波斯湾扎格罗斯盆地北段二叠系-新生界H_(2)S成因及分布规律  

Genesis and distribution law of H_(2)S in the Permian-Cenozoic in the north section of Zagros Basin,Persian Gulf

作　　者：周瑞 扈永杰 张洪 胡俊峰[1] 卢福长 刘子煊[1] 郑逸娴 张红霖 Zhou Rui;Hu Yongjie;Zhang Hong;Hu Junfeng;Lu Fuchang;Liu Zixuan;Zheng Yixian;Zhang Honglin(Sinopec International Petroleum Exploration and Production Corporation)

机构地区：[1]中国石化集团国际石油勘探开发有限公司

出　　处：《中国石油勘探》2023年第5期109-116,共8页China Petroleum Exploration

基　　金：国家科技重大专项“中东中亚富油气区勘探开发关键技术”(2008ZX05031)。

摘　　要：波斯湾扎格罗斯盆地碳酸盐岩含有丰富油气资源,但H_(2)S成因规律复杂。通过岩石学、流体包裹体测温和同位素地球化学等手段分析,厘清了该盆地北段的H_(2)S成因和分布规律。分析认为:新生界和白垩系,石膏、硬石膏和重晶石发育,H_(2)S含量较低(<5%),H_(2)S与硬石膏间的硫同位素分馏较大。这指示较高程度的细菌硫酸盐还原作用(BSR)。此外,白垩系部分储层发生干酪根热裂解作用,导致其H_(2)S含量一定程度增高。侏罗系—二叠系埋藏深,硫酸盐矿物发育,且方解石胶结物内可见烃类包裹体。H_(2)S含量高(最大约40%),且与硫酸盐矿物的硫同位素分馏较小。方解石的碳同位素受烃类等有机质的并入影响,存在明显的负漂(-10‰)。这指示其以热化学硫酸盐还原作用为主(TSR)。多种成因类型也导致H_(2)S含量在不同区块间的差异。There are abundant oil and gas resources in carbonate rocks in Zagros Basin,but the genesis of H_(2)S is complex.The petrology,homogenization temperature of fluid inclusions and isotopes are analyzed to identify the genesis and distribution law of H_(2)S.The study results show that gypsum,anhydrite and barite are well developed in the Cretaceous and Cenozoic,H_(2)S contents(<5%)are low and sulfur isotopic fractionation is large between H_(2)S and anhydrite,which indicate a high degree of bacterial sulfate reduction(BSR).In addition,thermal degradation of organic kerogen occurred in part of the Cretaceous reservoir,leading to the increase of H_(2)S content to a certain extent.The sulfate minerals are well developed in the Jurassic-Permian reservoirs with a great burial depth,and hydrocarbon inclusions are observed in calcite cements.H_(2)S contents are high(up to 40%)and the sulfur isotopic fractionation is large between H_(2)S and sulfate.Affected by the mixture of organic matter such as hydrocarbons,the carbon isotope of calcite shows a distinctly negative drift(-10‰).These suggest that thermochemical sulfate reduction was dominant.Multiple genetic types led to differences in H_(2)S contents in various blocks.

关 键 词：扎格罗斯盆地 深层碳酸盐岩 H_(2)S成因 BSR TSR 

分 类 号：TE125.1[石油与天然气工程—油气勘探]