高含硫气藏试井解释方法研究

气井投产之后，地层能量不断下降，当含多硫化氢天然气穿过递减的地层压力和温度剖面时，多硫化氢发生分解，单质元素硫析出。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，元素硫可直接在地层孔隙中沉积并聚集起来，对地层造成污染。在地层中将形成两个特征区域：硫沉积污染区和未污染外区。文中基于油气藏渗流理论和现代试井解释方法建立了高含硫气藏气井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，分析了流度比和污染半径对井底压力动态的影响。实例计算表明，该模型能够较好地解决高含硫气藏试井解释问题。

RESEARCH ON THE METHOD OF WELL TEST ANALYSIS IN HIGH SOUR GAS RESERVOIR

After gas well is put into production, the energy of reservoir is decreased continuously. When the gas with hydrogen poly-sulfide flow through the formation that the reservoir pressure and the temperature decreased by degrees, the hydrogen polysulfide reacted and decomposed, the sulfur has separated out. When the sulfur saturation reached a critical value and the gas can not take it out, the sulfur remained in the reservoir porous and got together. The reservoir will form two typical zones: sulfur pollution zone and unpolluted zone. In this article , we use the theory of the reservoir percolation and modem well test interpreting method to establish the two zones composite well test analysis mathematic model in sour gas reservoir. Using the calculation method of Stehfest obtained the type curve of bottom hole pressure response, and analyzed the influence of mobility ratio and the pollution radius on bottom hole pressure behavior. In practice, this model can actually resolve the high sour gas reservoir well test interpret problem.