基于溶解度实验的硫沉积模型及应用研究

四川东北部相继发现了普光、罗家寨等一大批高含硫气藏。高含硫气藏在气体开采过程中，随着地层压力不断下降，元素硫达到临界饱和态后将从气相中析出，并在储层孔隙及喉道中沉积，从而导致地层孔隙度和渗透率降低，严重时造成气井停产。根据硫在天然气中的溶解机理以及物质平衡原理建立了高含硫气藏硫沉积预测模型，以罗家寨气田罗7井为例，预测了不同压力范围下的含硫饱和度以及硫沉积对气井产量的影响。研究结果表明，当地层压力下降到40MPa时，气井产量下降了82.5％，地层压力下降到37MPa时，气井将停产。

SULFUR DEPOSITION MODEL AND THE APPLICATION BASED ON SOLUBILITY EXPERIMENT

Some gas reservoirs with high H2S content have been found in northeast Sichuan in China, such as PuGuang gas field, Luojiazhai gas field and so on. In the course of development of the gas reservoirs with high H2S content, as formation pressure falls continually, elemental sulfur will precipitate from gas phase after running up to critical saturation state and deposit at reservoir pore space and throat, consequently resulting in formation porosity and permeability reduction; gas well production halts when it becomes severe. Gas reservoirs with high H2S content sulfur deposition prediction model is set up according to dissolution mechanism of sulfur in nature gas and material balance theory and the Luo7 well taken as an example to forecast sulfurbearing saturation in different pressure range, as well as effect of sulfur deposition on production rate. Achievements show that，when gas reservoir pressure drops down to 40 MPa ，production rate falls by 82.5％;reservoir pressure drops down to 37 MPa，gas well production will halts.