井壁稳定的有效分析方法——以泥页岩为例

An Effective Method for Analyzing Well Wall Stability—Taking Shale as an Example

摘要: 井壁失稳是钻井工程中的一大难题，地层的岩性不同，其影响井壁稳定的因素也不大相同，但分析方法大体一致。基于此，以较为特殊的泥页岩储层为例，对岩石进行矿物组成试验，阳离子交换容量计算、比表面积计算、微观结构观察等理化性能试验以及三轴压缩和史氏压入等力学特性试验，确定影响井壁稳定的因素，然后根据影响因素建立耦合数学模型，最后将耦合模型带入数值模拟软件演练井壁破坏过程，证明试验确定的影响因素的真实性，达到井壁稳定性分析的目的。通过以泥页岩为例的井壁稳定分析表明该分析方法是可行有效的。

Abstract: Borehole instability is a big problem in drilling engineering, and the factors affecting borehole sta-bility are not the same with different lithology of strata, but the analysis methods are generally the same. Based on this, taking a special mud shale reservoir as an example, the rock is tested for min-eral composition, cation exchange capacity calculation, specific surface area calculation, micro-structure observation and other physical and chemical properties, as well as mechanical properties tests such as triaxial compression and Stellar well compression, so as to determine the factors af-fecting shaft wall stability, and then a coupling mathematical model is established according to the influencing factors. Finally, the coupled model is put into the numerical simulation software to drill borehole failure process, to prove the authenticity of the influencing factors determined by the test, to achieve the purpose of borehole stability analysis. The analysis of wellbore stability of shale shows that the method is feasible and effective.