论文部分内容阅读
为了探讨织金、纳雍地区煤层气的勘探开发潜力,运用各种测试手段从孔、裂隙系统角度研究了该区煤储层物性特征,分析了煤储层的聚气能力、渗流能力及其控制因素.研究后认为该区煤变质程度高,煤储层吸附能力强,对煤层气的吸附聚集较为有利;而煤储层渗流能力低,仅局部地区存在高渗条件,不利于煤层气的产出;煤储层物性特征受控于该区复杂的构造条件,前燕山期的深成变质作用使得煤岩吸附能力增强,渗流能力下降,而燕山期强烈的构造运动使得断裂带附近的煤储层吸附能力和渗流能力整体增大,改善了局部地区煤储层物性特征.研究结果表明:织金、纳雍地区煤储层孔隙中以吸附孔为主,吸附孔隙百分比为50.61%～89.71%,吸附能力较强;而煤储层渗流孔隙百分比仅为21.14%,且煤岩显微裂隙密度普遍低于100条/9cm2,裂隙连通性较差,煤储层的渗透率相对较低;强烈的构造活动产生了大量的断层,地下的岩浆热液通过断层向上侵入,使得局部地区煤的变质程度迅速增加,同时产生大量的孔裂隙,改善了断层发育区附近煤储层的孔渗条件,后期的矿化作用充填了部分孔裂隙,一定程度上控制了煤储层物性,不利于后期的煤层气开发.
In order to discuss the exploration and development potential of coalbed methane in Zhijin and Nayong areas, various physical and chemical properties of coal reservoir in this area were studied by using various testing methods from the perspective of pore and fracture system. The gas gathering ability and seepage capacity of coal reservoir were analyzed Control factors.After the study, it is considered that the coal metamorphism in this area is high, the adsorption ability of coal reservoirs is strong, which is more favorable for the adsorption and aggregation of coalbed methane. However, the seepage capacity of coal reservoirs is low, and only high permeability exists in some areas, which is unfavorable to CBM Output. The physical property of coal reservoirs is controlled by the complicated structural conditions in the area. The deep metamorphism in the former Yanshanian period enhanced the adsorption capacity of coal and decreased the ability of seepage. However, the intense tectonic movement in the Yanshan Period led to the coal The adsorption capacity and seepage capacity of the reservoir are increased as a whole, which improves the physical properties of the coal reservoir in some areas. The results show that the pores in the coal reservoirs in Zhijin and Nayong are dominated by adsorption pores and the percentage of adsorption pores is 50.61% ~ 89.71 %, And strong adsorption capacity. However, the percentage of seepage pores in coal reservoirs is only 21.14%, and the density of micro-fractures in coal rocks is generally less than 100 / 9cm2. The fracture connectivity is poor and the permeability of coal reservoirs is relatively low. strong The tectonic activities produced a large number of faults. The underground magmatic hydrothermal fluids invaded upwards through the faults, causing the degree of coal metamorphism in local areas to increase rapidly. At the same time, a large number of pore fissures were produced, which improved the porosity and permeability of coal reservoirs near the fault zone. Of the mineralization filled part of the pore fissures, to a certain extent, control the physical properties of coal reserves, is not conducive to the late CBM development.