  However,  it is possible that the Program's
cash flows could be disrupted by year-2000 problems  experienced by operators of
the Program's wells, buyers of the Program's oil and gas, financial institutions
or other persons.  Dyco is unable to quantify the effect, if any, on the Program
of year-2000 computer problems which may be experienced by these third parties.





                                       18
<PAGE>



ITEM 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA



      REPORT OF INDEPENDENT ACCOUNTANTS



TO THE PARTNERS

DYCO OIL AND GAS PROGRAM 1986-X LIMITED PARTNERSHIP


      We have audited the  financial  statements of the Dyco Oil and Gas Program
1986-X Limited  Partnership (a Minnesota limited  partnership) as listed in Item
14(a) of this Annual Report.  These financial  statements are the responsibility
of the  Program's  management.  Our  responsibility  is to express an opinion on
these financial statements based on our audits.

      We conducted our audits in accordance  with  generally  accepted  auditing
standards.  Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement.  An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements.  An audit also includes
assessing the  accounting  principles  used and  significant  estimates  made by
management,  as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.

      In our opinion, the financial statements referred to above present fairly,
in all material respects, the financial position of the Dyco Oil and Gas Program
1986-X Limited Partnership at December 31, 1997 and 1996, and the results of its
operations  and cash  flows  for each of the  three  years in the  period  ended
December 31, 1997, in conformity with generally accepted accounting principles.




                                          /s/ Coopers & Lybrand, L.L.P.


                                          COOPERS & LYBRAND L.L.P.


Tulsa, Oklahoma
March 25, 1998



                                       19
<PAGE>



                           DYCO OIL AND GAS PROGRAM
                          1986-X LIMITED PARTNERSHIP
                                Balance Sheets
                          December 31, 1997 and 1996

                                    ASSETS
                                    ------
                                                       1997           1996
                                                     --------       --------

CURRENT ASSETS:
   Cash and cash equivalents                         $ 21,256       $  8,796
   Accrued oil and gas sales                           34,977         40,805
                                                      -------        -------

      Total current assets                           $ 56,233       $ 49,601

NET OIL AND GAS PROPERTIES, utilizing
   the full cost method                                79,898         70,461

DEFERRED CHARGE                                        13,194         13,022
                                                      -------        -------

                                                     $149,325       $133,084
                                                      =======        =======

                       LIABILITIES AND PARTNERS' CAPITAL
                       ---------------------------------

CURRENT LIABILITIES:
   Accounts payable                                  $  2,637       $ 29,398
                                                      -------        -------
      Total current liabilities                      $  2,637       $ 29,398

ACCRUED LIABILITY                                       5,415          9,142

PARTNERS' CAPITAL:
   General Partner, issued and
      outstanding, 21 Units                             1,412            944
   Limited Partners, issued and
      outstanding, 2,000 Units                        139,861         93,600
                                                      -------        -------
      Total Partners' capital                        $141,273       $ 94,544
                                                      -------        -------

                                                     $149,325       $133,084
                                                      =======        =======





              The accompanying notes are an integral part of these
                              financial statements.



                                       20
<PAGE>



                           DYCO OIL AND GAS PROGRAM
                          1986-X LIMITED PARTNERSHIP
                           Statements of Operations
             For the Years Ended December 31, 1997, 1996, and 1995


                                              1997        1996        1995
                                            --------    --------    --------

REVENUES:
   Oil and gas sales, including
      $125,252 of sales to
      related parties in
      1995 (Note 2)                         $192,298    $191,618    $134,485
   Interest                                    1,187       1,224         681
                                             -------     -------     -------

                                            $193,485    $192,842    $135,166

COSTS AND EXPENSES:
   Lease operating                          $ 43,348    $ 50,808    $ 58,323
   Production taxes                           14,085      13,772       9,521
   Depreciation, depletion, and
      amortization of oil and gas
      properties                              16,518       6,950      17,395
   General and administrative                 22,280      21,766      21,713
                                             -------     -------     -------

                                            $ 96,231    $ 93,296    $106,952
                                             -------     -------     -------

NET INCOME                                  $ 97,254    $ 99,546    $ 28,214
                                             =======     =======     =======

GENERAL PARTNER (1%) - NET INCOME           $    973    $    995    $    282
                                             =======     =======     =======

LIMITED PARTNERS (99%) - NET INCOME         $ 96,281    $ 98,551    $ 27,932
                                             =======     =======     =======

NET INCOME per Unit                         $  48.12    $  49.26    $  13.96
                                             =======     =======     =======

UNITS OUTSTANDING                              2,021       2,021       2,021
                                             =======     =======     =======







              The accompanying notes are an integral part of these
                              financial statements.



                                       21
<PAGE>



                           DYCO OIL AND GAS PROGRAM
                          1986-X LIMITED PARTNERSHIP
                        Statements of Partners' Capital
             For the Years Ended December 31, 1997, 1996, and 1995


                                       General       Limited
                                       Partner      Partners         Total
                                      --------     ----------     ----------

Balances at December 31, 1994          $1,385       $137,184       $138,569
   Cash distributions                 (   404)     (  40,016)     (  40,420)
   Net income                             282         27,932         28,214
                                        -----        -------        -------

Balances at December 31, 1995          $1,263       $125,100       $126,363
   Cash distributions                 ( 1,314)     ( 130,051)     ( 131,365)
   Net income                             995         98,551         99,546
                                        -----        -------        -------

Balances at December 31, 1996          $  944       $ 93,600       $ 94,544
   Cash distributions                 (   505)     (  50,020)     (  50,525)
   Net income                             973         96,281         97,254
                                        -----        -------        -------

Balances at December 31, 1997          $1,412       $139,861       $141,273
                                        =====        =======        =======

























              The accompanying notes are an integral part of these
                              financial statements.



                                       22
<PAGE>

<TABLE>
<CAPTION>


                                 DYCO OIL AND GAS PROGRAM
                                1986-X LIMITED PARTNERSHIP
                                 Statements of Cash Flows
                   For the Years Ended December 31, 1997, 1996, and 1995

                                                   1997           1996           1995
                                                ---------      ----------     ---------
<S>                                             <C>            <C>            <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
   Net income                                    $97,254        $ 99,546       $28,214
   Adjustments to reconcile net
      income to net cash provided
      by operating activities:
      Depreciation, depletion, and
         amortization of oil and gas
         properties                               16,518           6,950        17,395
      (Increase) decrease in accrued
         oil and gas sales                         5,828       (  15,120)        1,836
      (Increase) decrease in
         deferred charge                        (    172)            934      (  8,393)
      Increase (decrease) in
         accounts payable                       ( 26,761)         24,776           615
      Increase (decrease) in
         accrued liability                      (  3,727)      (     577)        9,719
                                                  ------         -------        ------
   Net cash provided by operating
      activities                                 $88,940        $116,509       $49,386
                                                  ------         -------        ------

CASH FLOWS FROM INVESTING ACTIVITIES:
   Proceeds from sale of oil and
      gas properties                             $ 8,846        $  4,991       $ -
   Additions to oil and gas properties          ( 34,801)           -         (   817)
                                                  ------         -------        ------

   Net cash provided (used) by
      investing activities                      ($25,955)       $  4,991      ($  817)
                                                  ------         -------        ------

CASH FLOWS FROM FINANCING ACTIVITIES:
   Cash distributions                           ($50,525)      ($131,365)     ($40,420)
                                                  ------         -------        ------

   Net cash used by financing
      activities                                ($50,525)      ($131,365)     ($40,420)
                                                  ------         -------        ------
NET INCREASE (DECREASE) IN CASH
   AND CASH EQUIVALENTS                          $12,460       ($  9,865)      $ 8,149

CASH AND CASH EQUIVALENTS AT
   BEGINNING OF PERIOD                             8,796          18,661        10,512
                                                  ------         -------        ------
CASH AND CASH EQUIVALENTS AT
   END OF PERIOD                                 $21,256        $  8,796       $18,661
                                                  ======         =======        ======
</TABLE>

              The accompanying notes are an integral part of these
                              financial statements.



                                       23
<PAGE>



              DYCO OIL AND GAS PROGRAM 1986-X LIMITED PARTNERSHIP
                         Notes to Financial Statements
             For the Years Ended December 31, 1997, 1996, and 1995


1.    ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

      Organization and Nature of Operations

            The  Dyco  Oil and  Gas  Program  1986-X  Limited  Partnership  (the
      "Program"),  a Minnesota  limited  partnership,  commenced  operations  on
      December  12, 1986.  Dyco  Petroleum  Corporation  ("Dyco") is the General
      Partner  of the  Program.  Affiliates  of Dyco  owned 604  (29.9%)  of the
      Program's Units at December 31, 1997.

            The Program's sole business is the development and production of oil
      and gas with a concentration  on gas.  Substantially  all of the Program's
      gas reserves are being sold  regionally  in the "spot  market." Due to the
      highly  competitive  nature of the spot market,  prices on the spot market
      are  subject  to wide  seasonal  and  regional  pricing  fluctuations.  In
      addition,  such spot market sales are  generally  short-term in nature and
      are dependent upon the obtaining of  transportation  services  provided by
      pipelines.


      Cash and Cash Equivalents

            The Program considers all highly liquid  investments with a maturity
      of three  months  or less  when  purchased  to be cash  equivalents.  Cash
      equivalents  are not  insured,  which  cause the  Program to be subject to
      risk.


      Credit Risk

            Accrued  oil and gas sales  which are due from a variety  of oil and
      gas purchasers subject the Program to a concentration of credit risk. Some
      of these purchasers are discussed in Note 3 - Major Customers.  Subsequent
      to  year-end,  all oil and gas sales  accrued as of December 31, 1997 have
      been collected.


      Oil and Gas Properties

            Oil and gas  operations are accounted for using the full cost method
      of accounting. All productive and non-productive costs associated with the
      acquisition,  exploration,  and  development  of oil and gas  reserves are
      capitalized.  During 1997, the Program invested approximately $28,000 in a
      recompletion on one well in order to improve the recovery of reserves. The
      recompletion was


                                       24
<PAGE>



      unsuccessful.  Subsequently,  the  well  was  sold  for  salvage  value of
      approximately $8,300.  Capitalized costs are depleted on the gross revenue
      method using  estimates  of proved  reserves.  The full cost  amortization
      rates per equivalent  Mcf of gas produced  during the years ended December
      31, 1997, 1996, and 1995 were $0.20, $0.08, and $0.18,  respectively.  The
      Program's  calculation  of  depreciation,   depletion,   and  amortization
      includes estimated future expenditures to be incurred in developing proved
      reserves  and  estimated  dismantlement  and  abandonment  costs,  net  of
      estimated salvage values. In the event the unamortized cost of oil and gas
      properties  being  amortized  exceeds the full cost ceiling (as defined by
      the Securities and Exchange  Commission  ("SEC")) the excess is charged to
      expense in the year during  which such excess  occurs.  In  addition,  SEC
      rules  provide that if prices  decline  subsequent to year end, any excess
      that results from these declines may also be charged to expense during the
      current year.  Sales and  abandonments  of properties are accounted for as
      adjustments of capitalized  costs with no gain or loss recognized,  unless
      such  adjustments  would  significantly  alter  the  relationship  between
      capitalized costs and proved oil and gas reserves.


      Deferred Charge

            The Deferred Charge at December 31, 1997 and 1996  represents  costs
      deferred for lease  operating  expenses  incurred in  connection  with the
      Program's  underproduced  gas  imbalance  positions.   The  rate  used  in
      calculating  the deferred  charge is the average of the annual  production
      costs per Mcf. At December 31, 1997,  cumulative  total gas sales  volumes
      for  underproduced  wells were less than the Program's  pro-rata  share of
      total gas production from these wells by 22,748 Mcf,  resulting in prepaid
      lease  operating  expenses of $13,194.  At December 31,  1996,  cumulative
      total  gas  sales  volumes  for  underproduced  wells  were  less than the
      Program's  pro-rata  share of total gas  production  from  these  wells by
      23,625 Mcf, resulting in prepaid lease operating expenses of $13,022.


      Accrued Liability

            The  Accrued  Liability  at December  31,  1997 and 1996  represents
      charges accrued for lease operating  expenses  incurred in connection with
      the  Program's  overproduced  gas  imbalance  positions.  The rate used in
      calculating the accrued  liability is the average of the annual production
      costs per Mcf. At December 31, 1997,  cumulative  total gas sales  volumes
      for overproduced  wells exceeded the Program's pro-rata share of total gas
      production  from these  wells by 9,336  Mcf,  resulting  in accrued  lease
      operating expenses of


                                       25
<PAGE>



      $5,415.  At December  31,  1996,  cumulative  total gas sales  volumes for
      overproduced  wells  exceeded the  Program's  pro-rata  share of total gas
      production  from these wells by 16,585  Mcf,  resulting  in accrued  lease
      operating expenses of $9,142.


      Oil and Gas Sales

            The Program's oil and condensate  production is sold,  title passed,
      and revenue  recognized  at or near the Program's  wells under  short-term
      purchase  contracts at prevailing  prices in accordance with  arrangements
      which are  customary in the oil industry.  Sales of gas  applicable to the
      Program's  interest in producing oil and gas leases are recorded as income
      when the gas is metered  and title  transferred  pursuant to the gas sales
      contracts  covering the Program's  interest in gas  reserves.  During such
      times as the  Program's  sales of gas exceed its pro rata  ownership  in a
      well,  such sales are recorded as income  unless total sales from the well
      have  exceeded  the  Program's  share  of  estimated  total  gas  reserves
      underlying  the  property  at which  time  such  excess is  recorded  as a
      liability. At December 31, 1997 and 1996, no such liability was recorded.


      Use of Estimates in Financial Statements

            The preparation of financial statements in conformity with generally
      accepted  accounting  principles requires management to make estimates and
      assumptions that affect the reported amounts of assets and liabilities and
      disclosure  of  contingent  assets  and  liabilities  at the  date  of the
      financial  statements  and the  reported  amounts of revenues and expenses
      during the  reporting  period.  Actual  results  could  differ  from those
      estimates.  Further, the deferred charge and the accrued liability involve
      estimates which could materially differ from the actual amounts ultimately
      realized or incurred in the near term.  Oil and gas reserves  (see Note 4)
      also involve significant  estimates which could materially differ from the
      actual amounts ultimately realized.


      Income Taxes

            Income or loss for income tax purposes is  includable  in the income
      tax returns of the partners. Accordingly, no recognition has been given to
      income taxes in the accompanying financial statements.




                                       26
<PAGE>




2.    TRANSACTIONS WITH RELATED PARTIES

            Under  the  terms of the  Program  Agreement,  Dyco is  entitled  to
      receive  a   reimbursement   for  all  direct  expenses  and  general  and
      administrative,  geological,  and engineering expenses it incurs on behalf
      of the Program.  During the years ended December 31, 1997, 1996, and 1995,
      such expenses  totaled $22,280,  $21,766,  and $21,713,  respectively,  of
      which $16,080 was paid each year to Dyco and its affiliates.

            Affiliates  of  the  Program   operate   certain  of  the  Program's
      properties.  Their policy is to bill the Program for all customary charges
      and cost  reimbursements  associated with these activities,  together with
      any  compressor  rentals,  consulting,  or other services  provided.  Such
      charges are  comparable to third party charges in the area where the wells
      are located and are the same as charged to other working  interest  owners
      in the wells.

            During 1995 the Program sold gas at market  prices to El Paso Energy
      Marketing  Company,  formerly known as Premier Gas Company ("El Paso"). El
      Paso,  like other  similar gas  marketing  firms,  then resold such gas to
      third  parties at market  prices.  El Paso was an affiliate of the Program
      until December 6, 1995. During 1995, these sales totaled $125,252.


3.    MAJOR CUSTOMERS

            The following  purchaser  individually  accounted for 10% or more of
      the  combined  oil and gas  revenues  of the  Program  for the years ended
      December 31, 1997, 1996, and 1995:

            Purchaser               1997        1996        1995
            -------------           -----       -----       -----

            El Paso                 85.4%       85.8%       93.1%
            Transok, Inc.           11.9%         - %         - %

            In the  event of  interruption  of  purchases  by these  significant
       customers  or  the  cessation  or  material  change  in  availability  of
       open-access  transportation by the Program's pipeline  transporters,  the
       Program may encounter  difficulty in marketing its gas and in maintaining
       historic sales levels.  Alternative purchasers or transporters may not be
       readily available.






                                       27
<PAGE>

4.    SUPPLEMENTAL OIL AND GAS INFORMATION


            The  following  supplemental  information  regarding the oil and gas
      activities  of  the  Program  is  presented  pursuant  to  the  disclosure
      requirements promulgated by the SEC.


      Capitalized Costs

            The  Program's  capitalized  costs  and  accumulated   depreciation,
      depletion,  amortization, and valuation allowance at December 31, 1997 and
      1996 were as follows:


                                                     December 31,
                                             ------------------------------
                                                 1997              1996
                                             ------------      ------------

      Proved properties                       $9,214,142        $9,188,187

      Unproved properties, not
         subject to depreciation,
         depletion, and amortization                -                 -
                                               ---------         ---------

                                              $9,214,142        $9,188,187

      Less accumulated depreciation,
         depletion, amortization, and
         valuation allowance                 ( 9,134,244)      ( 9,117,726)
                                               ---------         ---------

      Net oil and gas properties              $   79,898        $   70,461
                                               =========         =========


      Costs Incurred

            The  Program  incurred  no  oil  and  gas  property  acquisition  or
      exploration  costs  during 1997,  1996,  and 1995.  Costs  incurred by the
      Program in connection with its oil and gas property development activities
      during 1997, 1996, and 1995 were as follows:


                                                     December 31,
                                          -------------------------------
                                           1997          1996        1995
                                          -------        ----        ----

      Development costs                   $34,801        $ -         $817
                                           ======         ===         ===



                                       28
<PAGE>



Quantities of Proved Oil and Gas Reserves - Unaudited

      Set forth below is a summary of the changes in the net  quantities  of the
Program's  proved crude oil and gas  reserves  for the years ended  December 31,
1997,  1996, and 1995.  Proved  reserves were  estimated by petroleum  engineers
employed by affiliates of Dyco. All of the Program's reserves are located in the
United  States  and there  are no proved  undeveloped  reserves.  The  following
information  includes  certain  gas  balancing  adjustments  which cause the gas
volumes to differ from the reserve information prepared by Dyco.

<TABLE>
<CAPTION>

                                       1997                      1996                      1995
                                ---------------------    ---------------------      -------------------
                                  Oil          Gas         Oil          Gas           Oil          Gas
                                (Bbls)        (Mcf)      (Bbls)        (Mcf)        (Bbls)        (Mcf)
                                -------     ---------    -------     ---------      -------     ---------

<S>                             <C>         <C>          <C>         <C>            <C>         <C>
Proved reserves,
   beginning of year             1,333       526,455      1,114       316,119        1,385       344,116

Revisions of previous
   estimates                       266      ( 40,347)       526       290,838          127        66,218

Sales of reserves                 -             -          -            7,032         -             -

Production                      (  305)     ( 80,262)    (  307)     ( 87,534)      (  398)     ( 94,215)
                                 -----       -------      -----       -------        -----       -------

Proved reserves,
   end of year                   1,294       405,846      1,333       526,455        1,114       316,119
                                 =====       =======      =====       =======        =====       =======

Proved developed reserves:
   Beginning of year             1,333       526,455      1,114       316,119        1,385       344,116
                                 -----       -------      -----       -------        -----       -------
   End of year                   1,294       405,846      1,333       526,455        1,114       316,119
                                 =====       =======      =====       =======        =====       =======

</TABLE>


                                       29
<PAGE>



            The process of estimating oil and gas reserves is complex, requiring
      significant   subjective   decisions  in  the   evaluation   of  available
      geological,  engineering,  and economic data for each reservoir.  The data
      for a given reservoir may change  substantially  over time as a result of,
      among other things,  additional development activity,  production history,
      and  viability  of   production   under   varying   economic   conditions;
      consequently,  it  is  reasonably  possible  that  material  revisions  to
      existing  reserve  estimates may occur in the near future.  Although every
      reasonable  effort  has been made to  ensure  that the  reserve  estimates
      reported  herein  represent the most  accurate  assessment  possible,  the
      significance  of  the  subjective  decisions  required  and  variances  in
      available data for various reservoirs make these estimates  generally less
      precise  than other  estimates  presented  in  connection  with  financial
      statement disclosures.  The Program's reserves were determined at December
      31,  1997 using oil and gas prices of $16.25 per barrel and $2.32 per Mcf,
      respectively.


ITEM 9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
         FINANCIAL DISCLOSURE

      None.

PART III

ITEM 10.  DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

      The Program is a limited  partnership  and has no  directors  or executive
officers.  The following  individuals  are  directors and executive  officers of
Dyco,  General  Partner.  The business  address of such  directors and executive
officers is Two West Second Street, Tulsa, Oklahoma 74103.

            NAME              AGE            POSITION WITH DYCO
      ----------------        ---     --------------------------------

      Dennis R. Neill          46     President and Director

      Patrick M. Hall          39     Chief Financial Officer

      Judy K. Fox              47     Secretary

      The  director   will  hold  office  until  the  next  annual   meeting  of
shareholders  of Dyco  and  until  his  successor  has  been  duly  elected  and
qualified.  All  executive  officers  serve at the  discretion  of the  Board of
Directors.

      Dennis R. Neill joined the Samson Companies in 1981, was named Senior Vice
President and Director of Dyco on June 18, 1991, and was named President of Dyco
on June 30, 1996. Prior to joining the Samson Companies,  he was associated with
a Tulsa law


                                       30
<PAGE>



firm,  Conner and Winters,  where his principal  practice was in the  securities
area.  He received a Bachelor of Arts degree in political  science from Oklahoma
State  University and a Juris Doctorate degree from the University of Texas. Mr.
Neill also serves as Senior Vice President of Samson  Investment  Company and as
President and Director of Samson Properties  Incorporated,  Samson  Hydrocarbons
Company, Berry Gas Company,  Circle L Drilling Company,  Compression,  Inc., and
Geodyne Resources, Inc. and its subsidiaries.

      Patrick  M. Hall  joined the Samson  Companies  in 1983,  was named a Vice
President of Dyco on June 18,  1991,  and was named Chief  Financial  Officer of
Dyco on June 30,  1996.  Prior to joining the Samson  Companies  he was a senior
accountant with Peat Marwick Main & Co. in Tulsa. He holds a Bachelor of Science
degree in accounting  from Oklahoma State  University and is a Certified  Public
Accountant. Mr. Hall also serves as Senior Vice President - Controller of Samson
Investment Company.

     Judy K. Fox joined the Samson  Companies in 1990 and was named Secretary of
Dyco on June 30, 1996. Prior to joining the Samson Companies,  she served as Gas
Contract Manager for Ely Energy Company.  Ms. Fox is also Secretary of Berry Gas
Company,  Circle L Drilling  Company,  Compression,  Inc.,  Samson  Hydrocarbons
Company,  Samson Properties  Incorporated,  and Geodyne Resources,  Inc. and its
subsidiaries.


ITEM 11.  EXECUTIVE COMPENSATION

      The Program is a limited  partnership and,  therefore,  has no officers or
directors.  The following  table  summarizes  the amounts paid by the Program as
compensation and  reimbursements  to Dyco and its affiliates for the three years
ended December 31, 1997:

             Compensation/Reimbursement to Dyco and its affiliates
                      Three Years Ended December 31, 1997

Type of Compensation/Reimbursement (1)                    Expense
--------------------------------------          ----------------------------
                                                 1997       1996      1995
                                                -------    -------   -------
Compensation:
   Operations                                     (2)        (2)       (2)
   Gas Marketing                                  (3)        (3)       (3)

Reimbursements:
   General and Administrative,
      Geological, and Engineering
      Expenses and Direct
      Expenses(4)                               $16,080    $16,080   $16,080

----------



                                       31
<PAGE>



(1)   The  authority  for  all of such  compensation  and  reimbursement  is the
      Program Agreement.  With respect to the Operations activities noted in the
      table, management believes that such compensation is equal to or less than
      that  charged by  unaffiliated  persons in the same  geographic  areas and
      under the same conditions.
(2)   Affiliates of the Program  serve as operator of a substantial  majority of
      the  Program's  wells.  Dyco,  as  General  Partner,  contracts  with such
      affiliates  for  services  as  operator of the wells.  As  operator,  such
      affiliates are  compensated at rates provided in the operating  agreements
      in effect and charged to all parties to such agreement.  The dollar amount
      of such  compensation paid by the Program to such affiliates is impossible
      to quantify as of the date of this Annual Report.
(3)   During 1995 El Paso, an affiliate of the Program  until  December 6, 1995,
      purchased a portion of the  Program's gas at market prices and resold such
      gas  at  market  prices  directly  to  end-users  and  local  distribution
      companies. During 1995, the Program sold $125,252 of gas to El Paso. After
      December  6,  1995  the  Program's  gas  was  marketed  by  Dyco  and  its
      affiliates,  who  were  reimbursed  for such  activities  as  general  and
      administrative expenses.
(4)   The  Program  reimburses  Dyco  and  its  affiliates  for  reasonable  and
      necessary general and administrative, geological, and engineering expenses
      and direct  expenses  incurred in  connection  with their  management  and
      operation of the Program. The directors,  officers,  and employees of Dyco
      and its  affiliates  receive no direct  remuneration  from the Program for
      their services to the Program. See "Salary Reimbursement Table" below. The
      allocable general and administrative, geological, and engineering expenses
      are apportioned on a reasonable  basis between the Program's  business and
      all other oil and gas  activities  of Dyco and its  affiliates,  including
      Dyco's  management  and  operation  of  affiliated  oil  and  gas  limited
      partnerships. The allocation to the Program of these costs is made by Dyco
      as General Partner.


      As noted in the  Compensation/Reimbursement  Table above,  the  directors,
officers,  and  employees  of  Dyco  and  their  affiliates  receive  no  direct
remuneration  from the Program for their services.  However,  to the extent such
services  represent direct  involvement with the Program,  as opposed to general
corporate  functions,  such persons' salaries are allocated to and reimbursed by
the  Program.  Such  allocation  to the  Program's  general and  administrative,
geological, and engineering expenses of the salaries of directors, officers, and
employees of Dyco and its affiliates is based on internal records  maintained by
Dyco and its affiliates,  and represents investor relations,  legal, accounting,
data  processing,   management,  gas  marketing  and  other  functions  directly
attributable  to the Program's  operations.  The following  table  indicates the
approximate amount of general and


                                       32
<PAGE>



administrative  expense  reimbursement  attributable  to  the  salaries  of  the
directors,  officers,  and  employees of Dyco and its  affiliates  for the three
years ended December 31, 1997:



                                       33
<PAGE>

<TABLE>
<CAPTION>


                                               Salary Reimbursement
                                        Three Years Ended December 31, 1997

                                                                              Long Term Compensation
                                                                       -----------------------------------
                                      Annual Compensation                      Awards              Payouts
                                   ---------------------------         -----------------------     -------
                                                                                       Securi-
                                                            Other                       ties                     All
     Name                                                   Annual     Restricted      Under-                   Other
      and                                                  Compen-       Stock         lying        LTIP       Compen-
   Principal                       Salary       Bonus      sation       Award(s)      Options/     Payouts     sation
   Position               Year       ($)         ($)         ($)          ($)          SARs(#)       ($)         ($)
---------------           ----     -------     -------     -------     ----------     --------     -------     -------
<S>                       <C>      <C>         <C>         <C>         <C>             <C>         <C>          <C>
C. Philip
Tholen,
President,
Chief Executive
Officer(1)(2)             1995       -           -           -           -              -            -           -
                          1996       -           -           -           -              -            -           -
Dennis R. Neill,
President(2)(3)           1996       -           -           -           -              -            -           -
                          1997       -           -           -           -              -            -           -
All Executive
Officers,
Directors,
and Employees
as a group(4)             1995     $8,780        -           -           -              -            -           -
                          1996     $9,407        -           -           -              -            -           -
                          1997     $9,606        -           -           -              -            -           -
----------
(1)   Mr. Tholen served as President and Chief  Executive  Officer of Dyco until
      June 30, 1996.
(2)   The  general  and   administrative   expenses  paid  by  the  Program  and
      attributable to salary  reimbursements  do not include any salary or other
      compensation attributable to Mr. Tholen or Mr. Neill.
(3)   Mr. Neill became President of Dyco on June 30, 1996.
(4)   No  officer  or  director  of Dyco or its  affiliates  provides  full-time
      services to the Program and no individual's  salary or other  compensation
      reimbursement from the Program equals or exceeds $100,000 per annum.
</TABLE>



                                       34
<PAGE>



      In addition to the  compensation/reimbursements  noted  above,  during the
three years ended December 31, 1997,  the Samson  Companies were in the business
of  supplying  field and  drilling  equipment  and  services to  affiliated  and
unaffiliated parties in the industry. Such companies may have provided equipment
and services for wells in which the Program has an interest. These equipment and
services were  provided at prices or rates equal to or less than those  normally
charged in the same or comparable  geographic  area by  unaffiliated  persons or
companies dealing at arm's length. The operators of these wells bill the Program
for a portion of such costs based upon the Program's interest in the well.


ITEM 12.  SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

      The following table provides information as to the beneficial ownership of
the  Program's  Units as of February 28, 1998 by each  beneficial  owner of more
than 5% of the issued and outstanding Units and by the directors,  officers, and
affiliates  of Dyco.  The address of each of such persons is Samson  Plaza,  Two
West Second Street, Tulsa, Oklahoma 74103.


                                                Number of Units
                                                 Beneficially
                                                Owned (Percent
             Beneficial Owner                   of Outstanding)
      -------------------------------           ---------------

      Samson Resources Company                  604      (29.9%)

      All directors, officers, and
         affiliates of Dyco as a group
         and Dyco (5 persons)                   604      (29.9%)


ITEM 13.  CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

      Certain affiliates of Dyco engage in oil and gas activities  independently
of the Program  which  result in  conflicts  of interest  that cannot be totally
eliminated.  The allocation of acquisition  and drilling  opportunities  and the
nature of the compensation  arrangements between the Program and such affiliates
also create potential conflicts of interest.  An affiliate of the Program owns a
significant  amount of the  Program's  Units and  therefore  has an  identity of
interest  with other  limited  partners  with respect to the  operations  of the
Program.

      In order to attempt to assure  limited  liability for limited  partners as
well as an orderly  conduct of business,  management of the Program is exercised
solely by Dyco. The Program Agreement grants Dyco broad discretionary  authority
with respect to the


                                       35
<PAGE>



Program's  participation  in drilling  prospects and  expenditure and control of
funds, including borrowings.  These provisions are similar to those contained in
prospectuses   and   partnership   agreements  for  other  public  oil  and  gas
partnerships.  Broad discretion as to general management of the Program involves
circumstances  where Dyco has  conflicts of interest and where it must  allocate
costs and  expenses,  or  opportunities,  among the Program and other  competing
interests.

      Dyco does not devote all of its time, efforts,  and personnel  exclusively
to the  Program.  Furthermore,  the  Program  does not have any  employees,  but
instead  relies on the  personnel  of the Samson  Companies.  The  Program  thus
competes with the Samson Companies  (including other currently sponsored oil and
gas programs) for the time and resources of such personnel. The Samson Companies
devote such time and personnel to the management of the Program as are indicated
by the circumstances and as are consistent with Dyco's fiduciary duties.

      Affiliates  of the Program  are solely  responsible  for the  negotiation,
administration,  and  enforcement of oil and gas sales  agreements  covering the
Program's  leasehold  interests.  Because  affiliates of the Program who provide
services to the Program have  fiduciary or other duties to other  members of the
Samson Companies, contract amendments and negotiating positions taken by them in
their effort to enforce contracts with purchasers may not necessarily  represent
the  positions  that the  Program  would take if it were to  administer  its own
contracts without involvement with other members of the Samson Companies. On the
other hand,  management  believes  that the Program's  negotiating  strength and
contractual  positions have been enhanced by virtue of its affiliation  with the
Samson Companies.


     For a description of certain other  relationships and related  transactions
see "Item 11. Executive Compensation."



                                       36
<PAGE>




PART IV


ITEM 14.  EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K

          (a)  Financial   Statements,   Financial  Statement   Schedules,   and
               Exhibits.

               (1)  Financial Statements: The following financial statements for
                    the  Program as of  December  31,  1997 and 1996 and for the
                    years ended  December 31, 1997,  1996, and 1995 are filed as
                    part of this report:

                        Report of Independent Accountants
                        Balance Sheets
                        Statements of Operations
                        Statements of Partners' Capital
                        Statements of Cash Flows
                        Notes to Financial Statements

               (2)  Financial Statement Schedules:

                        None.

               (3)  Exhibits:

                    4.1  Drilling  Agreement  dated  November  25, 1986 for Dyco
                         Drilling Program 1986-X, a Limited Partnership,  by and
                         between  Dyco  Oil  and Gas  Program  1986-X  and  Dyco
                         Petroleum  Corporation  filed as Exhibit  4.1 to Annual
                         Report on Form  10-K for the year  ended  December  31,
                         1991 on April 1,  1992 and is  hereby  incorporated  by
                         reference.

                    4.2  Program  Agreement dated November 25, 1986 for Dyco Oil
                         and Gas Program  1986-X by and between  Dyco  Petroleum
                         Corporation and the  Participants  filed as Exhibit 4.2
                         to  Annual  Report  on Form  10-K  for the  year  ended
                         December  31,  1991 on  April  1,  1992  and is  hereby
                         incorporated by reference.

                    4.3  Amendment  to  Program  Agreement  for Dyco Oil and Gas
                         Program 1986-X dated December 31, 1989 filed as Exhibit
                         4.3 to Annual  Report  on Form 10-K for the year  ended
                         December  31,  1991 on  April  1,  1992  and is  hereby
                         incorporated by reference.

                    4.4  Certificate  of Limited  Partnership,  as amended,  for
                         Dyco Oil and Gas Program 1986-X


                                       37
<PAGE>



                         Limited  Partnership  filed  as  Exhibit  4.4 to Annual
                         Report on Form  10-K  for  the year ended  December 31,
                         1991  on  April 1, 1992 and is hereby  incorporated  by
                         reference.

                   *27.1 Financial Data Schedule  containing  summary  financial
                         information extracted from the Dyco Oil and Gas Program
                         1986-X Limited Partnership's financial statements as of
                         December  31, 1997 and for the year ended  December 31,
                         1997.

                  All other Exhibits are omitted as inapplicable.


                  ------------------
                  *  Filed herewith.


          (b)  Reports on Form 8-K filed during the fourth quarter of 1997.

               None.




                                       38
<PAGE>



                                   SIGNATURES

Pursuant to the requirements of Sections 13 or 15(d) of the Securities  Exchange
Act of 1934,  the  registrant  has duly  caused  this report to be signed on its
behalf by the undersigned, thereunto duly organized.

                                    DYCO OIL AND GAS PROGRAM 1986-X
                                    LIMITED PARTNERSHIP

                                    By:   DYCO PETROLEUM CORPORATION
                                          General Partner

                                          March 31, 1998


                                    By:   /s/Dennis R. Neill
                                          ------------------------------
                                          Dennis R. Neill
                                          President

Pursuant to the requirements of the Securities Exchange Act of 1934, this report
has been signed below by the following  persons on behalf of the  registrant and
in the capacities on the dates indicated.

By:  /s/Dennis R. Neill         President and               March 31, 1998
     -------------------        Director (Principal
        Dennis R. Neill         Executive Officer)

     /s/Patrick M. Hall         Chief Financial             March 31, 1998
     -------------------        Officer (Principal
        Patrick M. Hall         Financial and
                                Accounting Officer)

     /s/Judy K. Fox             Secretary                   March 31, 1998
     -------------------
        Judy K. Fox



                                       39
<PAGE>



                               INDEX TO EXHIBITS


Exhibit
Number      Description
-------     -----------

4.1         Drilling Agreement dated November 25, 1986 for Dyco Drilling Program
            1986-X,  a  Limited  Partnership,  by and  between  Dyco Oil and Gas
            Program 1986-X and Dyco Petroleum  Corporation  filed as Exhibit 4.1
            to Annual  Report on Form 10-K for the year ended  December 31, 1991
            on April 1, 1992 and is hereby incorporated by reference.

4.2         Program  Agreement  dated  November  25,  1986  for Dyco Oil and Gas
            Program  1986-X by and between Dyco  Petroleum  Corporation  and the
            Participants  filed as Exhibit 4.2 to Annual Report on Form 10-K for
            the year  ended  December  31,  1991 on April 1,  1992 and is hereby
            incorporated by reference.

4.3         Amendment to Program  Agreement for Dyco Oil and Gas Program  1986-X
            dated  December  31, 1989 filed as Exhibit  4.3 to Annual  Report on
            Form 10-K for the year ended  December 31, 1991 on April 1, 1992 and
            is hereby incorporated by reference.

4.4         Certificate of Limited Partnership, as amended, for Dyco Oil and Gas
            Program  1986-X Limited  Partnership  filed as Exhibit 4.4 to Annual
            Report on Form 10-K for the year ended December 31, 1991 on April 1,
            1992 and is hereby incorporated by reference.

*27.1       Financial Data Schedule  containing  summary  financial  information
            extracted   from  the  Dyco  Oil  and  Gas  Program  1986-X  Limited
            Partnership's  financial  statements as of December 31, 1997 and for
            the year ended December 31, 1997.


------------------
*  Filed herewith.


                                       40