摘要
水压致裂后煤岩应力分布规律对水压致裂防冲效果起关键性作用。采用理论研究方法得出高压注水压致裂后及卸水后水区和气区的孔隙、瓦斯压力和煤体应力解析解。结果表明,致裂后水区孔隙压力沿径向变化不大,与注水压力接近;气区瓦斯压力沿径向呈递减趋势;在水区外围一定范围内形成瓦斯压力升高区;水区煤体环向应力将会减小,直到变为拉应力;气区煤体径向应力沿径向递减。卸水后水区孔隙压力、煤体径向应力沿径向呈递增趋势;气区煤体径向应力沿径向呈递增趋势,趋近于原始煤体应力;气区煤体环向应力沿径向呈递减趋势;气区孔隙压力沿径向呈递减趋势。这为煤层水压致裂预防冲击地压提供理论基础。
The law of coal and rock stress distribution after hydraulic fracturing plays a key role in the effect ofscour prevention. the theoretical method was used to study the fracture distribution of water area and gas area,methane pressure and analytical solution of stress on coal seam after hydraulic fracturing and water pressure relief.Study shows that the pore pressure of water area changes little along the radial direction after hydraulic fracturingand is close to water injection pressure, gas pressure of gas area showes a decreasing trend along the radial direction.In a certain extent, the gas pressure rise area is formed in the periphery of the water area. The circumferentialstress in the water area of the coal body will be reduced until it becoms tensile stress. Radial stress of coal body ingas area shows a decreasing trend along the radial direction. While after the water pressure is relieved, the porepressure and radial stress of coal body in water and gas area both show a decreasing trend along the radial directionand the value of the radial stress of coal body in gas area is close to primary stress of coal body. The tangentialstress and pore pressure of coal body in gas area shows a decreasing trend along the radial direction. All of thestudies have provided the theoretical basis for using hydraulic fracturing to prevent rock burst.
作者
吴春野
殷志祥
唐治
WU Chunye;YIN Zhixiang;TANG Zhi(Liaoning Technical University, Fuxin 123000, China;Tiandi Science and Technology Co., Ltd., Beijing 100013, China)
出处
《煤田地质与勘探》
CAS
CSCD
北大核心
2016年第4期114-118,共5页
Coal Geology & Exploration
关键词
水压致裂
冲击地压
煤岩应力
理论推导
hydraulic fracturing
rock burst
coal stress
theoretical derivation
