SecProbe.io

March 17, 2011

Via U.S. Mail and Facsimile

 Brian F. Maxted Chief Executive Officer Kosmos Energy Ltd. 8176 Park Lane, Suite 500 Dallas, Texas 75231
Re: Kosmos Energy Ltd.
Amendment No. 1 to Registrati on Statement on Form S-1
Filed March 3, 2011
  File No. 333-171700

Dear Mr. Maxted:

We have reviewed your amendment, and your  letter dated March 3, 2011, and we have
the following comments.  In some of our co mments, we may ask you to provide us with
information so we may better understand your disclosure.
 Please respond to this letter by amending your registration statement and providing the
requested information.  If you do not believe  our comments apply to your facts and
circumstances or do not believe an amendment is appropriate, please tell us why in your
response.
 After reviewing any amendment to your re gistration statement and the information you
provide in response to these comments, we may have additional comments.
 General

 1. Please file consents from Wood MacKen zie, African Business Review, and the
International Energy Agency.  Re fer to Securities Act Rule 436.

Brian F. Maxted
Kosmos Energy Ltd. March 17, 2011 Page 2  Management’s Discussion and Analysis of Financ ial Condition and Results of Operations, page 56

 Factors Affecting Comparability of Future Results, page 57

 General and Administrative, page 57

 2. We note your response to comment 16 in our le tter dated February 11, 2011.  With regard
to the $15 million payment, please provide the following:

 Please tell us the name of the individual or entity to whom the payment is due, and
why such payment is subject to confidentiali ty provisions that rest rict your ability to
disclose in your filing the identity of th e payee.  Notwithstanding the confidentiality
provisions in your payment agreement, it rema ins unclear to us why the name of the
individual to whom the payment is due is  not material information to investors;
 Explain to us why your response appears to indicate you accrued this amount in your
December 31, 2010 financial statements, but yo ur disclosure with respect to general
and administrative expenses on page 57 app ears to indicate the amount will impact
future periods;
 Describe to us your basis for either rec ognizing or not recogniz ing the amount in your
financial statements at December 31, 2010; and
 To the extent the $15 million was recorded as of December 31, 2010, tell us what
consideration you gave to discussing this payment as a significant fluctuation in your
results of operations discussion in accordan ce with Item 303(a)(3) of Regulation S-K.

In this regard, you cross-refere nce a “discussion of these expe nses incurred in connection
with this offering” in your  Underwriting section, but we  are unable to locate such a
discussion.
 Results of Operations, page 59

 Year Ended December 31, 2010 vs. 2009, page 59

 3. We note you recorded doubtful accounts expense of $39.8 million during the quarter
ended December 31, 2010.  Please expand your  disclosure to provide additional
information regarding the e xpense recorded, and descri be the specific facts and
circumstances that led you to conclude it was proper to record the amount during the
fourth quarter of 2010 rather than earlier pe riods.  Also tell us what consideration you
have given to including enhanced disclosure of the estimates and assumptions related to
your allowance for doubtful accounts within  your discussion of critical accounting
policies.

Brian F. Maxted
Kosmos Energy Ltd. March 17, 2011 Page 3  Critical Accounting Policies, page 66

 4. For many of the critical accounti ng policies disclosed under this heading, the disclosure is
the same as that provided in the notes to your financial statements.  Such disclosure
should supplement, not duplicate, the descrip tion of accounting policie s that are already
disclosed in the notes to the financial st atements.  The discussion in MD&A should
present your analysis of the un certainties involved in applying a principle at a given time
or the variability that is reas onably likely to result from its  application over time.  For
example, but without limitation, please revi se your discussion of asset retirement
obligations to include the information you pres ent in response to comment 26 in our letter
dated February 11, 2011.  Please see FRR 501.14 for further information, and revise your
disclosures accordingly.
 Business, page 80

 Kosmos Exploration Approach, page 84

 5. We note your response to comment 8 in our  letter dated February 11, 2011.  Your
carryover paragraph at the bottom of page 85 indicates that “Kosmos continuously
evaluates new opportunities,” that the “new venture gr oup reviews the exploration
potential of the West and East coast African  margins,” that you have “evaluated over 120
new venture opportunities,” and that you have “also begun to apply th e same exploration
approach” in other areas.  Expand your disclosu re to clarify whether this program has in
fact resulted in any acquisitions as suggest ed by your use of th e phrase “high-impact
acquisition program.”
 Our Reserves, page 102

 6. Please reconcile your measure of PV-10 to th e most directly comparable GAAP financial
measure as required by Item 10( e) of Regulation S-K.
 Oil Spill Response, page 116

 7. We note your response to comment 22 in our  letter dated February 11, 2011.  In
particular, we note your disclosu re at page 116 that “[t]he amount of insurance coverage
maintained is proportional to our interest in  a given well; with our current coverage being
$300 million multiplied by our working interest in  a well per incident for well control, re-
drilling, pollution and environmental damage  liabilities and $300 million multiplied by
our working interest in a well per incident (aggregated annua lly)[.]”  Please illustrate
your disclosure here with an example, and clarify whether there is any annual limit or
deductible.

Brian F. Maxted
Kosmos Energy Ltd. March 17, 2011 Page 4  Notes to Consolidated Financial Statements, page F-8

 Note 12 Asset Retirement Obligations, page F-26

 8. We note your response to comment 26 in our letter dated February 11, 2011.  We also
note your disclosure that a decommissioning plan will be prepared and submitted to the Ghana Environmental Protection Ag ency related to the Jubilee field.  With regard to your
retirement and abandonment obligations at this field, please provide us with the
following:

 Describe to us in more detail your obligati ons under Ghanaian law.  In this regard,
your response appears to indicate that  Ghanaian law both requires, under the
Petroleum Law, and does not expressly re quire, under current Ghana environmental
regulations, abandonment or re moval of offshore assets;
 Explain to us in more detail the step s you would take under in ternational industry
standards to abandon or remove offshore  assets and when you would incur an
obligation to perform those acti ons, as contemplated by ASC 410;
 Tell us whether you have any obligations regarding well equipment on the ocean
floor, and when those obligations are incurred;
 Describe to us any obligati ons regarding the FPSO, including, but not limited to when
you, or the unit operator, took ownership of  the FPSO and incurred the obligation to
abandon or retire the FPSO; and
 Provide us with a summary of the cont ent of the decommissioning plan that
specifically describes the nature and timing of the activities that give rise to the need
for the planned decommissioning activities.
 Note 16 Income Taxes, page F-31

 9. It appears from your response to comment 29 in our letter dated February 11, 2011 that
the positive evidence you considered focuse s on the expectation of the existence of
sufficient future sources of taxable income to realize your deferred tax assets, excluding
amounts offset for future reversals of exis ting taxable temporary differences.  Please
expand your response to address in detail  how you considered ASC 740-10-30-23, which
states that recent cumulative losses constitute  significant negative evidence, as follows:

 Explain how you considered the provision in  the aforementioned literature that
indicates positive evidence of equal or gr eater significance is needed to overcome
negative evidence before a tax benefit is  recognized for de ductible temporary
differences and loss carry-forwards based on a projection of future taxable income;
 In evaluating the positive evidence available, tell us why you believe your
expectations as to future taxable inco me are sufficient to overcome the negative
evidence of recent cumulative losses, even  if supported by detailed forecasts and
projections. Your response  should address your consid eration of the objectively
verifiable criterion in the aforementioned li terature as it relates to your positive

Brian F. Maxted
Kosmos Energy Ltd. March 17, 2011 Page 5
evidence when compared to the negative ev idence of your company’s historical loss
experience; and
 Describe to us any other available po sitive evidence you have considered as
contemplated in ASC 740-10-30-17 and 22.

Note 22 Pro Forma Information (unaudited), page F-36

 Per Share Information, page F-36

 10. The heading to the tables on page F-37 shows that such information is for the year ended
December 31, 2009.  Please clarify if such in formation will be provided for the year
ended December 31, 2010, rather than the year ended December 31, 2009, or please
advise.
Exhibits 99.1 and 99.2

 11. In the introductory paragraph of the report from your independen t reserve engineering
firm, we note the statement that “The estima tes in this report have been prepared in
accordance with the definitions and guideline s of the U.S. Securities and Exchange
Commission (SEC) and, with the exception of the exclusion of future income taxes,
conform to the FASB Accounting Sta ndards Codification Topic 932, Extractive
Activities—Oil and Gas. Definitions are presen ted immediately followi ng this letter.”
Please clarify your statement that your estima tes conform to the codification except for
the exclusion of income taxes.  In this regard, the net future revenue at December 31,
2010 discounted at 10% appears to include income taxes as it reconciles to your SMOG.

Engineering Comments

12. We note your response to comment 33 in our letter dated February 11, 2011.  However,
we still find the inclusion of technical terms that are not defined.  Examples of these are
listric faults, high energy deposition, tran s-tension, four way dip closures, channel
deposits, strong amplitude support, AVO anomal y and compressional anticline.  These
examples are not necessarily all inclusive.  Please revise your document to provide a
definition of all technical terms or replace them with a more commonly understood term
or description.
13. Also, address the following terms that are not defined in your document: development
costs, production costs, pres ent value of future net revenues (PV-10), standardized
measure, developed acreage, undeveloped acreage, proved undeve loped reserves, and
proved developed reserves.  These are exam ples and should not be considered all
inclusive.
14. In regards to your response to comment 48 in  our letter dated Fe bruary 11, 2011, please
add disclosure that explains since you do not  have a majority ownership in any of your

Brian F. Maxted
Kosmos Energy Ltd. March 17, 2011 Page 6
properties you may not be able to control the timing of exploration or development
activities or the amount of cap ital expenditures and, therefore, may not be able to carry
out your strategy of having signifi cantly shorter timelines from  discovery to first oil.
15. In regards to your response to comment 52 in  our letter dated Fe bruary 11, 2011, replace
the term “guidelines” with “regulations ” when discussing the SEC requirements.

Our Ghanaian, Cameroon and Moroccan Prospects, pages 94, 98 and 100

 16. For most of these undrilled prospects you have  disclosed estimated “net” pay, apparently
from seismic studies.  However, it is not appa rent that seismic alone can determine “net”
pay with the necessary reliability for disclo sure in a SEC filing.  At best, seismic may
determine gross thickness but it is not able to reliably determine oil, gas and water
saturations or porosity and permeability wit hout borehole calibration.  These values are
necessary in order to reliably  estimate “net” pay.  In additi on, according to information in
your supplemental response of March 2, 2011 to  our comment letter dated February 11,
2011, by Netherland & Sewell (Tabs S, T, a nd V), the estimated volumes in these
prospects are classified as contingent a nd prospective resources .  Information about
resources is not allowed in documents filed w ith the SEC.  Therefore, please remove the
reference to net pay for each of these undrilled prospects where it is disclosed.
 The same is true for hydrocarbon yield in undr illed prospects.  Since net pay cannot be
determined with reliability, oil in place ca nnot be determined and, therefore, hydrocarbon
yield cannot be determined with  the necessary reliability to be disclosed in a filing.  In
addition, these references to hydrocarbon yields are concerning contingent and
prospective resources which are not allowed in documents filed with the SEC.  Therefore,
please remove your estimated hydrocarbon yiel ds for each of the undrilled prospects
where they are disclosed.  Please se e the last Instruction to Item 1202.
 Supplemental Response on Statistical Claims

 17. In regards to the claim that specific reser voirs in the Tano Basin can reach permeabilities
up to 1,200 mD (Tab R), we do not concur that one sample out of 100 (or even one sample out of 19 in the UM2) that is 92% higher than the next higher UM2 sample (one
reservoir not specific reservoirs) is statistica lly valid and should be disclosed in a SEC
filing.  Therefore, please remove the refere nce of “permeabilities up to 1,200 mD.”
 Closing Comments

We urge all persons who are responsible for th e accuracy and adequacy of the disclosure
in the filing to be certain that the filing incl udes the information the Securities Act of 1933 and
all applicable Securities Act rules require.  Since the company and its management are in
possession of all facts relating to a company’s disc losure, they are responsible for the accuracy
and adequacy of the disclosures they have made.

Brian F. Maxted
Kosmos Energy Ltd. March 17, 2011 Page 7
Please refer to Rules 460 and 461 regarding re quests for acceleration.  We will consider a
written request for acceleration of  the effective date of the regi stration statement as confirmation
of the fact that those reques ting acceleration are aware of thei r respective responsibilities under
the Securities Act of 1933 and the Securities Excha nge Act of 1934 as they relate to the proposed
public offering of the securities specified in th e above registration stat ement.  Please allow
adequate time for us to review any amendment prior to the requested effective date of the
registration statement.
You may contact James Murphy, Petroleum E ngineer, at (202) 551- 3703 with questions
about engineering comments.  You may contact Ma rk Wojciechowski, Staff Accountant, at (202)
551-3759 or Mark Shannon, Branch Chief, at (2 02) 551-3299 if you have questions regarding
comments on the financial statements and rela ted matters.  Please contact Alexandra M.
Ledbetter, Staff Attorney, at (202) 551-3317 or me at (202) 551-3740 with any other questions.

Sincerely,

H. Roger Schwall Assistant Director

cc: Richard D. Truesdell, Jr., Esq.  Davis Polk & Wardwell LLP
Facsimile No. (212) 701-5674