测井在寺家庄煤层地应力研究中的应用

Application of Logging Data in Study of Coal Seam Stress in Sijiazhuang Minefield

为了预先获知阳泉矿区寺家庄井田待压裂煤层所在位置和层位的地应力大小和方位,从而提高煤层气井压裂的效果,有效构建煤层气井开发层位的裂隙缝网系统,针对8#煤层和15^#煤层开展了注入压降试验。结果显示:8^#煤闭合压力为9.70~12.10 MPa,破裂压力为10.60~12.80 MPa,储层压力为1.50~1.90 MPa;15^#煤闭合压力为9.40~11.70 MPa,破裂压力为9.60~12.10 MPa,储层压力为1.60~2.00 MPa,均属于低压储层。在此基础上建立了运用测井资料计算垂直应力、最大主应力和最小主应力的方位和大小的方法。该计算方法计算结果与实验测定结果接近,能够满足生产需要。

In order to know the stress magnitude and orientation of position and stratum of the coalbed to be fractured in Sijiazhuang minefield of Yangquan mining area in advance,so as to improve the fracturing effect of CBM wells and effectively constructing fracture network system in coalbed methane development layer,the injection pressure drop experiment was carried out for 8^#and 15^#coal seams.The results showed:closure pressure of 8^#coal was between 9.70 and 12.10 MPa,fracture pressure was between 10.60 and 12.80 MPa and reservoir pressure was between 1.50 and 1.90 MPa;closure pressure of15^#coal was 9.40 and 11.70 MPa,fracture pressure was between 9.60 and 12.10 MPa and reservoir pressure was between 1.60 and 2.00 MPa.Both 8^#coalbed and 15^#coalbed belonged to low pressure reservoir.On this basis,a method for calculating the orientation and magnitude of vertical stress,maximum principal stress and minimum principal stress by using logging data was established.The calculation results were closed to the experimental results and could meet the production needs.