Pit shaft casing-cement sheath cementing surface testing device for high temperature and pressure environments of hot dry rock stratum

Abstract

The invention discloses a pit shaft casing-cement sheath cementing surface testing device for high temperature and pressure environments of a hot dry rock stratum. With a casing as the center, in thehorizontal direction, the testing device successively includes a casing, a cement sheath, formation rock, a level loading power transmission member and a heat insulation layer from inside to outside.A heating device is uniformly arranged on the inner side of the heat insulation layer. The heating device adopts an electrothermal alloy wire as a heating element and the insulation heat layer adoptsa ceramic fiber board-microporous insulation board as an insulation material. The level loading power transmission member is connected with a hydraulic ram to obtain pressure in the horizontal direction. A vertical loading power transmission member is connected with a universal testing machine to obtain pressure in the vertical direction. The casing is connected with a water pump through a water pipe to constitute a circular system. The testing device further includes a leakage testing system. According to the pit shaft casing-cement sheath cementing surface testing device for the high temperature and pressure environments of the hot dry rock stratum, environmental temperature can meet the needs of the formation temperature of a hot and dry rock, and infliction of accurate and non-uniformstress field loading is provided so that the real indoor test data of the hot and dry rock are obtained.

Description

technical field [0001] The invention belongs to the field of dry-hot rock engineering well cementing, and in particular relates to a testing device and method for the bonding strength of wellbore casing and cement sheath under high-temperature and high-pressure environment of dry-hot rock formation. Background technique [0002] Geothermal resources are a new type of clean renewable energy, and it is one of the green new energy sources that can effectively solve traditional fossil fuels, energy shortages and air pollution. A large amount of geothermal energy is stored in hot dry rock (HDR) geothermal resources thousands of meters deep, so hot dry rocks are also called enhanced geothermal resources. Hot dry rock itself is a high-temperature rock mass with no fluid inside or only a small amount of underground fluid. There are few pores or fissures, and its permeability is extremely poor. , but it can also be Mesozoic and Cenozoic metamorphic rocks, or even massive sedimentary...

AI Technical Summary

Problems solved by technology

The application is based on the hydraulic fracturing chamber, and realizes three-dimensional pressure by applying pressure through multi-stage pistons; 8 pistons are used to apply pressure, which solves the problem of uneven pressure to a certain extent, but in the process of piston pressure, hydraulic The fracturing chamber itself will share a certain amount of pressure and at the same time produce a certain degree of deformation, making the pressures in the three directions interfere with each other, thus reducing the accuracy of the ground stress applied in the three directions

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