建南A井页岩气储层压裂改造潜力评价方法

Potential Evaluation Method for Shale Gas Reservoir Fracturing Remake of Well-A in Jiannan

岩石力学实验证明，弹性参数计算的脆性相较于通过脆性矿物成分计算的脆性指数能更好地表征岩石的脆性。而面缝率与泊松比、杨氏模量以及破裂压力的交汇关系表明，脆性与归一化后的破裂压力比值能较好地表现储层岩石在力学方面的压裂潜力。脆性矿物含量高以及粘土中伊利石含量高的储层具有较好的压裂潜力，天然裂缝发育的规模和倾角也是不可或缺的考虑因素。以此方法对建南A井进行评价，认为该井最适合进行压裂施工的层段在610-630m，并在610-646m进行试气压裂。压裂后，天然气最高产量为4000m^3／d，稳定产1860-2200m^3／d，证明了评价过程的合理性。

Rock mechanics experiment results show that brittleness index worked out by elastic parameter can better represent rocky brittleness compared to that worked out by brittle mineral composition. Intersection relationship among topstitching rate and Poisson ratio, Young modulus and fracture pressure shows that brittleness and normalized fracture pressure specific value can determine whether reservoir rocks have fracturing potential and that the reservoir with high contents of brittle mineral and illite in clay has better fracturing potential, taking the developmental scale and dip angle of natural fractures into consideration. By evaluating Well-A based on this method, this paper determines that the most suitable fracturing interval of this well is from 610 m to 630 rn. Gas test-oriented fracturing has been done between 610 m and 546 m with maximum production of natural gas 4 000 m^3 a day and stable production between 1 860 ms and 2 200 m^3 a day, proving the rationality in evaluation process.