高含硫气藏双孔介质硫沉积试井解释模型

Well Test Interpretation Model for Dual-Porosity Sulfur Deposit in High Sulfur-Bearing Gas Reservoir

在高含硫天然气藏中,随着地层能量不断下降,多硫化氢发生分解,硫析出。当分解出的硫量达到临界值后且流体水动力不足以携带固态颗粒的硫时,硫可直接在地层孔隙中沉积并聚集起来,形成硫污染区。基于油气藏渗流理论和现代试井解释方法,建立了双孔介质中高含硫气井硫污染区和未污染区两区复合试井解释数学模型,利用Stehfest反演算法计算了井底压力响应典型曲线,进行了相关参数对井底压力动态的敏感性分析。

In high sulfur-bearing gas reservoir, with decline of formation energy, the hydrogen polysulfide of gas will be decomposed and the sulfur element will be precipitated. When the sulfur amount precipitated reaches a critical value and the fluid hydrodynamic force is insufficient to carry it, the sulfur will deposit and accumulate in pores of formation, in which contamination will occur, and two characteristic regions will be formed such as contaminated zone and uncontaminated one of sulfur deposit. This paper presents such two- zone compound well test interpretation mathematical model for high suffur-bearing gas reservoir with dual porosity media. Using Stehfest inverse algorithm the corresponding typical curves of bottom-hole pressure are calculated, the correlate parameters＂ sensitivity to the bottom pressure performance is analyzed.