高含硫气藏元素硫沉积及其对储层伤害模型研究

根据元素硫的溶解沉积机理和物质平衡原理,利用高速非达西渗流理论,建立了元素硫沉积模型及受元素硫沉积影响的地层孔隙度、渗透率随生产时间的变化关系.研究表明:元素硫的沉积主要发生在近井地带1.5m以内,离井筒越近,沉积越严重,孔隙度和渗透率下降越大,对储层伤害越大;气井产量越大,硫沉积越严重,孔隙度和渗透率下降越大,合理产量应控制在(15~20)×104m3/d;高含硫气体的渗流表现出强烈的流固耦合特性.

Study on the reservoir damage of sulfur deposition in the gas reservoirs with high sulfur content

The sulfur deposition model is established based on the sulfur dissolution and deposition mechanism,material balance principle and high-speed non-Darcy seepage theory,and the relationships between reservoir porosity and permeability and production time under the effect of sulfur deposition are also established.The study of a case shows that,the sulfur deposition mainly occurs in the near wellbore zone of 1.5 m,the nearer the distance from the wellbore,the more the sulfur deposition and the reduction of the reservoir porosity and permeability,and therefore the severer the reservoir damage;the higher the gas-well yield,the more the sulfur deposition and the reduction of the reservoir porosity and permeability,and reasonable gas-well yield should be controlled in the range of (15～20)×104 m3/d;the seepage of the gas with high sulfur content presents the obvious characteristic of fluid-solid coupling.