----

|        | Occidental Energy Marketing, Inc.A subsidiary of Occidental Petroleum Corporation | 5 Greenway Plaza, Suite 110, Houston, Texas 77046-0521P. O. Box 27570, Houston, Texas 77227-7570Phone 713.215.7000 |
|--------|-----------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------|
|   |                                                                              |

| TO:    | Pioneer Natural Resources USA, Inc.                                      |                    |
|--------|--------------------------------------------------------------------------|-------------------------|
|   | Attn: Contract Management ServicesFax: (972) 969-3574Trader: Deb Stewart |                    |
|   |                                                                     |                    |
| FROM:  | Occidental Energy Marketing, Inc.                                        |                    |
|   | Trader: Mark Hafner                                                      |                    |
|   |                                                                     |                    |
| RE:    | Occidental Contract # 1101-PNR-176641-P                                  | Amendment  #1 |

|   | This Amendment Number 1 to the Crude Oil Contract between Occidental Energy Marketing, Inc. (“OEMI”) and Pioneer Natural Resources USA, Inc. (“Counterparty”) dated January, 2011 (the “Contract”) is entered into as of January 17, 2011. |
|--------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|   |                                                                                                                                                                                                                                                                           |
|   | For good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged and agreed, the Parties agree that the Contract is hereby amended effective January 1, 2011 as set forth below.                                                              |
|   |                                                                                                                                                                                                                                                                           |
|   | Add the Elizabeth Shoemaker 39 #1 R & 40 1 lease to the contract and Exhibit “A”.                                                                                                                                                                              |
|   |                                                                                                                                                                                                                                                                           |
|   | All other terms of the agreement are unchanged.                                                                                                                                                                                                                                |
|   |                                                                                                                                                                                                                                                                           |
|   | Agreed to and approved by:                                                                                                                                                                                                                                                     |
|   | OEMI                                                                                                                                                                                                                                                                           |
|   |                                                                                                                                                                                                                                                                           |
|   |                                                                                                                                                                                                                                                                                |   |
|   | Mark Hafner                                                                                                                                                                                                                                                                    |
|   | Director, Crude Oil Acquisitions                                                                                                                                                                                                                                               |
|   |                                                                                                                                                                                                                                                                           |
|   | Agreed to and approved by:                                                                                                                                                                                                                                                     |
|   | Pioneer Natural Resources USA, Inc.                                                                                                                                                                                                                                            |
|   |                                                                                                                                                                                                                                                                           |
|   |                                                                                                                                                                                                                                                                                |   |
|   | Hershal K. WolfeVice President Marketing                                                                                                                                                                                                                                       |   |

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| INTERFACE        |   | PRODUCT |   | OPERATOR                            |   | LEASE NAME                           |   | LEASE EFFECTIVEDATE |   | CONTROLLED%  |   | COUNTY |   | STATE  |   | TRANSPORTER |   | DELTA  |   | DELTAEFFECTIVEDATE |   | CONTRACT |   |   PRICE INDEX          |
|------------------|--------|---------|--------|-------------------------------------|--------|--------------------------------------|--------|---------------------|--------|--------------|--------|--------|--------|--------|--------|-------------|--------|--------|--------|--------------------|--------|----------|--------|----------------------------------|
|             |   |    |   |                                |   |                                 |   |                |   |         |   |   |   |   |   |        |   |   |   |               |   |     |   |                             |
| 742093480000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ABRAXAS 27                           |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093410000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ABRAXAS 27A                          |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093420000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ABRAXAS 28.28C CONSOL                |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093430000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ABRAXAS 28A/SLAUGHTER 19D.29A        |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093440000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ABRAXAS 30                           |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093470000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ABRAXAS 30B                          |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093450000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ABRAXAS 31                           |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093460000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ABRAXAS 32A CONSOL                   |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093990000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ALDWELL K 2                          |   | 1/1/2011            |   | 100.00000000 |   | REAGAN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 74209400000PNTS  |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ALDWELL K 45                         |   | 1/1/2011            |   | 100.00000000 |   | REAGAN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094010000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ALDWELL L & M                    |   | 1/1/2011            |   | 100.00000000 |   | REAGAN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093490000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ALLAR 11                             |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093500000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ALLAR 17A/WHEELER 17                 |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093510000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ALLAR 19                             |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093520000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ALLAR 27                             |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093530000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ALLAR 3                              |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093540000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ALLAR 37                             |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093550000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ARICK 34                             |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093560000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | CHIEFTAN/RAMSEY WL                   |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094460000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ELIZABETH SHOEMAKER 39 #1R& 40 1 |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093570000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ELLIS 8                              |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094030000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | H F NEAL                             |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094060000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | HACIENDA                             |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093530000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | HARRISON                             |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093590000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | HERNANDEZ 20                         |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094040000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | JACK GARNER                          |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094050000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | LANE 11                              |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 74209360000PNTS  |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | LOUDER 18/SLATTON                    |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093610000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | LOUDER 33                            |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093620000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | MARTIN CONSOL                        |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093640000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | MCADAMS 10                           |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093630000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | MCCLANE                              |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093650000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | MCMORRIES 1                          |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093660000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | MCMORRIES 10                         |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093670000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | MCMORRIES 33                         |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093680000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | MEEK A                               |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093690000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | MEEK D                               |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093700000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | MEEK E CONSOL                        |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093710000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | MEEK F                               |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093720000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | OA DICKENSON/CASAGA                  |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093730000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ORSON E                              |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093740000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ORSON G                              |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093750000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ORSON HIJ                            |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093760000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ORSON K                              |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093770000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ORSON L                              |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093780000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | ORSON M                              |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094070000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | OWENS /VINA VANCE                    |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094120000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | OWENS L                              |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094130000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | PEMBROOK 26                          |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093790000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | PINKERTON                            |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094140000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | RATLIFF 6                            |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093800000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | RICHARDS 25                          |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093810000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | RICHARDS 44                          |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094080000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | RUBY                                 |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093820000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | SCOTT 28                             |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093880000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 6-16, 6-17                |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093890000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 6-25 & 6-25A          |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093900000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 6-39 & 6-45           |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093860000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 6-43 & 7-1            |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093970000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 7-11, 7-18                |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093920000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 7-15                      |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093930000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 7-22                      |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093940000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 7-23, 7-33                |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093950000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 7-29                      |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093980000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 7-39                      |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093960000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 7-41 & 7-43           |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093910000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNIVERSITY 7-6 & 7-8             |   | 1/1/2011            |   | 100.00000000 |   | ANDREW |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094090000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | UNRUH                                |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093830000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | VOGLER 13                            |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093840000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | VOGLER 14                            |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742093850000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | VOGLER 6                             |   | 1/1/2011            |   | 100.00000000 |   | MARTIN |   | TX     |   | OET Trucks  |   | $1.15  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094020000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | WHEELER STORAGE                      |   | 1/1/2011            |   | 100.00000000 |   | REAGAN |   | TX     |   | OET Trucks  |   | $1.29  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094100000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | WOOLEY 7                             |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |
| 742094110000PNTS |   | WTI     |   | Pioneer Natural Resources USA. Inc. |   | WOOLRIDGE 11                         |   | 1/1/2011            |   | 100.00000000 |   | UPTON  |   | TX     |   | OET Trucks  |   | $1.19  |   | 1/1/2011           |   | 176641   |   | XPA - Midland Sweet + 7%AWTSdiff |

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