准噶尔盆地玛湖油田优快钻地质因素研究

Study of the geological factors of optimized fast drilling in Mahu Oilfield of Junggar Basin

准噶尔盆地玛湖10亿吨级特大油田成为当前国内油气资源增储上产的重要接替区之一,在该油田钻探过程中,多层段频发工程复杂,目的层油层分布不稳定,水平井地质导向施工难度大,严重制约了该区域钻井提速提效工作。针对上述难题,以MH 1区块为例开展了地层压力分布规律、裂缝分布规律、井壁失稳主控地质因素及水平井目标层隔夹层分布规律研究,得到井眼力学平衡和地层矿物的物理化学变化影响井壁稳定性的结论,总结出区域三叠系及以下地层压力和裂缝发育程度纵向递增、地层压力横向分区的特征,形成了基于随钻岩矿数据拟合测井参数获取随钻地层压力的方法和一套工程复杂地质因素分析技术,满足了预判工程复杂及保障油层钻遇率的需求,实现了优快钻井目的,助力玛湖油田提速提效,具有良好的借鉴价值。

As a giant oilfield in Junggar Basin,Mahu Oilfield produces a billion-ton oil,and has become one of the important replacement areas of increasing oil and gas reserves and production at present.In the process of drilling and exploration,the project complexity of multilayers often take place,the distribution of target reservoir is unstable,and the geological guiding construction of horizontal wells is of great difficulty,which seriously restrict the drilling speed and efficiency improvement in this region.In view of these difficulties,the authors carry out studies of distribution law of formation pressure,fracture distribution law,main controlling geological factors of borehole wall instability and distribution law of horizontal well target layer and interlayer by taking MH 1 block as an example.It is concluded that stability is influenced by borehole mechanical balance and physical and chemical changes of formation minerals,and the characteristics of vertical increase of formation pressure and fracture development degree and horizontal division of formation pressure in the region of Triassic and below are summarized.Finally,a method to obtain formation pressure while drilling based on data fitting logging parameters of rock mine while drilling has been formed and a set of analysis technology of engineering complex geological factors has also been accomplished.All of these can meet the needs of complex project prediction and guarantee the drilling rate of oil reservoir,meanwhile realize the purpose of optimal fast drilling,and help Mahu Oilfield improve speed and efficiency,and have a good reference value.