摘要
鄂尔多斯盆地姬塬地区上三叠统延长组长8、长6及长4+5油层组属于典型的低孔、低渗型砂岩储层,广泛发育的裂缝系统对储层物性改善和油气运聚成藏具有重要控制作用。综合应用野外剖面和钻井岩心,结合测井及镜下鉴定资料对该地区裂缝发育特征及其成因进行综合研究,结果表明:姬塬地区各油层组发育早期东西向和北西-南东向共轭剪切裂缝为主,晚期南北向和北东-南西向共轭剪切裂缝次之的2组高角度裂缝,且多为未充填的有效裂缝;在特定沉积相带背景下的燕山期构造运动和盆地低渗透致密砂岩储层形成过程的超压作用,是裂缝形成的重要因素;裂缝大量存在是研究区各油层组储层低孔却具备相对高渗带的主要原因,也为油气后期幕式快速充注成藏提供了通道条件,使低孔背景条件下的相对高渗带成为油气富集成藏的有利场所。
The Member Chang 8,Chang Member 6 and Chang Member 4＋5 in the Jiyuan area of Ordos Basin are typical sandstone reservoirs with poor porosity and low permeability.The widely-developed fractures system presents an important control role in improving the physical property of the reservoirs and the transportation of oil and gas.According to the observation of outcrops,well drilling,log information and microscopic study,the characteristics and genesis of the fractures have been studied.The result shows that there mainly develop two high angle fractures in the Jiyuan area：EW striking and NW-SE striking fractures in the early time,though some are SN striking and NE-SW striking fractures in the late time,and most of them are effective fractures without fillings.The Yanshan tectonic movement and diagenesis are the important elements of forming the fractures.Lots of fractures are the main reasons that the reservoirs in the area have poor porosity but high permeability,and these offers channels for oil and gas migration later stage episodic-fill in the model.And this makes the super low permeability sandstone reservoir become the beneficial house for oil and gas concentration.So,the（micro）fracture zones become the favorable prospecting targets.
出处
《成都理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2011年第2期220-228,共9页
Journal of Chengdu University of Technology: Science & Technology Edition
基金
国家重大专项(2008ZX05000-003-01)
关键词
致密砂岩储层
裂缝
延长组
姬塬地区
鄂尔多斯盆地
low permeability sandstone reservoir
fracture
Yanchang Formation
Jiyuan area
Ordos Basin
