导向槽定向水力压穿增透技术研究与应用

Study and application of guide slot directional hydraulic pressurized penetration and permeability improved technology

基于弹性力学理论和岩石破裂准则,建立了煤层水力压裂中的二维垂直裂缝诱导应力场计算模型,得出合理布置导向槽与控制钻孔位置及压裂顺序能够实现压裂裂缝转向形成网状裂隙。基于此提出导向槽定向水力压穿增透技术,利用导向槽和控制钻孔共同定向作用可实现导向槽钻孔与控制钻孔间煤体定向水力压穿,形成贯穿裂隙并通过高压水携带出大量煤屑,从而有效地实现煤层卸压和增加煤层透气性。进而研发出导向槽定向水力压穿成套装备,阐述了导向槽定向水力压穿增透工艺。现场应用表明:导向槽定向水力压穿技术能够有效预置导向槽,实现定向水力压穿,瓦斯抽采体积分数提高75%,单孔瓦斯抽采量提高了193%,区域消突措施有效。

Based on the elastic mechanics theory and the rock fracturing criterion,a calculation model of the two- dimensional induced stress field in the seam hydraulic fracturing was established and the rational set guide slot and the control borehole location and the fracturing sequence obtained could realize the fractured cracks changed to form net cracks. Based on the circumstances,the guide slot directional hydraulic pressurized penetration and permeability improved technology were provided,the application of the joint directional function of the guide slot and control borehole could realize the directional hydraulic pressurized penetration of the coal between the guide slot borehole and the control borehole,which would form the penetrated cracks and could clean the great coal cuttings with the high pressurized water and thus the seam pressure released and the seam permeability improved could be realized. Therefore,a completed set of the guide slot directional hydraulic pressurized penetration equipment was researched and developed and the guide slot directional hydraulic pressurized penetration and permeability improved technique was stated. The site application showed that the guide slot directional hydraulic pressurized penetration technology could effectively preset the guide slot and could realize the direction hydraulic pressurized penetration. The gas drainage volume fraction was improved by 75%,the gas drainage quantity from a single borehole was improved by 193%,the regional outburst elimination measures were effective.