川南深层页岩气储层含气量测井计算方法

Log Evaluation Method for Gas Content of Deep Shale Gas Reservoirs in Southern Sichuan Basin

页岩储层含气性是页岩气井获产的基础,含气量是页岩气储层评价的关键指标。通过岩心含水饱和度分析,建立了基于黏土含量与有机质含量双重因素影响的非电法页岩储层饱和度计算方法。通过岩心等温吸附实验,确立了兰格缪尔体积和兰格缪尔压力多因素动态计算方法。结合研究区地层在纵向上温度、压力以及总有机碳含量动态变化的特征,建立了基于兰格缪尔等温吸附模型的页岩吸附含气量测井计算模型,在川南地区龙马溪组五峰组深层页岩气储层含气性评价中取得了良好的应用效果。

Gas-bearing property determines whether a shale gas well can produce economical shale gas. Gas content is a key indicator for evaluating the effectiveness of shale gas reservoirs. Through the analysis of core water saturation, a non-electrical saturation method based on clay content and organic matter content was established for calculating the saturation of shale reservoirs. Then by carrying out isothermal adsorption experiments on cores, a multi-factor dynamic calculation method was established for calculating Langmuir volume and Langmuir pressure. Finally according to the dynamic changes of vertical temperature, pressure and TOC content in the study area, a logging calculation model for calculating adsorbed gas by shale reservoir was established based on a Langmuir isothermal adsorption model. Applied to the Longmaxi Formation-Wufeng Formation in southern Sichuan basin, the model worked well in evaluating the gas-bearing property of the deep shale gas reservoirs.