Device and method for solid-state fluidization mining of seabed shallow layer non-diagenetic natural gas hydrates

Patent metadata

Field	Value
Publication number	US-10655436-B2
Application number	US-201716063703-A
Country	US
Kind code	B2
Filing date	Apr 24, 2017
Priority date	Apr 17, 2017
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

The present invention discloses a device for solid-state fluidization mining of seabed shallow layer non-diagenetic natural gas hydrates. The device comprises a hydraulic jet nozzle set, a coiled tubing, a hydrate collecting ship arranged on the sea surface, a transfer station arranged in sea water and a riser arranged in a seabed surface layer. A guide seat is arranged in the riser. The hydraulic jet nozzle set is arranged in the guide seat. A delivery pipe connected with the transfer station sleeves a nozzle body. An opening is formed in a position where the delivery pipe is in contact with the nozzle body. The transfer station is connected with the hydrate collecting ship. The present invention further discloses a method for collecting seabed shallow layer non-diagenetic hydrates.

First claim

We claim:

1. A device for solid-state fluidization mining of seabed shallow layer non-diagenetic natural gas hydrates, comprising a hydraulic jet nozzle set, a coiled tubing, a hydrate collecting ship arranged on a sea surface, a transfer station arranged in sea water and a riser arranged in a seabed surface layer, wherein a guide seat is arranged in the riser; the hydraulic jet nozzle set is arranged in the guide seat; the hydraulic jet nozzle set comprises a nozzle body, a first sleeve, a second sleeve and a spray head, wherein a right end of the nozzle body is connected with a left end of the first sleeve; the nozzle body is internally provided with a flow passage which is communicated with the first sleeve; a cylindrical surface of the nozzle body is uniformly distributed with a plurality of first oblique jet holes communicated with the flow passage in a circumferential direction of the cylindrical surface of the nozzle body; the first oblique jet holes tilt to left and are arranged eccentrically from the nozzle body; the second sleeve consists of a big shaft and a small shaft which are connected in sequence; the big shaft is arranged in the first sleeve and has a gap therebetween; an asbestos filter net is propped between the big shaft and the nozzle body; the small shaft penetrates through the first sleeve along an axis of the first sleeve and is connected with the spray head; a left end of the spray head is provided with a cavity which is communicated with the second sleeve, and a right end of the spray head is provided with an axial jet hole communicated with the cavity; a cylindrical surface of the spray head is uniformly distributed with a plurality of second oblique jet holes communicated with the cavity in a circumferential direction of the cylindrical surface of the spray head; the second oblique jet holes tile to right and are arranged eccentrically from the spray head; the guide seat is internally provided with a straight channel and an L-shaped channel from top to bottom; the straight channel is connected with the transfer station via a pipeline; a delivery pipe is arranged in the L-shaped channel; a first end of the coiled tubing is connected to the hydrate collecting ship, and a second end of the coiled tubing penetrates through the pipeline from top to bottom and is communicated with the flow passage of the nozzle body; a first end of the delivery pipe sleeves the coiled tubing, and a second end of the delivery pipe sleeves the nozzle body; an opening is formed in each of two ends of the delivery pipe; the transfer station is connected with the hydrate connecting ship.

2. The device for solid-state fluidization mining of seabed shallow layer non-diagenetic natural gas hydrates according to claim 1 , wherein the right end of the nozzle body is provided with first external threads, a left end surface of the first sleeve is provided with a first threaded hole, and the first threaded hole of the first sleeve is connected with the first external threads of the nozzle body.

3. The device for solid-state fluidization mining of seabed shallow layer non-diagenetic natural gas hydrates according to claim 1 , wherein a right end of the small shaft is provided with second external threads, and the cavity is internally provided with a second threaded hole.

4. The device for solid-state fluidization mining of seabed shallow layer non-diagenetic natural gas hydrates according to claim 1 , wherein the spray head is fixedly connected to the second sleeve via a third threaded hole and second external threads of the small shaft.

5. The device for solid-state fluidization mining of seabed shallow layer non-diagenetic natural gas hydrates according to claim 1 , wherein a left end surface and a right end surface of the big shaft are respectively provided with a flow channel.

6. The device for solid-state fluidization mining of seabed shallow layer non-diagenetic natural gas hydrates according to claim 5 , wherein the flow channels are uniformly distributed in a circumferential direction of the big shaft.

7. The device for solid-state fluidization mining of seabed shallow layer non-diagenetic natural gas hydrates according to claim 1 , wherein the transfer station is a deliver pump.

8. A method for solid-state fluidization mining of seabed shallow layer non-diagenetic natural gas hydrates by using the device according to claim 1 , comprising the following steps:
S 1 , lowering of the riser: drilling from the seabed surface layer to a hydrate ore bed using a jet drilling method, and lowering the riser into a drilled wellbore, wherein the riser connects the seabed surface layer with the hydrate ore bed to form a drilling fluid circulating channel while isolating seawater, thereby realizing the lowering of the riser;
S 2 , lowering of the guide seat: controlling a drilling direction by using the guide seat, and adjusting a wellbore trajectory to a horizontal mode;
S 3 , lowering and mounting of the hydraulic jet nozzle set: lowering the hydraulic jet nozzle set to a horizontal channel of the L-shaped channel of the guide seat first, such that the hydraulic jet nozzle set is positioned in the hydrate ore bed; connecting the flow passage of the nozzle body and the hydrate collecting ship by using the coiled tubing, and then sleeving the nozzle body with one end of the delivery pipe; and finally connecting a straight channel of the guide seat and the transfer station by using the pipeline, thereby realizing the lowering and mounting of the hydraulic jet nozzle set;
S 4 , crushing of hydrates: introducing high-pressure seawater to the coiled tubing by using the hydrate collecting ship, wherein a part of high-pressure seawater sequentially flows through the flow passage, the first sleeve, the second sleeve and the cavity and is finally jetted from the axial jet hole and the second oblique jet holes B, hydrates in the horizontal direction are crushed by high-pressure jet water jetted from the axial jet hole to form solid particle hydrates while an advancing channel is opened up; however, the high-pressure seawater jetted from the second oblique jet holes has an opposite acting force, thereby forming a torque and further driving the spray head and the second sleeve to rotate circumferentially; the high-pressure jet water sweeps over a circle or a spiral line to crush the hydrates in the circumferential direction to form solid particle hydrates, thereby forming a cylindrical crushed ore cavity in the hydrate ore bed; the other part of high-pressure seawater is jetted from the first oblique jet holes to provide an advancing power for the whole hydraulic jet nozzle set and the coiled tubing; and
S 5 , collection of the crushed solid particle hydrates: driving, by water jetted from the first oblique jet holes, the solid particle hydrates to move backwards, wherein the solid particle hydrates enter the delivery pipe from an opening in a left side of the delivery pipe, move along the delivery pipe, flow out from an opening in a right side of the delivery pipe, pass through the straight channel and the pipeline in sequence and finally enter into the transfer station, and are ultimately delivered to the hydrate collecting ship from the transfer station and are collected, thereby realizing massive and high-efficiently collection of the crushed solid particle hydrates.

9. The method for solid-state fluidization mining of seabed shallow layer non-diagenetic natural gas hydrates according to claim 8 , wherein the right end of the nozzle body is provided with first external threads, a left end surface of the first sleeve-is provided with a first threaded hole, and the first threaded hole of the first sleeve is connected with the first external threads of the nozzle body.

Assignees

• Univ Southwest Petroleum

Inventors

• Liu Qingyou
• Wang Guorong
• Zhou Shouwei
• Wang Leizhen
• Huang Rong
• Li Qingping
• Fu Qiang

Classifications

• E21B43/01 Primary

  specially adapted for obtaining from underwater installations · CPC title

• E21B41/0099

  specially adapted for drilling for or production of natural hydrate or clathrate gas reservoirs; Drilling through or monitoring of formations containing gas hydrates or clathrates · CPC title

• E21B43/24

  using heat, e.g. steam injection · CPC title

• E21B49/00

  Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells · CPC title

• E21B2043/0115

  Fixed Constructions · mapped topic