ANALYSIS ON THE REASONS FOR THE GAS WELL TUBING BLOCKING CAUSED BY CORROSION INHIBITOR AND ITS COUNTERMEASURES

Under current technical conditions, to add proper corrosion inhibitor is the most economical and effective protective measures to protect the down-hole oil and casing in sour gas wells. The selection of corrosion inhibitor should have its pertinence, which means different corrosion inhibitors would be chosen according to different corrosion factors to gas wells. In view of the tubing blocking caused by corrosion inhibitor appeared in the eastern Sichuan basin in recent years and its practical field solutions,combined with the analysis on the underground scale and inference to the stemming in the process of removing plugging, the paper summarized the main reasons that the corrosion inhibitor causes tubing blocking, which include the poor adaptability of corrosion inhibitor, the unreasonable adding system, the defect of corrosion inhibitor quality, as well as the wrapping and clip of corrosion product. It is proposed that a compatibility type experiment should be taken before putting corrosion inhibitor into wells and regular well cleanout should be implemented to the gas wells adding corrosion inhibitor. Meanwhile, strengthening the control of corrosion inhibitor quality, field and production management, are put forward to ensure that the corrosion can be delayed in the gas wells where suitable corrosion inhibitor is added and shaft blocking caused by corrosion inhibitor can be reduced as much as possible, which provide basis for production decisions.