摘要
鄂尔多斯盆地临兴地区具有巨大的天然气勘探开发潜力,是我国重要的致密砂岩气接替区,但其致密砂岩储层物性较差,储层致密化成因复杂,制约了该区致密砂岩气的产业化发展。根据X射线衍射、扫描电镜、阴极发光、铸体薄片、流体包裹体及分析化验等资料,对研究区山西组致密砂岩储层特征及成因进行了系统研究。结果表明:该区砂岩储层岩性主要为岩屑砂岩和次岩屑砂岩,储集空间以剩余原生粒间孔和次生溶蚀孔为主;砂岩储层物性较差,平均孔隙度为5.9%,平均渗透率为0.073 m D,排驱压力和饱和度中值压力均较高,孔喉半径小且分选性较差,孔隙结构参数总体较差。对致密砂岩储层成岩序列的划分表明,该区砂岩储层具有4个世代的黏土充填,多期次的黏土充填使储层逐渐致密化。孔隙度演化定量分析表明,该区储层质量主要受压实作用和胶结作用的影响,早成岩阶段压实作用造成17.1%的孔隙度损失,中成岩阶段压实作用和胶结作用造成22.9%的孔隙度损失,其中,胶结作用中的黏土矿物大量充填孔隙并堵塞喉道,不仅导致原生粒间孔隙变成了微小的晶间孔隙,而且使孔隙表面变得粗糙,迂回度增加,导致储层孔隙度和渗透率大大降低。
Linxing area in Ordos Basin has great potential of natural gas exploration and development, so it is an important succeeding area for tight sandstone gas exploration. Due to the poor physical properties of tight sandstone reservoir and complex genesis of tight reservoir, the industrial development of tight sandstone gas in this area is restricted.Based on the data of X-ray diffraction, scanning electron microscope, cathodoluminescence, cast thin section, fluid inclusions and laboratory test, the characteristics and genesis of tight sandstone reservoirs of Shanxi Formation in Lingxing area were studied. The result shows that the sandstone reservoirs are mainly litharenite and sub-litharenite,and the pore types are mainly primary intergranular pores and secondary dissolved pores. The reservoir physical properties are poor, with the average reservoir porosity of 5.9% and the average permeability of 0.073 m D. Both the displacement pressure and the median saturation pressure are high. The pore throat radius is small and the sorting is poor.The diagenetic sequence of tight sandstone reservoir is divided into four generations of clay filling, which makes the reservoir tight. The quantitative analysis of porosity evolution shows that reservoir quality in the study area is mainly affected by compaction and cementation. The porosity loss due to the compaction is 17.1% at the early diagenetic stage,and the porosity loss due to the compaction and cementation is 22.9% at the middle diagenetic stage. In cementation, a large number of clay minerals filled the pores and clogged the throat, which makes the primary intergranular pores become tiny intercrystalline pores. In addition, it makes the pore surface rough and increases the detour degrees,resulting in the reservoir porosity and permeability greatly reduced.
出处
《岩性油气藏》
CSCD
北大核心
2016年第4期51-58,共8页
Lithologic Reservoirs
基金
国家科技重大专项"大型油气田及煤层气开发"子课题"鄂尔多斯盆地石炭-二叠系煤层气勘探开发示范工程"(编号:2011ZX05062-001)
关键词
致密储层
储层特征
成因
山西组
临兴地区
鄂尔多斯盆地
tight reservoir
reservoir characteristics
genesis
Shanxi Formation
Linxing area
Ordos Basin
作者简介
赵达（1990-），男，中国地质大学（北京）在读硕士研究生，研究方向为石油地质。地址：（100083）北京市海淀区学院路29号中国地质大学。E-mail：m17701266957@163．com。
