Analysis of reasons for wellbore blockage in sulfur-containing gas wells and research on blockage removal measures
In order to further improve the gas production of sour gas wells,a high sour gas well in a certain gas field in the western region was taken as the research object.The reasons for wellbore blockage in sour gas wells were analyzed,and appropriate measures to remove blockage and increase production were targeted and successfully applied on site.The results show that the composition of on-site plugging materials in the target sour gas well is relatively complex,and the main reasons for wellbore plugging are the deposition of organic substances such as sulfur and asphalt,and the generation of inorganic plugging materials such as mineral calcium carbonate and corrosion product iron disulfide produced in the formation.The active acid composite blockage removal system has good dissolution effects on simulated inorganic blockage,simulated organic blockage,and on-site wellbore blockage.When the reaction time is 12 hours,the dissolution rate can all reach over 90％.In addition,the active acid composite unblocking system also has good surface activity and anti-corrosion performance.The surface tension values after aging at 40℃～100℃ are all less than 25mN·m-1,and the corrosion rate of N80 steel sheets is less than 5g·(m2·h)-1 within 2 hours to 12 hours.After implementing active acid composite blockage removal measures in 5 sulfur-containing gas wells on site,the average daily gas production increased by 43.3％,and the effective period of the measures was longer,achieving good construction results.
sour gas wellswellbore blockageorganic blockagessulfur depositionunblocking measures
万方数据
维普
