We have provided a detailed analysis of the five largest projects, based on cost, for each category and for each period presented in the 2010 Form 10-K. This analysis is being provided to the Staff supplementally as Exhibit A-1 (2010 additions), Exhibit A-2 (2009 additions) and Exhibit A-3 (2008 additions). Pursuant to Rule 12b-4 under the Exchange Act, we are requesting that this supplemental information be returned to us as soon as practicable following the Staff’s review of such information. In addition, we are requesting that the Staff afford confidential treatment under the Freedom of Information Act to this information. The project costs included in the detailed analysis comprise approximately 79%, 50% and 56% of the total dollar amount of additions to “crude oil processing facilities” for 2010, 2009 and 2008, respectively.

For each project listed on Exhibits A-1, A-2 and A-3, we reassessed and redetermined the following pertinent factors:

Our detailed analysis consists of over one-half of all projects (based on the dollar amounts of additions) over the past three years, by year and in total, and we believe our analysis contains all of the pertinent factors and covers all of the various types and categories of our projects to illustrate that our additions have similar useful lives.

We believe the projects excluded from our detailed analysis have the same characteristics as the large projects presented with respect to each attribute presented in our detailed analysis. Our assertion is based on our consistent application of our accounting policies in all material respects, which have been provided to the Staff supplementally in response to the Staff’s comment three. However, in addition to the detailed analysis provided in Exhibits A-1, A-2 and A-3, our accountants and Engineers performed a high-level review

We also reanalyzed a substantial amount of our 2011 first quarter and second quarter additions for accounting policy compliance, to identify whether there were any projects whose estimated useful lives are outside the range of 20-plus years, with 25 to 30 years not being unreasonable, and to identify whether any major Units were replaced. We redetermined that we complied with our accounting policies in all material respects. We also determined that all additions had estimated useful lives of 20-plus years, with 25 to 30 years not being unreasonable, and we identified no major Unit replacements.

We also performed a high-level review of a listing of total additions made to each refinery for every year that we have owned each refinery. Years in which large additions occurred were examined in detail with our Engineers to identify any historical experience with respect to major replacements of Units before the end of their useful lives. Throughout our extensive historical experience of owning and operating refineries (over 25 years), we identified only one Unit of any significance that was shut down, disposed of or replaced before the end of its useful life, which related to the involuntary conversion of a significant portion of a Unit destroyed in a fire at our McKee Refinery, thereby reaffirming our assertion. We have experienced other fires within our refineries over the years, but in these cases the repairs were expensed as incurred. We also inquired of our Engineers as to whether any future capital project that is expected to occur during our five-year strategic planning period will involve the replacement of major Units, and they confirmed that no such replacements are expected. This information is being provided to the Staff supplementally in Exhibit B. Pursuant to Rule 12b-4 under the Exchange Act, we are requesting that this supplemental information be returned to us as soon as practicable following the Staff’s review of such information. In addition, we are requesting that the Staff afford confidential treatment under the Freedom of Information Act to this information. This information further supports our assertion that major replacements or dispositions of Units are infrequent and unusual (i.e., extraordinary).

Our detailed analysis and our historical experiences indicate the following:

“Major” and “abnormal” replacements of Units are extremely infrequent and unusual (i.e., extraordinary).

Betterments of Units often include de minimis or minor replacements of existing assets or infrastructure. As per our accounting policies and composite depreciation methodology, these amounts are not charged to income.

New assets, including entire new Units, and betterments are always designed, constructed and maintained to have a very long useful life in accordance with Shell EG-1 Guidelines or similar industry standards.

We maintain our composite groups at the refinery level due to the fact that the underlying Units within each refinery were designed, constructed and maintained to enable a very long useful life, and the underlying useful life of each Unit is not significantly or materially different from that of other Units. This was verified and supported by our Engineers.

Further, as discussed in the response letter we filed with the Commission on May 11, 2011, the Units of each refinery are aggregated into one composite group because these Units are substantially homogeneous with respect to their operation, their useful lives and their location, and we provided the basis for these assertions in that letter. With respect to useful lives, we described that our initial estimates were established at the time we acquired each refinery. We respectfully disagree with the Staff’s assertion that the complexities of our refineries and the substantial range of cost of our additions are indications of dissimilarities that would contribute to varying useful lives. While we agree that our refineries are complex in their processes, we have described in this and previous response letters that the Units (and Unit additions) within our refineries are designed, operated and maintained for extremely long useful lives (in excess of 20 years, with a 25 to 30 year life not being unreasonable). The cost of a property addition will only affect the composite group’s overall useful life if it is significant (i.e., major) and the effect would most likely be an extension of the composite group’s useful life, not a reduction.

We believe our accounting policy disclosure for property, plant and equipment is adequate under Regulation S-X and is comparable to our peers; however, we intend to expand our disclosure for property additions in the future. As such, we propose including the following policy disclosure in our Form 10-K for the year ending December 31, 2011.

We are providing a copy of our internal accounting policies, which are titled “Accounting for Property, Plant and Equipment” and “Accounting for the Depreciation and Retirement of Property, Plant & Equipment,” to the Staff supplementally as Exhibits C and D, respectively. Pursuant to Rule 12b-4 under the Exchange Act, we are requesting that this supplemental information be returned to us as soon as practicable following the Staff’s review of such information. In addition, we are requesting that the Staff afford confidential treatment under the Freedom of Information Act to this information. Some of the dollar

As a clarification, our refineries were not identified as one asset as a part of our purchase price allocations. Some of our appraisals provided asset values and the appraisers’ estimates of useful lives for underlying Units, but other appraisals did not. The important aspect of the appraisals that included estimated useful lives by Unit is that these appraisals corroborated and supported our Engineers’ assertions that the useful lives of Units within each refinery are extremely long-lived and substantially similar.

The nomenclature of “revamps,” “expansions,” and “conversions” are terms that generally consist of betterments of existing Units. The use of these terms is solely for the purpose of our Engineers and the investment community and does not have a specific technical accounting meaning. Our detailed analysis of the projects in Exhibits A-1, A-2 and A-3 provide an example of the accounting considerations for each type of project.

With respect to each project mentioned by the Staff, we supplementally provide the following information:

Regulatory projects often impact the infrastructure of legacy assets, but the cost of assets disposed of or replaced as a result of regulatory actions has historically been minor. Our detailed analysis of regulatory projects in Exhibits A-1, A-2 and A-3 supports this assertion. As such, per our accounting policies, these amounts have been charged to accumulated depreciation.

A listing of Units by refinery is being provided to the Staff supplementally as Exhibit E. Pursuant to Rule 12b-4 under the Exchange Act, we are requesting that this supplemental information be returned to us as soon as practicable following the Staff’s review of such information. In addition, we are requesting that the Staff afford confidential treatment

There have been no major replacements of Units during the periods presented in the 2010 Form 10-K.

The accounting treatment for assets replaced as part of a capital project is outlined in our accounting policies, which are provided in response to the Staff’s comment three. We have also presented our detailed considerations for replaced assets within the detailed analysis of our capital additions provided in our response to the Staff’s comment two.

Since the construction or acquisition of our refineries, there have been no major replacements of Units. Our historical experience has given us no indication that the useful lives assigned to our composite groups are too long nor are Units that comprise the composite groups significantly dissimilar in their useful lives. Should future circumstances indicate that a reevaluation of our composite useful lives is warranted, we will engage an independent consulting firm to perform a detailed study of the composite group lives and adjust our depreciation rates accordingly. Based on our experience and analysis, we would expect the composite useful lives to be extended, not shortened.

With respect to the specific projects discussed by the Staff, we supplementally provide the following information:

We are providing copies of our detailed appraisals to the Staff supplementally as Exhibits F through K. Pursuant to Rule 12b-4 under the Exchange Act, we are requesting that this supplemental information be returned to us as soon as practicable following the Staff’s review of such information. In addition, we are requesting that the Staff afford confidential treatment under the Freedom of Information Act to this information.

As a clarification, our appraisals were not used as the primary source of establishing the useful lives of our composite groups. In addition, certain appraisals did not address useful lives and certain appraisals did not address useful lives by Unit. The useful lives of our refineries were established through discussions with our engineers who performed our detailed due diligence procedures in connection with the acquisitions of our refineries. The engineers conduct extensive due diligence procedures as part of the acquisition process, including but not limited to:

Identification of all Units within the refinery;

Physical inspection of each Unit and related infrastructure;

Review of historical maintenance and safety records;

Review of historical improvements and expansions;

Assessment of the need for future Unit replacements due to design flaws or inefficiencies;

Evaluation of operating efficiency;

Evaluation of the environmental compliance status of the Units;

Discussions with Unit and refinery managers to determine the condition and reliability of the Units;

Review of all relevant Unit and entire refinery documentation; and

Professional evaluation using historical experience and industry expertise.

Although no formal reports were prepared by our engineers with respect to estimated useful lives, those estimates were compared to our peers in our industry and to our detailed appraisals (when provided), and they were determined to be reasonable.