Marine Gas Hydrate Accumulation-Development Simulation Experiment System and Method

Abstract

The invention relates to a marine natural gas hydrate accumulation-development simulation experiment system, which consists of a fluid injection part, a hydrate synthesis / decomposition part and a produced fluid metering part, and the fluid injection part includes a high-pressure displacement pump, a natural gas bottle, an intermediate container and seawater Storage tank; Hydrate synthesis / decomposition part includes high and low temperature test chamber, high pressure reactor, simulated vertical well pipeline, simulated horizontal well pipeline, temperature sensor, pressure sensor, computer, high pressure reactor is located in the high and low temperature test chamber, at the end of the kettle body The lid and the wall are arranged with fluid injection and extraction interfaces, and the pressure sensor and temperature sensor are connected to the computer through lead wires; the produced fluid metering part includes a back pressure valve, a gas-liquid separator, a graduated cylinder, and a gas meter. The system can be used for experiments such as synthesis simulation of marine gas hydrate reservoirs or exploitation of marine gas hydrates. The invention is easy to operate, and can provide important support for the evaluation and establishment of marine natural gas hydrate reservoir development technology.

Description

technical field [0001] The invention belongs to the field of marine natural gas hydrate development, in particular to a marine natural gas hydrate accumulation-development simulation experiment system and method. Background technique [0002] Natural gas hydrate is composed of water and hydrocarbons (mainly methane), non-hydrocarbons (CO 2 , H 2 S) An ice-like non-stoichiometric cage crystal compound formed by small molecular gases at low temperature and high pressure. Most of the natural gas hydrates are distributed in the permafrost zone and in the shallow depths of the deep sea. At present, the total proven reserves of natural gas hydrates in the world are about twice the existing reserves of natural gas and oil. Only the South my country Sea has proven natural gas hydrates. Reserves have reached 64970 billion m 3 , under standard conditions, 1m 3 of natural gas hydrate can release 150-200m 3 of natural gas. Due to its wide distribution, large reserves and high gas s...

AI Technical Summary

Problems solved by technology

The high-pressure reactor is different from the seabed sediment layer. The pore water in the sediment layer in the reactor cannot flow freely, so that the relative permeability of the injected natural gas is very low. After the natural gas is injected into the autoclave, it can only form natural gas hydrate with water on the surface of the sediment layer. The formation of gas hydrate will further reduce the seepage ability of natural gas in the sedimentary layer, making the generated gas hydrate uneven in the sedimentary layer, and the conversion rate of water to hydrate is low.

Lang Xuemei (Lang Xuemei, Cao Yuan, Fan Shuanshi, Wang Yanhong. A method and device for the formation and replacement of natural gas hydrate [P].CN106544070A, 2017-03-29) proposed to freeze the water-containing sedimentary solid particles first, so that the water was evenly dispersed in the Natural gas is re-injected between solid particles, so that a more uniformly distributed hydrate reservoir can be synthesized, but the rate of ice and natural gas combining to form gas hydrate is very low

However, the decompression and injection of hydrates directly from the top or bottom of the autoclave cannot effectively simulate the actual process. The fact that the development well is drilled inside the reservoir

Moreover, the reported experimental systems basically do not consider the influence of water intrusion characteristics in the hydrate development process.

Images