巴楚西段古生界储层裂缝发育规律及其油气成藏效应

Fracture development regularity and its effects on hydrocarbon accumulations in Paleozoic reservoirs in western Bachu Uplift

马中远 杨红彩 黄苇 张黎 兰明杰

Ma Zhongyuan Yang Hongcai Huang Wei Zhang Li Lan Mingjie

中国石化 西北油田分公司 勘探开发研究院, 乌鲁木齐 830011

Research Institute of Exploration and Production, SINOPEC Northwest Company, Urumqi, Xinjiang 830011, China

利用岩心、薄片、地球物理和分析化验等资料对巴楚西段古生界储层裂缝开展系统分析,研究表明石炭系裂缝最发育,奥陶系次之,志留系和泥盆系欠发育;裂缝主要为构造裂缝,其中斜交裂缝最发育,其次为水平裂缝和垂直裂缝;石炭系裂缝一般为方解石、白云石、陆源碎屑、硬石膏等所半充填,充填不严重,而奥陶系储层裂缝总体上充填严重,多为方解石、泥质所全充填、半充填;裂缝的发育受控于构造、岩性、厚度与岩石组合.裂缝不仅可以改善储层的储渗性能,而且有助于溶蚀作用的发生,为次生孔隙的形成创造有利条件.裂缝也是油气运聚过程中的重要介质,控制了油气的运聚成藏.

Based on core, thin section, geophysical and testing data, the fracture development in the Paleozoic reservoirs in the western Bachu Uplift was studied. It was concluded that fractures were most developed in Carboniferous, and second in Ordovician, and least in Silurian and Devonian. The fractures were usually structural ones, among which the oblique fractures were most common, followed by the horizontal and vertical fractures. The fractures in Carboniferous were half-filled by calcite, dolomite, terrigenous clastic and anhydrite, etc, while those in Ordovician were filled or half-filled by calcite and shale. The development of the fractures was controlled by tectonic stress and position, fault, lithology, thickness and rock combination. Fractures could not only improve reservoir performance, but also help karstification and create favorable conditions for the formation of se-condary pores. Fractures were also an important medium in the process of oil and gas migration and accumulation, and controlled oil and gas accumulation.

国家科技重大专项专题"塔里木盆地碎屑岩层系大中型油气田富集规律与勘探方向"(2011ZX05002-003).

https://doi.org/10.11781/sysydz2014S1001