裂缝性致密砂岩油藏水平井井筒延伸方位优化

Optimization on extensional direction of horizontal wellbore in fractured tight sandstone reservoir

红河油田长8油藏为裂缝性低渗透致密砂岩油藏,主体开发方式为水平井配合压裂改造.在长8储层水平井实际生产情况的基础上,从地质、钻井、压裂、采油的角度论证了水平井井筒延伸方位对工程、产能和防水的影响.结果表明：井筒延伸方位和最大水平地应力夹角介于25～75°时,可获得较高的砂岩钻遇率和显示钻遇率;夹角介于60～90°时,同时避开泥岩和断层,是钻井过程中利于井壁稳定和储层保护的最优方向;夹角介于50～90°时,避开泥岩和断层,是减少出现压裂施工复杂情况的最优方向;夹角介于50～80°时,可获得较好的防水效果;夹角介于40～75°时,可获得较高的单井产能,是利于工程施工、提高单井产能和防水淹的最优方向.

Chang 8 oil reservoir in Honghe Oilfield is the fractured tight sandstones reservoir, whose main development mode is horizontal wells with fracturing. Based on the actual production of Chang 8 reservoir horizontal well, the effect of wellbore extensional direction on engineering, productivity and waterproof is demonstrated from the perspective of geology, drilling, fracturing and oil production in this paper. The results show that when the angle between the wellbore extensional direction and the maximum horizontal stress orientation ranges between 25-75 °, the high drilling rate of sandstone and hydrocarbon show can be obtained; when the angle is between 60-90°, avoiding mudstone and fault is beneficial for wellbore stability and reservoir protection in the process of drilling; when the angle is between 50-90°, avoiding mudstone and fault is beneficial for reducing the complexes in the process of fracturing; when the angle is between 50-80°, the good effect of waterproof can be obtained; when the angle is between 40-75°, the productivity of single well can be obtained, which is beneficial for improving engineering, productivity and waterproof.