三江盆地绥滨断陷地质特征及煤层气资源潜力

Geological features and potential resources of coal bed methane in Suibin fault depression of Sanjiang Basin

三江盆地在晚侏罗—早白垩世为陆缘断陷盆地,其上叠加了新生代坳陷层序;经过晚白垩世的构造反转,现今呈改造残留型含煤盆地。绥滨断陷作为三江盆地的次一级构造单元,在下白垩统发育有多套煤系地层,成为重要的气态烃的来源。在研究绥滨断陷中生界地质特征的基础上,运用蒙特卡罗法重新计算了盆地内的煤层气资源量,确定了断陷内煤层气资源量的概率分布函数图,得出绥滨断陷煤层气资源量在0.1、0.5、0.9的概率下,分别为3.82×1011m3、2.85×1011m3、1.87×1011m3。研究结果表明,三江盆地绥滨断陷具有较好的煤层气资源潜力。

Sanjiang Basin was an epicontinental fault basin during Late Jurassic- Early Cretaceous, superimposed by the Cenozoic depression strata sequence, and it has become a relict coal-bearing basin after tectonic reverse in Late Cretaceous, now. The Suibin fault depression, as a sub-structural unit of the Saniiang Basin, was deposited many suits of coal in Early Cretaceous, which are the vital origin of gaseous hydrocarbon. On the basis of study of Mesozoic geological features, the resources of coal bed methane in the Suibin fault depression were recalculated by Mente-carlo method. A map of distribution function of coal bed methane was made, and the different possibilities of the resource were drawn. The resources of CBM in the Suibin fault depression at the probability of 0.1, 0.5, 0.9 are3.82×10^11m^3、2.85×10^11m^3、1.87×10^11m^3. The results show that Suibin fault depression has a good potential of coal bed methane resource.