临兴地区砂岩含气特征及其主控因素

Characteristics and Its Main Controlling Factors of Sandstone Gas Content in Linxing Area

鄂尔多斯盆地东缘临兴地区致密砂岩气资源丰富。为了明确该区砂岩含气量的主要控制因素,针对砂岩孔隙度、含气饱和度、砂岩埋深、盖层排替压力、泥质含量、储层压力等6个影响因素,采用灰色关联分析法进行统计分析。结果显示:临兴地区砂岩含气量影响因素与含气量之间的关联度变化在0.245 2~0.788 8,表明上述影响因素对含气量均有一定程度影响;其中砂岩孔隙度与含气量之间的关联度最大(0.788 8),其次为含气饱和度(关联度0.577 9),表明该区砂岩含气量主要受砂岩孔隙度和砂岩含气饱和度的影响。据此优选出3个天然气成藏有利区:赵家坪乡LX4-LX7井区、圪垯上乡LX2-LX8以西区域和兔坂镇LX1-TB05周边区域。

The tight sandstone gas resources are abundant in Linxing area of the eastern margin of Ordos Basin.In order to pinpoint the main controlling factors of sandstone gas content in this area,six influence factors were analyzed by Grey correlation analysis,including sandstone porosity,gas saturation,buried depth of sandstone,displacement pressure of caprock,shale content and reservoir pressure.The results show that the correlation between sandstone gas content and its influence factors vary from 0.245 2 to 0.788 8 in Linxing area,indicating that all the above factors have a certain impact on gas content.The correlation between sandstone porosity and gas content is the highest(0.788 8),followed by gas saturation(correlation degree 0.577 9).This means that the sandstone gas content in this area is mainly affected by sandstone porosity and sandstone gas saturation.Based on these results,three favorable areas for gas accumulation were optimized:The LX4-LX7 well area in Zhaojiaping town,the LX2-LX8 well area in the west of Gedashang town and the LX1-TB05 well area in the surrounding areas of Tuban town.