论文部分内容阅读
准噶尔盆地中部地区是胜利油田西部新区的重点勘探区块之一,中生界侏罗系地层为本区主要目的层,储层埋藏深。本区地质情况复杂,井壁稳定及压力异常问题突出,钻井过程中复杂较多,导致钻井周期长,成本高。通过对准噶尔盆地中部地区已钻井资料分析,利用测井资料,建立了本区地应力模型,确定了三个主应力的方向及大小,并对地应力模型进行验证,其中最大水平主应力方向为近南北方向。建立了本区地层三压力剖面,针对不同目的层,形成了两套井身结构推荐方案,根据地应力模型,确定了有利于井壁稳定的钻井方位和有利于压裂改造的钻井方位,进行了水平井轨道方向优选,形成了本区钻井优化设计方案,并进行实钻应用。现场应用表明,新钻井较周围邻井平均机械钻速提高15%,钻井周期缩短10%,钻井复杂明显减少,井身质量大幅提高。
The central part of the Junggar Basin is one of the key exploration blocks in the western part of Shengli Oilfield. The Jurassic strata in the Mesozoic are the main strata of interest in this area, and the reservoirs are deep buried. The geological conditions in this area are complex, the wellbore stability and pressure anomalies are prominent, and the drilling process is complicated, resulting in long drilling cycles and high costs. Through the analysis of drilling data in the central part of Junggar Basin and the use of well logging data, this paper established the in-situ stress model, determined the direction and size of the three principal stresses and verified the stress model. The maximum horizontal principal stress direction is Near North-South direction. Based on the in-situ stress model, the drilling azimuth which is propitious to the stability of borehole wall and the drilling azimuth which is favorable for fracturing reformation are determined, and the three well pressure profiles are established for different target layers. Horizontal well orbit preferred direction, the formation of the area drilling optimization design, and real drilling applications. The field application shows that the average drilling penetration rate of the new drilling is 15% higher than that of the neighboring adjacent wells, the drilling cycle is shortened by 10%, the drilling complexity is obviously reduced, and the well quality is greatly improved.