Distribution and Origin of Hydrogen Sulphide in Heavy Oil Block, Liaohe Oil-Field
辽河油田稠油区块硫化氢分布特征及成因研究

Steam drive is a good method to exploit heavy oil. But in the process of steam exploitation, hydrogen sulphide occurred in the heavy oil block of the Liaohe Oilfield. The concentration of hydrogen sulphide in the steam drive block is especially high. Through field investigation, monitoring and oil and gas analysis, it is considered that the sulfur sources are sulfides in heavy oil, sulfate minerals in stratums and sulphur\|bearing chemical reagents. The distribution and its control factors of hydrogen sulphide are also summarized in this paper. According to sulphide isotope analysis and simulated tests, the origin of hydrogen sulphide in the heavy oil block of the Liaohe Oilfield is mostly thermal decomposition of sulfides, secondly thermochemical sulfate reduction.