声波时差资料在天然气综合扩散系数预测中的应用

Estimation of comprehensive gas diffusion coefficient of a sandstone and mudstone combination bv acoustic interval transit time

大庆石油学院,黑龙江大庆 163318

Daqing Petroleum Institute, Daqing, 163318, China

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;通过天然气扩散系数与岩石孔隙度之间的关系以及孔隙度与声波时差之间的关系,确立了天然气扩散系数与声波时差之间的关系。在此基础上,根据砂泥岩天然气扩散系数随埋深的变化关系以及砂泥岩在其组合中的相对发育情况,提出了利用声波时差资料研究砂泥岩组合天然气综合扩散系数的方法。将该方法应用于松辽盆地昌德气藏的泉一段和泉二段盖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组合天然气综合扩散系数是可行的。

This paper studies the change characteristics of gas diffusion coefficients of sandstone and mudstone by analyzing the factors influencing the gas diffusion coefficients. A functional relation between the diffusion coefficient and acoustic interval transit time is established based on the relation between porosity and acoustic interval transit time. A method for estimating comprehensive gas diffusion coefficients for a sandstone and mudstone combination using acoustic interval transit time is proposed. The comprehensive gas diffusion coefficients of Quan 1 and Quan 2 segments in Dechang gas reservoir in Songliao Basin is estimated. The results agree well with geology.