塔里木盆地致密砂岩气层异常高压的测井计算方法

Logging Calculate Method of Abnormal High Pressure in Tight Sandstone Gas Reservoirs in Tarim Basin

针对塔里木盆地克深地区强烈构造封闭挤压作用导致异常高压在声波时差测井曲线上无明显异常增大特征的问题,讨论ED法、ET法、FP法和BS法计算地层孔隙压力的适用性,将这些方法优化编程,重点计算有实测压力数据井段的地层孔隙压力。通过计算分析和验证,给出BS法中A、B、U等3个关键参数的取值范围,认为基于有效应力卸载机理的BS法更适合于计算当声波时差曲线变化不明显时的异常高地层压力。该法较好地解决了塔里木盆地克深地区利用声波时差测井曲线准确计算异常高压的难题。

To address the problem that the abnormal high pressure in the Keshen area of the Tarim Basin caused by strong tectonic confinement extrusion has no obvious abnormal increase on the acoustic travel time logging curve, the applicability of the ED method, ET method, FP method and BS method are discussed. The methods are optimized and programed to calculate the formation pore pressures of the well sections with measured pressure data. Through calculation analysis and verification, the range of values of three key parameters A, B and U in BS method is determined. It is considered that the BS method based on the effective stress unloading mechanism is more suitable for calculating the abnormal pressure when the variation of the acoustic travel time curve is not obvious. The proposed method could better address the problem of accurate calculation of abnormal high pressure using acoustic travel time logging in the Keshen area of the Tarim Basin.