预测地层破裂压力的一种录测井新方法

A New Logging Method for Predicting Formation Fracture Pressure

为了提高页岩气储层地层破裂压力预测精度和方法的适应性,在总结前人成果的基础上,建立了利用地层孔隙流体压力梯度、地层孔隙度、地层脆性指数及等效上覆地层压力梯度、上覆地层岩性系数等参数计算地层破裂压力梯度、地层破裂压力的数学模型。建南气田、涪陵页岩气田及丁山、湘鄂西、宜昌等地区390多口井的应用实践表明,本方法克服了传统方法计算包括页岩气在内的等非常规油气储层地层破裂压力误差偏大、不适用的问题,60口井的抽样检查显示平均误差小于10%。

In order to improve the adaptation of shale gas reservoir formation fracture pressure prediction precision and method,this paper,on the basis of summarizing the predecessors'achievements,sets up the mathematic model to calculate formation fracture pressure gradient and formation fracture pressure by using the parameters such as formation pore fluid pressure gradient,formation porosity,formation brittleness index and the equivalent pressure gradient in the overlying strata and overlying strata lithology coefficient.The application of more than 390 wells in Jiannan Gasfield,Fuling Shale Gasfield as well as areas including Dingshan,yichang and Western Hubei and Hunan shows that this method overcomes the problem of big error in calculating formation fracture pressure of unconventional oil and gas reservoirs,including shale gas based on the traditional method.Sample inspections of 60 wells shows an average error of less than 10%.