土库曼斯坦阿姆河右岸地区盐下碳酸盐岩气藏类型及油气富集因素

土库曼斯坦阿姆河右岸地区盐下中上侏罗统卡洛夫-牛津阶碳酸盐岩油气资源丰富,但是油气分布规律的研究相对滞后,通过对典型气藏解剖,分析了油气藏类型,探讨了油气富集高产的主控因素。结果表明,该区盐下碳酸盐岩发育有构造气藏、岩性气藏和构造-岩性复合气藏3大类及背斜气藏、断背斜气藏、逆冲断裂背斜气藏、生物礁岩性气藏和构造-岩性气藏等5小类气藏。海西期基底古隆起控制了大气田的形成,喜马拉雅期挤压构造运动形成了逆冲断裂油气聚集带,沉积相带控制了气藏含油气丰度,盐膏岩盖层保存条件好,形成断背斜气藏。大型完整背斜构造与高能礁滩体相配,是西部查尔朱阶地天然气富集高产的主控因素;逆冲断裂背斜构造圈闭与大规模的缝洞型储集体配合,是东部别什肯特坳陷和基萨尔褶皱隆起区天然气富集高产的主控因素。

Types of pre-salt carbonate gas reservoirs and hydrocarbon enrichment factors of Amu Darya right bank area in Turkmenistan

Hydrocarbon resources in the Middle-Upper Jurassic Callovian-Oxfordian carbonate rocks are abundant; however, research on the distribution law of hydrocarbon is relatively backward. Through the study of typical gas reservoirs, analysis of the type of hydrocarbon reservoirs and discussion of the major reasons for high hydrocarbon output, we determined that there are three main types of pre-salt gas reservoirs in carbonate rocks:structural, lithologic and structural-lithologic compound gas reservoirs. Additionally, there are five minor gas reservoirs:anticline, faulted anticline, thrust faulted anticline, reefs and structural-lithologic gas reservoirs. We also discovered that Hercynian basement paleo-uplift controlled the formation of large gas fields and Himalayan extruded tectonic movement formed thrust faulted hydrocarbon accumulation zones. The abundance of gas was controlled by sedimentary facies belts and good seal provided by salt-gypsum cover contributing to the formation of faulted anticline gas reservoirs. The coincidence of large anticline structures and high energy reef beach body was the major controlling factor for the enrichment of natural gas in the west Zarzhu terrace. The coincidence of thrust faulted anticlinal structural traps and large scale fissure type reservoirs is the main reason for the enrichment and high yield of natural gas in the east Bieshikent Depression and Jisaer folded uplift zone.