A quantitative evaluation device and method for engineering simulation and quantitative evaluation of cementing prefluid flushing efficiency

Abstract

The invention discloses an engineering simulation set and method for quantitative evaluation of flushing efficiency of cementing pre-flushing fluid. The set mainly comprises a support, a bearing disc, an artificial core, a core holder, a variable speed motor, a mass sensor and a computer acquiring terminal. A height adjusting fixture is disposed on the support. A slurry cup for holding cementing pre-flushing fluid is disposed on the bearing disc. The height adjusting fixture is connected with the mass sensor, the variable speed motor and the core holder in order. The core holder is used for holding the artificial core. By adjusting the speed of the variable speed motor, speed of the artificial core in the pre-flushing fluid is controlled to simulate construction displacement. The mass sensor connected with the computer acquiring terminal is used for acquiring, recording and storing, in real time, mass changes of a filter cake on the surface of the artificial core and calculating flushing efficiency so as to draw curves. The engineering simulation set and method has the advantages that a principle is reliable, operating is simple, full-course quantitative evaluation and analysis of flushing efficiency is achieved, and basis is provided for the optimization of pre-flushing fluid systems, the optimization of pre-flushing fluid performance and the optimization of construction parameters such as flushing time and displacement.

Description

technical field [0001] The invention relates to an evaluation device and method for flushing efficiency of cementing prefluid in well cementing engineering in the field of petroleum drilling engineering. Background technique [0002] Improving the interface bonding quality between cement stone, casing and well wall is the most important link to ensure the quality of cementing. However, due to the incompatibility between drilling fluid and cement slurry, the adhesion on the casing wall The drilling fluid and the filter cake formed by the dehydration of the drilling fluid on the well wall will directly affect the bonding quality of cement stone, casing and well wall. In order to improve the cementing quality of the cementing interface and prolong the production life of oil and gas wells, it is necessary to inject a liquid slug into the well before cementing to clean the well wall and casing wall, which is called pre-fluid. After years of research, considerable progress has be...

AI Technical Summary

Problems solved by technology

[0004] Generally speaking, the current evaluation device or evaluation method mainly has the following two deficiencies: (1) It cannot truly simulate the existence of filter cake in the well

In the existing evaluation method, the filter cake is formed by immersing the core in the drilling fluid, which cannot truly reflect the situation that the drilling fluid forms a dense filter cake on the surface of the borehole wall under the action of the pressure difference in the well. Much harder to remove than sticky drilling fluid

(2) It cannot reflect the flushing process in real time

Existing test methods can only capture the data of the start point and the end point, and can only produce one result within a period of time. If you want to investigate the flushing efficiency under different flushing time conditions, you need to repeat the experiment. The workload is heavy and the flushing process is not complete. It cannot provide scientific guidance on the key construction parameters of the optimal amount of pre-fluid, flushing time, and displacement.

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