Evaluation device and method of well cementation flushing efficiency

Abstract

The invention provides an evaluation device and method of well cementation flushing efficiency. Designed according to the Reynolds number equality theory, the device comprises a simulated well casing, a heating water tank, a power pump and an electromagnetic flowmeter, wherein the simulated well casing mainly comprises an inner barrel and an outer barrel; the inner barrel comprises an inner barrel body, steel screen meshes with different mesh numbers and an inner barrel end cover; the inner barrel can simulate a stratum under the circumstance that the steel screen meshes are covered with filter paper or the inner barrel is filled with quartz sand; the outer barrel can rotate; guide vanes with different forms are designed to simulate a casing pipe. The method is easy to operate, high in comparability and low in workload, can effectively form a filter cake, simulate and evaluate the characteristics of the flushing efficiency under the circumstance that the casing pipe rotates or a spiral centralizer is used, can evaluate the flushing efficiency of flushing fluid for a first interface and a second interface, can evaluate and optimally select the flushing fluid system and design the dosage of the flushing fluid, and is wide in application.

Description

technical field [0001] The invention relates to the field of oil and gas well cementing, in particular to a cementing flushing efficiency evaluation device and evaluation method. Background technique [0002] Cementing flushing fluid is usually prepared by adding surfactants to water or diluting and mixing with drilling fluid. It can be used at the same time as the spacer, but before the spacer. The main purpose of the flushing fluid is to clean the drilling fluid and filter cake adhered to the well wall and casing wall, and to improve the bonding strength of the cementing interface. When the borehole is drilled, the drilling fluid is easy to form a thin, tough and dense filter cake on the well wall, which can effectively control the filtration loss of the drilling fluid and reduce complex accidents in drilling engineering. However, during cementing, the drilling fluid and filter cake remaining on the well wall and casing wall will prevent the cement slurry from directly c...

AI Technical Summary

Problems solved by technology

However, the current simulated wellbore evaluation device and flushing efficiency evaluation method have the following shortcomings: the design of the device is complex, the operation is relatively cumbersome, and the function is relatively simple; due to the use of artificial cores, the workload is large and the repeatability is limited. At the same time, The design of the device is also not conducive to the formation of a uniformly compacted filter cake; the device cannot fully simulate the real filter cake formation and flushing displacement process, and the evaluation method is not widely applicable

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