6 / 2022-11-14 13:41:13

1_王中兴_分会场报告_页岩气藏“甜点”测井响应分析”(以四川盆地威远页岩气田为例)

纵向综合甜点；测井响应；交会图

摘 要:页岩气纵向综合“甜点”同时兼顾页岩储层的有机质、物性、含气性等地质条件与脆性等储层工程条件，是水平井纵向靶体最佳位置。因此，确定页岩纵向综合“甜点”位置，成为页岩气评价的重点工作。通过分析威远气田页岩气层测井响应特征,优选出自然伽马、无铀伽马、电阻率、中子、密度、声波时差、硅含量、钙含量等测井敏感曲线。并总结出威远地区页岩纵向综合甜点段测井曲线特征表现为“五高、三低”的特点，即高自然伽马、铀含量、电阻率、声波时差、硅含量和低无铀伽马、中子和密度曲线值。根据各曲线特征优选密度和自然伽马、密度和电阻率、中子和密度、硅钙和钙含量四组曲线进行重叠和交会，可以区分普通页岩、富有机质页岩、富含气页岩和高脆性页岩层段，进而快速的对页岩纵向综合甜点进行有效的识别。经过岩心实测有机质含量、总含气量结果验证，曲线重叠法和交会图分析法所得结果与实测数据分析结果一致性较好，可以作为水平井纵向靶体位置选取依据。

关键词:页岩气；纵向综合甜点；测井响应；交会图。

Logging identification for the vertically comprehensive sweet spots of shale gas:

a case study of the Weiyuan shale gas field, Sichuan Basin

Abstract: Vertically comprehensive "sweet spots" of shale gas consider both of the geological condition like organic matter, gas content and physical properties, and the engineering condition like brittle properties, It is the best target interval of horizontal wells. Determine the vertically comprehensive "sweet spots" of shale gas position, is the most important part of the shale gas evaluation work. By studying the logging response characteristics of shale gas reservoir in Weiyuan shale gas field, than choose the most sensitive logging curve ,include natural gamma ray(GR), no uranium gamma ray(KTH), resistivity(RT), neutron(CNL), density(DEN), sonic(AC), silica conten t (Si) and calcium content(Ca). And have a conclusion that the "comprehensive sweet spots" on conventional log curves are generally featured by high GR, uranium, RT, AC, Si, and low KTH, CNL and DEN in weiyuan shale gas field. Based on the logging curves characteristics of shale gas reservoir, the DEN-GR, DEN-RT, CNL-DEN and Si-Ca cross plot were optimized and to identify the organic-rich shale, gas-rich shale and good brittle properties from the shale very well. Then to identify the vertically comprehensive "sweet spots" of shale gas effectively. The results obtained by curve overlap method and cross plot analysis method are consistent with the results of core analysis data. It provides an important basis for the target interval selection of horizontal wells.

Keywords: Shale gas; Vertically comprehensive sweet spots; Logging response; Cross plot.