Our History
Diamond Testing, LLC has been a family-owned and operated drill stem testing company since 1982. Roger Friedly (deceased) 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 4 trucks and stands as one of the oldest and largest drill stem testing companies operating in the United States.
Roger began his oilfield career by following in his father’s footsteps, working as a roughneck for several oilfield companies throughout Kansas in the 1970's before starting Diamond Testing. With the oilfield coursing through their veins, Roger and Joree dedicated the better part of a half-century to Diamond Testing and its oilfield customers, a journey together that culminated in early 2026 with Roger's passing. Diamond Testing continues operations under Joree's ownership, ensuring that our testers and managment team can continue to serve old and new customers alike with class-leading drill stem testing services.
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 superior drill stem testing services and an enhanced experience to our valued customers, now and in the future. Come discover the Diamond difference!