中国陆上最深井塔深1井寒武系优质储集空间主控因素分析

Analysis on main controlling factors of Cambrian reservoir space with high quality for Well Tashen 1,the deepest subaerial well in China

塔深1井是世界上第一口以寻找石油和天然气为目的的超深科学探井。根据岩性、岩性组合、电性特征对塔里木盆地沙雅隆起阿克库勒凸起东部塔深1井寒武系地层储集空间进类型进行划分,主要有裂缝、溶蚀孔(洞)、白云岩晶间角孔、晶间溶孔、颗粒(鲕粒)内溶孔及压溶型缝合线等。其中,裂缝、溶蚀孔(洞)是组成塔深1井寒武系不同类型白云岩的主要储集空间类型,相应的可构成以裂缝为主的裂缝型储层类型和以溶蚀孔洞为主的溶蚀孔洞型储层类型及裂缝+溶蚀孔(洞)复合型储层类型。结合宏观地质背景,储集空间主控因素有原始沉积环境、成岩作用中白云石化、重结晶、深埋溶蚀、充填和胶结作用、多期构造运动及运动产生的裂缝系统的热液流体有关的溶蚀作用等。通过对塔深1井地区储集空间及主控因素的研究,表明该井地区具备发育成优质储层的条件,存在着巨大的勘探潜力,这不仅对塔里木盆地北部深层油气勘探具有重大的实际意义,而且在理论上对石油地质学和沉积学都有极高的研究价值。

Well Tashen 1, an extremely deep well, is the first scientific exploration well to search for oil and gas. According to the lithology, lithologic combination and electrical characteristics, the reservoir space types of Cambrian stratum in Well Tashen 1 of Akekule Arch located in eastern part of Shaya Uplift in Tarim Basin are mainly categorized into fracture, dissolved pore/vug, dolomite intergranular angular pore, intercrystalline dissolved pores, dissolved pores in particles and suture of pressure solution type. Among them, the fracture and dissolved pore/vug are the main reservoir space types of different Cambrian dolomite. Correspondingly, they can form the fractured reservoir type dominated by fracture, the dissolved pore reservoir type dominated by dissolved pores, and composite the reservoir type of fracture and dissolved pore. This kind of reservoir space development with dissolved pores, vugs and fractures is infrequent over the world. Combined with the macroscopic geological background, the main controlling factors of such good reservoir space include original sedimentary environment, diagenesis such as dolomitization, recrystallization, deep-lying dissolution, cementation, multistage tectonization and corrosion effect concerned with hydrothermal fluids in the fracture system. Through studying on the reservoir space and main controlling factors of Well Tashen 1, it is shown that this well has the condition of developing into a high quality and huge exploration potential reservoir, which not only has great practical significance for the deep oil/gas exploration in the north of Tarim Basin, but also has high theoretical research value for petroleum geology and sedimentology study.