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About NSAI

Netherland, Sewell & Associates, Inc. (NSAI) is a worldwide leader of petroleum property analysis for industry and financial organizations and government agencies. We deliver high quality, fully integrated engineering, operational, geological, geophysical, petrophysical, and economic solutions for all facets of the upstream energy industry.

Established in 1961
Offices in Dallas and Houston, Texas
55+ Engineers, Geologists, Geophysicists, and Petrophysicists
70+ Engineering and Geology Analysts
Expertise in most producing basins worldwide
Well known within the oil & gas and financial communities
Chosen by more companies for their SEC reserves reporting than any other petroleum consulting firm
Focused on building client relationships and delivering exceptional service

Our Story

Clarence Netherland and Fred Sewell

Clarence Netherland and Fred Sewell

In 1961 Clarence Netherland started his own petroleum consulting firm, and decided from the outset that it would be the top organization of its kind in the world. He handpicked each employee with the right combination of experience, technical skills, and professional judgment. He knew that relationships built on trust would be the key to our success, and developed a culture based on serving the needs of our clients and the financial community.

One of Clarence’s favorite sayings was “Methods are many, principles are few. Methods change often, but principles never do.” Throughout his career spanning many decades in the oil and gas industry, he held firm to the principle that we would never compromise on integrity, and that we would always strive to provide the best product at a fair price while providing trusted results and exceptional service.

When Clarence decided, in 1969, that he needed some help with his growing consulting business, he turned to his friend Fred Sewell. He knew that Fred had a head for business, and that he embodied the spirit and ethics that Clarence had built the business on. When Fred joined NSAI it had fewer than six employees, and when he retired in 2008 they had grown the firm into the most respected global upstream petroleum organization in the world. Fred was instrumental in developing the firm’s business model, the concept of teamwork and integration, and the “core values” that permeate the company today. His emphasis on reputation and respect served both our clients and our employees well.

Today, we provide services to the worldwide petroleum industry that include reserves reports and audits, acquisition and divestiture evaluations, simulation studies, exploration resources assessments, equity determinations, and management and advisory services. Although technologies and methodologies have changed over time and will continue to evolve, we recognize that professional expertise, sound judgment, integrity, and top quality service are always valued.

When you need expert petroleum consulting services and reliable reserve reports that are well respected by the financial community, contact NSAI.

I believe, as Clarence and Fred before me, that what sets us apart is our people. Time and again I see our team rise to meet any challenge. Whether it’s a quick look at an acquisition or a complex technical study conducted over several months, we devote the right combination of expertise, resources, and judgment to get to the right answer. We consider it a point of pride that many of our clients keep us involved in multiple aspects of their business and call on us throughout the year for advice on reserves issues, to talk through their latest development plan, or maybe just get our opinion on a certain field or reservoir. We work hard to establish those relationships. Our clients know there is a difference in consulting firms. And those in the financial community know that a Netherland Sewell report means unquestionable quality and reliability.”

– Scott Rees, Executive Chairman