中文摘要：

页岩气是指赋存于富含有机质泥页岩中以吸附和游离状态为主要存在方式的天然气，中国资源量丰富，地域分布广泛.页岩气开采能缓解我国常规油气产量不足、煤化石燃料引起环境污染等问题，已成为中国绿色能源开发的重要领域.尽管北美页岩气“革命”取得了成功，目前也仅有预期产量5%15%的采收率.与北美地区相比，中国页岩气埋藏深，赋存条件差，自然丰度低，因此，高效开采面临更多的困难和挑战.近年来，围绕国家重大能源战略需求,瞄准技术发展前沿，学术界和工业界联合对页岩气高效开采的关键科学和技术问题展开研究.本文结合近三年四川、重庆地区的页岩气试验区块遇到的新问题，针对中国未来3500m以下深部开采的新挑战，如地质沉积、裂缝发育构造不同、上覆压力增加、水平应力场变化等新问题，介绍和总结了目前中国页岩气高效开采面临的力学科学问题，主要包括多重耦合下的安全优质钻完井力学理论和方法、水力压裂体积改造和多尺度缝网形成机制、多尺度渗流力学特性与解吸附机理等.“深部页岩气高效开采”的研究面向国家重大能源需求，科学意义重大，工程背景明确，需要工程力学、石油工程、地球物理、化学工程和环境工程等多学科专家合作，开展理论研究、物理模拟、数值模拟及现场试验等综合应用基础研究，取得高效开采页岩油气理论与技术的突破.学科交叉是研究页岩气高效开采问题、突破技术瓶颈的桥梁，只有力学与石油工程、地球科学等学科实现深度交叉融合，才能更加有效地推动页岩油气等非常规油气资源的开发.

英文摘要：

Shale gas is unconventional natural gas stored in shale in free or absorbed forms and sometimes in free fluid phase.The exploitation of shale gas has become a promising field of green energy development in China.Although great success has been achieved in shale gas revolution in North America with the technique of hydraulic fracturing,there is only5%_15%of the stored oil and gas could be exploited,which is still a puzzle for petroleum engineers.Compared with the North America,China's shale gas reservoirs are deep burial,the geologic construction conditions are complicated and natural quality is low,therefore,e_cient exploitation is facing more di_culties and challenges.In recent years,aiming at the national major energy strategy and the frontier of technological development,China's academia and industry have carried out the preliminary study on some of the key scientific and technical issues.Around the new issues encountered in the shale gas extraction in Sichuan and Chongqing areas in recent three years,this paper introduces and summarizes the key mechanics problems and challenges that the high e_cient shale gas extraction is facing,mainly includes the multifield coupling safe and high quality drilling mechanics,hydraulic fracturing and multi-scale fracture network formation mechanism and multi-scale seepage and desorption mechanism of shale gas,to solve the challenges in deep exploitation below3500meters in China,such as geologic sedimentation,di_erent fracture development,increasing overburden pressure,the change of horizontal stress,etc.The deep shale gas exploitation is not only to adapt to the national energy demand,but also has scientific and engineering significance.To realize the e_cient exploitation of shale oil and gas,it needs the interdisciplinary collaboration of mechanical engineering,petroleum engineering,geophysics,chemical engineering and environmental engineering to carry out basic theoretical research,physical simulation,numerical simulation and field experiment.It has been recognized that int