Western Midstream Partners, LP - Quarter Report: 2013 March (Form 10-Q)

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

Or

Commission file number: 001-35753

WESTERN GAS EQUITY PARTNERS, LP

(Exact name of registrant as specified in its charter)

(832) 636-6000

(Registrant’s telephone number, including area code)

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 such filing requirements for the past 90 days.    Yes  þ    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  þ    No  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  þ

There were 218,895,515 common units outstanding as of May 2, 2013.

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DEFINITIONS

As generally used within the energy industry and in this quarterly report on Form 10-Q, the identified terms have the following meanings:

Barrel or Bbl: 42 U.S. gallons measured at 60 degrees Fahrenheit.

Btu: British thermal unit; the approximate amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.

Condensate: A natural gas liquid with a low vapor pressure mainly composed of propane, butane, pentane and heavier hydrocarbon fractions.

Cryogenic: The fractionation process in which liquefied gases, such as liquid nitrogen or liquid helium, are used to bring volumes to very low temperatures (below approximately -238 degrees Fahrenheit) to separate natural gas liquids from natural gas. Through cryogenic processing, more natural gas liquids are extracted than when traditional refrigeration methods are used.

Drip condensate: Heavier hydrocarbon liquids that fall out of the natural gas stream and are recovered in the gathering system without processing.

Fractionation: The process of applying various levels of higher pressure and lower temperature to separate a stream of natural gas liquids into ethane, propane, normal butane, isobutane and natural gasoline.

Imbalance: Imbalances result from (i) differences between gas volumes nominated by customers and gas volumes received from those customers and (ii) differences between gas volumes received from customers and gas volumes delivered to those customers.

MBbls/d: One thousand barrels per day.

MMBtu: One million British thermal units.

MMcf/d: One million cubic feet per day.

Natural gas liquid(s) or NGL(s): The combination of ethane, propane, normal butane, isobutane and natural gasolines that, when removed from natural gas, become liquid under various levels of higher pressure and lower temperature.

Residue: The natural gas remaining after being processed or treated.

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PART I. FINANCIAL INFORMATION

Item 1. Financial Statements

WESTERN GAS EQUITY PARTNERS, LP

CONSOLIDATED STATEMENTS OF INCOME

(UNAUDITED)

See accompanying Notes to Consolidated Financial Statements.

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WESTERN GAS EQUITY PARTNERS, LP

CONSOLIDATED BALANCE SHEETS

(UNAUDITED)

See accompanying Notes to Consolidated Financial Statements.

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WESTERN GAS EQUITY PARTNERS, LP

CONSOLIDATED STATEMENT OF EQUITY AND PARTNERS’ CAPITAL

(UNAUDITED)

See accompanying Notes to Consolidated Financial Statements.

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WESTERN GAS EQUITY PARTNERS, LP

CONSOLIDATED STATEMENTS OF CASH FLOWS

(UNAUDITED)

See accompanying Notes to Consolidated Financial Statements.

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WESTERN GAS EQUITY PARTNERS, LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(UNAUDITED)

1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION

General. Western Gas Equity Partners, LP is a Delaware master limited partnership formed in September 2012 to own three types of partnership interests in Western Gas Partners, LP, a publicly traded partnership. Western Gas Equity Partners, LP was formed by converting WGR Holdings, LLC into a limited partnership and changing its name. Western Gas Partners, LP (together with its subsidiaries, “WES”) is a Delaware master limited partnership formed by Anadarko Petroleum Corporation (“APC”) in 2007 to own, operate, acquire and develop midstream energy assets.

For purposes of these consolidated financial statements, “WGP” refers to Western Gas Equity Partners, LP in its individual capacity or to Western Gas Equity Partners, LP and its subsidiaries, including Western Gas Holdings, LLC and WES, as the context requires. “WES GP” refers to Western Gas Holdings, LLC, individually as the general partner of WES, and excludes WES itself. WGP’s general partner, Western Gas Equity Holdings, LLC (“WGP GP”), is a wholly owned subsidiary of Anadarko Petroleum Corporation. “Anadarko” refers to Anadarko Petroleum Corporation and its consolidated subsidiaries, excluding WGP and WGP GP. “WGP and Affiliates” refers to subsidiaries of Anadarko, including WGP in its individual capacity, and “affiliates” refers to subsidiaries of Anadarko, excluding WGP and its consolidated subsidiaries, and includes the interests in Fort Union Gas Gathering, LLC (“Fort Union”), White Cliffs Pipeline, LLC (“White Cliffs”) and Rendezvous Gas Services, LLC (“Rendezvous”). “Equity investment throughput” refers to WES’s 14.81% share of Fort Union and 22% share of Rendezvous gross volumes.

The three types of partnership interests in WES owned by WGP are as follows: (i) a 2.0% general partner interest in WES, held through a consolidated subsidiary, WES GP; (ii) 100% of the incentive distribution rights (“IDRs”) in WES, which entitle WGP to receive increasing percentages, up to the maximum level of 48.0%, of any incremental cash distributed by WES as certain target distribution levels are reached in any quarter; and (iii) a significant limited partner interest in WES. WES GP owns a 2.0% general partner interest in WES, which constitutes substantially all of WES GP’s business, which primarily is to manage the affairs and operations of WES. Refer to Note 4 for a discussion of WGP’s holdings of WES equity.

In December 2012, WGP completed its initial public offering (“IPO”) of 19,758,150 common units representing limited partner interests, including 2,577,150 common units issued in connection with the full exercise of the underwriters’ over-allotment option, at a price of $22.00 per common unit, generating net proceeds of $412.0 million. WGP used approximately $409.4 million of the net proceeds from its IPO to purchase common and general partner units of WES.

WES is engaged in the business of gathering, processing, compressing, treating and transporting natural gas, condensate, NGLs and crude oil for Anadarko, as well as third-party producers and customers. As of March 31, 2013, WES’s assets included ownership and operation of twelve gathering systems, seven natural gas treating facilities, seven natural gas processing facilities, one NGL pipeline, one interstate natural gas pipeline, and one intrastate natural gas pipeline. In addition, WES had interests in five non-operated gathering systems, three operated processing systems, one operated gathering system, and one NGL pipeline, with separate interests in Fort Union, White Cliffs and Rendezvous accounted for under the equity method. These assets are located in East and West Texas, the Rocky Mountains (Colorado, Utah and Wyoming), north-central Pennsylvania, and the Mid-Continent (Kansas and Oklahoma). WES also had facilities under construction in South Texas and Northeast Colorado at the end of the first quarter of 2013.

Basis of presentation. The consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”). The consolidated financial statements include the accounts of WGP and entities in which it holds a controlling financial interest, including WES and WES GP. All significant intercompany transactions have been eliminated. Investments in non-controlled entities over which WES, or WGP through its investment in WES, exercises significant influence are accounted for under the equity method. WGP proportionately consolidates WES’s 33.75% share of the assets, liabilities, revenues and expenses attributable to the Non-Operated Marcellus Interest and Anadarko-Operated Marcellus Interest (see Note 2) and WES’s 50% share of the assets, liabilities, revenues and expenses attributable to the Newcastle system in the accompanying consolidated financial statements.

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WESTERN GAS EQUITY PARTNERS, LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(UNAUDITED)

1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED)

The consolidated financial results of WES are included in WGP’s consolidated financial statements due to WGP’s 100% ownership interest in WES GP and WES GP’s control of WES. Throughout these notes to consolidated financial statements, and to the extent material, any differences between the consolidated financial results of WGP and WES are discussed separately. WGP has no independent operations or material assets other than its partnership interests in WES. WGP’s consolidated financial statements differ from those of WES primarily as a result of (i) the presentation of noncontrolling interest ownership in WGP (attributable to the limited partner interests in WES held by the public and Anadarko Marcellus Midstream, L.L.C. (“AMM”) (see Note 2)), (ii) the elimination of WES GP’s investment in WES with WES GP’s underlying capital account, and (iii) income tax expense and liabilities incurred by WGR Holdings, LLC, computed on a separate-return basis prior to its conversion into a limited partnership.

In preparing financial statements in accordance with GAAP, management makes informed judgments and estimates that affect the reported amounts of assets, liabilities, revenues, and expenses. Management evaluates its estimates and related assumptions regularly, utilizing historical experience and other methods considered reasonable under the particular circumstances. Changes in facts and circumstances or additional information may result in revised estimates and actual results may differ from these estimates. Effects on the business, financial condition and results of operations resulting from revisions to estimates are recognized when the facts that give rise to the revision become known. The information furnished herein reflects all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the consolidated financial statements, and certain prior-period amounts have been reclassified to conform to the current-year presentation.

For the three months ended March 31, 2012, operating cash inflows and investing cash outflows in the unaudited consolidated statements of cash flows include a reduction of $14.0 million attributable to the correction of an error discovered during analysis of accounts payable balances. This analysis revealed that certain 2012 invoices received, but not yet paid, were properly attributable to WES’s ongoing capital projects rather than to operating expenses. Management concluded that this misstatement was not material relative to the three months ended March 31, 2012, and has corrected the error within the unaudited statement of cash flows for the three months ended March 31, 2012, as included in this report.

Certain information and note disclosures commonly included in annual financial statements have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Accordingly, the accompanying consolidated financial statements and notes should be read in conjunction with WGP’s 2012 Form 10-K, as filed with the SEC on March 28, 2013. Management believes that the disclosures made are adequate to make the information not misleading.

Noncontrolling interests. The interests in Chipeta Processing LLC (“Chipeta”) held by a third-party member and the publicly held limited partner interests in WES are reflected as noncontrolling interests in the consolidated financial statements for all periods presented.

Chipeta. In July 2009, WES acquired a 51% interest in Chipeta and became party to Chipeta’s limited liability company agreement (the “Chipeta LLC agreement”). On August 1, 2012, WES acquired Anadarko’s then remaining 24% membership interest in Chipeta (the “additional Chipeta interest”). Prior to this transaction, the interests in Chipeta held by Anadarko and a third-party member were reflected as noncontrolling interests in the consolidated financial statements. The acquisition of Anadarko’s then remaining 24% interest was accounted for on a prospective basis as WES acquired an additional interest in an already-consolidated entity. As such, effective August 1, 2012, noncontrolling interest excludes the financial results and operations of the additional Chipeta interest. The remaining 25% membership interest held by the third-party member is reflected within noncontrolling interests in the consolidated financial statements for all periods presented. See Note 2.

WES. The publicly held limited partner interests in WES are reflected as noncontrolling interests in the consolidated financial statements for all periods presented. In addition, in March 2013, WES acquired a 33.75% interest in both the Liberty and Rome gas gathering systems from AMM, a wholly owned subsidiary of Anadarko Petroleum Corporation. As part of the consideration paid, WES issued 449,129 WES common units to AMM. The limited partner interest in WES held by AMM is reflected within noncontrolling interests in the consolidated financial statements for the three months ended March 31, 2013. See Note 2.

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WESTERN GAS EQUITY PARTNERS, LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(UNAUDITED)

1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED)

Presentation of WES assets. References to “WES assets” refer collectively to the assets indirectly owned by WGP, through its partnership interests in WES, as of March 31, 2013. Because Anadarko controls WES through its ownership and control of WGP, which owns WES GP, each of WES’s acquisitions of assets from Anadarko has been considered a transfer of net assets between entities under common control. As such, WES assets acquired from Anadarko were initially recorded at Anadarko’s historic carrying value, which did not correlate to the total acquisition price paid by WES. Further, after an acquisition of assets from Anadarko, WES and WGP (by virtue of its consolidation of WES) may be required to recast their financial statements to include the activities of such assets as of the date of common control. See Note 2.

For those periods requiring recast, the consolidated financial statements for periods prior to the acquisition of WES assets from Anadarko, including the Non-Operated Marcellus Interest, have been prepared from Anadarko’s historical cost-basis accounts and may not necessarily be indicative of the actual results of operations that would have occurred if WES had owned the assets during the periods reported. Net income attributable to WES assets for periods prior to WES’s acquisition of such assets is not allocated to the limited partners for purposes of calculating net income per common unit.

2. ACQUISITIONS

The following table presents the acquisitions completed by WES during 2013 and 2012, and identifies the funding sources for such acquisitions:

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WESTERN GAS EQUITY PARTNERS, LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(UNAUDITED)

2. ACQUISITIONS (CONTINUED)

Non-Operated Marcellus Interest acquisition. Because the Non-Operated Marcellus Interest acquisition was a transfer of net assets between entities under common control, WGP’s historical financial statements include the results attributable to the Non-Operated Marcellus Interest as if WES owned such assets for all periods presented. The consolidated financial statements for periods prior to WES’s acquisition of WES assets from Anadarko, including the Non-Operated Marcellus Interest, have been prepared from Anadarko’s historical cost-basis accounts and may not necessarily be indicative of the actual results of operations that would have occurred if WES had owned the assets during the periods reported.

The following table presents the impact to the historical consolidated statements of income attributable to the Non-Operated Marcellus Interest, including the elimination of intercompany activity between such assets:

Anadarko-Operated Marcellus Interest acquisition. The Anadarko-Operated Marcellus Interest acquisition has been accounted for under the acquisition method of accounting. The assets acquired and liabilities assumed in the Anadarko-Operated Marcellus Interest acquisition were recorded in the consolidated balance sheet at their estimated fair values as of the acquisition date. Results of operations attributable to the Anadarko-Operated Marcellus Interest were included in the consolidated statements of income beginning on the acquisition date in the first quarter of 2013.

The following is a preliminary allocation of the purchase price as of March 31, 2013, including $0.5 million of post-closing purchase price adjustments, to the assets acquired and liabilities assumed in the Anadarko-Operated Marcellus Interest acquisition as of the acquisition date:

The purchase price allocation is based on an assessment of the fair value of the assets acquired and liabilities assumed in the Anadarko-Operated Marcellus Interest acquisition. The fair values of the interests in the land, right-of-way contracts, and gathering systems were based on the market and income approaches. All fair-value measurements of assets acquired and liabilities assumed are based on inputs that are not observable in the market and thus represent Level 3 inputs. The current purchase price allocation is preliminary and is subject to change pending post-closing purchase price adjustments; finalization of fair value estimates; and completion of evaluations of property, plant and equipment, asset retirement obligations, contractual arrangements and legal and environmental matters as additional information becomes available and is assessed by WES.

The following tables present the pro forma condensed financial information as if the Anadarko-Operated Marcellus Interest acquisition had occurred on January 1, 2012:

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WESTERN GAS EQUITY PARTNERS, LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(UNAUDITED)

2. ACQUISITIONS (CONTINUED)

The pro forma information is presented for illustration purposes only and is not necessarily indicative of the operating results that would have occurred had the Anadarko-Operated Marcellus Interest acquisition been completed at the assumed date, nor is it necessarily indicative of future operating results of the combined entity. The pro forma information in the table above includes $0.7 million of revenues and $0.1 million of operating expenses, excluding depreciation, amortization and impairments, attributable to the Anadarko-Operated Marcellus Interest that are included in the consolidated statement of income for the three months ended March 31, 2013. The pro forma adjustments reflect pre-acquisition results of the Anadarko-Operated Marcellus Interest including (a) estimated revenues and expenses; (b) estimated depreciation and amortization based on the purchase price allocated to property, plant and equipment and estimated useful lives; and (c) interest on borrowings under WES’s revolving credit facility to finance the Anadarko-Operated Marcellus Interest acquisition. The pro forma adjustments include estimates and assumptions based on currently available information. Management believes the estimates and assumptions are reasonable, and the relative effects of the transaction are properly reflected. The pro forma information does not reflect any cost savings or other synergies anticipated as a result of the Anadarko-Operated Marcellus Interest acquisition, nor any future acquisition related expenses.

3. PARTNERSHIP DISTRIBUTIONS

WGP partnership distributions. WGP’s partnership agreement requires it to distribute all of its available cash (as defined in WGP’s partnership agreement) to WGP unitholders of record on the applicable record date within 55 days of the end of each quarter, beginning with the quarter ended December 31, 2012.

On February 21, 2013, WGP paid a prorated quarterly distribution of $0.03587 per common unit, or $7.9 million in aggregate, to WGP unitholders of record at the close of business on February 1, 2013. This was the first distribution declared by the board of directors of WGP GP and was prorated for the 20-day period from the date of the closing of WGP’s IPO on December 12, 2012, through the end of the fourth quarter 2012, pursuant to the terms of WGP’s partnership agreement. In addition, on April 17, 2013, the board of directors of WGP GP declared a cash distribution to WGP unitholders of $0.17875 per common unit, or $39.1 million in aggregate, for the first quarter of 2013. The distribution is payable on May 22, 2013, to WGP unitholders of record at the close of business on April 30, 2013.

WES partnership distributions. WES’s partnership agreement requires WES to distribute all of its available cash (as defined in WES’s partnership agreement) to WES unitholders of record on the applicable record date within 45 days of the end of each quarter. The board of directors of WES GP declared the following cash distributions to WES unitholders for the periods presented:

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WESTERN GAS EQUITY PARTNERS, LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(UNAUDITED)

4. EQUITY AND PARTNERS’ CAPITAL

Holdings of WGP equity. WGP’s common units are listed on the New York Stock Exchange under the symbol “WGP.” As of March 31, 2013, Anadarko held 199,137,365 WGP common units, representing a 91.0% limited partner interest in WGP. The public held 19,758,150 WGP common units, representing a 9.0% limited partner interest in WGP.

Net income per common unit. Net income attributable to periods prior to WGP’s IPO is attributable to subsidiaries of Anadarko and therefore not allocated to the limited partners for purposes of calculating net income per common unit. As a result, pre-IPO net income, representing the financial results prior to WGP’s IPO on December 12, 2012, has been excluded from the limited partners’ interest in net income.

Holdings of WES equity. As of March 31, 2013, WGP held 49,296,205 WES common units, representing a 46.0% limited partner interest in WES, and, through its ownership of WES GP, WGP indirectly held 2,145,096 general partner units, representing a 2.0% general partner interest in WES, and 100% of WES’s IDRs.

As of March 31, 2013, AMM, a subsidiary of Anadarko, held 449,129 WES common units, representing a 0.4% limited partner interest in WES, and the public held 55,364,348 WES common units, representing a 51.6% limited partner interest in WES, which are reflected as noncontrolling interests within the consolidated financial statements of WGP (see Note 1 and Note 2).

WES public equity offerings. In June 2012, WES closed a public offering of 5,000,000 common units at a price of $43.88 per unit. In connection with this offering, WES issued 102,041 general partner units to WES GP in exchange for WES GP’s proportionate capital contribution to maintain its 2.0% general partner interest. Net proceeds to WES from the offering of $216.4 million were used for general partnership purposes, including the funding of capital expenditures.

WES common and general partner units. The following table summarizes WES common and general partner units issued during the three months ended March 31, 2013:

5. TRANSACTIONS WITH AFFILIATES

Affiliate transactions. Revenues from affiliates include amounts earned by WES from services provided to Anadarko as well as from the sale of residue, condensate and NGLs to Anadarko. In addition, WES purchases natural gas from an affiliate of Anadarko pursuant to gas purchase agreements. Operating and maintenance expense includes amounts accrued for or paid to affiliates for the operation of the WES assets, whether in providing services to affiliates or to third parties, including field labor, measurement and analysis, and other disbursements. A portion of general and administrative expenses is paid by Anadarko, which results in affiliate transactions pursuant to the reimbursement provisions of the omnibus agreements of WES and WGP. Affiliate expenses do not bear a direct relationship to affiliate revenues, and third-party expenses do not bear a direct relationship to third-party revenues. See Note 2 for further information related to contributions of assets to WES by Anadarko.

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WESTERN GAS EQUITY PARTNERS, LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(UNAUDITED)

5. TRANSACTIONS WITH AFFILIATES (CONTINUED)

Cash management. Anadarko operates a cash management system whereby excess cash from most of its subsidiaries’ separate bank accounts is generally swept to centralized accounts. Prior to the acquisitions of WES assets, third-party sales and purchases related to such assets were received or paid in cash by Anadarko within its centralized cash management system. Anadarko charged or credited WES interest at a variable rate on outstanding affiliate balances for the periods these balances remained outstanding. The outstanding affiliate balances were entirely settled through an adjustment to net investment by Anadarko in connection with the acquisition of the WES assets. Subsequent to the acquisition of the WES assets from Anadarko, transactions related to such assets are cash-settled directly with third parties and with Anadarko affiliates, and affiliate-based interest expense on current intercompany balances is not charged. Chipeta cash settles its transactions directly with third parties and Anadarko, as well as with the other subsidiaries of WES.

Note receivable from and amounts payable to Anadarko. Concurrently with the closing of WES’s May 2008 IPO, WES loaned $260.0 million to Anadarko in exchange for a 30-year note bearing interest at a fixed annual rate of 6.50%, payable quarterly. The fair value of the note receivable from Anadarko was approximately $326.0 million and $334.8 million at March 31, 2013, and December 31, 2012, respectively. The fair value of the note reflects consideration of credit risk and any premium or discount for the differential between the stated interest rate and quarter-end market interest rate, based on quoted market prices of similar debt instruments. Accordingly, the fair value of the note receivable from Anadarko is measured using Level 2 inputs.

In 2008, WES entered into a five-year $175.0 million term loan agreement with Anadarko, which was repaid in full in June 2012 using the proceeds from the issuance of 4.000% Senior Notes due 2022. See Note 8.

During the first quarter of 2012, the board of directors of WES GP approved the continued construction by WES of the Brasada and Lancaster gas processing facilities in South Texas and Northeast Colorado, respectively, which were previously under construction by Anadarko. WES agreed to reimburse Anadarko for $18.9 million of certain expenditures Anadarko incurred in 2011 related to the construction of the Brasada and Lancaster plants. In February 2012, these expenditures were transferred to WES and a corresponding current payable was recorded, which was repaid during the fourth quarter of 2012.

Commodity price swap agreements. WES has commodity price swap agreements with Anadarko to mitigate exposure to commodity price volatility that would otherwise be present as a result of the purchase and sale of natural gas, condensate or NGLs. Notional volumes for each of the commodity price swap agreements are not specifically defined; instead, the commodity price swap agreements apply to the actual volume of natural gas, condensate and NGLs purchased and sold at the Granger, Hilight, Hugoton, Newcastle, MGR and Wattenberg assets, with various expiration dates through December 2016. The commodity price swap agreements do not satisfy the definition of a derivative financial instrument and, therefore, are not required to be measured at fair value. WES has not entered into any new commodity price swap agreements since the fourth quarter of 2011.

Below is a summary of the fixed price ranges on WES’s outstanding commodity price swap agreements as of March 31, 2013:

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WESTERN GAS EQUITY PARTNERS, LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(UNAUDITED)

5. TRANSACTIONS WITH AFFILIATES (CONTINUED)

The following table summarizes realized gains and losses on commodity price swap agreements:

Gas gathering and processing agreements. WES has significant gas gathering and processing arrangements with affiliates of Anadarko on a majority of its systems. Approximately 60% and 66% of WES’s gathering, transportation and treating throughput (excluding equity investment throughput and volumes measured in barrels) for the three months ended March 31, 2013 and 2012, respectively, was attributable to natural gas production owned or controlled by Anadarko. Approximately 55% and 57% of WES’s processing throughput (excluding equity investment throughput and volumes measured in barrels) for the three months ended March 31, 2013 and 2012, respectively, was attributable to natural gas production owned or controlled by Anadarko.

Equipment purchases. The following summarizes WES’s purchases of pipe and equipment from Anadarko:

Western Gas Equity Partners, LP 2012 Long-Term Incentive Plan (“WGP LTIP”). During the three months ended March 31, 2013, WGP GP awarded phantom units under the WGP LTIP to its independent directors, which will vest one year from grant date in January 2014. Compensation expense is recognized over the vesting period and was approximately $53,000 for the three months ended March 31, 2013.

Western Gas Partners, LP 2008 Long-Term Incentive Plan (“WES LTIP”). WES GP awards phantom units under the WES LTIP primarily to the Chief Executive Officer and its independent directors. The phantom units awarded to the independent directors vest one year from the grant date, while all other awards are subject to graded vesting over a three-year service period. Compensation expense is recognized over the vesting period and was approximately $0.1 million for the three months ended March 31, 2013 and 2012.

Equity incentive plan and Anadarko incentive plans. General and administrative expenses include equity-based compensation costs allocated by Anadarko for grants made pursuant to (i) the Western Gas Holdings, LLC Equity Incentive Plan, as amended and restated (the “Incentive Plan”) and (ii) the Anadarko Petroleum Corporation 2008 and 2012 Omnibus Incentive Compensation Plans (“Anadarko Incentive Plans”).

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WESTERN GAS EQUITY PARTNERS, LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(UNAUDITED)

5. TRANSACTIONS WITH AFFILIATES (CONTINUED)

For the three months ended March 31, 2013 and 2012, general and administrative expenses include $0.7 million and $0.8 million, respectively, of equity-based compensation expense for awards granted to the executive officers of WES GP and other employees under the Anadarko Incentive Plans, which was allocated by Anadarko.

For the three months ended March 31, 2012, general and administrative expenses include $3.3 million of compensation expense for grants of Unit Value Rights, Unit Appreciation Rights (“UARs”) and Distribution Equivalent Rights under the Incentive Plan to certain executive officers of WES GP as a component of their compensation, which was allocated to WES by Anadarko. Awards outstanding under the Incentive Plan at March 31, 2012, were valued at $718.00 per UAR. WGP’s IPO in December 2012 resulted in the vesting of all then unvested Incentive Plan awards and the effective termination of the Incentive Plan.

Capital expenditures transfer. As described in Note receivable from and amounts payable to Anadarko within this Note 5, Anadarko incurred certain expenditures related to the construction of the Brasada and Lancaster gas processing facilities during 2011. These amounts, along with related capitalized interest, were transferred to WES in the first quarter of 2012, and are included in the balance of property, plant and equipment as of March 31, 2013 and December 31, 2012. See Note 6.

Summary of affiliate transactions. Affiliate transactions include revenue from affiliates, reimbursement of operating expenses and purchases of natural gas. The following table summarizes affiliate transactions, including transactions with Anadarko, its affiliates, WGP GP and WES GP:

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WESTERN GAS EQUITY PARTNERS, LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(UNAUDITED)

5. TRANSACTIONS WITH AFFILIATES (CONTINUED)

Concentration of credit risk. Anadarko was the only customer from whom revenues exceeded 10% of consolidated revenues for all periods presented on the consolidated statements of income.

6. PROPERTY, PLANT AND EQUIPMENT

A summary of the historical cost of property, plant and equipment is as follows:

The cost of property classified as “Assets under construction” is excluded from capitalized costs being depreciated. These amounts represent property that is not yet suitable to be placed into productive service as of the respective balance sheet date. See Note 7.

7. COMPONENTS OF WORKING CAPITAL

A summary of other current assets is as follows:

A summary of accrued liabilities is as follows: