Natural gas hydrate reservoir true triaxial hydraulic fracturing simulation test device and method

Abstract

The invention provides a natural gas hydrate reservoir true triaxial hydraulic fracturing simulation test device and method, belongs to the technical field of geotechnical engineering and testing, and aims to realize monitoring of a hydrate-containing sediment fracture process and a fracturing fluid flowing process. According to the device, a true triaxial hydraulic fracturing system provides a high sealing condition for a test piece, applies principal stress in three directions, and can also inject fracturing fluid to simulate a hydraulic fracturing process; a temperature control system controls test temperature and maintains the state of a hydrate during the fracturing test; a gas-liquid collecting system is used for collecting and measuring gas and water produced in the test; a neutron image pickup monitoring system monitors the contents of carbon, hydrogen and oxygen elements in the hydrate, analyzes the disordered distribution of guest molecules in a water cage, and monitors the evolution condition of the water content in the test piece during true triaxial hydraulic fracturing and the thermodynamic and dynamic processes of the phase change process of the hydrate in a pore medium; and a fracturing control and data acquisition system is used for adjusting three-way pressure and acquiring data. Test operation is simple and convenient.

Description

technical field [0001] The invention relates to the technical field of geotechnical engineering and testing, in particular to a true triaxial hydraulic fracturing simulation test device for natural gas hydrate reservoirs and a method for performing simulation tests using the device. Background technique [0002] Natural gas hydrate, also known as combustible ice, is a kind of green energy with extremely high calorific value. The heat released by its complete combustion under the same conditions can reach dozens of times that of coal gas. The carbon content in natural gas hydrates that have been explored and proven is equivalent to twice the total carbon content of proven fossil energy (oil, natural gas, and coal), which can meet human energy needs in the next 1,000 years. Therefore, natural gas hydrate is considered to be a new type of energy with great potential to replace traditional energy sources such as oil, coal, and natural gas. [0003] Natural gas hydrates are ofte...

AI Technical Summary

Problems solved by technology

This is mainly due to: (1) Compared with tight rock reservoirs, the occurrence state of gas hydrate reservoirs can only be maintained under low temperature and high pressure conditions; (2) the six surface positions of the true triaxial loading equipment All have pressure heads and production wells need to be arranged, and the sealing problem in the process of hydrate formation and decomposition has not been effectively solved; (3) The internal structure of natural gas hydrate reservoirs is complex, and it is difficult to monitor the hydraulic pressure with existing acoustic emission detection techniques. The flow of fracturing fluid during the fracturing process and the response characteristics inside the reservoir

Images