Abstract: Conventionally, casing valve was used for underbalanced completion. But it cost a lot and could not achieve underbalanced completion once failed. So gel valve was studied. This is an intelligent chemical colloid for underbalanced completion. Once gelatinized in borehole, it has certain strength and can withstand compression performance. It can play the isolation effect and prevent liquid which is in the well into the reservoir. It can form static sealing in the wellhole and form dynamic seal with the completion tube, then control the oil and gas overflow. After well completion, it can achieve gel breaking liquefaction, and use nitrogen or water return discharge. The product adapts to the temperature between 55℃ and 100℃ and bearing pressure from 2 MPa to 5MPa. Now gel valve technology has been applied to oil and gas wells. The types of underbalanced completion include hanger screen pipe completion and open-hole completion, with the success rate reaching 100%. Gel valve can not only ensure successful underbalanced completion, but can also reduce the cost remarkably. It is significant to enriching underbalanced drilling technique connotation and expanding underbalanced drilling technology.

Key words: gel valve, intelligent colloid, underbalanced completion

摘要： 为实现欠平衡完井,常规做法是采用套管阀,但采用套管阀成本高,且套管阀一旦失效就无法实现欠平衡完井,为此研究了冻胶阀。冻胶阀是一种用于欠平衡完井的智能化学胶体,在井筒中具备一定的抗压差性能,可隔离其上下流体。完井管柱能穿透冻胶阀,在管柱穿透过程中冻胶阀能实现环空动密封,避免油气溢出。完井结束后冻胶阀可实现破胶液化,采用氮气或清水即可实现残液的全部返排。该产品适应温度为55~100℃,每百米抗压差能力为2~5MPa,目前已应用在油井、气井上,完井方式包括了筛管完井和裸眼完井,成功率达100%。冻胶阀不但能保障欠平衡完井的顺利实现,还能大幅度降低欠平衡完井费用,对丰富欠平衡钻井技术内涵、推广欠平衡钻井技术具有重要意义。

关键词: 冻胶阀, 智能胶体, 欠平衡完井