Dynamic leaking stoppage evaluation device and method

Abstract

The invention provides a dynamic leaking stoppage evaluation device and method, which can simulate the leaking stoppage effect of leaking stoppage materials of different types and different sizes when a plurality of leakage channels (cracks, artificial cores and pores of different sizes) coexist under the conditions of underground temperature, pressure and circulating fluid in a laboratory. The whole device comprises an air source, a high-pressure reducing valve, a mud tank, a circulating pipeline, a flow meter, a shaft, a steel ball leakage bed holder, a seam plate holder, a core holder, a control line, a back pressure controller, a valve, a measuring cylinder, a console, an annular pressure pump, a computer, a printer, a data collector, a shell and the like. The novel dynamic leaking stoppage simulation experiment device can simulate the dynamic leaking stoppage effect of leaking stoppage materials of different sizes and different types under different pressures and under the flowing state of underground working fluid when multiple leakage channels coexist, and therefore a drilling fluid or cement paste system meeting the well drilling and cementing requirements is preferably selected. The device is suitable for the field of working fluid leakage control in the well drilling and cementing process.

Description

technical field [0001] The invention belongs to the technical field of working fluid loss control in the drilling and completion process, and in particular relates to a dynamic leakage plugging evaluation device and method. Background technique [0002] In drilling and completion engineering, the problem of downhole leakage is becoming more and more complicated. If the leakage formation is not blocked in time, a large amount of downhole working fluid will be lost, which will seriously affect the downhole construction operation. The commonly used plugging method is to add plugging materials to drilling fluid or cement slurry, and the indoor evaluation method of leak prevention and plugging is an important experimental method to evaluate the plugging effect of drilling fluid, cement slurry and leakage prevention and plugging materials. The leakage simulation channel of the current plugging evaluation instrument is quite different from the actual leakage layer channel, which ma...

AI Technical Summary

Problems solved by technology

And for conventional vertical wells, the direction of gravity of the plugging material is perpendicular to the direction of the lost channel, so it is difficult for the plugging material to accumulate at the entrance of the leaky channel, and the plugging process is relatively difficult to achieve.

However, the current common leak plugging instruments are all equipped with a lost channel at the bottom of the leak plugging instrument. The gravity of the plugging material is consistent with the direction of the lost channel, and the downhole fluid is in a static state, so the plugging material is easy to be at the entrance of the lost channel. It is easier to block the leakage channel due to retention and accumulation, but this is not consistent with the actual situation on site, so the reliability of the experimental results is not high

The patent (Application No.: 2005200975898) discloses a dynamic plugging evaluation experimental device, but the simulated wellbore size of the device is too small, and it is difficult for the plugging material with large particles to pass through it.

In addition, the flow channel of drilling fluid or cement slurry in this equipment is a cylinder, while the actual flow channel of drilling fluid or cement slurry is an annular space (drill pipe and casing annulus, drill pipe and formation annulus, casing and Casing annulus, casing and formation annulus), the flow of laminar fluid in the annular space is significantly different from the flow state (velocity distribution, etc.) in the cylinder, which will greatly affect the plugging of the plugging material Effect

Cylindrical flow channels are difficult to accurately simulate the actual plugging effect of plugging materials

Images