三维地质建模技术在水平井地质导向中的应用——以苏丹F油田为例

Application of 3D geological modeling technology in horizontal well geo-steering——by taking Sudan F Oilfield as an Example

苏丹F油田目的层Bentiu组砂岩储层埋藏较浅,且较疏松,水平井施工过程中易发生垮塌风险,因此,对井眼轨迹的质量要求较高,同时Bentiu组砂岩非均质性较强,泥岩隔夹层较发育,难以保证优质砂岩储层的钻遇率,对该地区的水平井地质导向带来巨大挑战。通过利用三维地质模型,精细刻画储层空间展布特征,并精准预测水平井地区储层构造及储层岩性变化,结合随钻GR曲线和电阻率曲线,实时更新地质模型,及时优化调整实钻轨迹,确保轨迹顺利入靶,有效地提高砂体钻遇率,保证井眼轨迹的平滑,也为后期水平井高产奠定基础。

The target layer of sandstone reservoir in Bentiu Formation of Sudan F Oilfield is shallowly buried and relatively loose,making collapse risk easy to occur during horizontal well construction,and then the quality requirement of well trajectory is high.Meanwhile Bentiu sandstone has a strong heterogeneity and the mudstone interlayer is relatively developed,so it’s not easy to guarantee the drilling ratio of high-quality sandstone reservoirs.Therefore,all the mentioned above bring great challenge to geo-steering of horizontal wells in this area.By using 3D geological model,a fine description of reservoir spatial distribution characteristics,an accurate prediction of reservoir structure variation and lithology characteristics in horizontal well area have been made.Combined with GR and resistivity curve,the geological model in real time has been updated and the actual drilling trajectory has been optimized in time,making the smooth entry of the trajectory into the target,improved drilling ratio of sand body and the smoothness of the wellbore trajectory,which lays a foundation for high production of horizontal wells in later stage.