吐哈盆地柯柯亚区块侏罗系钻探中的钻头选型

Bit Selection for Drilling of Jurassic in Kekeya Block in Tuha Basin

吐哈盆地柯柯亚构造地层主要为砾岩和泥岩、砂岩混层,岩性致密、耐研磨、可钻性低,导致机械钻速较慢,钻井效率不高。用地层可钻性剖面法,结合主成分分析法和数理统计学方法,最终选取最优的钻头类型。实践证明,在吐哈油田运用上述综合方法优选出的牙轮钻头和PDC钻头能切实提高机械钻速,减少复杂事故的发生,从而缩短了钻井周期,节省了钻井成本,对该地区邻近区块的钻头选型具有一定的指导意义。

Proper bits can not only obviously improve the rate of penetration(ROP) and drilling quality,reduce drilling cost,but also decrease the complex cases of downhole.The main lithology of Kekeya structure in Tuha basin is dominated by conglomerate and mudstone-sandstone mixing layer and characterized by dense,grinding resistance and low drillability,causing low ROP and drilling efficiency.By means of drillability profile,combined with the principal component analysis and mathematical statistics methods,this paper selected the optimal bits for the lithology.Practices indicate that the cone bits and PDC bits selected by the synthetical methods can increase the ROP and decreases the complex cases,thus shorten the drilling cycle and save the cost,being meaningful to bits selection of neighbor wells and blocks in this area.