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对塔中地区石炭系、寒武-奥陶系油田水常量元素、氢氧同位素资料的研究表明,油田水中rCa/rMg值的高低可指示白云化或方解石溶解作用的强弱,与次生孔隙是否发育有关。rCa/rMg值、δ18O值正偏移是油田水封闭性、水-岩反应增强的结果。在高温、深埋条件下,储集层沥青与高丰度的有机酸共生,伴有石膏假晶、还原硫化物的出现,可能是由于烃类热化学硫酸盐还原作用。奥陶系油田水与石炭系油田水的氢氧同位素值相近,指示油田水发生了混合。
The study on the data of water and oxygen isotopes in Carboniferous and Cambrian-Ordovician oilfields in Tazhong area shows that the rCa / rMg values in the water of the oilfield can indicate the strength of dolomitization or dissolution of calcite, Whether or not related to development. The rCa / rMg value and the δ18O value positive offset are the result of water-oil sealing and enhanced water-rock reaction. Under the conditions of high temperature and deep burial, reservoir bitumen coexists with highly abundant organic acids, accompanied by pseudomorphic gypsum and the occurrence of reduced sulfides, probably due to the thermochemical sulfate reduction of hydrocarbons. The hydrogen and oxygen isotopic values of water in the Ordovician and Carboniferous oil fields are similar, indicating that oilfield water has been mixed.