摘要
鄂尔多斯盆地周家湾地区三叠系延长组长8致密砂岩储层特征和优质储层控制因素研究薄弱,制约了该区油气的勘探与开发进程。在岩心观察的基础上,结合大量铸体薄片、扫描电镜、压汞及常规物性等分析化验资料,对周家湾地区长8致密砂岩储层的宏观和微观特征及其影响因素进行了研究。结果表明,长8储层岩石类型以岩屑长石砂岩和长石岩屑砂岩为主,填隙物含量较高;长81和长82小层的孔隙度分别为8.03%和8.17%,渗透率分别为0.17 mD和0.25 mD,均属致密砂岩储层,储层物性较差;储集空间以剩余原生粒间孔和次生长石溶孔为主,微细喉道,形成了长8储层高排驱压力、高中值压力及低退汞效率的特征。受沉积和成岩作用的共同控制,研究区长8油层组有利储层主要发育于分流河道和水下分流河道沉积微相中,压实作用、碳酸盐胶结作用和硅质胶结作用致使储层物性变差,溶蚀作用则有效改善了储层孔渗条件。
The characteristics and controlling factors of Chang 8 tight sandstone reservoir of Triassic Yanchang Formation in Ordos Basin is unclear, which restricts the hydrocarbon exploration and development in this area. Based on core observation and data of cast thin sections, scanning electronic microscope, mercury intrusion and conventional physical properties, the characteristics and influencing factors of the Chang 8 tight sandstone reservoir were analyzed. The results show that the Chang 8 reservoir rocks are mainly composed of lithic arkose and feldspathic lithic sandstones, with high content of matrix. The porosity of Chang 81 and Chang 82 sublayers are 8.03% and 8.17%, respectively, and the permeability are 0.17 mD and 0.25 mD, respectively, showing the poor properties and tight sandstone reservoirs. The pores are dominated by the remaining primary intergranular pores and secondary feldspar dissolved pores, together with small throat, which characterizes the Chang 8 reservoir with high expulsion pressure, high median pressure and low ejection efficiency. Under the control of deposition and diagenesis, the favorable reservoirs are mainly developed in distributary channel and subaqueous distributary channel. Compaction, carbonate and siliceous cementation make the reservoir properties poor, and dissolution improve the reservoir porosity and permeability.
作者
王维斌
朱静
马文忠
冯顺彦
刘艳妮
赵静
WANG Weibin ZHU Jing MA Wenzhong FENG Shunyan LIU Yanni ZHAO Jing(Research Institute of Exploration and Development, PetroChina Changqing Oilfield Company, Xi＇an 710018, China National Engineering Laboratory for Exploration and Development of Low Permeability Oil and Gas Fields, Xi＇ an 710018, China Xi, an Changqing Chemical Group Co., Ltd, PetroChina Changqing Oilfield Company, Xi,an 710018, China)
出处
《岩性油气藏》
CSCD
北大核心
2017年第1期51-58,共8页
Lithologic Reservoirs
基金
国家重大科技专项"鄂尔多斯盆地致密油资源潜力
甜点预测与关键技术应用"(编号:2016ZX05046-005)资助
关键词
储层特征
影响因素
成岩作用
延长组
周家湾地区
鄂尔多斯盆地
reservoir characteristics
influencing factors
diagenesis
Yanchang Formation
Zhoujiawan area
Ordos Basin
