Tanner Sykes is an associate in Mayer Brown’s Houston office and a member of the Corporate & Securities, Private Equity and Oil & Gas practices. He is experienced representing public and private oil and gas companies in acquisitions, divestitures, joint venture, farmout and participation agreements. He is also experienced in the development of oil and gas properties, oil and gas transportation and gathering agreements and other commercial transactions in the energy sector. 

Previously, he served as VP-Land & General Counsel for Sierra Resources, LLC.  While in this role, Sierra partnered with Post Oak Energy Capital and GSO Capital Partners in the acquisition, development and divestment of multiple oil and gas developments in the Gulf Coast Basin.

Tanner has extensive upstream oil and gas experience in most of the onshore US basins and with a deep understanding of all phases of oil and gas development, operations, regulatory compliance and financing. He is a Certified Professional Landman and began his career with El Paso Corp in 2007 where is served as Business Development Project Manager for EP Energy, LLC, the successor to El Paso Corp.


  • Divested a horizontally-developed Olmos field which was developed by Sierra Resource Partners, LP, to a private oil and gas operator in La Salle and McMullen Counties, Texas.
  • Acquired 55k-acre horizontal Wilcox development in Allen, Beauregard, Rapides, and Vernon Parishes, Louisiana.
  • Acquired producing properties from ConocoPhillips, Murphy Oil Corporation and Foundation Energy Management in La Salle and McMullen Counties, Texas.
  • Formed a DrillCo JV for EP Energy with Apollo-backed Wolfcamp Drillco in the Midland Basin.*
  • Acquired Eagle Ford assets from Goodrich Petroleum in Frio and La Salle Counties, Texas.*
  • Divested E&P assets of El Paso in Frio County, Texas to Blackbrush Oil and Gas.*

* denotes transactions conducted in a Landman capacity (and not as an attorney)



South Texas College of Law, JD

Texas Tech University, MA

Texas Tech University, BA


  • Texas


  • State Bar of Texas: Oil, Gas and Mineral Law Section
  • Houston Bar Association
  • American Association of Professional Landmen