Device for separating hydrogen in coal bed gas at wellhead

Abstract

The utility model belongs to the field of petroleum and natural gas exploration and development, and particularly relates to a device for separating hydrogen in coal bed gas at a wellhead. The problem that at present, a device for effectively separating hydrogen in coal bed gas at a wellhead is lacked is solved. The device comprises a slurry return pipe, a liquid nitrogen tank and a condenser, one end of the slurry return pipe is connected with the side wall, close to the outlet, of the meter sleeve, the other end of the slurry return pipe is closed, and the pipe wall of the slurry return pipe is connected with a first metal pipe through an air suction pipe; one end of the first metal pipe hermetically extends out of the liquid nitrogen tank and is connected with the air suction pipe, and the other end of the first metal pipe hermetically extends out of the liquid nitrogen tank and is connected with a second metal pipe through a communicating pipe; one end of the second metal pipe hermetically extends out of the condenser and is connected with the communicating pipe, the other end hermetically extends out of the condenser and is respectively connected with a hydrogen tank and a helium tank through pipelines, and the pipelines of the hydrogen tank and the helium tank are respectively connected with a second switch and a third switch in series.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of petroleum and natural gas exploration and development, concretely is a device for separating hydrogen in coal bed gas at wellhead. BACKGROUND

[0002] In the exploration and development of coal bed gas, it is found that the hydrogen content in some core barrels is particularly high. These wells with high hydrogen content are not universal, but only exist in some local wells. Hydrogen is most abundant when the well is just opened, but there is currently a lack of a device that can effectively separate hydrogen in coal bed gas at the wellhead, which cannot collect gas in the abnormal section of gas logging well, causing difficulty in subsequent hydrogen component analysis and failure to timely discover abnormal wells. CONTENT OF UTILITY MODEL

[0003] The utility model discloses to solve the current lack of a device that can effectively separate hydrogen in coal bed gas at the wellhead, and provides a device for separating hydrogen in coal bed gas at the wellhead.

[0004] The utility model discloses a device for separating hydrogen in coal bed gas at the wellhead, including the mud backflow pipe for being connected with the surface sleeve of drilling, still including liquid nitrogen tank and condenser, the one end of mud backflow pipe is connected with the lateral wall of surface sleeve near the export, the other end of mud backflow pipe is closed, the first metal pipe in liquid nitrogen tank is connected on the pipe wall of mud backflow pipe through the suction pipe, and the suction pump and first flow meter are connected in series on the suction pipe along the gas outlet direction, the first liquid hydrocarbon collection tank is arranged in the first metal pipe below and is connected with the first metal pipe through the separation pipeline in liquid nitrogen tank, the one end of first metal pipe is sealed and extends to liquid nitrogen tank and is connected with the suction pipe, the other end of first metal pipe is sealed and extends to liquid nitrogen tank and is connected with the second metal pipe in the condenser through the communication pipe, and the second flow meter and first switch are connected in series on the communication pipe along the gas outlet direction, the second liquid hydrocarbon collection tank is arranged in the second metal pipe below and is connected with the second metal pipe through the separation pipeline in the condenser, the one end of second metal pipe is sealed and extends to condenser and is connected with the communication pipe, and the other end is sealed and extends to condenser and is connected with hydrogen tank and helium tank through the pipeline, and the pipeline of hydrogen tank and helium tank is connected with second switch and third switch respectively.

[0005] Further, the other end of the second metal pipe is connected with the hydrogen tank through the connecting pipe, and the helium tank is connected with the connecting pipe through the helium connecting pipe; the second switch is connected between the connecting pipe and the helium connecting pipe to the inlet of the hydrogen tank, and the third switch is connected on the helium connecting pipe.

[0006] Further, the pipe wall of the mud backflow pipe is upwardly protruded with a gas collecting cap, and the suction pipe is connected to the top of the gas collecting cap.

[0007] Further, the middle sections of the first metal pipe and the second metal pipe are in spiral structure, and the separation pipeline is connected to the bottom of the middle sections of the first metal pipe and the second metal pipe.

[0008] The utility model is applied to coal bed gas exploration, through the utility model is arranged at well mouth, can separate hydrogen in coal bed gas of drilling well fast, and then the subsequent operation is convenient according to hydrogen component (hydrogen content) analysis of its genesis, in order to find this abnormal well in time when drilling, and pay high attention. BRIEF DESCRIPTION OF DRAWINGS

[0009] In order to more clearly illustrate the technical scheme of the utility model embodiment, the following will be needed to use the drawings in the embodiment briefly introduced, should understand, the following drawings only shows some embodiments of the utility model, therefore should not be regarded as the limited scope, for the ordinary skilled person in the art, under the premise of not paying the creative labor, can also obtain other related drawings according to these drawings.

[0010] Figure 1 It is a kind of device structure schematic diagram for separating hydrogen in coal bed gas at well head.The mark in figure:1-drill pipe, 2-sleeve, 3-mud backflow pipe, 4-gas cap, 5-gas suction pipe, 6-gas suction pump, 7-first flowmeter, 8-liquid nitrogen tank, 9-first metal pipe, 10-first liquid hydrocarbon collection tank, 11-communication pipe, 12-second flowmeter, 13-first switch, 14-second metal pipe, 15-condenser, 16-second liquid hydrocarbon collection tank, 17-connection pipe, 18-helium connection pipe, 19-second switch, 20-third switch, 21-hydrogen tank, 22-helium tank. DETAILED DESCRIPTION

[0011] As Figure 1As shown, a device for separating hydrogen in coal bed gas at wellhead, comprising a mud return pipe 3 for connecting with the surface sleeve 2 of the well; further comprising a liquid nitrogen tank 8 and a condenser 15; one end of the mud return pipe 3 is connected with the side wall of the surface sleeve 2 close to the outlet, the other end of the mud return pipe 3 is closed, a first metal pipe 9 (mainly located in the liquid nitrogen tank 8) is connected with the inside of the liquid nitrogen tank 8 through a suction pipe 5 on the wall of the mud return pipe 3, a suction pump 6 and a first flow meter 7 are connected in series on the suction pipe 5 in the gas outlet direction; a first liquid hydrocarbon collection tank 10 is arranged in the liquid nitrogen tank 8 below the first metal pipe 9 and connected with the first metal pipe 9 through a separation pipe; one end of the first metal pipe 9 is sealed and extends out of the liquid nitrogen tank 8 and connected with the suction pipe 5, the other end of the first metal pipe 9 is sealed and extends out of the liquid nitrogen tank 8 and connected with a second metal pipe 14 (mainly located in the condenser 15) in the condenser 15 through a communication pipe 11, a second flow meter 12 and a first switch 13 are connected in series on the communication pipe 11 in the gas outlet direction, a second liquid hydrocarbon collection tank 16 is arranged in the condenser 15 below the second metal pipe 14 and connected with the second metal pipe 14 through a separation pipe; one end of the second metal pipe 14 is sealed and extends out of the condenser 15 and connected with the communication pipe 11, the other end of the second metal pipe 14 is sealed and extends out of the condenser 15 and connected with a hydrogen tank 21 and a helium tank 22 through a pipe, and the pipes of the hydrogen tank 21 and the helium tank 22 are connected in series with a second switch 19 and a third switch 20 respectively. The switch refers to the valve on the pipeline, which is generally an electromagnetic valve; the sealed extension refers to the sealed connection between the pipeline and the side wall of the liquid nitrogen tank or the condenser.

[0012] The other end of the second metal pipe 14 is connected with the hydrogen tank 21 through a connecting pipe 17, the connecting pipe 17 is connected with the helium tank 22 through a helium connecting pipe 18; the second switch 19 is connected in series between the connecting pipe 17 and the helium connecting pipe 18 to the inlet of the hydrogen tank 21, and the third switch 20 is connected in series on the helium connecting pipe 18.

[0013] The wall of the mud return pipe 3 is upwardly protruded to form a gas collecting cap 4, and the suction pipe 5 is connected to the top of the gas collecting cap 4.

[0014] The middle sections of the first metal pipe 9 and the second metal pipe 14 are in spiral structure to increase the cooling area, and the separation pipe is connected to the bottom of the middle sections of the first metal pipe 9 and the second metal pipe 14.

[0015] On the basis of the above embodiment, in the specific application, the coal bed gas well being drilled is selected and the following steps are implemented:

[0016] Step one: the mud is injected into the well bottom from the drill pipe 1, carries the cuttings and gas to the mud return pipe 3 along the surface sleeve 2; the gas collecting cap 4 is arranged above the mud return pipe 3; the suction pipe 5 is linked through the threads above the gas collecting cap 4, the suction pump 6 and the first flow meter 7 are sequentially linked between the gas collecting cap 4 and the liquid nitrogen tank 8;

[0017] Step two: fill the liquid nitrogen tank 8 with liquid nitrogen, insert the first metal pipe 9 in the middle; the lower part of the first metal pipe 9 is connected with the first liquid hydrocarbon collection tank 10 through the separation pipeline;

[0018] Step three: link the first metal pipe 9 with the communication pipe 11, link the second flow meter 12, the first switch 13 in turn from the first metal pipe 9 to the second metal pipe 14;

[0019] Step four: place the second metal pipe 14 in the middle of the condenser 15, link the second metal pipe 14 with the second liquid hydrocarbon collection tank 16 below, link the other end of the second metal pipe 14 with the connecting pipe 17, and then link the helium connecting pipe 18, the second switch 19 and the hydrogen tank 21; link the third switch 20, the helium tank 22 on the helium connecting pipe 18.

[0020] Working principle: when drilling coal rock, coal bed gas will flow to the gas collection cap 4 along the mud return pipe 3, the gas suction pump 6 will absorb the gas and input it into the liquid nitrogen tank 8 through the gas suction pipe, the first metal pipe 9 and the first liquid hydrocarbon collection tank 10 are immersed in the liquid nitrogen tank 8. Because the temperature of liquid nitrogen is-196 degrees Celsius, gaseous hydrocarbon is liquefied and enters the first liquid hydrocarbon collection tank 10, the remaining hydrogen and helium flow along the communication pipe 11 to the condenser 15 with a temperature of-257 degrees Celsius, the second metal pipe 14 and the second liquid hydrocarbon collection tank 16 are placed in the condenser 15; after the remaining hydrogen and helium pass through the condenser 15, the hydrogen is liquefied and enters the second liquid hydrocarbon collection tank 16, close the second switch 19, open the third switch 20, the helium enters the helium tank 22 along the connecting pipe 17 and the helium connecting pipe 18. After the helium is collected, close the third switch 20 and open the second switch 19; turn off the power of the condenser 15, and the liquid hydrogen gasifies and flows to the hydrogen tank 21 along the connecting pipe 17 and the second switch 19. Separate and store the hydrogen.

Claims

1. A device for separating hydrogen from coal bed gas at a well head, comprising a mud return pipe (3) for connection to a surface casing (2) of a well; characterized in that, The mud backflow pipe (3) is connected with the side wall of the bushing (2) near the outlet, and the other end of the mud backflow pipe (3) is closed. The first metal pipe (9) located in the liquid nitrogen tank (8) is connected to the wall of the mud backflow pipe (3) through the suction pipe (5). The suction pump (6) and the first flow meter (7) are connected in series on the suction pipe (5) in the gas outlet direction. The first liquid hydrocarbon collection tank (10) is arranged in the liquid nitrogen tank (8) below the first metal pipe (9) and is connected to the first metal pipe (9) through a separation pipeline. One end of the first metal pipe (9) is sealed and extends out of the liquid nitrogen tank (8) and is connected to the suction pipe (5). The other end of the first metal pipe (9) is sealed and extends out of the liquid nitrogen tank (8) and is connected to the second metal pipe (14) located in the condenser (15) through the communication pipe (11). The second flow meter (12) and the first switch (13) are connected in series on the communication pipe (11) in the gas outlet direction. The second liquid hydrocarbon collection tank (16) is arranged in the condenser (15) below the second metal pipe (14) and is connected to the second metal pipe (14) through a separation pipeline. One end of the second metal pipe (14) is sealed and extends out of the condenser (15) and is connected to the communication pipe (11). The other end of the second metal pipe (14) is sealed and extends out of the condenser (15) and is connected to the hydrogen tank (21) and the helium tank (22) through pipelines, and the pipelines of the hydrogen tank (21) and the helium tank (22) are connected in series with the second switch (19) and the third switch (20) respectively.

2. A device for separating hydrogen from coal bed gas at a wellhead as claimed in claim 1, wherein, The other end of the second metal pipe (14) is connected to the hydrogen tank (21) through the connecting pipe (17), and the connecting pipe (17) is connected to the helium tank (22) through the helium connecting pipe (18). The second switch (19) is connected between the connecting pipe (17) and the helium connecting pipe (18) and the inlet of the hydrogen tank (21). The third switch (20) is connected on the helium connecting pipe (18).

3. A device for separating hydrogen from coal bed gas at a wellhead as claimed in claim 1 or 2, characterised in that, The wall of the mud backflow pipe (3) is upwardly protruded by a gas collecting cap (4), and the suction pipe (5) is connected to the top of the gas collecting cap (4).

4. A device for separating hydrogen from coal bed gas at a wellhead as recited in claim 1, wherein, The middle sections of the first metal pipe (9) and the second metal pipe (14) are in spiral structures, and the separation pipelines are connected to the bottom of the middle sections of the first metal pipe (9) and the second metal pipe (14).

5. A device for separating hydrogen from coal bed gas at a wellhead as recited in claim 3, wherein, The middle sections of the first metal pipe (9) and the second metal pipe (14) are in spiral structures, and the separation pipelines are connected to the bottom of the middle sections of the first metal pipe (9) and the second metal pipe (14).

Images