CN203856451U

CN203856451U - Device for exploiting natural gas hydrate in cryolithozone

Info

Publication number: CN203856451U
Application number: CN201320747711.6U
Authority: CN
Inventors: 赵杉林; 潘振; 刘俊杰; 商丽艳; 张磊
Original assignee: Liaoning Shihua University
Current assignee: Liaoning Shihua University
Priority date: 2013-11-21
Filing date: 2013-11-21
Publication date: 2014-10-01
Anticipated expiration: 2023-11-21

Abstract

With economic development in recent years, the demand for energy continues to increase, and the exploitation value of natural gas hydrate gradually becomes particularly important. The exploitation method and technology are continuously improved and perfected. The utility model provides a device for exploiting natural gas hydrate in a cryolithozone. Through a fracturing technology, the reaction contact area is increased, and the exploitation efficiency and the exploitation rate are improved. The N2 density is higher than the natural gas density, accordingly, when N2 is injected into a well, the natural gas decomposed by the hydrate is effectively exhausted. The utility model is an effective device for exploiting the natural gas hydrate.

Description

A kind of device of exploiting permafrost region gas hydrates

Technical field

The present invention relates to a kind of exploitation method of gas hydrates, is a kind of device of exploiting permafrost region gas hydrates.Belong to field of energy source developing technology.

Background technology

Along with the continuous research to gas hydrates, its exploitation method has become the large technical bottleneck of this problem one, and the quality of exploitation method has directly affected gas hydrates benefit and the energy and has been worth.Good exploitation method can, in production of resources to greatest extent, can be taken into account and accomplish neither local geographical environment to be worked the mischief, and also can not damage geologic structure, can not have potential harm of later stage.This device is just according to principle above, in reaching exploitation of gas hydrate, and N ₂vacancy when having filled up original natural gas and existing, can be because of the problem such as cause that geology is subsided after exploiting.

Summary of the invention

The present invention utilizes N ₂this stable chemical nature and the large gas of density ratio natural gas density carry out natural gas method and the device that displacer gas decomposition of hydrate goes out.Make up the underground geology causing because the tapping natural gas series of problems such as subside.

Wherein specifically comprise: N ₂supplement car (1); Gas control valve (2); N ₂liquefying plant (3); Liquefaction N ₂holding vessel (4); Natural gas storage tanks (5); Natural gas filter (6); Gas fractionation unit (7); Compressor (8); Data acquisition and processing (DAP) system (9); Detection instrument (10); Recovery well (11); Horizontal well (12); Injection Well (13); End cap (14); Compressor (15); Well mouth sealing device (16); Pressure break parting (17); Gas hydrates layer (18).The concrete order of connection is: N ₂supplement car (1) and be connected by gas control valve (2), then device separated from the gas (7) pipeline converges rear connection N ₂liquefying plant (3), through liquefaction N ₂after holding vessel (4), compressor (15), well mouth sealing device (16), be connected with Injection Well (13), after horizontal well (12), recovery well (11), be connected with compressor (8) successively, finally after gas fractionation unit (7), natural gas filter (6), be connected with natural gas storage tanks (5); Detection instrument (10) is connected by data line with data acquisition and processing (DAP) system (9).

This device reduces borehole pressure by compressor, so that the decomposition of gas hydrates, when pressure in well is little, to setting value, its sniffer transfers data to data acquisition and processing (DAP) system, and now end cap is opened, N ₂in Injection Well, the pressure while making pressure in well return to firm exploitation.Natural gas and N ₂after separating in gas fractionation unit, natural gas can offer user, and N ₂pass through hydraulic means and liquefy N ₂be stored in storage tank, in order to re-injecting in well, thereby realize N ₂recycle.

Brief description of the drawings

A kind of device of exploiting permafrost region gas hydrates of Fig. 1

Detailed description of the invention

Below in conjunction with drawings and the embodiments, patent of the present invention is described in further detail:

Patent of the present invention is specifically related to a kind of device of exploiting permafrost region gas hydrates, detailed description of the invention is: the initial stage of production of 1., stop up plug, the natural gas decompositing because of fracturing fracture in recovery well well head compressor operating out well, now in recovery well, horizontal well and Injection Well hypomere form a vacuum, now along with the reduction of pressure, gas hydrates decompose in a large number, its product is constantly extracted out by compressor, detection instrument imports the pressure in well and temperature data into data acquisition and processing (DAP) system, draw and the difference of set condition pressure values by natural gas P-V-T gas equation, 2. in the time that this difference exceedes capping, its extraction well well head compressor quits work, and Injection Well end cap is opened, and N now liquefies ₂holding vessel outlet valve is opened, N ₂after gasification, be injected in well by Injection Well well head compressor, 3. along with N ₂the pressure injecting into well recover gradually initially, until when initial pressure, liquefaction N ₂outlet valve is closed, and end cap is closed, 4. due to N ₂density ratio natural gas density is large, works as N ₂in Injection Well time, can discharge natural gas in well in maximum ground, 5. in the time that in well, pressure returns to initial pressure, the work of extraction well well head compressor starts, now starts again to enter step 1., 6. the mist of extraction enters after gas fractionation unit processing, and isolated natural gas can be collected in natural gas storage tanks for user after natural gas filter, 7. isolated N ₂after liquefying plant, liquefy, be stored in N ₂in liquefied pot, prepare against and recycle.

It has increased the decomposition area of gas hydrates pressure break parting, and the reason that its pressure break slight crack produces is in horizontal well cutting process, beats or holes at large hydrate tomography machinery, then injects fracturing fluid, makes gas hydrates layer produce a large amount of pressure break slight cracks.

Enter well from Injection Well, ensured original pressure of well, make can not cause and subside because the extraction internal pressure of natural gas is too small in recovery well.N ₂injection made up the space that natural gas is discharged.

Select N ₂advantage as substitution gas has: 1. N ₂larger than natural gas density, can effectively discharge natural gas in well; 2. N ₂safety and wide material sources, to obtain; 3. N ₂as a kind of inorganic gas of stable chemical nature, be warm and be of quite diverse character at physics and chemistry with organic gas, for separating, gas creates favorable conditions.

Use liquefaction N ₂to consider liquefaction N ₂condition ratio is easier to, and with respect to manufacturing large-scale gaseous state N ₂holding vessel, liquefaction N ₂cost lower and save take up an area space.

Mining system of the present invention is manufactured economical clean, can not pollute threat to fresh groundwater, splits fief matter and can not cause potential harm of later stage, splits fief matter also without particular/special requirement simultaneously, is applicable to tundra and region, deep-sea exploitation of gas hydrates.The present invention, taking gas hydrates step-down extraction system as theoretical foundation, on to simple step-down exploitation method major tuneup basis, realizes note N ₂carry out the method for replacement exploitation of gas hydrate.Be widely used in the exploitation of the many sea areas in tundra and China gas hydrates such as China Qinghai-Tibet Platean.For solving China energy problem, provide a kind of method of the effective and exploitation of gas hydrate that cost is relatively low, reliable.

Claims

1. a device of exploiting permafrost region gas hydrates, specifically comprises in device: N ₂supplement car (1); Gas control valve (2); N ₂liquefying plant (3); Liquefaction N ₂holding vessel (4); Natural gas storage tanks (5); Natural gas filter (6); Gas fractionation unit (7); Compressor (8); Data acquisition and processing (DAP) system (9); Detection instrument (10); Recovery well (11); Horizontal well (12); Injection Well (13); End cap (14); Compressor (15); Well mouth sealing device (16); Pressure break parting (17); Gas hydrates layer (18);

It is characterized in that: specifically the order of connection is, N ₂supplement car (1) and be connected by gas control valve (2), then device separated from the gas (7) pipeline converges rear connection N ₂liquefying plant (3), through liquefaction N ₂after holding vessel (4), compressor (15), well mouth sealing device (16), be connected with Injection Well (13), after horizontal well (12), recovery well (11), be connected with compressor (8) successively, finally after gas fractionation unit (7), natural gas filter (6), be connected with natural gas storage tanks (5); Detection instrument (10) is connected by data line with data acquisition and processing (DAP) system (9).