黔西地区煤储层物性差异及其成因机制分析

摘要

In order to explore the potential of coalbed methane exploration and development in Qianxi District,based on various tests,the differences in physical properties(such as the pore structure,adsorptivity,porosity and permeability,etc.)of coal reservoirs in two typical areas(Zhina and Panguan)were systematically analyzed,and the origin mechanism of their differences were furthermore deeply analyzed. The results show that the differences in physical properties of coal reservoirs in Qianxi District are mainly controlled by the evolution degree of coal reservoirs.The evolution degree is dominated by the sedimentary and burial history as well as the tectonic thermal events afterwards. The sedimentary and burial history determines the differences in coal ranks between Zhina area and Panguan area,while the tectonic ther-mal events are the main controlling factors of their internal differences in coal ranks.Resulting from the various sedimentary and burial his-tory or tectonic thermal events,different evolution processes and physical-chemical structures generate,which in return determine the phys-ical properties of coal reservoirs in Qianxi District.%为了探究黔西地区煤层气勘探开发潜力，采用多种测试手段，系统分析了该地区2种典型区块（织纳和盘关）的煤储层在孔隙结构、吸附性、孔渗特征等方面的差异，并深入剖析了该差异的形成机制。结果表明：黔西地区煤储层物性差异的主控因素是煤的变质程度，而煤的变质程度又受控于煤层的沉积埋藏史和后期的构造热事件；沉积埋藏史决定了织纳和盘关两区之间的煤阶差异，而后期的构造热事件是织纳和盘关地区内部煤阶差异的主控因素。不同的沉积埋藏史及构造热事件产生了不同的煤化作用史，导致了煤岩在物理、化学结构上的差异，从而决定了黔西地区煤储层物性的差异。