【作者】 吴茂炳； 王毅； 张永贵； 胡文萱；

【Author】 WU Mao-bing, WANG Yi, ZHANG Yong-gui, HU Wen-xuan ( Institute of Oil Exploration and Development, SINOPEC, Beijing 100083, China; Department of Geosciences, Nanjing University, Nanjing 210093, China)

【机构】 中国石化石油勘探开发研究院； 南京大学地球科学系；

【摘要】 通过塔中地区重要井段的奥陶系碳酸盐岩详细的岩石学、矿物学和地球化学研究,提出热液溶蚀的判识标志为岩石热褪色、热碎裂和典型热液矿物的发育,如萤石、重晶石、黄铁矿、石英和闪锌矿等。溶蚀区岩石的地球化学特征表现为:Na和Mg等元素淋滤丢失;Fe,Mn和Si等元素富集增高;3He／4He比值为0．02Ra,表现为典型的壳源特征。其发育模式为来源于深部壳源岩浆流体,沿断裂与不整合等主要通道发生运移,并对其流经的碳酸盐岩围岩发生溶蚀作用。热液溶蚀是塔中地区奥陶系碳酸盐岩次生溶蚀孔隙发育的重要因素,同时热液矿物的形成对储层物性产生有利的影响。更多还原

【Abstract】 With a detail study on petrology, mineralogy and geochemistry of some important Ordo-vician carbonate well cores in central Tarim basin, the distinguishing symbols of thermal karstification were put forward as the phenomena of rock hot fading, hot cataclasm and the appearance of typical thermal minerals such as fluorite, barite, pyrite, quartz and sphalerite. Dissolved rocks have typical geochemistry features of low Na and Mg, high Fe, Mn and Si contents. The ratio of 3 He/4 He is 0. 02Ra (Ra= the 3 He/4 He value of the normal air), indicating the typical continental crust origin. The thermal fluid karstification pattern may be described as follows; the deep hot fluid from crust magma shifts along ruptures and unconformities, and dissolves the surrounding carbonates while it flows. The thermal karstification is an important process to forming hypo-dissolved holes in Ordovician carbonates of central Tarim basin, and the forming of thermal minerals also has favorable influence on carbonate reservoirs.更多还原