Measuring method for displacement efficiency of simulated well cementation cementing

Abstract

The invention relates to a measuring method for displacement efficiency of simulated well cementation cementing, which comprises the following steps: 1) taking a PIV (Particle Image Velocimetry) system as a measuring device; 2) respectively injecting a displaced solution and a displacing solution into a simulated shaft and distributing tracer particles in a displacing solution flow field; 3) causing the tracer particles to generate scattered light through a laser of the PIV system, and shooting and recording the positions of the tracer particles in the flow field in real time by using a CCD (Charge Coupled Device) camera of the PIV system; 4) obtaining a moving image of the tracer particles in the flow field, selecting a group at equal intervals from the moving image as analysis identifying information, and obtaining the areas occupied by the tracer particles in different time periods in an annular cross section of the simulated shaft; 5) obtaining the displacement efficiency of the displacing solution for the displaced solution in a certain time period according to the total area of the annular cross section of the simulated shaft and the data obtained through analysis identification; and 6) drawing a displacement efficiency graph through the obtained displacement efficiency in the simulated shaft in different time periods, thereby obtaining the whole displacement efficiency in the simulated shaft.

Description

Technical field [0001] The invention relates to a measuring method for simulating cement injection displacement efficiency. Background technique [0002] The construction operation of running casing into the well and injecting cement into the annular space between the wellbore and the casing is called cementing, which is an important operation in the drilling process. In order to grasp the displacement efficiency of cement injection under various well conditions and to inject suitable cement into the well, it is necessary to simulate the displacement efficiency of cement injection under various well conditions before the cementing operation. At present, there are many simulation devices designed for the efficiency of cement injection displacement. Among them, the most widely used are the full-scale displacement simulation experimental device, the actual density cement slurry and similar-sized casing displacement experimental device, and similar liquid simulation small gap Displa...

AI Technical Summary

Problems solved by technology

The measurement methods of these simulation devices have their own advantages, but their common disadvantages are: only the results of the displacement efficiency of the displacement fluid to the displaced fluid can be obtained, but the flow state of the displacement fluid in the flow field cannot be truly grasped. The whole process of replacing the displaced liquid by the displacing liquid is not conducive to ensuring the accuracy and reliability of the displacing efficiency, and there is a certain error in the obtained displacing efficiency; in addition, the measurement methods of these simulation devices are very limited and cannot be used universally

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