页岩微观力学性质是页岩油气储层可压性评价、压裂工程甜点优选的关键依据。以四川盆地龙马溪组海相页岩，内蒙古石拐盆地长汉沟组、新疆塔里木盆地杨叶组陆相页岩为对象，采用纳米压痕试验获取不同沉积相页岩弹性力学性质、硬度、断裂韧度参数信息，提出一种基于加−卸载全程能耗比的页岩脆性评价方法，并结合不同沉积相页岩微观力学性质构建了弹脆性、弹塑性、塑性页岩微观断裂机理及储层压裂裂缝延展形式，最后提出页岩储层工程力学品质评价指标体系，结果表明：四川盆地、内蒙古石拐盆地、新疆塔里木盆地页岩加−卸载曲线滞回环依次增大，表明上述地区页岩塑性形变能占比随之增高，对外部能量吸收效率增强，指示岩石脆性减弱。试验显示四川、石拐、塔里木盆地页岩弹模/硬度为60.27/3.05 GPa、34.87/1.21 Gpa、23.40/0.57 Gpa，断裂韧度分别为1.56、0.75、0.28 MPa·m^0.5，不同沉积相页岩刚度韧性差异很大，其中四川盆地海相页岩断裂韧度高于石拐、塔里木盆地陆相页岩，能够形成高的裂缝净压力助推裂缝转向，利于营造复杂缝网；而陆相页岩断裂韧度较低不利于裂缝流体憋压，很难达到高的裂缝流体净压力，裂缝转向困难不利于形成复杂压裂缝网；笔者提出利用压痕实验全程弹性能与塑性能与断裂能和的比(脆性系数)评价页岩脆性，其中四川页岩脆性系数为0.89，属于弹脆性页岩，外载下裂缝沿矿物晶界开裂形成窄缝；石拐页岩脆性系数为0.27，属于弹塑性页岩，储层非均质性强，裂缝遇到坚硬矿物绕行形成曲折裂缝裂缝；塔里木盆地页岩脆性系数0.04，为塑性页岩，易形成宽缝；笔者综合岩石弹性模量、硬度、断裂性能、脆性指数、黏土矿物含量、矿物接触方式等7类指标综合提出一种页岩工程力学品质的分类评价方法，以期为页岩储层压裂品质评价及压裂工程甜点优选提供定量化科学依据。

The micromechanical properties of shale are the key basis for shale reservoir compressibility evaluation. In this paper, the Marine shales of Longmaxi Formation in Sichuan Basin, Changhanguou Formation in Shiguai Basin in Inner Mongolia and Yangye Formation continental shales in Tarim Basin are selected as objects. The elastic mechanical properties, hardness, and fracture toughness parameters of shales are obtained by nano-indentation test. A method for evaluating shale brittleness is proposed. The fracture extension forms of reservoir fracturing are constructed. Finally, the evaluation index system of shale reservoir engineering mechanical quality is proposed. The results show that: The hysteretic loops of shale loading and unloading curves in Sichuan Basin, Shiguai Basin in Inner Mongolia and southwestern Tarim Basin increase, indicating that the proportion of plastic deformation energy of shale increases, indicating that rock brittleness is weakened. The test results show that the shale elastic modulus/hardness of Sichuan, Shiguai and Tarim basins are 60.27/3.05 GPa, 34.87/1.21 Gpa and 23.40/0.57 Gpa, and the fracture toughness is 1.56, 0.75 and 0.28 MPa·m^0.5, respectively. The stiffness and toughness of these shale rocks vary greatly. The fracture toughness of southern Sichuan shales is higher than that of Shiguai and southwest Tarim continental shales, which can form high net fracture pressure to form fracture turning and facilitate the construction of complex fracture network. However, the low fracture toughness of continental shale is not conducive to the pressure holding of fracture fluid, and it is difficult to reach the high net fracture fluid pressure, and the difficulty of fracture steering is not conducive to the formation of complex pressure fracture network. In this paper, the ratio of elastic energy, plastic energy and fracture energy during the indentation process (brittleness coefficient) is proposed to evaluate the brittleness of shale. The brittleness coefficient of Sichuan shale is 0.89, which belongs to elastic-brittleness shale, and the fractures under external load crack along mineral grain boundaries to form narrow cracks. The brittleness coefficient of crutchy shale is 0.27, which belongs to elastoplastic shale. The reservoir is highly heterogeneous, and the fractures form tortuous fractures when they encounter hard minerals. The brittleness coefficient of shale in Tarim Basin is 0.04, which is plastic shale and easy to form wide fractures. In this paper, a quantitative classification evaluation method for shale engineering mechanical quality is proposed based on seven indexes, including rock elastic modulus, hardness, fracture property, brittleness index, clay mineral content and mineral contact mode, in order to provide a quantitative scientific basis for shale reservoir fracturing quality evaluation and optimal selection of fracturing engineering desserts.