井筒中含硫化氢的施工质量风险管理与实践

Construction Quality Risk Management in Presence of Hydrogen Sulfide in Wellbore and Its Practice

针对井筒中含硫化氢气体对操作人员产生较大伤害和增加施工难度的问题,运用PDCA质量管理控制,根据硫化氢溶于水的特性,优选4口硫化氢含量较高的采出井。通过开展硫化氢溶于水特性确定试验、氢硫酸溶液腐蚀性确定试验、氢硫酸溶液稳定性确定试验,总结出在施工过程中发现,使用低温清水压井液反循环压井,压井成功后硫化氢溶于水形成氢硫酸溶液,氢硫酸溶液较为稳定,硫化氢气体不随温度变化析出等;同时,氢硫酸溶液具有腐蚀性,在井筒实际生产环境中腐蚀率约为0.01545 mm/a。将试验确定的诸多特性应用于实际作业施工中,确保施工安全。

Aiming at the problem that there is hydrogen sulfide gas in wellbore,resulting to great harm to operators and increase of construction difficulty,four production wells with high hydrogen sulfide content are selected using PDCA quality management control.The hydrogen sulfide water-dissolving characteristic test,the hydrogen sulfate solution corrosiveness test and the hydrogen sulfate solution stability test are carried out according to the dissolving characteristics of hydrogen sulfide in water.It is found that when there is hydrogen sulfide gas during construction,reverse circulation well killing should be carried out using low-temperature clean water kill fluid.After successful well killing,hydrogen sulfide dissolves in water and becomes hydrogen sulfuric acid solution.Hydrogen sulfuric acid solution is relatively stable,and hydrogen sulfide gas will not precipitate with temperature change.At the same time,it is found that hydrogen sulfuric acid solution is corrosive,and the corrosion rate is about 0.01545 mm/a in the actual production environment of the wellbore.