靖边气田马五_(1+2)气藏相对富水区成因及开发

GENESIS AND EXPLOITATION OF RELATIVE RICH AQUIFER REGIONS IN MAWU_ (1+2) GAS RESERVOIR OF JINGBIAN GAS FIELD

靖边气田下古生界马五1+2气藏是靖边气田的主力气藏,但该气藏存在大小不等的相对富水区,大的上百平方公里,小的仅几平方公里,它们既不同于边水、也不同于底水,而是一种含水饱和度相对较高且可移动的成藏滞留水。特殊的地层水类型决定了其开发的特殊性。随着开发井网的完善,相对富水区数量也相应增加。文章通过分析相对富水区的成因、气水移动规律,研究了相对富水区开发技术,提出“内降外控、以排为主”的开发技术,大的富水区通过采取各种排液措施,降低水体内部地层压力,控制相对富水区外围纯气区的气井产量、保持相对富水区外围较高地层压力;孤立、透镜状小水体,通过强排,降低其地层压力,控制水体外侵,提高气藏采收率。

Mawu1+2 gas reservoir is the pillar reservoir of Jingbian gas field. But there are big or small relative rich aquifer regions in the reservoir. The biggest aquifer region reaches more than 100 km2 and the smallest aquifer region is only a few km2. They differ' from either edge water or bottom water, They are moveable pool-forming resident water with high water saturation. They have to be exploited with special method because of the special type of the formation water. As the production well pattern is completed, the number of relative rich aquifer regions increases correspondingly. With analyzing the genesis of relative rich aquifer regions and the law of gas/water migration, the exploitation techniques of relative rich aquifer regions are studied. The exploitation technology of 'Pressure downing inside an pressure keeping outside, Taking drainage as key measure is proposed. As for big rich aquifer regions, various liquid draining measures should be taken to reduce the formation pressure inside the aquifer regions, and the production of gas wells in the pure gas regions outside the relative rich aquifer regions should be controlled to keep high formation pressure outside the relative rich aquifer regions. As for the separated lenticular small aquifer regions, strong drainage should be conducted to reduce their formation pressure, avoid water flowing out, and improve the recovery factor of the gas reservoir.