渝东南黔江地区龙马溪组页岩气储层测井解释评价研究

Well logging interpretation and evaluation of gas shale reservoir at Longmaxi formation in Qianjiang area of Southeast of Chongqing area

渝东南黔江地区地质构造复杂,广泛发育海相沉积的黑色页岩.区内龙马溪组页岩气储层地球物理响应具有高伽马、低密度、低孔隙度、低渗透率的特征.综合岩心分析、常规测井和特殊测井资料建立了测井解释模型,对研究区龙马溪组页岩气储层的有机碳含量(TOC)、储层物性、裂缝特征等进行了解释评价.研究表明,该区龙马溪组共发育3套优质页岩储层,总厚度达74.8m.孔隙类型以基质孔隙为主,脆性矿物含量达58%～66%,TOC含量较高,顶部发育微裂缝,具有较好的开发潜力.

The geological structure is complicated in Qianjiang,southeast of Chongqing. The black shale in Longmaxi formation from marine sedimentary is widely distribution.The geophysical characteristics are respond to high gamma ray,low density,porosity and ultralow permeability.The total organic carbon（TOC）content,reservoir properties and fracture characteristics are interpreted based on logging interpretation model, which is integrated with shale cores analysis,conventional and special logging data.The results show that the Longmaxi formation in the study area has three high grade sets of black shale reservoirs and the thickness is up to 74.8m.In this group,the matrix porosity is dominant among the pores,the content of brittle mineral is 58% ～ 66%,TOC is high,the micro-fracture is development at the bottom of the group.As a result,the study area has good development potential.