A device and method for measuring subsidence deformation field of hydrate reservoir

Abstract

The invention proposes a device and method for measuring the subsidence deformation field of a hydrate reservoir, including a natural gas hydrate reservoir simulation reactor module, a fluid supply and control module, a mining process simulation module and an optical fiber subsidence field sensing module. The invention is a hydrate reservoir subsidence deformation field simulation device and simulation method based on stimulated Brillouin time-domain analysis technology, which realizes the high-pressure and low-temperature conditions for simulating hydrate formation, forms hydrate-containing simulated reservoirs, and can simulate Observing the vertical subsidence and deformation law of the hydrate reservoir under certain overlying formation pressure conditions and production conditions can also simulate the vertical subsidence and deformation law of the hydrate reservoir when the underlying formation has a certain upturning pressure. The invention realizes the simulated measurement of the subsidence deformation of the hydrate deep reservoir, can obtain the deformation characteristics of the entire deformation field, and is of great significance for evaluating the occurrence and development of engineering qualification risks and their impact on mining.

Description

technical field [0001] The invention belongs to the field of laboratory experiment evaluation in the hydrate exploitation process, and in particular relates to a device and method for measuring reservoir subsidence law and longitudinal distribution characteristics in the natural gas hydrate exploitation process. Background technique [0002] The subsidence of marine natural gas hydrate mining reservoirs mainly comes from two factors: the lack of formation material and the change of stress state. The material deficit in the formation mainly includes the two factors of hydrate decomposition output and formation sand production, while the change of stress state mainly refers to the reduction of mechanical properties of sediments caused by hydrate decomposition, and the decrease of pore pressure caused by fluid output. The result of the combined effect is the sediment The effective stress experienced increases. As a result, the subsidence of hydrate reservoirs may lead to a ser...

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Problems solved by technology

As a result, the subsidence of hydrate reservoirs may lead to a series of engineering geological risks

[0003] For the actual hydrate production process on site, it is impossible to measure the subsidence and deformation characteristics of the actual gas hydrate reservoir. It is an inevitable requirement to predict the risk of hydrate production through laboratory experiments to study the subsidence behavior in the process of hydrate production, but there is currently a lack of corresponding Simulation equipment and corresponding methods

[0004] The traditional method of testing the reservoir deformation field is point measurement, such as using the form of subsidence markers to observe the characteristics of subsidence deformation at a specific point in the reservoir. This point measurement result cannot obtain the deformation change law on the entire sediment depth profile , the concept of "field" cannot be formed, so a lot of information in the reservoir is inferred through point measurement results, and the accuracy of the data is questionable; Might not happen where a point measurement sensor is located, where point measurement is simply not adequate for analog needs

[0005] Therefore, on the one hand, the subsidence and vertical distribution of gas hydrate reservoirs during the development of natural gas hydrate accumulation and production (the emphasis is on the production process) are the key to predict the occurrence and development of engineering geological risks caused by production and their potential impact on production. It is urgent to develop corresponding experimental equipment and methods to carry out research in this area; on the other hand, the existing point-type subsidence monitoring methods cannot meet the needs of monitoring the distribution of hydrate reservoir subsidence fields.

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