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割理是广泛存在于煤层中对煤层气的产出具有重要意义的内生裂隙系统 ,是煤层经过干缩作用、煤化作用、岩化作用和构造压力等各种过程形成的天然裂隙。由于在煤层气勘探中 ,割理及割理渗透率形成与保存对煤层气高产富集区预测有着重要意义 ,所以了解割理的成因和分类及相应的研究方法对煤层气地质选区评价至关重要。本次研究结论如下 :①割理形成既有外生成因 ,也有内生成因。煤层割理是干缩作用、煤化作用、成岩作用及古构造应力等内外地质作用共同作用的结果 ,双重成因假说更为贴切。②提出了一套研究煤层割理及割理系统的方法 ,并完善了用割理评价渗透率的方法。③通过对影响割理发育的内在因素的分析 ,认为割理是外在地质作用 (煤化作用、构造应力等 )通过煤层内在属性 (煤厚、煤岩组成、灰分等 )形成的 ,是各种地质作用在煤储层中的综合反映。煤层内在属性和外在地质作用缺一不可 ,这两者都是形成割理、改善煤层渗透性的必要条件。
Cleftness is an endogenous fracture system that is of great significance to the output of coalbed methane widely existing in coal seams. It is a natural fracture formed by various processes such as dry shrinkage, coalification, petrification and tectonic pressure. Since the formation and preservation of cuttings and cuttings permeability in coalbed methane exploration are of great significance for the prediction of high productivity and richness of coalbed methane, it is important to understand the causes and classification of cuttings and the corresponding research methods to evaluate the CBM geological selection important. The conclusions of this study are as follows: ① Cleft formation has both exogenous and endogenic causes. Coal seam cleavage is the result of synergy of internal and external geological processes such as dry shrinkage, coalification, diagenesis and palaeostructure stress. The double causal hypothesis is more appropriate. (2) A set of methods to study coal-bed cutting and cleaving system is put forward and the method to evaluate permeability by cleaving is improved. (3) By analyzing the internal factors that influence the development of cleavage, the cleavage is considered to be formed by the intrinsic geological features (coalification, tectonic stress, etc.) through the intrinsic properties of the coal seam (coal thickness, coal and rock composition, Geological role in the coal reservoir in a comprehensive reflection. Both intrinsic and extrinsic geological functions of the coal seam are indispensable, both of which are necessary conditions for forming a cleat and improving the permeability of the coal seam.