LG37井φ177.8mm×φ193.7mm复合尾管悬挂固井技术

φ177.8 mm×φ193.7 mm composite liner hanging and cementing technology of LG37 well

LG37井在四开钻进过程中钻遇漏失层、大段膏盐层、高压盐水层,井下条件十分复杂。现场决定四开钻至5900m中途完钻,下φ177.8mm×φ193.7mm复合尾管固井。采用一级三凝加砂、防窜、防漏、抗盐加重水泥浆体系,该体系具有良好的控制失水和防漏失、防窜性能;采用一次注水泥至设计返高,下入特殊厚壁高抗挤、抗硫的φ193.7mm套管至膏盐层段,在盐水层位下入管外封隔器等工艺,圆满完成了作业。该井复合尾管悬挂固井的成功经验可为同类复杂井固井施工提供借监。

Downhole conditions of LG37 well are very complicated, because leakage layer, massive gypsum-salt layer, and highpressuresaline layer may be encountered during the drilling process. So it is determined to complete drilling when drilled to the depth of5900 m, φ177.8 mm×φ193.7 mm composite liner is applied to cementing.The first grade triple-setting sand, anti-channeling, leak-proof,salt-resisting heavyweight cement slurry system is applied to the cementing. The cement slurry system has favorable performance incontrolling water loss, leakage loss and anti-channeling. Cementing operations are completed successfully, by applying the technologiesof primary cementing to top cement, making anti-sulfur φ193.7 mm casing with extraordinary thickness and high resistance to extrusioninto the gypsum-salt layer, and running external casing packer to the saline layer. The successful experience in composite liner hangingand cementing could provide reference for cementing operations in similarly complex wells.