鄂尔多斯盆地平凉北地区上三叠统长8段储层低含油饱和度油藏特征及成因  

Characteristics and genesis of Upper Triassic Chang 8 reservoir with low oil saturation in northern Pingliang area,Ordos Basin

作　　者：白杨 张晓磊[3] 刚文哲[1,2] 张忠义[3] 杨尚儒 庞锦莲[3] 曹晶晶 侯云超 BAI Yang;ZHANG Xiaolei;GANG Wenzhe;ZHANG Zhongyi;YANG Shangru;PANG Jinlian;CAO Jingjing;HOU Yunchao(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Research Institute of Exploration and Development,PetroChina Changqing Oilfield Company,Xi’an 710018,China;Research Institute of Oil and Gas Technology,PetroChina Changqing Oilfield Company,Xi’an 710018,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中国石油长庆油田公司勘探开发研究院,西安710018 [4]中国石油长庆油田公司油气工艺研究院,西安710018

出　　处：《岩性油气藏》2023年第3期66-75,共10页Lithologic Reservoirs

基　　金：国家自然科学基金面上项目“富有机质沉积岩中有机氮与无机氮同位素组成特征及其地质意义”(编号:41972127)资助。

摘　　要：通过岩心物性分析、恒压压汞和核磁共振测试,结合油源、构造等资料,对鄂尔多斯盆地平凉北地区上三叠统长8段储层低含油饱和度油藏的特征及成因进行了分析。研究结果表明:①平凉北地区上三叠统长8段储层含油饱和度普遍低于20%,而含水饱和度则普遍高于50%,属于典型的低含油饱和度油藏,且单井产量低,油水分异差,油藏呈零星状分布在长8段储层顶部。②供烃量不足是研究区油藏含油饱和度低的根本原因。M53井区为异地成藏,供烃距离较远导致供烃量不足;Y80井区为原地成藏,原地烃源岩排烃量小导致油气充注不足。③M53井区受低幅度构造影响,油气垂向和侧向运移动力不足。全区储层物性非均质性强,微细孔喉较为发育,束缚水占比大,可动水占比小,导致油气驱替可动水后其饱和度较低,从而使研究区油藏分布较分散、含油饱和度较低。④M53井区上新庄地区西南部构造高部位物性较好的储层为下一步增储上产的重要目标。Through core physical property analysis,constant pressure mercury injection and nuclear magnetic resonance testing,combined with oil source and structure,the characteristics and genesis of Upper Triassic Chang 8 reservoir with low oil saturation in northern Pingliang area of Ordos Basin were analyzed.The results show that:(1)The oil saturation of Upper Triassic Chang 8 reservoir is generally less than 20%,while the water saturation is generally greater than 50%.It is a typical low oil saturation reservoir with low single well production and poor oil-water difference.The reservoir is sporadically distributed at the top of Chang 8 member.(2)Insufficient hydrocarbon supply is the fundamental reason for the low oil saturation of the reservoirs in the study area.It is an allochthonous oil reservoir in well M53 well,and the long distance of hydrocarbon supply leads to insufficient hydrocarbon supply.It is in-situ hydrocarbon accumulation in well Y80,and the small amount of hydrocarbon expulsion from in-situ source rocks results in insufficient oil and gas filling.(3)Affected by low-amplitude structures,vertical and lateral migration power is insufficient in well M53 well.The strong physical heterogeneity of the reservoirs in the whole area,the relatively developed micro pore throats in the pore structure,and the high percentage of bound water,resulted in low saturation after oil and gas displacement of movable water,which indirectly led to scattered distribution and low oil saturation of the reservoirs in northern Pingliang area.(4)The reservoirs with good physical property at the structural high point in the southwestern Shangxinzhuang area in M53 well area are important targets for the next step of increasing reserves and production.

关 键 词：低含油饱和度 油气充注 供烃距离 束缚水 可动水 长8段 上三叠统 平凉北地区 鄂尔多斯盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]