延长石油探区延长组页岩总含气量综合预测模型

通过页岩样品的等温吸附实验,计算了延长组页岩的吸附气含量,通过建立公式和测井综合解释计算了延长组页岩的游离气含量和溶解气含量,结果表明延长石油探区延长组页岩总含气量为2.25~5.08 m3/t,其中吸附气含量为1.75~4.21 m3/t,游离气含量为0.20~0.60 m3/t,溶解气含量为0.05~0.52 m3/t.通过不同赋存状态页岩气与多个地质因素的相关性分析,认为吸附气含量主要受控于温度、压力、总有机碳含量和含水饱和度,游离气含量主要受控于孔隙度和含气饱和度,溶解气含量主要受控于残余油含量、温度、压力、天然气相对密度和原油相对密度。建立了延长石油探区不同赋存状态页岩气总含气量综合预测模型,用现场解吸法获得的总含气量的实测值进行检验,证实页岩总含气量综合预测模型可靠性较高。

Comprehensive Prediction Model of Total Gas Content in the Shale of Yanchang Formation in Yanchang Petroleum Exploration Area

Based on isothermal adsorption experiments of shale samples, the content of adsorbed gas in the shale of Yanchang formation is calculated, and the contents of free gas and dissolved gas in the shale of Yanchang formation are calculated by establishing formulas and logging interpretation. The calculation results show that the total gas content of the shale of Yanchang formation in Yanchang petroleum exploration area is 2.25~5.08 m ³/t, among which the content of the adsorbed gas is 1.75~4.21 m ³/t, the free gas content is 0.20~0.60 m ³/t, the dissolved gas content is 0.05~0.52 m ³/t. Based on the analysis of the correlation between shale gas in different occurrence states and geological factors, it is considered that the content of the adsorbed gas is mainly controlled by temperature, pressure, TOC and water saturation, the content of the free gas is mainly controlled by porosity and gas saturation, and the content of the dissolved gas is mainly constrained by residual oil content, temperature, pressure and relative densities of natural gas and crude oil. A comprehensive prediction model of total shale gas content in different occurrence states is established for Yanchang petroleum exploration area. The measured values of the total shale gas content obtained with in-situ desorption method are used to verify the comprehensive prediction model and the results show that the model is highly reliable.