塔中地区碳酸盐岩地层压力监测应用研究

Application Study on Formation Pore Pressure Monitoring of Carbonate in Middle Tarim

塔中地区目的层属于碳酸盐岩层,运用现有的地层压力计算方法得出的结果不准确。从Sigma录井指数法监测地层压力机理出发,根据顺南区块钻遇碳酸盐岩目的层时,高钻速、高压耗对岩石抗钻强度的影响,对Sigma指数计算方法进行了修正,然后根据钻速方程中各个参数的关系,确定了顺南区块的地层压力监测方法。同时将此方法应用到顺南区块某典型井实例计算中,结果表明本计算方法适应于此区域的地层压力监测,与实钻情况相比,误差较小,并且比Dc指数法的计算精度平均可提升19%,可以推广应用。

The main strata of Shunnan district of middle Tarim is carbonate layers,and the pore pressure based on the present monitoring and predicting method is not correct.Based on the principle of Sigma logging,the Sigma index is corrected on the basis of the drilling rate and the high loss of pressure.Then the pore pressure monitoring method of Shunnan district is obtained by the correcting of the parameters of drilling rate equations.Meanwhile,the method in this paper is used in the typical well in Shunnan district.The results shows that,the calculation method presented in this paper is more applicable in this district.Compared with the real drilling situation,there are smaller errors,and the results of the method is 10% more accurate than Dc method,which indicates that the method can be promoted.