一种气井井筒用新型中性清防垢剂的研究与应用

Study and application of a novel neutral scale removing/inhibiting agent for gas well

关键词:  苏里格  井筒  中性  解堵  清防垢剂 

Key words:  Sulige  wellbore  neutral  blockage removal  scale removing/inhibiting agent

摘要:

针对苏里格下古气田因出水引起井筒缓慢堵塞,导致部分井产量下降的问题,开展了堵塞原因分析。为了减少入井液对管柱的腐蚀、延缓检修周期,开发出一种中性清防垢剂。产品室内评价结果表明:该产品16 h对堵塞物溶解率可达到95%以上,对管柱腐蚀极低；质量浓度为40 mg/L时,对不同种类无机垢的阻垢率达到80%以上,可延缓井筒结垢周期。产品现场应用3井次,解除了井筒堵塞,平均单井日产气量提高了213.3%。 

Abstract:

Aiming at the problem that wellbore blockage slowly induced by water production in the gas field of lower palaeozoic in Sulige, and the decrease of production in some wells caused by this, the reasons of wellbore blockage were analyzed. Through the analysis of the blocking components by the instruments in laboratory, a neutral scale removing/inhibiting agent was developed to reduce well tubular corrosion caused by fluids and to extend maintenance cycle. The indoor evaluation experiments show that the dissolution rate of plug of the agent can reach 95% in 16 hours, while the corrosion rate is very low. The inhibition rate can achieve 80% or above for different types of inorganic scale when the dosage is 40 mg/L, and then the wellbore scaling cycle can be delayed. The product was applied to 3 wells, and the wellbore blockage was removed with daily gas production of average single well improving 213.3%. The application of this technology meets the need of late stage exploitation of gas field with safety, speed, and efficiency. The trend of cost efficiency development of gas field also provide guidance for the advancement of competing technologies.