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                                                                    EXHIBIT 99.4
 
                         CHESAPEAKE ENERGY CORPORATION
 
                               OFFER TO EXCHANGE
                                      ITS
                     9 5/8% SERIES B SENIOR NOTES DUE 2005
                       FOR ANY AND ALL OF ITS OUTSTANDING
                     9 5/8% SERIES A SENIOR NOTES DUE 2005
 
To Our Clients:
 
     Enclosed for your consideration are the Prospectus, dated             ,
1998 (the "Prospectus") and the related Letter of Transmittal (which together
with the Prospectus constitute the "Exchange Offer") in connection with the
offer by Chesapeake Energy Corporation, an Oklahoma corporation (the "Company"),
to exchange its 9 5/8% Series B Senior Notes due 2005 (the "New Notes") for any
and all of the outstanding 9 5/8% Series A Senior Notes due 2005 (the "Old
Notes"), upon the terms and subject to the conditions set forth in the Exchange
offer.
 
     We are the Registered Holder of Old Notes held for your account. An
exchange of the Old Notes can be made only by us as the Registered Holder and
pursuant to your instructions. The Letter of Transmittal is furnished to you for
your information only and cannot be used by you to exchange the Old Notes held
by us for your account. The Exchange Offer provides a procedure for holders to
tender by means of guaranteed delivery.
 
     We request information as to whether you wish us to exchange any or all of
the Old Notes held by us for your account upon the terms and subject to the
conditions of the Exchange Offer.
 
     Your attention is directed to the following:
 
          1. The New Notes will be exchanged for the Old Notes at the rate of
     $1,000 principal amount of New Notes for each $1,000 principal amount of
     Old Notes. The New Notes will bear interest (as do the Old Notes) at a rate
     equal to 9 5/8% per annum from their date of issuance. Interest on the New
     Notes is payable semi-annually on May 1 and November 1, commencing November
     1, 1998. Holders of Old Notes that are accepted for exchange will receive,
     in cash, accrued interest thereon to, but not including, the date of
     issuance of the New Notes. Such interest will be paid with the first
     interest payment on the New Notes. Interest on the Old Notes accepted for
     exchange will cease to accrue on the day prior to the issuance of the New
     Notes. The form and terms of the New Notes are the same in all material
     respects as the form and terms of the Old Notes (which they replace) except
     that the New Notes have been registered under the Securities Act of 1933,
     as amended (the "Securities Act").
 
          2. Based on the interpretation by the staff of the Securities and
     Exchange Commission (the "SEC"), New Notes issued pursuant to the Exchange
     Offer in exchange for Old Notes may be offered for resale, resold and
     otherwise transferred by holders thereof (other than any such holder which
     is an "affiliate" of the Company within the meaning of Rule 405 under the
     Securities Act or a "broker" or "dealer" registered under the Securities
     Exchange Act of 1934, as amended (the "Exchange Act")) without compliance
     with the registration and prospectus delivery provisions of the Securities
     Act provided that such New Notes are acquired in the ordinary course of
     such holders' business and such holders have no arrangement with any person
     to participate in the distribution of such New Notes.
 
          3. The Exchange Offer is not conditioned on any minimum principal
     amount of Old Notes being tendered.
 
          4. Notwithstanding any other term of the Exchange Offer, the Company
     will not be required to accept for exchange, or exchange New Notes for, any
     Old Notes not theretofore accepted for exchange, and may terminate or amend
     the Exchange Offer as provided herein before the acceptance of such Old
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     Notes, if any of the conditions described in the Prospectus under "The
     Exchange Offer -- Conditions of the Exchange Offer" exist.
 
          5. Tendered Old Notes may be withdrawn at any time prior to 5:00 p.m.,
     New York City time, on             , 1998 (the "Expiration Date") unless
     extended by the Company.
 
          6. Any transfer taxes applicable to the exchange of the Old Notes
     pursuant to the Exchange Offer will be paid by the Company, except as
     otherwise provided in Instruction 4 of the Letter of Transmittal.
 
     If you wish to have us tender any or all of your Old Notes, please so
instruct us by completing, detaching and returning to us the instruction form
attached hereto. An envelope to return your instructions is enclosed. If you
authorize a tender of your Old Notes, the entire principal amount of Old Notes
held for your account will be tendered unless otherwise specified on the
instruction form. Your instructions should be forwarded to us in ample time to
permit us to submit a tender on your behalf by the Expiration Date.
 
     The Exchange Offer is not being made to, nor will tenders be accepted from
or on behalf of, holders of the Old Notes in any jurisdiction in which the
making of the Exchange Offer or acceptance thereof would not be in compliance
with the laws of such jurisdiction or would otherwise not be in compliance with
any provision of any applicable securities law.
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                         CHESAPEAKE ENERGY CORPORATION
 
                               OFFER TO EXCHANGE
                                      ITS
                     9 5/8% SERIES B SENIOR NOTES DUE 2005
                       FOR ANY AND ALL OF ITS OUTSTANDING
                     9 5/8% SERIES A SENIOR NOTES DUE 2005
 
             INSTRUCTION TO REGISTERED HOLDER FROM BENEFICIAL OWNER
 
     The undersigned acknowledge(s) receipt of your letter and the enclosed
Prospectus and the related Letter of Transmittal, in connection with the
Exchange Offer by the Company to exchange New Notes for Old Notes.
 
     This will instruct you to tender the principal amount of Old Notes
indicated below held by you for the account of the undersigned, upon the terms
and subject to the conditions set forth in the Prospectus and the related Letter
of Transmittal.
 
     The undersigned represents that (i) the New Notes acquired pursuant to the
Exchange Offer are being obtained in the ordinary course of its business, (ii)
it is not participating, does not intend to participate, and has no arrangement
or understanding with any person to participate, in the distribution of such New
Notes, and (iii) it is not an "affiliate," as defined under Rule 405 of the
Securities Act, of the Company or, if it is an affiliate, that it will comply
with the registration and prospectus delivery requirements of the Securities Act
to the extent applicable.
 
     If the undersigned is a "broker" or "dealer" registered under the Exchange
Act that acquired Old Notes for its own account pursuant to its market-making or
other trading activities (other than Old Notes acquired directly from the
Company), the undersigned understands and acknowledges that it may be deemed to
be an "underwriter" within the meaning of the Securities Act and, therefore,
must deliver a prospectus relating to the New Notes meeting the requirements of
the Securities Act in connection with any resales by it of New Notes acquired
for its own account in the Exchange Offer. Notwithstanding the foregoing, the
undersigned does not thereby admit that it is an "underwriter" within the
meaning of the Securities Act.
 
     You are hereby instructed to tender all Old Notes held for the account of
the undersigned unless otherwise indicated below:
 
K Do not tender any Old Notes
 
K Tender Old Notes in the principal amount of 
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                                            SIGNATURE:
 
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                                                Name of Beneficial Owner (please
                                                                          print)
 
                                            By:
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                                                                       Signature
 
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                                                                         Address
 
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                                                                        Zip Code
 
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                                                  Area Code and Telephone Number
 
                                            Dated:                , 1998