利用地应力测量技术探查油井地层注水分布特征

DISTRIBUTION CHARACTERISTICS OF OIL WELL WATER INJECTION EXPLORED BY IN-SITU STRESS MEASUREMENT

对油层所在层段进行压裂注水驱油可以提高油田采收率,而确定注水的流向是合理部署注采井网的重要依据。利用电磁波地应力测量新技术对周庄G1井地层注水空间分布特征进行探查,并将探测得到的电压值换算成地应力值,研究表明,地应力值的大小与富水程度具有一定的相关性,低地应力值对应于强富水,高地应力为弱富水或不富水。从注水层段地应力纵向和平面分布及含水层厚度3个方面分析注水影响范围及富水性平面分布特征。探测结果显示:在G1井东部40 m及SW50 m处存在2个近南北向地应力低值条带,为注水后富水的区域,其后的采油实际资料证实了探测结果的可靠性,为油井旧井挖潜的有效技术手段。

Water injection oil displacement through oil well stratum fracturing can enhance oil recovery factor,and the determination of stratum aquifer distribution after water injection is important basis for appropriately designing injection production well network.The natural electromagnetic wave in-situ stress measurement has been applied to detect the distribution features of stratum water injection in Zhouzhuang well G1.The voltage value obtained through measurement is converted into in-situ stress.Research results show that in-situ stress value has a certain correlation with the water abundance,low in-situ stress value is corresponding to abundant water,high in-situ stress value is low water abundance or have no water.Water injection influence scope and water abundance plane distribution features have been analyzed based on the horizontal and vertical distribution of in-situ stress and aquifer thickness in water injection section.The test result of the exploration shows that existing two water abundance low in-situ stress value zones trending near NS direction at 40 m east and 50 m southwest of well G1.The correctness of the result has been proved by afterwards oil production,this method provides a effective technical means for old oil well potential tapping.