四川盆地东南缘林滩场地区上奥陶统五峰组-龙马溪组页岩气储层甜点预测

Prediction of shale reservoir sweet spots of the Upper Ordovician Wufeng-Longmaxi Formations in Lintanchang area， southeastern margin of Sichuan Basin

葛勋 郭彤楼 马永生 王国力 黎茂稳 余小群 赵培荣 温真桃 王鹏

Xun Ge Tonglou Guo Yongsheng Ma Guoli Wang Maowen Li Xiaoqun Yu Peirong Zhao Zhentao Wen Peng Wang

中国石化西南油气分公司2017年在四川盆地东南缘林滩场完钻的探井林页1井，证实林滩场构造在奥陶纪末—早志留世处于深水陆棚有利相带，页岩气形成条件较好。为进一步落实该区勘探开发潜力，实现五峰组-龙马溪组页岩气的商业突破，对林滩场进行区域构造和沉积特征分析。在大量基础地质实验数据分析的基础上，优选总有机碳（）含量、有效孔隙度（）和含气量（）作为地质甜点评价参数，脆性指数（）和水平主应力差作为工程甜点评价参数，地层倾角、断裂影响和地层压力作为保存条件评价参数。利用叠前反演求取地震弹性参数（纵横波速度比、密度和泊松比），通过岩心样品测试分析数据、储层地质岩性特征以及储层岩石物理分析，建立储层评价参数与地震弹性参数之间的定量关系，根据定量关系利用叠前反演CRP道集内岩性信息的AVO特征，对各项页岩储层评价参数进行平面预测，最终优选出林滩场页岩气有利目标区。应用地质-测井-地球物理一体化方法对页岩储层甜点区做出精准平面预测，对实现川东南盆缘复杂构造区页岩气勘探开发一体化具有重要的指导意义。

Well LY 1， an exploration well drilled by Sinopec Southwest Oil & Gas Company in the southeastern margin of Sichuan Basin in 2017， has proven that the Lintanchang structure was in a zone of deep water shelf facies during the Late Ordovician to Early Silurian， favorable for shale gas generation. In order to further explore the shale gas potential in this area and realize commercial breakthrough in shale gas development in the Wufeng-Longmaxi Formations， the study analyzes the structure and sedimentary features of Lintanchang area. Based on an array of geological data for tests， we select the content， effective porosity and gas content of high-quality shale as the key parameters for evaluating the geological sweet spots， brittleness index and horizontal principal stress difference for determining engineering sweet spots， and dip angle， fracture influence and formation pressure for assessing preservation conditions. Seismic elastic parameters （including transverse to longitudinal velocity ratio， density and Poisson’s ratio） are obtained by pre-stack inversion. The quantitative relationship between reservoir evaluation parameters and seismic elastic parameters is established by core sample tests， as well as petrophysical analysis and lithologic characters of reservoir rocks. In addition， the AVO characteristics of lithologic information in CRP gathers are applied to predict planar changes of the shale reservoir parameters related， and eventually the favorable shale gas target in the Lintanchang structure is determined. The accurate planar mapping of shale reservoir sweet spots in structurally complex areas in the southeastern margin of the Sichuan Basin by a combination of geological-logging-geophysical methods is of guiding significance to the integrated exploration and development of shale gas therein.

10.11743/ogg20220312