地层剖面中砂泥岩石组合天然气综合扩散系数模拟及应用

在研究砂泥岩样品天然气扩散系数测试方法的基础上,建立了一套实测天然气扩散系数地层条件校正的方法。通过分析地层剖面中砂泥岩天然气扩散系数的影响因素,研究了地层剖面中砂泥岩天然气扩散系数的变化特征为随着埋深增加砂泥岩天然气扩散系数逐渐减小。根据砂泥岩天然气扩散系数随埋深变化关系及砂泥岩在其组合中的相对发育程度,提出了一种研究砂泥岩石组合天然气综合扩散系数的方法,并将其应用松辽盆地昌德气藏上覆地层天然气综合扩散系数的研究中,其结果符合实际地质条件,表明该方法用于研究砂泥岩石组合天然气综合扩散系数及其变化是可行的。

A METHOD TO SIMULATE GAS COMPREHENSIVE DIFFUSION COEFFICIENT OF SANDSTONE AND MUDSTONE COMBINATION IN STRATA SECTION AND ITS APPLICATION

Based on the study of the measuring method for the gas diffusion coefficients of sandstone and mudstone samples, in this paper, a method to correct measured gas diffusion coefficients to the strata conditions is established. By analysing the factors influencing the gas diffusion coefficients in strata section, the change characteristics of gas diffusion coefficients of sandstone and mudstone in strata section are studied. Their gas diffusion coefficients decrease vs. the increase of their depth. According to the relation between gas diffusion coefficients of sandstone or mudstone and their depths and also the development degree of sandstone and mudstone in their combination, a method to study the gas comprehensive diffusion coefficients of sandstone and mudstone combination is put forward, which is applied in studying the gas comprehensive diffusion coefficients of upper sandstone and mudstone combination in Changde gas reservoir of Songliao Basin.The result tallies with actual geological conditions,It indicates that it is practical to use the method to study the gas comprehensive diffusion coefficients of sandstone and mudstone combination and its change.