Mac Marshall focuses on a wide range of energy-related projects located onshore, offshore, upstream, midstream, and internationally. His extensive portfolio of work with energy industry clients includes the following:

  • Acquisitions and divestitures of producing and non-producing oil and gas properties
  • Acquisitions, divestitures, construction and financing of pipelines, gathering systems and storage facilities for natural gas, crude oil, condensate, and natural gas liquids
  • Oil and gas joint ventures and exploration and development programs
  • Exploration and development project agreements including joint operating agreements, COPAS accounting procedures
  • Exploration and development agreements and joint operating agreements
  • Natural gas purchase, sales and marketing agreements and NAESB agreements
  • Natural gas gathering, processing and treating agreements, oil and gas transportation agreements, and related midstream agreements
  • Gas storage agreements
  • Bankruptcy asset sales and restructurings
  • Production handling agreements
  • Master service agreements and drilling contracts
  • Hedging agreements
  • Seismic data licenses and acquisition agreements

Mac also represents lenders and borrowers in a wide variety of conventional and mezzanine energy financings and related secured transactions, including reserve-based lending and revolving and term credit facilities.

Mac is Board Certified by the Texas Board of Legal Specialization in Oil, Gas and Mineral Law.

  • Board Certified - Oil Gas Mineral
  • 2022 Chambers Global



J.D., University of Houston Law Center, 2006

Houston Journal of International Law, Editorial Board

B.A., Vanderbilt University, Economics, magna cum laude, 2001





Mac Marshall’s representations have included the following:

  • A Japanese conglomerate in a $1.4 billion venture with a major U.S. oil and gas company to jointly explore for and develop natural gas in the Marcellus Shale.
  • A large US exploration company in an approximate $3.2 billion Marcellus Shale joint venture (including acquiring a related gathering company and structuring gathering agreements).
  • A major Eagle Ford Shale exploration company in negotiating gathering, processing, transportation, treating, and related agreements for its Eagle Ford shale joint venture acreage originally acquired for $1.325 billion.
  • A major Marcellus Shale exploration company in restructuring gas gathering and processing agreements for acreage originally acquired in an $11 billion merger.
  • Texas-based exploration and production companies in disposing of their interests in Colombian concession agreements.
  • A private equity company in a $400 million venture with a major U.S. oil and gas company to jointly explore for and develop natural gas in the Eagle Ford Shale Formation.
  • Numerous oil and gas exploration companies in establishing and funding joint ventures and partnerships for oil and gas exploration and development projects.
  • Numerous oil and gas producing companies in acquiring and divesting onshore and offshore producing oil and gas properties.
  • A refining company in structuring a $500 million crude feedstock supply agreement for a refinery in Hawaii.
  • An agent bank in gas storage project financing.
  • Commercial banks in producer financings in excess of $500 million secured by onshore and offshore producing oil and gas properties.
  • The agent bank in a $900 million syndicated credit facility for a pipeline company.
  • The agent bank in a $375 million syndicated credit facility for a refining company.




State Bar of Texas, Member

Houston Bar Association, Member

Houston Young Lawyers Association, Member

Vanderbilt Alumni Association, Member

Houston Livestock Show & Rodeo, Member

Boy Scouts of America, Eagle Scout