基于地质构造分区的瓦斯地质单元区划方法

Gas Geological Unit Dividing Method Based on Geological Structure Zoning

瓦斯地质单元的合理划分是矿井瓦斯分区分级治理的前提和基础,同时也是正确认识井田瓦斯赋存特征的依据。以瓦斯指标为主的传统瓦斯地质区划往往不能真实反映区域瓦斯的波动,尤其是对复杂地质条件下煤层瓦斯预判结果失真,从而导致瓦斯事故频发。在分析井田地质构造特征及区域构造演化的基础上,运用构造地质学、瓦斯地质学等理论与方法,以地质构造定量评价为基础,提出以构造等性块段法来划分井田构造分区的方法,采用块段构造指标分别描述不同地质块段构造复杂程度,建立地质构造自然边界和人工边界来区划不同瓦斯地质单元方法。以城郊井田为例,选择断层、褶皱、岩浆侵入3个地质指标对井田构造复杂程度进行评价,并进行了瓦斯区划应用研究。结果显示:运用该方法可以对复杂地质条件下不同瓦斯地质单元进行较准确划分,城郊井田共划分出5个相对独立的瓦斯地质单元,分别研究了5个单元的瓦斯赋存特征。

The reasonable dividing of gas geological units is the premise and basis for the classification and management of mine gas zones, and it is also the basis for correctly understanding gas law of mine fields. Traditional gas geological dividing methods based on gas indicators often fail to truly reflect regional gas fluctuations, especially coal seam gas prediction results show wrong and distortion under complex geological conditions, leading to frequent gas accidents. Based on the analysis of the geological structure characteristics and regional structural evolution of mine fields and structural geology, gas geology, and other theories and methods, using the quantitative evaluation way of geological structures,presents to use the structural isomorphic block method to divide whole field into structural zones. The method uses block structural indicators to describe the structural complexity of different geological zones, and establishes natural and artificial boundaries of geological structures to distinguish different gas and geological units. Taking Chengjiao mine field as an example, three geological indicators, as fault, fold and magma intrusion, were chosen to evaluate the complexity of the field structure and to conduct gas zoning application study. The results show that this method can be used to accurately divide the whole field into different gas geological units under complex geological conditions. There are5 relatively independent gas geological units in the Chengjiao mine, and then the gas occurrence characteristics of the 5 units are studied.