【摘要】：頁(yè)巖氣吸附機(jī)理和模型的研究對(duì)于頁(yè)巖氣地質(zhì)儲(chǔ)量計(jì)算和開發(fā)方案編制等具有重要意義.結(jié)合低溫氮?dú)馕綄?shí)驗(yàn)和高壓甲烷等溫吸附實(shí)驗(yàn),對(duì)龍馬溪組頁(yè)巖的微觀孔隙結(jié)構(gòu)和超臨界吸附特征進(jìn)行了分析.結(jié)果表明,孔隙體積和比表面積主要受中孔(2~200 nm)控制;在壓力較大時(shí)(10 MPa),頁(yè)巖過剩吸附量隨著壓力增大而降低.4種常用吸附模型的對(duì)比分析表明:對(duì)于微孔充填方式,D-A模型的擬合效果要優(yōu)于D-R模型;對(duì)于單層吸附方式,L-F模型的擬合效果要優(yōu)于Langmuir模型.結(jié)合孔隙體積分析結(jié)果,通過兩種假設(shè),證明了甲烷不是以單一的微孔充填或者單分子層吸附方式在頁(yè)巖中進(jìn)行吸附的,推測(cè)其吸附機(jī)理為微孔充填和單分子層吸附并存.并基于該吸附機(jī)理,建立了頁(yè)巖氣超臨界吸附新模型——DA-LF模型.新模型比4種常用模型具有更好的擬合效果,并可以分別計(jì)算出微孔和中孔的吸附量.計(jì)算表明微孔充填吸附量比單層吸附量大,占總吸附量的76%左右.這表明頁(yè)巖氣超臨界吸附機(jī)理可以進(jìn)一步深化為:微孔充填為主、單分子層吸附并存.
[Abstract]:The study on the mechanism and model of shale gas adsorption is of great significance for the calculation of shale gas geological reserves and the preparation of development plans. Combined with low temperature nitrogen adsorption experiment and high pressure methane isothermal adsorption experiment, the microscopic pore structure and supercritical adsorption characteristics of Longmaxi formation shale were analyzed. The results show that the pore volume and specific surface area are mainly controlled by mesoporous (2 ~ 200 nm). When the pressure is high (10 MPa),) the excess adsorption capacity of shale decreases with the increase of pressure. 4 kinds of commonly used adsorption models are analyzed. The results show that the fitting effect of D-A model is better than that of D-R model for micropore filling mode. The fitting effect of L-F model for monolayer adsorption is better than that of Langmuir model. Based on the results of pore volume analysis and two hypotheses, it is proved that methane is not adsorbed in shale by single micropore filling or monolayer adsorption, and the adsorption mechanism of methane is presumed to be the coexistence of micropore filling and monolayer adsorption. Based on the adsorption mechanism, a new supercritical adsorption model of shale gas, DA-LF model, was established. The new model has better fitting effect than four common models, and the adsorption capacity of micropore and mesopore can be calculated respectively. The results show that the adsorption capacity of micropore filling is more than that of monolayer, accounting for about 76% of the total adsorption capacity. This indicates that the mechanism of supercritical adsorption of shale gas can be further deepened as follows: micropore filling is dominant and monolayer adsorption coexists.
【作者單位】： 北京大學(xué)工學(xué)院能源與資源工程系;中國(guó)石油勘探開發(fā)研究院;國(guó)家能源頁(yè)巖氣研發(fā)(實(shí)驗(yàn))中心;
【基金】：國(guó)家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃(2013CB2281)資助
【分類號(hào)】：P618.13
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本文編號(hào)：2258649