unstable formation

The wells through weak-face formation in directional well are apt to be unstable.

研究结果表明,弱面地层的存在易使井壁失稳.

The formation is unstable and the wall caving are severe.

地层不稳定,井壁垮塌严重.

Vaterite is a thermodynamically unstable phase of calcium carbonate, so its formation is often controlled by kinetic factors.

球霰石是碳酸钙矿物的热力学不稳定相，其形成过程往往受动力学因素控制。

In this paper, a new method is presented to define formation pressure in short-term closed-in pressure, which based on the research about theory of unstable well testing of fractal reservoirs.

通过分形油藏压力不稳定试井理论的研究，提出了一种使用短期关井压力数据确定地层压力的新方法。

unstable formation was often met in drilling engineering.

工程施工钻孔中，经常遇到不稳定地层。