Natural gas hydrate reservoir sand prevention device

Abstract

The invention provides a natural gas hydrate reservoir sand prevention device. The natural gas hydrate reservoir sand prevention device comprises a sand blocking cylinder, a base pipe and a plurality of sand prevention units. The sand blocking cylinder and the base pipe are each of a hollow structure with the top end open. The base pipe is located in the sand blocking cylinder. The sand prevention units are arranged in the circumferential direction of the side wall of the base pipe. Each sand prevention unit comprises a cover cap, a cover body and a metal sheet. The cover caps and the cover bodies are each of a hollow cavity structure with the two ends open. Grooves are formed in the inner sides of the cover caps. The metal sheets are placed in the grooves. Each cover body comprises a cover body upper portion and a cover body lower portion. Each cover cap is in threaded connection with the corresponding cover body upper portion. Each cover body lower portion is in threaded connection with the side wall of the base pipe. The metal sheets only allow fine sand particles with the diameter not larger than 5 micrometers to pass. The sand prevention device provided by the invention can effectively prevent sand grains with the diameter more than 5 micrometers from passing.

Description

technical field [0001] The invention relates to the field of natural gas hydrates, in particular to a sand control device for natural gas hydrate reservoirs. Background technique [0002] The test production of natural gas hydrate reservoirs is often accompanied by sand production. If the sand production is large, it will affect the development of the production. The sand production problem is the bottleneck restricting the safe and efficient production of hydrates. Existing sand control devices for gas hydrate reservoirs are mainly derived from sand control methods commonly used in conventional oil production, including gravel packing sand control, screen sand control, etc. Compared with conventional oil and gas reservoirs, hydrate reservoirs have the characteristics of weak consolidation and high shale. The shale content of typical hydrate reservoirs in China is as high as more than 25%, and the median particle size reaches 10-15 microns. The muddy fine silt is the main p...

AI Technical Summary

Problems solved by technology

Although the volume of this part of water is small, it forms a huge capillary force and liquid drag force in the reservoir, which easily causes sand carrying and very high displacement resistance

[0003] Conventional oil and gas sand control methods have the following disadvantages: 1. The sand control precision is low, and sand control at the micron level cannot be achieved; 2. The purpose of capillary seepage drainage and gas production cannot be effectively achieved while sand control is in progress

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