川东地区高含硫气井元素硫沉积分析及防治措施探索

Analysis on Elemental Sulphur Deposit in High-sulphur Gas Wells in Eastern Sichuan Basin and Countermeasures

近年来,川东地区长兴、飞仙关等高含硫气藏气井的投产,为弥补天然气产量递减起到了关键作用。但是,高含硫气井在生产过程中,天然气中的硫会随气体状态的变化而析出,堵塞气流通道,影响气井正常生产。结合高含硫气藏生产特征及气质组分,分析认为,元素硫沉积的主要影响因素是气流速度和压力、温度,而压力、温度的影响主要表现在硫的溶解度上。对典型高含硫生产井峰X井进行元素硫沉积分析。提出相应的防治措施:通过适当提高采气速度,控制井筒压力和温度的变化,并采取加注化学硫溶剂等措施,可以防治元素硫沉积;特别提到了采用高抗硫材质小直径管加注工艺,这是结合川东地区高含硫气井完井管柱特点(油套环空安装有永久封隔器)采用的药剂加注工艺。通过对高含硫气井元素硫沉积的影响因素分析和防治措施的推荐,为高含硫气井的稳定开采提供借鉴。

In recent years,the gas wells of high-sulfur gas reservoir of Changxing,Feixianguan and so on in eastern Sichuan Basin have played key role in control production decline of natural gas.But in the production process of the high-sulphur gas wells,the sulphur in the natural gas will be dissolved out along with the change of gas state,and make airflow channel block up,which will influence normal production of gas wells.Through the production features and gas component in the high-sulphur gas reservoir,we know that the main influencing factors of elemental sulphur deposit are gas flow velocity,pressure and temperature,and the pressure and temperature influence dissolubility of the sulphur mainly.Elemental sulphur deposit is analyzed on Feng X well of typical high-sulphur production well.Corresponding countermeasures are put forward.Elemental sufphur deposit may be controlled through raising gas recovery rate properly to control the change of borehole pressure and temperatur and infilling chemical sulphur solvent.Infilling technology of bore tube with high sulfur resistance material is adopted that is suitable for the characteristics of completion string of the high-sulphur gas wells in Eastern Sichuan Basin（permanent packer is assembled in casing tubing ananulus）.Analysis on influencing factors and countermeasures of the elemental sulphur deposit makes references for stable production in high-sulphur gas wells.