变流量缝网压裂技术在松软煤层中的研究与应用

水力压裂是提高煤层瓦斯抽采效率的常用增透措施之一，在常规水力压裂的基础上，根据松软煤层缝网压裂的机理及力学原理，推导出了含天然裂隙的松软煤层产生缝网，需施工裂缝内的净压力大于煤储层水平应力之间的差值，同时对裂缝进行模拟，得出变流量注入可以提高裂缝内净压力，形成缝网结构，并在平煤十二矿己₁₅-31040采面进行水力压裂现场试验。试验结果表明:采用变流量缝网压裂水力压裂保压压力、累计注水量等相关参数以及单孔瓦斯抽采浓度、纯量均高于原始煤层及稳定流量常规压裂，说明变流量缝网压裂增透效果明显较好，该方法可以作为水力压裂增透技术借鉴的一种方法。

Research on variable flow network fracturing technology and its application in soft coal seam

Hydraulic fracturing is commonly used to improve coal seam gas extraction efficiency one anti-reflection measures，based on the basis of conventional hydraulic fracturing，puts forward the seam fracturing mechanism，
and on this basis，according to the soft coal seam fracture mechanics principle，derived the joint network with natural fractures of soft coal seam，to construction cracks within the net pressure is greater than the difference in value between coal reservoir horizontal stress，for simulating crack at the same time.It was concluded that variable flow injection can increase the net pressure in fracture and form fracture network structure，hydraulic fracturing field test was carried out in Ⅵ-31040 mining face of Pingdingshan No.12 Coal Mine. The test results showed that:after determination of prespliting and inspection hole fracturing pressure change of gas content and gas pressure is single span gas extraction concentration and scalar，the original coal seam and stable flow compared to conventional fracturing method，variable flow net seam fracturing antireflection effect is better，
this method can be used as hydraulic fracturing anti-reflection technology of a kind of method.