Abstract:

Three kinds of fractures, i.e., regional, local and compound fractures, are present in the petroliferous Lower Jurassic Series in the western edge of the central segment of Huaying Mountain, Sichuan basin. The regional fractures ( joints ) include 4 sets which make up 2 sys tems, and are characterized by steady strikes, deep cut, long stretches and being vertical to the stratification plane. Each set of the joints has the same original strike, and the distribution of the joints is controlled by the nature of the rock and the thickness of the strata, and not by the structure.In comparison, the distribution of the local fractures is controlled not only by the nature of the rock and the thickness of the strata, by also by the structural feature. Local fractures are smaller in scale, shorter and typically wider than the regional ones. The compound fractures display the character of both regional and local fractures, with their distribution being only local, controlled by local structure features.

Key words: 下侏罗统, 裂缝, 特征, 分布, 研究