煤岩缝网改造关键因素分析及应用研究
发布时间：2019-05-18 13:14
【摘要】：为提高低渗煤层瓦斯抽采效率,在分析页岩气"缝网压裂"基础上,提出了煤矿井下煤岩储层缝网压裂的技术思路。通过分析影响缝网形成的关键因素,采用Mshale模拟水力压裂脆性指数-泊松比-单一水力裂缝体积三者关系,判断天然裂缝发生张性断裂和剪切断裂的力学条件,试验模拟不同地应力差水力裂缝特征。研究表明:在注入量一定条件下,随着脆性指数增加,单一水力裂缝体积减小,水力裂缝数量增加;随着主应力差的增大,试样破裂面表面积增加且渐为粗糙,裂缝张开度减小;水力裂缝和天然裂缝相交角越小,水力裂缝越易沿天然裂缝剪切破坏;主应力差较小时,水力裂缝易出现转向、分叉等。在鹤壁中泰矿业有限公司进行了缝网压裂试验,压裂有效面积达21 666 m2,钻孔日抽采量是缝网压裂前的13倍,是常规水力压裂的2.6倍,采用CYT探测了水平剖面和垂直剖面视电阻率的变化,证实了水力压裂缝网的存在。
[Abstract]:In order to improve the efficiency of gas extraction in low permeability coal seam, based on the analysis of shale gas "fracture net fracturing", the technical idea of fracture net fracturing in underground coal and rock reservoir is put forward. By analyzing the key factors affecting the formation of fracture net, Mshale is used to simulate the relationship between hydraulic fracturing brittleness index, Poisson's ratio and single hydraulic fracture volume, and the mechanical conditions of tensile fracture and shear fracture of natural fracture are judged. The characteristics of hydraulic fissures with different ground stress differences are simulated. The results show that with the increase of brittleness index, the volume of single hydraulic fracture decreases and the number of hydraulic fracture increases. With the increase of principal stress difference, the surface area of the fracture surface increases and becomes rough, and the fracture opening decreases, and the smaller the intersection angle between the hydraulic fracture and the natural fracture, the easier the hydraulic fracture is to shear along the natural fracture. When the principal stress difference is small, hydraulic cracks are easy to appear steering, bifurcation and so on. The fracture net fracturing test was carried out in Hebi Zhongtai Mining Co., Ltd., the effective area of fracturing is 21 666 m 2, and the daily extraction amount of drilling is 13 times as much as that before fracture net fracturing and 2.6 times as much as that of conventional hydraulic fracturing. The apparent resistance of horizontal section and vertical section is detected by CYT, and the existence of hydraulic pressure fracture network is confirmed.
【作者单位】： 河南理工大学能源科学与工程学院;中原经济区煤层(页岩)气河南省协同创新中心;河南能源化工集团研究院有限公司;
【基金】：2015年河南省科技攻关资助项目(152102310095) 焦作市科技局科技攻关资助项目(应用基础研究)(2014400018)
【分类号】：TD712.6
，
本文编号：2480039
[Abstract]:In order to improve the efficiency of gas extraction in low permeability coal seam, based on the analysis of shale gas "fracture net fracturing", the technical idea of fracture net fracturing in underground coal and rock reservoir is put forward. By analyzing the key factors affecting the formation of fracture net, Mshale is used to simulate the relationship between hydraulic fracturing brittleness index, Poisson's ratio and single hydraulic fracture volume, and the mechanical conditions of tensile fracture and shear fracture of natural fracture are judged. The characteristics of hydraulic fissures with different ground stress differences are simulated. The results show that with the increase of brittleness index, the volume of single hydraulic fracture decreases and the number of hydraulic fracture increases. With the increase of principal stress difference, the surface area of the fracture surface increases and becomes rough, and the fracture opening decreases, and the smaller the intersection angle between the hydraulic fracture and the natural fracture, the easier the hydraulic fracture is to shear along the natural fracture. When the principal stress difference is small, hydraulic cracks are easy to appear steering, bifurcation and so on. The fracture net fracturing test was carried out in Hebi Zhongtai Mining Co., Ltd., the effective area of fracturing is 21 666 m 2, and the daily extraction amount of drilling is 13 times as much as that before fracture net fracturing and 2.6 times as much as that of conventional hydraulic fracturing. The apparent resistance of horizontal section and vertical section is detected by CYT, and the existence of hydraulic pressure fracture network is confirmed.
【作者单位】： 河南理工大学能源科学与工程学院;中原经济区煤层(页岩)气河南省协同创新中心;河南能源化工集团研究院有限公司;
【基金】：2015年河南省科技攻关资助项目(152102310095) 焦作市科技局科技攻关资助项目(应用基础研究)(2014400018)
【分类号】：TD712.6
，
本文编号：2480039
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