深井延迟长脉冲燃爆压裂火药优配与评价

针对燃爆压裂火药爆燃加载速率快、措施安全与裂缝规模难以平衡的问题,基于对成熟火箭推进剂配方的深入考察,借助密闭爆发器、燃速测试仪、落锤仪、摩擦感度仪和差热分析仪等实验设备,筛选优化了延迟长脉冲燃爆压裂火药配方,测试并得到了其从低压到高压的燃速图版,评价了其爆燃加载特性.结果表明,相对传统燃爆压裂火药,该延迟长脉冲火药燃速更低、持压时间更长,且具有较强的耐撞击、摩擦和高温性能,适用于深层、超高压地层油气井.在20℃下测试,延迟长脉冲火药在7 MPa下爆燃加载持压时间78.1ms,为传统燃爆火药的2.12倍;45~70MPa超高压环境下燃速36.4~39.5mm/s,低于传统燃爆火药燃速一半,可有效提高燃爆压裂火药最大装药量、扩大裂缝延伸长度和破裂规模.

The formula optimization and evaluation of explosive fracturing gunpowder in deep wells

For the issues of quick deflagration loading rate of explosive fracturing gunpowder, unbalance between measure security and crack scale, based on the in-depth investigation on propellant powder formulations, by means of experimental equipment as confined explosive devices,burning rate tester,falling weight instrument,the friction sensitivity device and the differential thermal analyzer to screen and optimize formulations of delay long pulse explosive fracturing powder. Then test and obtained the burning rate plate from low to high pressure,and evaluate the deflagration loading feature. The results show that according to the traditional explosive fracturing gunpowder, the delay long pulse powder has lower burning rate, longer holding pressure time, excellent resistance to impact and friction properties, and high temperature performance,which is suitable for deep and high pressure wells. At 20 ℃ and 7 MPa,the deflagration loading time of the powder is 78.1 ms, which is 2.12 times longer than that of traditional high-energy gas powder;at 45～70 MPa,the burning rate of former is 36.4 ～39.5 mm/s,which is half of the latter. Therefore,it can effectively upgrade the maximum loading dose of HEGF and expand the length of crack and the scale of fracturing.