Silica Sand Supply Agreement

„We are pleased to announce our agreement with U.S. Silica, which Pioneer will provide for the foreseeable future to inexpensive West Texas sands,“ said Timothy Dove, President and CEO of Pioneer Natural Resources. „Strategically located near our Midland Basin area, the sand delivered from the Lamesa mine will cost about half of our currently delivered sands, reducing the cost of the well through 2019 and beyond. The long-term nature of this agreement will benefit both companies. U.S. Silica is a major commercial silica manufacturer, which is used in the oil and gas industry and in a variety of industrial applications with headquarters in Katy, Texas, and with offices in Chicago, Illinois, and Frederick, Maryland. For more information on American silica, visit www.ussilica.com. According to Pioneer, the Lamesa mine is expected to produce about 6 million tonnes per year, mainly finely finely 100 mesh and 40/70 mesh sands, with initial production expected in the fourth quarter of 2018. Pioneer also expects the first volume of sand to increase in the first quarter of 2019, from about 1.4 million tonnes in 2019 to 2 million tonnes in 2020 and beyond.

Select Sands President and CEO Zig Vitols said: „Our strategy of making more efficient use of Eagle Ford`s operators and printing pumps with our new recharging capabilities at George West is a success with the signing of this contract with this bigwig exploration and production company. This delivery contract will provide Select Sands with guaranteed minimum purchases from our proppant, while the operator will have reliable and quality support near their wells, which will allow them to save money on the last kilometre. By signing this agreement, the two companies ensure that 100 high-quality Northern Mesh White Sand are used to achieve production results that seek successful exploration and production companies. We are very pleased to announce this multi-year contract and look forward to starting to deliver our sands in January 2020. We continue to focus on ensuring other potential opportunities in all basins for our high quality white sand. Pioneer Natural Resources entered into a long-term sand supply contract with Us-Silica and purchased a stake in the Us-Silica sand reserves at its Lamesa mine in West Texas. Joe O`Rourke Director of Sales Phone: 713-689-8000 Joe.orourke@selectsands.com „What is unique, Very Long Term Contract on our new lamesa site offers significant value to both Perm companies and clearly aligns with our stated goal of achieving a sustainable and predictable return on free cash flow from our oil and gas assets,“ said Bryan Shinn, President and CEO of U.S. Silica. DALLAS— (BUSINESS WIRE)–sep. 11, 2018– Pioneer Natural Resources Company (NYSE: PXD) („Pioneer“) and U.S. Silica Holdings, Inc. (NYSE: SLCA) („U.S. Silica“) announced today that the companies have entered into a long-term sand delivery agreement with which Pioneer will acquire a stake in U.S.

dollars.