贵州凤冈区牛蹄塘组页岩气成藏条件分析

Analysis of Shale Gas Accumulation Conditions of Niutitang Fm in Fenggang Area,Guizhou

对贵州凤冈区野外实地调研,测绘野外露头剖面,并对目的层黑色页岩进行系统采样,利用XRD、压汞、SEM、等温吸附等手段对所采露头样品进行测试分析。结合收集资料及本次测试结果综合研究认为,牛蹄塘组黑色页岩TOC大于2%,厚度为45.1 m,Ro为2.67%~3.13%,有机质类型为Ⅰ型,孔隙度为0.71%~1.09%,微孔隙比较发育且连通性较好,含气量达1.70 m3/t,埋深普遍为500~3 500 m,具有较好的页岩气成藏条件,并采用综合信息叠加法,预测马山—复兴—洗马一带为勘探有利区。

Field survey,description of field outcrops and systematic sampling of black shale in target formations have been performed in Fenggang area,Guizhou Province. In addition,XRD,mercury penetration,SEM,isothermal adsorption and other techniques are mobilized to test and analyze outcrop samples. Combining the study results and the collected data,it is found that the black shale in the Niutitang Fm has TOC of more than 2%,thickness of 45. 1 m,Roof 2. 67%- 3. 13% with Type I organic matters,and porosity of 0. 71%- 1. 09%. It has micro- pores well developed with superior connectivity,gas content up to 1. 70 m3/t and average buried depth of 500- 3 500 m. The formation has favorable accumulation conditions for shale gas. Through overlapping of available data,the Mashan- Fuxing- Xima can be determined as the favorable exploration belt.