鹤岗矿区煤层气成藏控气因素分析

FACTORS' ANALYSES ON THE CBM RESERVOIR ACCUMULATION AND GAS CONTROL IN HEGANG LEASE

鹤岗盆地煤层厚度大、埋藏适中、含气量较高,显示出较好的生气能力,但尚未获得工业气流。依据煤矿井、实验分析及地震等现有资料,综合分析了煤层的厚度、埋深、演化程度、渗透性、含气性以及气保存条件等5个成藏控气要素。研究认为:新一矿部分地区煤层曾受过岩浆作用,煤阶大幅提升,生气能力变好;南一、新一矿区煤层厚度大、分布面积广、埋深适宜、保存条件好,是下步勘探的最有利区;断层发育程度以及顶、底板封盖条件是制约煤层气成藏规模的关键因素。

The coal beds in Hegang Lease are characterized by big thickness, moderate buried depth and much higher gas resources, and moreover show pretty favorite gas productivity, but can not reach the industrial standards. On the bases of the following existed data such as wells, experimental analyses, seismic informations and so on, five key reservoir-accumulating and gas controlling factors are comprehensively analyzed： seam thickness, buried depth, evolution degree, permeability, gas-bearing and preserving conditions. The studies prove that partial coal seams in Xinyi Block have undergone magmatic action, the coal rank is enhanced higher, so the CBM productivity becomes much better; the coal beds in Nanyi and Xinyi Blocks are pretty thick and wide-distributed, the buried depth is moderate, the preserving conditions are much better, so they are the next preferential exploration areas; the developed degree of the faults and the sealing condition of top and bottom plates are the key factors of controlling the size of CBM reservoir accumulation.