摘要
利用已知埋深储层在一定温度下甲烷吸附特征,预测深部或浅部储层不同温度和不同压力条件下的吸附能力,对页岩气藏的勘探开发具有重大实用意义。基于Polanyi吸附势理论与Langmuir吸附理论,揭示了温度对吸附曲线的影响规律,提出了＂仅利用一条等温吸附曲线预测其他温度吸附曲线＂的方法。利用本研究方法,在龙马溪组页岩S1室内实验30℃吸附数据的基础上,预测出45~120℃吸附曲线,同时,结合实际储层压力梯度与地温梯度,量化了储层埋深与页岩吸附能力关系曲线。验证结果表明：页岩S1在不同温度下的吸附曲线预测结果与实验数据基本吻合;且预测的等温吸附曲线符合Clausius-Clapeyron等量吸附热理论,从而可以仅利用一条等温吸附曲线计算出该页岩样品吸附热,将为高效评估储层条件下页岩吸附气含量奠定理论基础。
Prediction of adsorption isotherms under different temperatures is significant to reserve estimation of shale gas reservoir.Based on the Polanyi’s adsorption potential theory and Langmuir adsorption theory,a method was presented to predict adsorption isotherms with different temperatures only by one isotherm.In this method,the relationship between Langmuir pressure and temperature was quantified.Otherwise,the independent relationship of Langmuir volume and temperature were also found.By utilizing this method,we predicted adsorption isotherms of Longmaxi shale from 45℃to 120℃according to experiment data under 30℃.Meanwhile,by considering the pressure and temperature gradients,we also predicted the relationship between depth and adsorption capacity of Longmaxi shale gas reservoir.Result shows that,the adsorption data predicted by our method is in accord with experimental data and the error coefficient is less than 5%.In addition,the adsorption heat of Longmaxi shale can be calculated by predicting adsorption data based on Clausius-Clapeyron theory.Therefore,our study will supply the theoretical foundation for the efficient evaluation of shale adsorbed gas content under reservoir condition.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2016年第6期1116-1127,共12页
Natural Gas Geoscience
基金
国家自然基金项目(编号:51490654)
国家科技重大专项(编号:2016ZX05039)
国家科技重大专项(编号:2016ZX05042)联合资助
关键词
页岩
温度
吸附势
吸附热
吸附曲线预测
Shale
Temperature
Adsorption potential
Adsorption heat
Adsorption isotherms prediction
