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经现场连续监测,证明渤海湾盆地渤中25-1/S油田硫化氢是长期的、持续的。通过气样采集和样品分析及相关资料整理,对硫化氢形成的地质地球化学条件进行了系统研究,并探讨其相关证据。经研究说明,天然气中CH4含量高达98.68%,CO2含量为0.34%~3.34%,H2S含量为0.001%~0.032%,硫化氢含量明显偏低,说明硫化氢不是来自干酪根热解;沙河街地层温度为120℃~135℃,超出了细菌生长的温度极限;硫化氢硫同位素为6.7‰~11.8‰,偏重;这些硫化氢是由沙河街组气藏及附近的石膏经硫酸盐热化学还原作用(TSR)而成。但由于只含有一定的石膏、黄铁矿和硫酸盐等物质,不具备形成高含硫化氢气藏,属于低含——微含硫化氢天然气,并且油气来源于黄河口凹陷沙河街组。
After continuous on-site monitoring, it was proved that hydrogen sulfide in the Bozhong 25-1 / S oilfield in the Bohai Bay Basin is long-term and continuous. Through the gas sampling and sample analysis and related data collation, the geochemical conditions of the formation of hydrogen sulfide were systematically studied and the related evidences were discussed. The research shows that CH4 content in natural gas is as high as 98.68%, CO2 content is 0.34% -3.34%, H2S content is 0.001% -0.032%, hydrogen sulfide content is obviously low, indicating that hydrogen sulfide is not derived from kerogen pyrolysis; The temperature ranged from 120 ℃ to 135 ℃, which was beyond the temperature limit of bacterial growth. The hydrogen sulphide sulfur isotopes ranged from 6.7 ‰ to 11.8 ‰, with a strong emphasis. These hydrogen sulphide was reduced by sulphate thermochemical reduction of the gas pools in the Shahejie Formation and nearby gypsum (TSR). However, due to containing only a certain gypsum, pyrite and sulfate and other substances, do not have the formation of high hydrogen sulfide gas reservoir, a low content of - containing hydrogen sulfide gas, and oil and gas from the Shahejie Formation of the Yellow River estuary depression.