水平井套管固井关井工具研制与应用

Development and Application of Casing Cementing Shut-down Valve in Horizontal Wells

长庆油田规模应用水平井固井+分段压裂工艺,实现了低渗透油气藏的高效开发。由于水平井套管固井的特殊性,固井施工完成后浮箍浮鞋单流阀功能易失效,不能实现有效断流,导致大量的井留水泥塞影响后期作业。针对以上问题,借鉴关闭滑套原理,研制了套管关井滑套及配套固井胶塞,在固井施工完毕实现碰压后可以实现硬关井,克服了传统单流阀断流易失效等问题。现场开展了200余口水平井固井试验,关井成功率100%,后期探人工井底表明,水泥塞满足压裂要求。

Horizontal well cementing and staged fracturing technologies were applied in Changqing oil field on a scale, which achieved the efficient development of low permeability reservoirs. But horizontal well casing cementing is special, non-return valve function is easy to fail in float collar and shoe after cementing. It can＇t effectively cut off flowing and lead to cement plug in a large number of wells. Facing with these problems, shut-in casing valves and matching cementing plugs were developed, which can close the sliding sleeve to cut off flowing. So it can overcome the failure of traditional non-return valve. Horizontal well cementing experiment was carried out in more than 200 holes,and shut-in success rate reached 100%. The late artificial bottom hole shows that it can meet the demands of fracturing.