Phillip G. Lancaster

Bronco Drilling Co., Inc. provides contract land drilling and workover services to independent oil and natural gas exploration and production companies throughout the United States. The company conducts its operations through two operating segments: Contract Land Drilling and Well Servicing. The Contract Land Drilling segment provides contract land drilling services. The Well Servicing segment encompasses a full range of services performed with a mobile well servicing rig, including the installation and removal of downhole equipment and elimination of obstructions in the well bore to facilitate the flow of oil and gas. The company was founded on June 1, 2001 and is headquartered in Edmond, OK.

Diamondback Energy Services, Inc. provides oil and natural gas exploration services. Its services include drilling, stimulation and pumping, fluid logistics, well completion, and production. The company's clients include Chesapeake Energy, EOG Resources, and Devon Energy. Diamondback Energy Services was founded in December 2005 and is headquartered in Oklahoma City, OK.

Oilfield Management Services LLC is a diversified oilfield service company. It provides horizontal drilling and well stimulation services primarily in the onshore unconventional tight sands and shale oil and natural gas. The company operates through two segments: Completion & Production Services and Horizontal & Directional Drilling Services. The Completion & Production Services segment provides pressure pumping and pressure control services. The Horizontal & Directional Drilling Services segment is designed to drill unconventional wells. The company was founded on September 29, 2005 and is headquartered in Oklahoma City, OK.

Mammoth Energy Partners LP provides oil and natural gas exploration services. The company was founded in February 2014 and is headquartered in Oklahoma City, OK.