Our History
Diamond Testing, LLC has been a family owned and operated drill stem testing company since 1982. Roger Friedly and his wife, Joree, started the company as a humble one truck operation with assets purchased from a company out of Ellinwood, KS. From there, together, they grew the company with the inevitable ebbs and flows of the oilfield, purchasing trucks, tools and accessories as needed throughout the subsequent decades as the business expanded. Today Diamond Testing proudly operates 5 trucks and stands as one of the largest drill stem testing companies operating in the central United States.
Roger began his oilfield career by following in his father’s footsteps, working as a roughneck for several oilfield companies throughout Kansas before starting Diamond Testing. With the oilfield coursing through his veins and his bloodline, he has naturally passed his love of the oilfield down to his daughter, Jennifer, and son-in-law, Jacob McCallie. Jacob started his career at Diamond Testing in 2011 working as a drill stem tester and now holds the position of General Manager for the company in charge of overall operations.
As the oldest continually operating DST company in the state, Diamond Testing has grown to service multiple states and hundreds of oil and gas producing customers all over the Midcontinent region. Through honesty, integrity, hard work and the dedication of its employees and management team, Diamond Testing continues to grow and thrive in this decade, providing and enhancing our services to our valued customers now and in the future.