石油实验地质2018，Vol.40Issue(3)：389-396,8.DOI:10.11781/sysydz201803389
页岩中丙烷的降解特征及对页岩气组成的影响
Degradation characteristics of propane in shale rocks and its implication to shale gas composition
摘要
Abstract
Propane and shale samples taken from the same well and different depths in the Longmaxi Formation in the Sichuan Basin were selected to carry out different series of simulation experiments in order to investigate the influence of the degradation of small molecular hydrocarbons on the composition of shale gas in the shale during the over-mature stage.The constant temperature thermal simulation experiments of a gold tube-restricted system were carried out on C3H8,C3H8+shale,C3H8+shale+water at 360℃ and 50 MPa for 72,216,360,720 h.Other pyrolysis experiments were performed using C3H8and C3H8+shale samples at 400,450,500 and 550℃ with a pressure of 50 MPa for 72 h in order to increase the degradation degree of C3H8.The results showed that the CH4,C2H6yields and the CH4/C2H6ratio of C3H8+shale at 360℃ are higher than those of C3H8alone.The experiments with S1 shale rock which contains more clay minerals generated more CH4and C2H6than those with S2 rock sample,and generally showed higher CH4/C2H6 ratios. After increasing the simulation temperature,the conversion of C3H8was significantly increased. The yields of CH4and C2H6in the C3H8+shale experiment were all higher than those in the control experiment,and the yield of CH4was higher than that of C2H6. These results indicated that clay minerals can catalyze C3H8degradation and produce more CH4.The yields of CH4and C2H6,and the CH4/C2H6ratio from the hydrous experiments were higher than those from anhydrous experiments,which indicated that water can promote the cracking of C3H8to produce more CH4. The positive effect of clay mineral and water in shale on C3H8cracking increased the dryness index of shale gas. The degradation of small hydrocarbon molecules had an important influence on the composition of shale gas particularly in high- to over-mature shale rocks. It seems that water played a significant role and its effect on the evaluation of shale gas reserve should be thoroughly investigated especially for high-to over-mature shale rocks.关键词
丙烷裂解/矿物催化/干燥系数/页岩气Key words
propane degradation/mineral catalysis/dryness index/shale gas分类
能源科技引用本文复制引用
徐建兵,梁允干,邓倩,程斌,廖泽文..页岩中丙烷的降解特征及对页岩气组成的影响[J].石油实验地质,2018,40(3):389-396,8.基金项目
国家自然科学基金面上项目(41772117)和中科院页岩气先导专项(B类)(XDB10010203)资助. （41772117）
