Exhibit 99.3

UNAUDITED PRO FORMA COMBINED FINANCIAL INFORMATION

Subject to the terms and conditions of the merger agreement and in accordance with Delaware law, the merger agreement provides for the merger of Merger Sub, a subsidiary of Breitburn, with and into QRE, with QRE surviving the merger as a wholly-owned subsidiary of Breitburn.

The pro forma financial statements have been prepared using the acquisition method of accounting for business combinations under U.S. GAAP.

The historical financial information included in the columns entitled “Breitburn” was derived from the unaudited financial statements included in Breitburn’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2014 and its Annual Report on Form 10-K for the year ended December 31, 2013. The historical financial information included in the columns entitled “QRE” was derived from financial information included in QRE’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2014, and Annual Report on Form 10-K for the year ended December 31, 2013, which are attached as Exhibit 99.2, respectively, to this Current Report on Form 8-K.

On December 30, 2013, Breitburn completed acquisitions of oil and natural gas properties located in the Permian Basin in Texas from CrownRock, L.P. for approximately $282 million in cash, and in December 2013, Breitburn completed the acquisition of additional interests in certain of the acquired assets in the Permian Basin from other sellers for an additional $20 million (collectively, the “Permian Basin Acquisitions”).

On July 15, 2013, Breitburn completed the acquisition of certain oil and natural gas and midstream assets located in Oklahoma, New Mexico and Texas, certain CO2 supply contracts, certain crude oil swaps and interests in certain entities from Whiting Oil and Gas Corporation (“Whiting”) for approximately $845 million in cash (the “Whiting Acquisition”), including post-closing adjustments.

The unaudited pro forma combined balance sheet at June 30, 2014 has been presented to show the effect as if the merger and the pro forma adjustments had occurred on June 30, 2014. The Whiting Acquisition and the Permian Basin Acquisitions were included in Breitburn’s historical balance sheet at June 30, 2014, and, as such, there are no pro forma adjustments related to the Permian Basin Acquisitions and the Whiting Acquisition.

The unaudited pro forma combined statement of operations for the six months ended June 30, 2014 and for the year ended December 31, 2013 have been presented based on Breitburn’s individual statement of operations, and reflect the pro forma operating results attributable to the merger agreement, the Permian Basin Acquisitions and the Whiting Acquisition as if the merger and acquisitions and the related transactions had occurred on January 1, 2013. Breitburn’s historical statements of operations include operating results from the Permian Basin Acquisitions for the six months ended June 30, 2014 and, as such, there are no pro forma adjustments related to the Permian Basin Acquisitions for this period. Breitburn’s historical statements of operations include operating results from the Whiting Acquisition for the period from July 15, 2013 to June 30, 2014 and, as such, the pro forma adjustments related to the Whiting Acquisition for the period January 1, 2013 to July 15, 2013 are included for the year ended December 31, 2013.

Pro forma data is based on currently available information and certain estimates and assumptions as explained in the notes to the unaudited pro forma combined financial statements. Pro forma data is not necessarily indicative of the financial results that would have been attained had the merger agreement and Permian Basin and Whiting acquisitions occurred on January 1, 2013. As actual adjustments may differ from the pro forma adjustments, the pro forma amounts presented should not be viewed as indicative of operations in future periods.

The unaudited pro forma combined financial information is based on assumptions that Breitburn believes are reasonable under the circumstances and are intended for informational purposes only. Actual results may differ from the estimates and assumptions used. The unaudited pro forma combined financial information is not necessarily indicative of the financial results that would have occurred if these transactions had taken place on the dates indicated, nor is it indicative of future consolidated results.

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Breitburn Energy Partners LP and Subsidiaries

Unaudited Pro Forma Combined Balance Sheet

As of June 30, 2014

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See the accompanying notes to the unaudited pro forma combined financial statements.

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Breitburn Energy Partners LP and Subsidiaries

Unaudited Pro Forma Combined Statement of Operations

For the Six Months Ended June 30, 2014

See the accompanying notes to the unaudited pro forma combined financial statements.

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Breitburn Energy Partners LP and Subsidiaries

Unaudited Pro Forma Combined Statement of Operations

For the Year Ended December 31, 2013

See the accompanying notes to the unaudited pro forma combined financial statements.

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Notes to the Unaudited Pro Forma Combined Financial Statements

The QRE historical financial statements reflect the balance sheet and results of operations derived from QRE’s audited financial statements as of and for the year ended December 31, 2013 and the unaudited financial statements for the six months ended June 30, 2014. The QRE historical financial statements as presented include the following reclassifications to conform to Breitburn’s financial statement presentation.

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The merger agreement provides that, at the effective date, each QRE common unit and Class B unit issued and outstanding, or deemed issued (including Contingent Class B units) and outstanding as of immediately prior to the effective time will be converted into the right to receive 0.9856 Breitburn common units. However, in no event will Breitburn be obligated to issue in excess of 72,001,686 common units as consideration for the merger. Using a closing Breitburn unit price at September 18, 2014 of $21.70, the estimated value of Breitburn’s common unit consideration is $1,562.4 million. The final value of Breitburn’s common unit consideration will be determined based on the actual number of Breitburn units issued and the market price of Breitburn’s common units as of the date of acquisition. A five percent increase or decrease in the closing price of Breitburn’s common units, compared to the September 18, 2014 closing price of $21.70, would increase or decrease the value of Breitburn’s common unit consideration by approximately $78 million.

In addition, under the terms of the merger agreement, the holders of QRE Class C units will receive an amount of cash equal to $350 million divided by the number of Class C units outstanding immediately prior to the effective time.

The preliminary estimated purchase price allocation is based on discounted cash flows, quoted market prices and estimates made by management, the most significant assumptions related to the estimated fair values assigned to oil and gas properties. To estimate the fair values of the properties, estimates of oil and gas reserves were prepared by management in consultation with independent engineers. We apply strip pricing to the estimated reserve quantities acquired, and estimate future operating and development costs to arrive at estimates of future net revenues. For estimated proved reserves, the future net revenues are discounted using a weighted average cost of capital of approximately 9%. Accordingly, the pro forma fair value adjustments are preliminary and have been made solely for the purpose of providing pro forma financial statements. The actual fair values of the assets acquired and liabilities assumed may differ materially from the amounts presented in the below purchase price allocation as further analysis is completed. Accordingly, the final allocation of the purchase price may result in different adjustments than those shown in the unaudited pro forma financial statements, and these differences may have a material impact on the accompanying pro forma financial statements and the combined future results of operations and financial position.

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QRE owns a 59% ownership interest in East Texas Salt Water Disposal Company (“ETSWDC”), a saltwater disposal company, and it consolidates the results for this company as it holds a majority interest. At June 30, 2014, the fair value was approximately $14.8 million, which is reflected in non-oil and gas assets. The non-controlling interest for ETSWDC at June 30, 2014 was $9.3 million.

The unaudited pro forma combined statements of operations have been adjusted as follows:

Reflects an increase in operating costs of $0.1 million and $0.6 million, respectively, to account for geological, geophysical and delay rental expenditures using the successful efforts method rather than the full cost method used by QRE.

Reflects $3.6 million of incremental depletion, depreciation and amortization (“DD&A”) calculated using the fair value of QRE’s oil and gas properties.

Reflects $3.2 million of incremental DD&A calculated using the fair value of QRE’s oil and gas properties.

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Reflects a $12.3 million decrease in interest expense associated with QRE’s debt, assuming the retirement of QRE’s senior notes and the refinancing of all debt under our new credit facility (as detailed in 2 (a) through 2 (e) above). The assumed variable rate was 2.279% for the six months ended June 30, 2014. If the variable interest rate increased or decreased by 0.125% from the assumed variable rate, the six month ended June 30, 2014 pro forma interest expense would have increased or decreased by $2.4 million.

Reflects a $19.0 million decrease in interest expense attributable to the elimination of QRE’s historical interest expense of $48.0 million, partially offset by $29.0 million of interest expense associated with borrowings to fund the QRE merger and the Whiting and Permian Basin acquisitions. The assumed variable rate was 2.189% for the year ended December 31, 2013. If the variable interest rate increased or decreased by 0.125% from the assumed variable rate, the year ended December 31, 2013 pro forma interest expense would have increased or decreased by $2.2 million.

Eliminate the $12.0 million loss on Deferred Class B unit obligation based on the terms of the merger agreement (see 4 (f) above for a discussion of the Class B units).

Give effect, as of January 1, 2013, of the 72.0 million Breitburn common units issued as partial consideration for the merger to the denominator for calculating net income (loss) per unit.

Give effect, as of January 1, 2013, of the 72.0 million Breitburn common units issued as partial consideration for the merger to the denominator for calculating net income (loss) per unit, and the Breitburn common units issued for the February 2013 and November 2013 equity offerings. Also, include weighted average participating securities and dilutive units (previously not included in the denominator of net income (loss) per unit) as the pro forma combined statement of operations is in an income position compared to a loss position for Breitburn’s historical statement of operations.

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4. Supplemental Oil and Gas Information (Unaudited)

The following table sets forth certain unaudited pro forma information regarding estimates of Breitburn’s proved crude oil, natural gas and NGL reserves for the year ended December 31, 2013, giving effect to the merger as if it had occurred on January 1, 2013. Because reserve estimates are inherently imprecise and require extensive judgments of reservoir engineering data, they are generally less precise than estimates made in conjunction with financial disclosures.

Unweighted average first-day-of-the-month oil and natural gas prices used to determine our total estimated proved reserves as of December 31, 2013 were $96.94 per Bbl of oil and $3.67 per MMBtu of gas.

Summarized in the following table is information for Breitburn’s unaudited pro forma standardized measure of discounted cash flows relating to estimated proved reserves as of December 31, 2013, giving effect to the merger. The standardized measure of discounted future net cash flows was determined based on the economic conditions in effect at December 31, 2013. The disclosures below do not purport to present the fair market value of Breitburn’s oil and gas reserves. An estimate of the fair market value would also take into account, among other things, the recovery of reserves in excess of proved reserves, anticipated future changes in prices and costs, a discount factor more representative of the time value of money and risks inherent in reserve estimates. The pro forma standardized measure of discounted future net cash flows is presented as follows:

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The following table sets forth unaudited pro forma information for the principal sources of changes in the standardized measure of discounted future net cash flows for the year ended December 31, 2013, giving effect to the merger:

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