True triaxial drilling leakage blockage simulation assessment device

Abstract

The invention relates to a true triaxial drilling leakage blockage simulation assessment device, which consists of a servo pressure-boosting system, a hydraulic pressure-stabilizing source, an acoustic emission instrument, a leakage blockage liquid separator and a true triaxial leakage layer simulation structure. The true triaxial leakage layer simulation structure comprises an artificial rock core, the artificial is fixedly arranged in a frame body, and the hydraulic pressure-stabilizing source exerts pressure on space outside of the artificial rock core from three directions; the outer sideface of the artificial rock core is at least provided with an acoustic emission probe emitting a signal to the acoustic emission instrument; the artificial rock core is provided with an uncased wellbore downwards from the top surface, the inner wall surface of the wellbore is provided with a simulation crack and a simulation pore towards the inside of the rock core; and the well mouth part on theupper end of the wellbore is provided with a sealing structure, the sealing structure is provided with a through hole, the through hole is communicated with the leakage blockage liquid outlet of the leakage blockage liquid separator, and the servo pressure-boosting system is connected with the leakage blockage liquid separator and controls injection of the leakage blockage liquid into the uncasedwellbore. The invention can simulate the real bearing state of the formation, and provide effective guarantee for research on the mechanical principle of leakage blockage of the crack formation and the pore formation.

Description

technical field [0001] The invention relates to a drilling plugging simulation experiment system, in particular to a true triaxial drilling plugging simulation evaluation device. Background technique [0002] Lost circulation in the process of drilling and well completion has brought great challenges to the petroleum engineering industry. Once lost, it will inevitably cause complex accidents such as well collapse, blowout and pipe sticking. Lost circulation has become one of the technical bottlenecks restricting the improvement of drilling speed. . Especially when drilling prestress-sensitive formations, the formation pressure system changes abnormally due to different pore types and complex and diverse fracture shapes, which makes the leakage problem more prominent. [0003] In the process of deep well drilling, the same open hole section often passes through multiple sets of pressure formations, and lost circulation and the downhole complex situation caused by lost circul...

AI Technical Summary

Problems solved by technology

At present, the plugging evaluation devices used for fracture-type and pore-type formation leakage at home and abroad mainly use rigid cut-off plates of different widths and steel balls of different sizes to simulate the fracture-type and pore-type leakage channels. This kind of device is not effective. Simulate the real shape of fractures and pores inside the formation; even if artificial cores are used to simulate fracture-type and pore-type formations, the plugging device can only test the confining pressure of cylindrical artificial cores, and cannot load the cores in three directions. Stress, unable to simulate the real stress state of the core in the formation

[0004] Due to the large difference between the existing experimental conditions and the actual formation properties, there is a large gap between the experimental results and the field application results, and it is impossible to make a more realistic and effective evaluation of the actual formation conditions

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