孤北古1井上古生界煤成气藏成藏特征分析

Accumulating characteristic of Upper Paleozoic coal-genetic gas pool of well Gubeigu 1

目的研究孤北古1井的气藏特征及成藏过程。方法对孤北古1井的生、储、盖条件进行地质分析,用模拟实验分析天然气的运移、聚集规律,结合两者综合分析孤北古1井的成藏特征。结果孤北古1井烃源岩主要为上古生界石炭—二叠系的煤系地层,储集层主要为上古生界的上、下石盒子组和山西组砂岩,为低孔低渗储层,气藏为低幅背斜圈闭气藏;孤北古1井烃源岩与储集层空间分离,断裂是天然气从烃源岩向储集层运移的主要通道。结论孤北古1井成气期主要在第三纪末—第四纪的沉降埋藏期,由于断裂和裂缝的产生使天然气从烃源岩中运移出来,并通过断裂和裂缝运移至构造高部位聚集成藏。

Aim To study the Upper Paleozoic coal-genetic gas pool characteristic and accumulating process of well Gubeigu I. Methods The geological methods are used to analyze source rock, reservoir and overlying formation of well Gubeigu 1. The simulating tests are used to analyze migration and accumulation of gas. Both are used synthetically to analyze the accumulating characteristic of well Gubeigu 1. Results The source rock of well Gubeigu 1 is mainly coal measure strata of Neopaleozoic Permo-carboniferous. The reservior is mainly in the upper and lower Shihezi Geogrop and Shanxi Geogrop sandstone. Gas is in a low amplitude anticlinal trap. The soure rock and reservior of well Gubeigu 1 separate in space. Conclusion The gas of well Gubeigu 1 was produced during subsidence and was buried in Tertiary. The gas mierates and accumulates from source rock to reservoir through fractures.