海上平台旧式采油树隐患治理技术实践

Practice of Hidden Danger Treatment Technology for Old Christmas Tree of Offshore Platform

埕北油田是渤海最早的对外合作开发油田,当前在役采油树最长服役年限达到36年,受原始生产套管尺寸及井下生产管柱尺寸制约,旧式采油树井口电缆穿越为三芯线单独穿越形式。随着平台超期服役,旧式采油树电缆穿越处打火、油气泄漏时有发生。通过改造并更换采油树及油管头四通,增大油管悬挂器的尺寸,将原有的电缆三芯线单独穿越形式升级为整体穿越形式,提升井口装置安全系数,现场实施井口更换辅助以配套的临时封井技术,彻底解决井口隐患问题。以埕北油田某井为例,总结了老式井口改造工艺以及封隔器配合风暴阀临时封井技术,对类似井口隐患治理工作有一定的借鉴意义。

Chengbei oilfield is the earliest foreign cooperative development oilfield in Bohai Sea.At present,the longest service life of Christmas trees in service reaches 36 years.Restricted by the original production casing size and downhole production string size,triax⁃ial cable crosses through the old Christmas tree wellhead in a single line independent crossing form.With the extending of the platform service,sparking and oil and gas leakage often occur at the crossing-through position of cable.In order to eliminate the hidden dan⁃gers,through the transformation and the replacement of Christmas tree and tubing head four-way valve,the original single line cross⁃ing-through form of cable is changed into overall crossing-through form so as to improve the safety coefficient of wellhead device.And the temporary well sealing technology is implemented in the replacement of wellhead to completely solve the hidden dangers of the well⁃head.Taking a well in Chengbei oilfield as an example,thewellhead reconstruction technology of old Christmas trees and the temporary well sealing technology by combing tubing head four-way valve with packer are summarized,which has certain reference significance for the treatment of similar wellhead hidden dangers.