Abstract: A comprehensive study on dolomite reservoir in Tarim Basin showed that the dolomite reservoir in the Lower Paleozoic of Tarim Basin was resulted from the combination of multiphase and multi-type geological processes. The main elements to form dolomite reservoir include the favorable sedimentary facies, multiphase dolomitization, various corrosion, fracturing and associate cracks. The corrosions contain the deep-buried dolomite dissolution, corrosion of multi-supplying organic acid in hydrocarbons, magmatic hydrothermal corrosion, the corrosion of acid fluid generated by thermochemical sulfate reduction, squential-interface corrosion and unconformity karstification. The comprehensive evaluation of dolomite reservoir and the systematic analysis of reservoir-forming conditions showed that the Cambrian-Lower Ordovician dolomite reservoirs in Tarim Basin were wide-ranging and also had the preferable reservoir-forming conditions. The key factors for hydrocarbon accumulation are mainly the efficient cap-rock and the steady tectonic settings. Three new domains of exploration, including dolomite buried-hill-type reservoirs in the regions of Yingmaili-Yakela, Tazhong and Mazhatage, the dolomite inside-type reservoirs in the Akekule and Tazhong regions, and the reservoirs under the middle Cambrian halo-anhydrites in Tazhong and Bachu regions, were illustrated.

Key words: Tarim Basin, Lower Paleozoic, dolomite reservoir, origins, exploration prospect

摘要： 综合研究表明,塔里木盆地下古生界白云岩储层的形成是多期次、多类型地质作用的综合结果,有利的原始沉积相带、多期白云岩化作用、多种类型的溶蚀作用、断裂作用及其伴生裂缝是该类储层形成的关键。其中溶蚀作用包括深埋条件下白云石的自身溶解、多期供烃携带的有机酸溶蚀作用、岩浆热液溶蚀作用、硫酸盐热化学还原反应所产生酸性流体的溶蚀作用、层序界面和不整合面岩溶作用等。白云岩储层综合评价及油气成藏条件系统分析表明,塔里木盆地寒武系—下奥陶统白云岩储层非常发育,且具备较好的成藏条件,其中有效盖层及后期较为稳定的构造环境是油气成藏的关键。英买力—雅克拉地区、塔中主垒带和玛扎塔格构造带的白云岩潜山储层、阿克库勒和塔中地区的下奥陶统—上寒武统白云岩内幕储层以及塔中和巴楚地区的中寒武统盐下白云岩储层是下一步勘探的3个重要领域。

关键词: 塔里木盆地, 下古生界, 白云岩储层, 成因, 勘探前景