吐哈盆地褐煤中水对煤吸附性的影响及流体压力演化研究

发布时间：2018-04-26 10:29

  本文选题：煤层气 + 褐煤储层　； 参考：《中国矿业大学》2015年硕士论文

【摘要】：为了探究褐煤储层水的赋存方式及其对煤吸附性的影响、褐煤储层的流体压力演化历程,选择吐哈盆地大南湖凹陷东一勘查区的褐煤储层,分析了褐煤储层中水的含量及其赋存形式,采用平衡水煤样、空气干燥基煤样吸附甲烷对比实验,探讨了水对褐煤吸附性的影响。采用Petro Mod盆地数值模拟软件,通过研究区“四史”模拟,揭示了煤储层流体压力的演变过程。研究表明,褐煤中水赋存方式包括外在水、孔隙水、分子水、结晶水4种,其中对煤吸附性影响最大的是孔隙水和分子水,其次是外在水,结晶水则对吸附几乎没有影响;空气干燥基煤样的饱和吸附量在低温时(30-50℃)随温度升高而下降,而随着温度的继续升高,不同褐煤样由于不同方式赋存水的脱除造成的吸附量增加正效应与温度升高所致的吸附量减少负效应此消彼长,其饱和吸附量呈现相反的变化趋势;研究区褐煤储层经历了稳定构造演化背景下的低温埋藏史(Tmax=47℃),热成因气与生物成因气均占一定的比重,但总量较小;生气速率决定了生烃增压的演变,而褐煤储层煤化程度低(Ro,max=0.34%)及自生自储的特点削弱了生烃增压对流体压力的贡献,气压最高尚不到0.02 MPa,因而褐煤的储层压力主要受制于埋藏史控制下的水压变化;虽然含气性较低(0.4 cm3/g),但随埋深的增加,保存条件渐好,有利于煤层气的赋存。研究成果对褐煤储层煤层气的勘探开发具有指导作用。
[Abstract]:In order to investigate the water storage mode of lignite reservoir and its influence on coal absorption, and the evolution of fluid pressure in lignite reservoir, the lignite reservoir in Dongnanhu sag of Turpan-Hami Basin was selected. The water content and its occurrence in lignite reservoir are analyzed. The effect of water on the adsorption of lignite is discussed by using equilibrium water coal sample and air dry base coal sample to adsorb methane. The evolution process of fluid pressure in coal reservoir is revealed by using Petro Mod basin numerical simulation software and "four history" simulation in the study area. The results show that there are four types of water storage in lignite, including external water, pore water, molecular water and crystalline water, among which pore water and molecular water have the greatest influence on the adsorption of coal, followed by external water, and crystal water has little effect on adsorption. The saturated adsorption capacity of air-dried coal samples decreased with the increase of temperature at 30 鈩，

本文编号：1805675