Research on Control Technologies for Hydrogen Sulfide BearingShale Oil Wells in China’s Shengli Oilfield

Abstract

Pyrite is abundant in some shale oil blocks of the Shengli Oilfield, China. During the development process, the high-temperature and high-pressure
formation environment induces a thermochemical reaction between pyrite and hydrocarbons, generating and releasing hydrogen sulfide (H₂S). This poses a serious threat to safe production, environmental protection, and crude oil quality. This paper provides an in-depth analysis of the formation mechanism of hydrogen sulfide in shale formations, identifying the high-temperature pyrolysis of pyrite in a closed system as the primary sulfur source. To address this issue, a high-temperature desulfurizer suitable for shale oil wells has been developed. This desulfurizer exhibits excellent characteristics, including hightemperature resistance (adaptable to formation temperatures), rapid reaction, high desulfurization efficiency, large sulfur capacity, and partial regenerability. By injecting the desulfurizer into the formation alongside fracturing fluid during the fracturing process, source control and treatment of hydrogen sulfide
are achieved. Successful field applications in five wells demonstrate that this technology significantly reduces hydrogen sulfide concentrations during well opening and production, yielding effective treatment results. It provides an efficient technical approach for the safe and high-efficiency development of similar hydrogen sulfide-bearing shale oil reservoirs.