Simulation device and method for monitoring integrity of hydrate stratum cement sheath through DAS

Abstract

The invention relates to a simulation device and method for monitoring integrity of a hydrate stratum cement sheath through DAS. A simulated stratum system comprises a kettle cover and a kettle body, and the kettle cover and the kettle body are connected through a gland bolt; the kettle cover comprises a top and a bottom, an annular hydraulic oil cavity is formed in the top of the kettle cover, an annular protrusion protrudes out of the bottom of the kettle cover, and a hydraulic oil pressurizing opening protrudes out of one side of the kettle cover and communicates with the hydraulic oil cavity. The kettle body is provided with a hydrate generation chamber and a refrigeration cavity, and a refrigeration cavity inlet and a refrigeration cavity outlet convexly extend from one side of the kettle body; a simulation shaft system is arranged at the bottom of the hydrate generation chamber; a monitoring system is in data connection with the simulated stratum system; a pressure control system comprises a first pressurizing oil pump and a first pressure gauge; the first pressurizing oil pump and the first pressure gauge are connected in series and then connected with the hydraulic oil pressurizing opening; a low-temperature control system comprises a refrigeration fluid tank, the outlet of the refrigeration fluid tank is connected with the refrigeration cavity inlet, and the inlet of the refrigeration fluid tank is connected with the refrigeration cavity outlet.

Description

Technical field [0001] The present invention relates to the field of oil and gas mining, in particular to a simulation apparatus and method for monitoring the integrity of hydrate formation of hydrated formation of hydrate formation. Background technique [0002] As a new type of clean energy, natural gas hydrate is a focus on the focus of the oil and gas field due to its advantages of a wide range of clean energy. At present, the mining of natural gas resources in my country is still in the test stage, one of the main reasons for the commercial mining of natural gas hydrate is the integrity of cement ring. Good cement ring integrity, can effectively seal the formation fluid, prevent the formation fluid leak, but under the action of temperature pressure changes during the mining of natural gas hydrate, the cement ring integrity is destroyed, resulting in failure of cement ring integrity. Cement ring integrity failure may cause casing damage, even caused accidents such as surge, b...

AI Technical Summary

Problems solved by technology

Good cement sheath integrity can effectively seal formation fluid and prevent formation fluid leakage. However, under the action of factors such as temperature and pressure changes in the process of natural gas hydrate production, the integrity of the cement sheath is destroyed, resulting in the failure of the cement sheath integrity.

The failure of the integrity of the cement sheath may cause damage to the casing, and even cause accidents such as well kicks and blowouts. Therefore, in order to realize the commercial exploitation of natural gas hydrate, a kind of equipment and technology that can monitor the integrity of the cement sheath is needed. To monitor the location and degree of cement sheath integrity failure, and help oilfield workers to do workover and other work

[0003] The current cement sheath integrity monitoring technologies are acoustic logging, acoustic variable density logging, and cement bond logging tools, etc., but these are mostly single-point instantaneous monitoring, and it is difficult to monitor the cement sheath integrity in real time, continuously, and in the entire well section

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