贵州绥阳地区下寒武统牛蹄塘组页岩气地质特征及勘探方向

Geological Characteristics and Exploration Prospect of Lower Cambrian Niutitang Shale Gas in Suiyang Area, Guizhou

贵州绥阳地区广泛发育下寒武统牛蹄塘组海相黑色碳质页岩.页岩的厚度在30-50 m,埋藏深度小于3 000 m, 具有较好的区域性封盖层,保存条件良好,是区内主要的页岩气目的层.页岩的有机质丰度roc为3.0%,,成熟度R0为1.0%-3.5%.推测总含气量为0.3-1.2m^3/t,地质资源量为639.5×l0^8m^3,资源潜力较大.页岩气可在区内隆起的低部 位等处富集成藏.综合页岩气的区域地质特征和保存条件,提出了绥阳地区东北部是今后页岩气的重点勘探区域.

Based on observation and analysis of samples from outcrops and wells,a set of 30~50m thick Lower Cambrian Niutitang carbonaceous black shale is deep buried in Suiyang area,in the north of Guizhou.Thick regional overlying cap make the shale good condition of gas preservation so it is a good target of shale gas prospect in Guizhou.The analysis result shows that TOC is in the range of 1.5%~3% and Ro changes in 1.0%~3.5% in the gas-bearing black shale.The total desorbed gas content of 0.3~1.2m3/t and the potential gas reserves of 639.5 × 108m3 mean great resources potential in this area.It is indicated that shale gas can accumulate in the low positions of arches in this area.It is suggested that the best favorable prospecting area of shale gas is in the northeast of Suiyang area in the future.