Fracability is a property widely used to evaluate whether reservoirs can effectively fracture to increase production capacity. The brittleness index, which is used to evaluate reservoir fracability, is calculated via various methods, and the evaluation process of the brittleness index is complicated and not sufficiently intuitive. Thus, we used triangle method to evaluate reservoir fracability. The shale composition is classified into strong (quartz + pyrite), moderate (carbonate + plagioclase + siderite), and poor (clay + TOC + porosity) fracability based on the mechanical parameters of each shale component, which were integrated as the endpoints of the triangle method. Meanwhile, the triangle method is divided into four fracability evaluation grades: strong (I), moderate (II), weak (III) and poor (IV) fracability; each major evaluation grade has four sub-categories: best for fracturing (1), better for fracturing (2), poor for fracturing (3) and worst for fracturing (4). The triangle method is simpler and more convenient than the conventional method, dividing the fracability evaluation grades more specifically. The difference in fracability between samples can be shown intuitively, which enhances the accuracy and reliability of the evaluation of transitional shales and provides theoretical support for reservoir reconstruction.

压裂性是一种广泛用于评估储层是否能够有效压裂以提高生产能力的属性。用于评价储层压裂性的脆性指数通过多种方法计算，脆性指数的评价过程复杂且不够直观。因此，我们使用三角形方法来评估储层的可压性。根据页岩各组分的力学参数，将页岩成分分为强（石英+黄铁矿）、中等（碳酸盐+斜长石+菱铁矿）和差（粘土+TOC+孔隙度）可压性，综合作为终点三角法。同时，三角法分为四个压裂性评价等级：强（I）、中（II）、弱（III）和差（IV）压裂性；每个主要评价等级有四个子类别：压裂最佳（1）、压裂较好（2）、压裂差（3）和压裂最差（4）。三角法比传统方法更简单方便，更具体地划分了可压性评价等级。样品之间的可压裂性差异可以直观地展现出来，提高了过渡页岩评价的准确性和可靠性，为储层改造提供了理论支持。