RU2425952C1 - Device for obtaining core from hydrate-containing rocks - Google Patents

Abstract

FIELD: oil and gas industry. ^ SUBSTANCE: device includes double core equipment including rock destruction tool, external core barrel, coupling adapter, non-rotating internal pipe with suspension and fixation assembly and with cooling system containing compartment with liquefied gas bottle and throttle; upper coupling adapter, lower coupling adapter in which circulation channels and non-return valve, detachable core barrel with core-retaining device is located. Cooling system is equipped with compartment of gas ejector the nozzle of which is fixed in upper coupling adapter, and diffuser is fixed in lower coupling adapter in which an outlet channel is also provided. ^ EFFECT: higher sampling quality of core samples and preservation of their natural composition, structure and properties. ^ 1 dwg

Description

The invention relates to technical means for core sampling from wells in the search and exploration of natural gas hydrate deposits.

Known core-gas sampling shell of the design "DonbassNIL" (Reference for drilling wells for coal / G.P. Novikov, O.K. Belkin, L.K. Klyuev and others - M .: Nedra, 1988. - pp. 184-189) designed for overburdening coal seams of different structures and varying degrees of metamorphism. The core gas sampling shell consists of an adapter, an outer core pipe, a non-rotating inner pipe with a suspension unit, a thrust bearing, a disk spring package, a ball valve, a core receiving cassette, and a rock cutting tool. The projectile can work in different modes - without rotation and with the rotation of the inner pipe due to the inclusion of a spring-friction mechanism in the design.

The disadvantage of this device is the lack of tightness of the non-rotating inner core-receiving pipe, which does not allow to maintain stable thermobaric conditions.

Known removable core gas sampler SGN-48 (KGNS), used as part of the KSSK-76 complex (Handbook for drilling exploration wells / Editor-in-chief of the publication, Prof. EA Kozlovsky. - SPb .: Nedra LLC, 2000. - Pages. 374-386). The projectile is designed to take gas from coal seams, includes a rock cutting tool, a stabilizer expander, an outer core pipe, a connecting adapter, a non-rotating inner pipe with a suspension and fixation unit, a core receiver with a core holding device.

The disadvantage of this device is the inability to preserve the natural thermobaric conditions of gas hydrate inclusions when lifting the core due to insufficient sealing of the core receiver.

The well-known "Method of producing core from hydrated rocks and a device for its implementation" (patent RU No. 2369719, publ. 10.10.2009), adopted as a prototype. A device for producing a core from hydrated rocks contains a double core projectile, which includes a rock cutting tool, a stabilizer expander, an outer core pipe, a connecting adapter, a non-rotating inner pipe with a suspension and fixing unit, and a shell-and-tube removable core receiver with a core holding device. In this case, the non-rotating inner pipe is equipped with a cooling system, which includes a section with a cylinder of liquefied gas and a throttling device and a section with coolant and with a spiral-tube heat exchanger connected by connecting adapters, in one of which there are circulation channels and a check valve, in the other - a sealed channel with connecting fasteners and a check valve.

The disadvantage of the prototype is the low efficiency of the core cooling system in the core receiver, due to the use of an intermediate coolant and the laminar mode of its circulation in the shell and tube device of the core receiver. This determines the technical complexity of manufacturing the device.

The basis of the invention is the creation of a device for sampling core samples from hydrated rocks, the design of which would provide sufficient cooling of the sample, which will improve the quality of core samples taken, as well as simplifying the design of the device.

The technical result is to improve the quality of core sampling from hydrated rocks while maintaining the natural composition, structure and properties of the gas hydrate inclusions contained in them.

The technical result is achieved in that in a device for producing core from hydrated rocks containing a double core projectile, including a rock cutting tool, an outer core pipe, a connecting adapter, a non-rotating inner pipe with a suspension and fixing unit and with a cooling system containing a section with a liquefied gas cylinder and a throttle, an upper connecting adapter, a lower connecting adapter, in which the circulation channels and a check valve are located, a removable core receiver with rnouderzhivayuschim device, the cooling system is provided with a section of the gas ejector nozzle is fixed in the upper adapter coupling, and a diffuser secured to the lower coupling adapter, which is further adapted output channel.

The essence of the technical solution is illustrated by the drawing. The drawing shows a diagram of a device for producing core from hydrated rocks, where the following positions are indicated:

1 - Drill string adapter

2 - The unit of fixation and suspension of the removable part of the projectile

3 - Connection adapter

4 - Section housing with LPG cylinder and throttle

5 - LPG bottle

6 - Throttle

7 - Upper connecting adapter

8 - Nozzle

9 - Diffuser

10 - Lower junction adapter

11 - Circulation channels

12 - Flow through the check valve

13 - Check valve

14 - Core receiver

15 - Kern

16 - The gap between the core and the inner wall of the core receiver

17 - Rock cutting tool

18 - Flushing channels

19 - Annular gap between the drill and the wall of the well

20 - Wall of the well

21 - The outer tube of the core projectile

22 - output channel

23 - Total flow

24 - Housing gas ejection section

25 - Camera displacement

26 - The primary stream.

A device for producing core from hydrated rocks works as follows. After filling the core receiver 14 with core 15 at the end of the flight, the throttle 6 of the LPG cylinder 5 opens and a low-temperature gas-liquid primary stream 26 is formed, which, passing through the nozzle 8 located in the upper connecting adapter 7, acquires a speed equal to the speed of sound and further reduces its temperature due to the complete transition of its liquid phase to gaseous. Entering the diffuser 9, the low-temperature gas primary stream 26 creates a vacuum in the mixing chamber 25 and, as a result, the possibility of reverse circulation of the gas primary stream 26 in the core receiver 14. The low-temperature gas primary stream 26 passes through the outlet channel 22 into an annular circulation channel (not shown) between the body of the core receiver 14 and the outer tube 21 of the core projectile and goes to the rock cutting tool 17, while cooling the core receiver 14. In the washing channels 18 of the rock cutting tool and 17, the cooling primary stream 26 is divided into two parts: its main part through the washing channels 18 of the rock cutting tool 17 enters the annular gap 19 between the drill and the walls of the bore 20 and rises up the annular gap 19, in contact with the walls of the bore 20, composed of hydrate-containing rocks while cooling the outer pipe 21. Another (smaller) part (12) of the primary stream 26 enters the core receiver 14 and, rising along the gap 16 between the core 15 and the inner wall of the core receiver 14, additionally cool gives a core. Then, the stream 12 enters through the check valve 13 and the circulation channel 11 of the lower connecting adapter 10 into the mixing chamber 25 of the gas ejection section 24, and the total stream 23 is formed. Next, the total stream 23 is generated from the primary stream 26 and the stream through the check valve 12. This a constant low temperature of the total flow is achieved 23. Thus, as a result of efficient heat transfer of the low-temperature circulation flows 26 and 12 of the gaseous medium with the outer wall of the core receiver 14 and directly with the core 15 hydrate-containing rocks is intensive cooling of the core core receiver 14 core 15 to negative temperatures, providing the manifestation of the effects of conservation of gas hydrate inclusions during subsequent transportation of the removable core receiver 14 to the surface. This improves the quality of core sampling from hydrated rocks by preserving the natural composition, structure and properties of gas hydrate inclusions contained in them.

Claims (1)

A device for producing a core from hydrate-bearing rocks, comprising a double core projectile, including a rock cutting tool, an outer core pipe, a connecting adapter, a non-rotating inner pipe with a suspension and fixing unit and a cooling system containing a section with a liquefied gas cylinder and a throttle, an upper connecting adapter, lower connecting adapter, in which circulating channels and a check valve are located, a removable core receiver with a core holding device, characterized by The cooling system is equipped with a gas ejector section, the nozzle of which is fixed in the upper connecting adapter, and the diffuser is fixed in the lower connecting adapter, in which the output channel is additionally made.

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