海上探井水泥环高度对隔水导管承载力的影响研究

Research on the influence of cement sheath height on the riser bearing capacity in offshore exploration wells

针对目前浅水探井钻入法下隔水导管后固井水泥浆返高达不到泥线的技术难题,根据海上钻入法下隔水导管的作业特点,建立了隔水导管轴向力的分析模型,并在精确设计隔水导管入泥深度的基础上推导出了考虑水泥环高度时隔水导管承载力的计算模型。实例分析表明,本文提出的考虑水泥环高度时隔水导管承载力计算模型能够为隔水导管入泥深度的确定提供参考依据,可有效防止井口下沉或失稳等复杂事故。

Aiming at the problem that in exploration wells in shallow water areas cement slurry cannot return to the mud line after setting riser by drilling, a model for axial force analysis in the riser was es- tablished in this paper, based on the operating features of installing riser by drilling. Thenacomputa- tion method for riser bearing capacity was derived, taking the influence of cement sheath height into account, and based on precision design of the riser setting depth. Case analysis indicates that the mod- el for riser bearing capacity proposed by this paper can provide reference for determining the ultimate setting depth of risers, and effectively prevent accidents such as sinking or instability of wellhead in field operation.