南堡油田封隔式尾管回接工艺的应用与认识

针对南堡油田潜山油藏埋藏较深,储层温度高,且地层压力系数在0.99~1.01之间,钻井液密度稍有波动就会发生溢流或井漏的特殊井况,提出了一种特殊封隔式尾管回接工艺,其回接装置选用带顶部封隔器的回接插头、盲板短节、旋流短节和浮箍,使用防退卡瓦在封隔器坐封的同时实现坐挂,防止固井过程由于水泥浆和钻井液密度差引起的套管回缩上移。该工艺采用先回接、坐封,再进行注水泥固井的施工流程,能够避免施工过程中井漏的发生。现场实践表明,封隔式尾管回接工艺管串结构合理、操作简便、回接装置密封可靠、耐高温,有针对性地解决了南堡油田溢漏同存井的尾管回接难题,现场应用效果良好。

Application and understanding of packer-type liner tieback technology in Nanpu Oilfield

The burial depth of buried hills in Nanpu Oilfield is deep, the reservoir temperature is high, and the formation pressure coefficients are between 0.99 and 1.01, so overflow or fluid loss may occur even there is a slight change in drilling fluid density. For this end, a special packer-type liner tie-back technology has been developed, whose tie-back device includes the tie-back plug with top packer, blind sub, vortex sub and float collar; the liner is set when the packer is setting, using anti-back slips, which prevents upward movement of casing retraction caused by the difference between cement slurry and drilling fluid density during cementing. This technology procedure is tieback, setting, and cementing, which can effectively prevent lost circulation. Field practice shows that this pipe string used in this packer-type liner tie-back technology is rational in structure, easy to use, good sealing reliable of the tie-back device and resistant to high temperature, specially solve the liner tie-back problem in Nanpu Oilfield, where has co-existence of overflow and leakage, and has been successfully used in the oilfield.