Casing pipe buckling evaluation method in inclined well cementing process

Abstract

The invention relates to a casing pipe buckling evaluation method in an inclined well cementing process. The method comprises the following steps of making a well wall simulation unit be in an inclined state through an inclination control unit so as to simulate an inclined well; making a cement paste control valve be opened to make cement paste in a cement paste storage and collection device flowinto a cavity; detecting a vertical tension, a torque and displacement of a hollow casing pipe, and recording a pressure value detected by an annulus pressure sensor; performing buckling evaluation onthe hollow casing pipe according to the pressure value detected by the annulus pressure sensor and the vertical tension, the torque and the displacement of the hollow casing pipe; and by analyzing astress change process of the hollow casing pipe, realizing monitoring and evaluation of the buckling of the hollow casing pipe. The method is easy to implement, convenient to operate and good in feasibility, the influence of cement paste buoyancy on a stress change of the hollow casing pipe in the inclined well cementing process can be simply, conveniently, quickly and quantitatively evaluated, and a purpose of evaluating the buckling of the casing pipe is achieved.

Description

technical field [0001] The invention relates to the technical field of drilling process, in particular to a casing buckling evaluation method in the cementing process of deviated wells. Background technique [0002] Cementing is a late process in drilling engineering, the purpose is to form a cement sheath between the outer wall of the casing and the wellbore, and provide a foundation for later oil well development. During the cementing process, it is necessary to inject pre-fluid, cement slurry, post-fluid, etc. into the hollow casing, so that the liquid such as cement slurry returns from the bottom of the casing and finally fills the annulus. However, during the cement slurry injection process, the height of the liquid column inside the casing is gradually decreasing, while the height of the liquid column in the annulus is constantly rising, and the buoyancy generated by the difference in the liquid level inside and outside the casing will affect the casing. When the casi...

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Problems solved by technology

[0003] At present, the effect of buoyancy on casing is usually calculated by empirical formulas in the field. However, due to the complex casing stress and various well paths in the actual well site, the effect of a single variable on casing is not clear, so it is impossible to calculate the effect of buoyancy on casing. Efficient evaluation of the impact of casing

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