Leadership Team

C. Susan Howes is President of SCA where she enables organizations to strengthen
decision quality and subsurface capability. She brings extensive leadership experience
from Anadarko and Chevron across reservoir engineering, business development,
human resources, organizational capability, and reservoir management. An active
leader in SPE and a recognized industry volunteer, including serving as 2027 SPE
President, Susan also serves on several academic advisory boards. She holds a BS in
petroleum engineering, cum laude, from The University of Texas at Austin.

Hal Miller is the Chairman of Subsurface Consultants & Associates, LLC’s Board of Directors after serving as President for 10 years. During that time, he was responsible for managing SCA’s global operations and guiding the company’s strategic direction. Prior to joining SCA in 2004 as Vice President of Operations, Hal spent a total of 26 years working at Conoco and ConocoPhillips. He held a variety of positions including operations, exploration, and human resource management at the business unit level, and corporate level skills management for the geoscience and reservoir engineering disciplines. Hal received his undergraduate degree in 1974 from Williams College in Massachusetts and his M.S. in Geology in 1977 from the University of Colorado, where he serves on the Department of Geosciences Advisory Board.

Matt joined SCA in 2012 and is currently Director of Finance, overseeing the firm’s accounting, financial operations, payroll, and regulatory documentation.  He also contributes to SCA’s marketing efforts through the creation of branded materials.  Matt earned a BBA in Finance from Baylor University and is a member of Pi Kappa Phi Fraternity and Beta Gamma Sigma honor society.

Matthew Nowak has been active in the oil and gas industry since 2000. He joined SCA in 2006 as a Business Development Manager and currently serves as Vice President of Business Development, overseeing sales and recruiting initiatives while leading the promotion of SCA’s internal Projects & Studies teams. Matthew holds a Bachelor’s degree in Marketing from Texas A&M University.

Tim joined SCA in 2008 and currently serves as Vice President of Recruiting and Director of Business Development.  Tim manages recruiting and sales operations tailored to SCA's core strengths.  He maintains strong professional ties with a massive network of independent geological and engineering experts, connecting clients to SCA’s tailored solutions including direct hire staffing, internal & external consulting projects, and specialized training programs. Tim earned his business degree from Texas Lutheran University.

Deborah Ryan is Vice President of Engineering at Subsurface Consultants & Associates LLC, where she leads petroleum engineering and carbon management engagements and serves as SCA's internal lead on engineering and decarbonization projects. Prior to SCA, Ryan was a Partner at MHA Petroleum Consultants and Senior Manager at Sproule, where she focused on reserves and resources evaluations, fair market value assessments, litigation support, reservoir simulation, field studies, and teaching.

Ryan's carbon management background spans both industry and academia. She held roles at S&P Global focused on carbon and commodity markets, and teaches Carbon Markets for Business at the University of Colorado Denver. Ryan holds a BS in Chemical Engineering and an MS in Petroleum Engineering, both from Curtin University in Perth, and an MBA from Penn State University. She is a Licensed Professional Engineer (P.E.) in Colorado and Texas.

Vanessa Mills is an oil and gas sourcing and recruiting specialist with over 20 years of experience supporting the energy industry. Her expertise spans recruiting across geoscience, petroleum engineering, land, legal and other professional support functions. Vanessa is known for building strong candidate relationships and identifying top talent for specialized and hard-to-fill positions.

Tricia is an HR Manager with a strong background in organization, coordination and process development.  After an extended career pause, she returned to the workforce joining SCA with a fresh perspective and a passion for supporting both people and business operations.  She is excited to work alongside the SCA team and contribute to the company’s commitment to strengthening capabilities and delivering value across the energy industry.

Brandon Wright is Business Development Manager at SCA, bringing more than a decade of experience spanning business development, recruiting, and client relationship management. With a background studying Geological and Earth Sciences at Trinity University, Brandon combines an understanding of the geosciences with extensive experience connecting clients with technical talent and solutions across the energy industry.