Autry Stephens, the billionaire founder of Endeavor Energy Resources, has died aged 86, the company reported on Friday, after the man was diagnosed with cancer.

Stephens passed on during the early hours of Friday, according to a source who was privy to the information.

He had also been described as very hard-working and miserly; he continued to work while in hospital and was brought to Houston in a private aircraft by friends for cancer treatment.

How He Became One Of The Richest Oilman?

Stephens originally established a sole proprietorship in 1979 with which the Midland-headquartered Endeavor Energy Resources was established; the company is currently up for acquisition by Diamondback Energy for $26bn and is expected to be closed later in the year.

He undertook his first employment with the Humble Oil and Refining Company in 1962. Stephens began his professional practice at Humble after his graduation, and after practising for two years as a civil engineer in the company, he left to join the Army Corp of Engineers for two years.

Fond of the oil and gas industry, he applied for pipeline engineering and was in Lieutenant and Platoon leader rank handling fuel installations. It was an eye-opening experience as well as a way of expanding his interest in the oil and gas profession.

Stephens moved back to Humble for further service until he decided to part with the company after a total of five years of service and moved to Midland, Texas.

Before establishing UD, Stephens worked as a reservoir engineer for a local Midland bank; from a similar client base of entrepreneurs who regularly dealt with the bank, Stephens was aware of the receptiveness he would one day get from the institution when he managed to convince it to invest in his venture.

As an entrepreneur, Stephens began to acquire land rights and started to develop an impressive position in the Permian Basin and slightly beyond. He also bought out several energy service companies to render him the lowest operating cost for his exploration and production company.

Stephens earned his first degree, a Bachelor of Science degree in Petroleum Engineering from the University of Texas at Austin.