【作者】 张勇；

【导师】 杜志敏；

【作者基本信息】 西南石油大学 ， 油气田开发工程， 2006， 博士

【摘要】 近几年来，我国在四川东北部相继发现了一系列高含硫气藏，如罗家寨气田和普光气田等。高含硫气藏含有大量的硫化氢。硫化氢气体具有剧毒性和强腐蚀性，因此高含硫气藏属于高危气藏。2003年12月23日发生在罗家寨气田的恶性井喷事故向人们警示了开发高含硫气藏存在的危险性。在开发上，高含硫气藏属于一类特殊气藏。开发过程中，伴有元素硫的析出、沉积、气相组成变化和沉积硫堆积在孔隙喉道污染地层等特殊现象。其中硫微粒的沉积将降低地层孔隙度和渗透率，影响气藏的产能。严重的硫沉积甚至会导致气井报废。 论文在分析高含硫气藏地质成因、相态变化特征、渗流特征、硫微粒溶解、析出、和运移沉积机理的基础上，引入空气动力学中描述气固流动的理论，建立了描述硫微粒运移的动力学模型和描述微粒沉降的携带微粒临界气流速度模型。以上述两模型为基础，并考虑沉积的硫微粒对地层孔隙度和渗透率的影响，建立了高含硫气藏硫微粒运移沉积数学模型。将该模型离散为数值模型，利用VB语言编制了模型的计算机求解程序，模拟计算了SPE36707论文高含硫气藏算例。计算结果与文中Roberts计算结果趋势一致，由于模型考虑了硫微粒的运移，因此模型计算值偏高，但仍能说明论文模型是可靠的。 在所建立的高含硫气藏硫微粒运移沉积模型基础上，模拟分析了高含硫气藏硫微粒沉积影响因素：气藏初始溶解元素硫和是否饱和溶解元素硫是高含硫气藏硫沉积发生的重要前提条件；硫沉积对气井产能的影响主要表现在三方面：稳产时间减少，产量递减期缩短和递减期内递减率增加，以及气藏最终采出程度降低；在定产量生成的情况下，孔隙度越高，硫微粒的沉积速度越低，渗透率越低，硫沉积速度越高；元素硫在高含硫气体中的溶解是随硫化氢浓度的增加而增加，因此硫化氢浓度越高，元素硫溶解就越多，硫沉积就越严重；温度和压力是影响元素硫在高含硫气体中溶解的重要因素，当地层初始饱和溶解元素硫，并且气井是定产量生产时，地层初始压力越高，温度越高，硫沉积速度就越快；气流速度越大，地层的压降也越大，则硫沉积速度就越大；地层表皮系数越大，井筒附近地层的附加压降就越大，则该区域地层的硫沉积速度就越快。 论文以西南油气田重庆气矿高桥气田飞仙关组高含硫气藏为例，在假设气藏初始饱和溶解元素硫的条件下，模拟分析了硫微粒沉积对气井产能的影响。模拟发现：气藏中只要存在压力降的区域都会有硫微粒沉积，但是硫沉积严重的区域主要集中在井筒周围的地层中。更多还原

【Abstract】 In recent years, some gas reservoirs with high H₂S content have been found in northeast of Sichuan Province in China, such as LuoJiaZhai gas field and PuGuang gas field. Gas reservoir with high H₂S content contains a great quantity of hydrogen sulfide. Hydrogen sulfide is a kind of serious poisonous and corrosion gas, therefore, gas reservoir with high H₂S content s belongs to dangerous gas reservoir. Then, gas reservoir with high H₂S content s belongs to special gas reservoir, because There is some special phenomenon, the sulfur deposition, the change of gas phase composition, and damage to the reservoir due to the solid sulfur built-up in the pore, during the gas reservoir development. The sulfur deposition would decline the porosity and pemieability of reservoir, affects the productivity of gas reservoir.Based on the passed theory of gas reservoir with high H₂S content, and has introduced the gas-solid flow theory in aerodynamics field, has made the dynamics model to simulate the sulfur particle flowing and the critical gas flow velocity model to simulate the particle precipitation. In the paper, based on the dynamics model and the critical gas flow velocity model, has made the sulfur particle flowing and deposition mathematic model of gas reservoir with high H₂S content, and included the porosity decline model and the permeability decline model. Then, has made the finite difference model, and developed the computer program of the model by VB to simulate gas reservoir with high H₂S content calculation example in SPE36707 paper. Solution of the paper’s model is consistent with the solution of Roberts’s, but solution of the paper’s model is a little higher than that of Roberts’s for the model in the paper including the sulfur particle flowing. Therefore, the model in the paper is reliable.Based on the sulfur particle flowing and deposition model of gas reservoir with high H₂S content in the paper and calculation program, has calculated and studied factors of affecting sulfur particle deposition, and made some conclusions: it is important and necessary to the sulfur is resolved into gas as first and the sulfur concentration is saturated; there are three affected respects that the period of steadily production would be shorted, the period of production decline would be shorted, the decline rate in the period of production decline would decline, and the degree of reserve recovery would decline, due to the sulfur deposition. When the gas rate is constant, the porosity is higher and the sulfur particle deposition rate is slower; the permeability is higher and sulfur particle deposition rate is slower; the H₂S content更多还原