全国煤层气资源动态评价与可利用性分析

按照统一的全国油气资源评价方法体系框架,运用体积法,对陆上41个主要含煤盆地(群)煤层气资源的品质、分布状况以及可利用性进行了分析评价。结果表明:全国埋深2 000 m以浅的煤层气地质资源量为30.05×10~(12)m~3,可采资源量为12.50×10~(12)m~3。煤层气资源区域分布较为集中,鄂尔多斯、沁水等10个大型含气盆地煤层气资源占全国总量的85%以上,层系上主要分布在上古生界和中生界。煤层气整体品质一般,类型以II类为主,其次为Ⅰ类,可采性差异大,可采性较好的地区有限。与新一轮全国煤层气资源评价相比,本次动态评价地质资源量减少了6.76×10~(12)m~3,可采资源量增加了1.63×10~(12)m~3,主要由于含气量数据可靠程度增加和对埋深认识的变化。我国煤层气具有地面规模开发条件的可采资源量在4×10~(12)m~3左右。沁水、鄂尔多斯、滇东黔西、准噶尔等几个大型盆地具有优先开发的地质条件。

Dynamic assessment of coalbed methane resources and availability in China

Under the frame of oil and gas resources assessment method system,the coal-bed methane(CBM) resources of 41 major basins(basin groups) containing CBM were evaluated by volumetric method.The quality,distribution and availability of CBM resources were analyzed.The results show that the original CBM in-place is 30.05×1012 m3 in the coal layers with a burial depth of less than 2 000 m,of which 12.50×1012 m3 is ultimately recoverable.The CBM resources are concentrated in 10 large basins such as Ordos,Qinshui and so on,which account for more than 85% of national CBM resources.Resources are mainly distributed in Upper Palaeozoic and Mesozoic.The quality of resources is average.The main type is type II,followed by type I.There are great differences in the recoverability of CBM and limited areas with good recoverability.Compared with the latest evaluation,the original CBM in-place has decreased by 6.76×1012 m3,and the recoverable resources have increased by 1.63×1012 m3.It is mainly due to the increased reliability of gas content data and the changes in the understanding of buried depth.The reliable recoverable resources CBM is around 4×1012 m3 which have the conditions for development by ground technology.Several large basins have priority development conditions,such as Qinshui,Ordos,Eastern Yunnan-Western Guizhou and Junggar.