CN219262347U - While-drilling detection device for downhole gas - Google Patents

Abstract

The utility model provides a detection while drilling device for downhole gas, which comprises a first nipple; the control mechanism is arranged in the first short section; the detection mechanism is arranged between the first short joint and the control mechanism and comprises a separation bin for receiving underground gas, a detection bin and an adjusting component; and the second nipple is internally provided with a gas injection mechanism which is communicated with the separation bin and used for injecting carrier gas, wherein the control mechanism is connected with the adjusting component so as to promote underground gas and carrier gas to flow into the separation bin and the detection bin in sequence through the adjusting component, and the underground condition is evaluated through a detection device in the detection bin. The utility model can detect the complex gas in the well in real time, thereby ensuring that ground personnel can grasp the information of the oil gas in the stratum in the well in real time, and further accurately judging the property and the productivity of the reservoir.

Description

While-drilling detection device for downhole gas

Technical Field

The utility model relates to the field of petroleum geological exploration drilling and safety production, in particular to a detection device while drilling for underground gas.

Background

During drilling, gas intrusion is a very risky phenomenon. Especially, serious accidents such as kick and even blowout can be caused by a little carelessness in the underground with complicated conditions. For example, at high pressure, high yield and high hydrogen sulfide containing "tri-high" wells or formation properties are less well known.

The traditional gas intrusion detection is mainly judged by the liquid level of a mud pit on the ground or by the change of outlet flow. However, both of the above methods are very susceptible to interference from external factors, thereby affecting the accuracy of the determination. In addition, the two modes have the condition of information lag, so that the later exhaust and the underground safety are extremely easy to be greatly influenced.

If the information of the oil and gas content of the underground stratum can be mastered, the method is beneficial to judging the property and the productivity of the reservoir. At present, most of hydrocarbon logging technologies need to separate hydrocarbons in drilling fluid on the ground, and then detect and evaluate the hydrocarbons by means of chromatography, fluorescence, infrared spectroscopy and the like to obtain downhole information, but the technologies have the problems of high price, unquantified oil gas evaluation, slow analysis speed and the like.

CN209413900U discloses a downhole gas-liquid separation detection device while drilling, which comprises a separation cylinder and a laser raman detection device, wherein a solid-liquid separation membrane is fixedly arranged at the opening end face of the separation cylinder, a gas-liquid separation membrane, a piston and a separation wall are sequentially arranged in the separation cylinder, one end of an inner double lead screw and an outer double lead screw, which are positioned outside the separation wall, is vertically connected with the piston, and a second ball return device is arranged at the part of the inner double lead screw and the outer double lead screw, which is positioned inside the separation wall; one end of the inner screw rod is vertically provided with a gas-liquid separation membrane, the inner screw rod is meshed with the inner screw rod and the outer screw rod, and the other end of the inner screw rod is provided with a first ball return device; the two ends of the two ball return devices are provided with shaft shoulders, the middle section is provided with gear teeth, each ball return device is meshed with a corresponding gear, and each gear is arranged at the power output end of a corresponding motor; the laser Raman detection device comprises a laser Raman detector and a laser Raman probe, and the laser Raman detector is connected with the laser Raman probe.

The apparatus is capable of acquiring downhole information in a well known to the nature of the formation. Because "tri-high" wells or formation properties are less known about space and uncertainty in the drill string in a well, laser raman detectors are often bulky and therefore difficult to install efficiently in a drill string with less space. In addition, since laser raman detection is a precision instrument, it is more difficult to ensure accuracy in acquiring downhole information in the event of drill string vibration or downhole high temperatures.

Accordingly, it is desirable in the art to provide a while drilling detection apparatus for downhole gases that addresses the above-described issues.

Disclosure of Invention

The utility model aims to provide a detection device while drilling for underground gas, which can be used for more accurately detecting the components and the concentration of underground complex gas through a gas sensor array, so that ground personnel can grasp the information of underground stratum oil-gas content in real time, and further can accurately judge the property and the productivity of a reservoir.

According to a first aspect of the present utility model there is provided a while-drilling detection apparatus for downhole gas comprising a first sub;

the control mechanism is arranged in the first short section;

the detection mechanism is arranged between the first short joint and the control mechanism and comprises a separation bin for receiving underground gas, a detection bin arranged at the upstream of the separation bin and an adjusting component arranged between the separation bin and the detection bin; and

the second nipple is arranged at the downstream of the first nipple, a gas injection mechanism which is communicated with the separation bin and used for injecting carrier gas is arranged in the second nipple,

the control mechanism is connected with the adjusting assembly, so that underground gas and carrier gas are caused to flow into the separation bin and the detection bin in sequence through the adjusting assembly, and the underground condition is evaluated through a detection device in the detection bin.

In one embodiment, the while-drilling detection device comprises a V-shaped diversion trench disposed in an outer wall of the first sub, and a solid filter disposed on the V-shaped diversion trench, wherein the V-shaped diversion trench comprises a radially outer inlet, a radially inner first outlet, and a radially outer second outlet axially upstream of the inlet, the V-shaped diversion trench being configured to be capable of receiving downhole fluid through the inlet and the solid filter.

In one embodiment, the adjustment assembly includes a piston member in communication with the separation chamber, and a first one-way valve disposed upstream of the piston member and in communication with the detection chamber,

the control mechanism is configured to enable underground gas in the V-shaped diversion trench and carrier gas in the gas injection mechanism to flow into the separation bin and mix through controlling the piston member, and enable mixed gas to flow into the detection bin through controlling the first one-way valve.

In one embodiment, the separation bin comprises at least one through hole and a gas-liquid separation membrane arranged in the through hole, wherein the gas-liquid separation membrane is axially located within the range of the first outlet of the V-shaped diversion trench, so that the downhole fluid flowing through the V-shaped diversion trench is separated and the separated gas is allowed to enter the separation bin, and the separated liquid flows back into the well through the second outlet of the V-shaped diversion trench and the solid filter.

In one embodiment, the detection device comprises a gas sensor array composed of a plurality of metal semiconductor thin sheets circumferentially arranged in the detection bin.

In one embodiment, the gas injection mechanism comprises a cylinder in communication with the separation chamber, a flow controller disposed at an outlet end of the cylinder, and a sealing connector for connection with a downstream end of the separation chamber, wherein the control mechanism is in communication with the flow controller.

In one embodiment, the gas injection mechanism further comprises a second one-way valve disposed at the outlet end of the cylinder, thereby allowing gas within the cylinder to flow to the separation chamber.

In one embodiment, the while-drilling detection device further comprises a plurality of roller-type centralizing blocks circumferentially disposed in an annulus between the second nipple and the gas injection mechanism, the gas injection mechanism being configured to maintain a fixed attitude under the influence of the roller-type centralizing blocks.

In one embodiment, the control mechanism includes a circuit module connected to the conditioning assembly and the gas injection mechanism, respectively, a memory module in communication with the gas sensor array and recording the detection results in real time, and an interface module in communication with the upstream MWD, wherein the interface module is configured to signal the data within the memory module and transmit to the MWD in real time.

Compared with the prior art, the utility model has the advantages that: the utility model utilizes the good high temperature and high pressure resistance of the gas sensor array in the pit and the capability of more accurately detecting the components and the concentration of the gas sensor array when facing complex mixed gas, thereby ensuring the accuracy and the authority of the detection result, further enabling ground personnel to master the information of the underground stratum oil gas in real time, and further accurately judging the property and the productivity of the reservoir. In addition, the gas sensor array has higher sensitivity in the underground and smaller overall volume, so that the gas sensor array can be lowered into the well along with the drilling tool. Thus, the present utility model is still more readily adaptable to situations where space within the drill string is small and with uncertainty when in a "three-high" well or well where formation properties are less known.

Drawings

The utility model will be described in detail below with reference to the attached drawing figures, wherein:

FIG. 1 is a schematic diagram of a first portion of a while-drilling detection apparatus for downhole gas according to the present utility model;

FIG. 2 is a schematic diagram of a second portion of a while-drilling detection apparatus for downhole gas according to the present utility model;

fig. 3 shows the structure of a while-drilling detection device for downhole gas according to the present utility model.

In the drawings, like parts are designated with like reference numerals. The figures are not drawn to scale.

Detailed Description

In order to make the technical solution and advantages of the present utility model more apparent, exemplary embodiments of the present utility model will be described in further detail below with reference to the accompanying drawings. It will be apparent that the described embodiments are only some of the embodiments of the present utility model and are not exhaustive of all embodiments. And embodiments of the utility model and features of the embodiments may be combined with each other without conflict.

For ease of understanding, the directional terms "longitudinal" or "axial" or the like refer to the length direction of the while-drilling detection device for downhole gas, i.e., the vertical direction in fig. 1. The directional terms "transverse" or "radial" or the like refer to a direction perpendicular to "longitudinal" or "axial", i.e., a horizontal direction in fig. 1.

The directional term "upstream" or "above" or the like refers to a direction closer to the wellhead, i.e., the top direction in fig. 1. The directional term "downstream" or "below" or the like refers to a direction away from the wellhead, i.e., the bottom end direction in fig. 1.

Fig. 1 is a schematic diagram of a first portion of a while-drilling detection apparatus 100 for downhole gas according to the present utility model. Fig. 2 is a schematic diagram of a second portion of a while-drilling detection apparatus 100 for downhole gas according to the present utility model. FIG. 3 shows the structure of a while-drilling detection device for downhole gas according to the present utility model

As shown in fig. 1 to 3, the while-drilling detection apparatus 100 for downhole gas according to the present utility model mainly includes a first nipple 1 and a second nipple 2. The upstream end of the first nipple 1 is connected to an MWD (measurement while drilling) so that the detected information can be transmitted to the surface in real time through the MWD. The downstream end of the second sub 2 is fixedly connected to a downhole motor so that the while-drilling inspection apparatus 100 can follow the motor into the well for inspection.

According to the present utility model, as shown in fig. 1, the while drilling detection device 100 further comprises a control mechanism 2 and a detection mechanism 3. Wherein the control mechanism 2 is arranged in the first nipple 1, and the detection mechanism 3 is arranged between the control mechanism 2 and the first nipple 1. Preferably, the control mechanism 2 and the detection mechanism 3 are in a split layout, so that the control mechanism 2 and the detection mechanism 3 have relatively independent working environments, and further the working efficiency of the while-drilling detection device 100 and the accuracy of detection information are improved. The contents of which are described below.

In one embodiment, the first nipple 1 acts as a support skeleton for the control mechanism 2 and the detection mechanism 3, thereby being able to provide a stable and safe working environment downhole for both.

According to the utility model, as shown in fig. 1, the detection mechanism 3 comprises a separation bin 32 and a detection bin 31. Wherein the separation bin 32 is in communication with the well (not shown) through the V-shaped channels 11 so as to be able to receive downhole gas. The detection chamber 31 is disposed upstream of the separation chamber 32, and the detection chamber 31 communicates with the outside through a valve (not shown), so that the detected gas can be discharged. It is readily understood that downhole in the present utility model refers to the annulus between the drill string and the well; downhole gas refers to gas in the annulus between the drill string and the well; downhole fluid refers to fluid in the annulus between the drill string and the well.

In one embodiment, the detection bin 31 and the separation bin 32 are both fixed in the first nipple 1 through threaded connection, so that the detection bin 31 and the separation bin can always rotate along with the first nipple 1 in the drilling process, and a stable working environment is provided.

According to the utility model, as shown in fig. 1, the detection mechanism 3 further comprises an adjustment assembly 33. An adjustment assembly 33 is disposed between the separation chamber 32 and the detection chamber 31 so as to be able to selectively communicate the separation chamber 32 with the detection chamber 31. Further, the control mechanism 2 communicates with the adjustment assembly 33, and can control the opening and closing of the adjustment assembly 33. The contents of which are described below.

In one embodiment, as shown in fig. 2, an air injection mechanism 41 is provided within the second sub 2. The gas injection mechanism 41 communicates with the separation chamber 32 and can inject carrier gas into the separation chamber 32, thereby facilitating improvement of accuracy of detection results of gas in the well.

In one embodiment, the second nipple 2 acts as a support backbone for the gas injection mechanism 41, thereby providing a stable and safe working environment for it.

According to one embodiment of the present utility model, the control mechanism 2 is configured to enable the downhole gas and carrier gas in the gas injection mechanism 41 to flow into the separation chamber 32 and the detection chamber 31 sequentially by the adjustment assembly 33, thereby evaluating the downhole situation by the detection means in the detection chamber 31. The contents of which are described below.

According to the utility model, as shown in fig. 1, the adjusting assembly 33 comprises a piston member 331. Wherein the piston member 311 communicates with the upstream end of the separation chamber 32. Therefore, when the control mechanism 2 controls the piston member 311 to operate, the negative pressure environment in the separation chamber 32 can be promoted (that is, the pressure in the separation chamber 32 gradually decreases), so that the underground gas in the V-shaped diversion trench 11 (described below) and the carrier gas in the gas injection mechanism 41 enter the separation chamber 32 under the action of the pressure difference, and the underground gas and the carrier gas can be fully mixed, and the accuracy of the underground gas detection result is further improved.

In one embodiment, the pressure in the separation chamber 32 is balanced with the pressure in the drilling tool in the initial state, and a pressure difference is generated between the inside and the outside of the drill string only when the piston member 331 is operated (i.e. the pressure in the separation chamber 32 is gradually reduced), so that the downhole gas in the V-shaped diversion trench 11 and the carrier gas in the gas injection mechanism 41 are simultaneously guided into the separation chamber 32, so as to ensure the accuracy and the authority of the subsequent detection result.

According to the present utility model, as shown in FIG. 1, the adjustment assembly 33 further includes a first one-way valve 332. The first check valve 332 is disposed upstream of the piston member 331 and communicates with the downstream end of the detection chamber 31. Therefore, when the control mechanism 2 controls the first check valve 332 to operate, the mixed gas (the downhole gas as described above and the carrier gas in the gas injection mechanism 41) in the separation chamber 32 can be caused to flow into the detection chamber 31. The downhole gas can then be rapidly detected by the detection means within the detection bin 31 and the detection result transmitted to the surface in real time via the MWD.

Further, the first check valve 332 has a unidirectional transport function, and thus, the mixed gas in the separation chamber 32 can flow only into the detection chamber 31. Thus avoiding the possibility of regurgitation and thus improving the accuracy and authority of the test results of the while-drilling test device 100.

In a preferred embodiment, the detection device is a gas sensor array 311. The gas sensor array 311 includes a plurality of metal-semiconductor thin sheets disposed in the circumferential direction within the detection chamber 31, and each of the metal-semiconductor thin sheets has a rectangular shape.

It is easy to understand that since gas-sensitive sensors have good selectivity, in other words, each sensor is sensitive to only one or a few gases. The formation gas and the natural gas in the well gas are both mixed gas, so that the utility model arranges a plurality of metal semiconductor thin sheets in the detection bin 31 in an array mode, thereby being capable of more accurately detecting the components and the concentration of the well gas, ensuring the accuracy and the authority of the detection result, and further effectively avoiding the underground erroneous judgment caused by the error of the detection result.

Compared with the precision instruments such as laser Raman detection in the prior art, the gas sensor array 311 adopted in the utility model has good high temperature resistance and high pressure resistance, and can detect the components and the concentration of the complex mixed gas more accurately, so that the accuracy and the authority of a detection result are ensured. Therefore, the while-drilling detection device 100 can grasp the information of the oil and gas in the underground stratum in real time, so that the property and the productivity of the reservoir can be accurately judged.

In addition, the gas sensor array 311 in the utility model has good sensitivity and smaller volume (for example, the gas sensor array can be directly connected with a drilling tool to be lowered into a well), so that the gas sensor array can be more easily adapted to a 'three-high' well or a well with less known stratum characteristics under the protection of the first nipple 1, and the property and the productivity of a reservoir under the well can be accurately judged.

According to the present utility model, as shown in fig. 1, the while drilling test apparatus 100 further includes a V-shaped guide groove 11 and a solid filter (not shown). The V-shaped diversion trench 11 is disposed in an outer wall of the first sub 1 for directing fluid in the annulus of the drill string and well to the separation chamber 32. The solid filter is provided on the V-shaped diversion trench 11 so as to filter solids in the annulus. It is easy to understand that the inside of the well is multiphase flow containing rock debris, water, oil gas and the like during downhole operation, so solid phase substances such as solid rock debris and the like must be completely filtered out, otherwise, the subsequent gas separation membrane (described below) is extremely easy to break down and fail.

According to one embodiment of the present utility model, as shown in fig. 1, the V-shaped channel 11 includes an inlet 111, a first outlet 112, and a second outlet 113. With the inlet 111 radially outward for receiving downhole fluids. The first outlet 112 is radially inward and communicates with the gas-liquid separation membrane 322 for delivering separated gas to the separation cartridge 32. The second outlet 113 is radially outward and axially upstream of the inlet 111, and discharges the separated liquid under a flow pressure differential.

In accordance with one embodiment of the utility model, because the fluid in the annulus between the drill string and the well is moving upstream, the fluid in the annulus enters the V-groove 11 through the inlet 111 and the solids filter under a flow differential pressure. The separation chamber 32 is configured to create a negative pressure environment under the action of the piston member 331, thereby causing the fluid within the V-shaped flow guide 11 to pass through the first outlet 112 and the gas-liquid separation membrane 322 to deliver separated gas into the separation chamber 32, and the separated liquid to flow back to the annulus through the second outlet 113 and the solids filter. In this way, on the one hand, the solid phase material in the well material is filtered out by the solid filter, thereby allowing only the downhole fluid to enter the V-shaped channels 11. On the other hand, the liquid in the downhole fluid is filtered out by the gas-liquid separation membrane 322, allowing only downhole gas to enter the separation bin 32. Therefore, the while-drilling detection device 100 can ensure that all the gases enter the separation bin 32, thereby ensuring the accuracy of the subsequent detection results.

In another embodiment, the while drilling test apparatus 100 further includes a cover plate 12. The solid filter is mounted on the inner wall of the cover plate 12, and the cover plate 12 is configured to partially extend into the inlet 111 and the second outlet 113 of the V-shaped guide groove 11 to form a fixed connection, thereby effectively protecting the solid filter and the V-shaped guide groove 11.

In one embodiment, as shown in FIG. 1, the separation bin 32 includes at least one through-hole, and a gas-liquid separation membrane 322. The through holes are aligned with the first outlets 112 of the V-grooves 11, allowing fluid within the V-grooves 11 to enter through the first outlets 112. The gas-liquid separation membrane 322 is provided in the through hole, so that the fluid in the V-shaped diversion trench 11 can be separated. The contents of which are described below.

In accordance with one embodiment of the present utility model, separation chamber 32 is configured to create a negative pressure environment under the influence of piston member 331 to facilitate the entry of downhole fluid within V-groove 11 into separation chamber 32. Thus, the downhole fluid is separated by the gas-liquid separation membrane 322 and the separated gas enters the separation chamber 32, and the separated liquid flows back to the annulus through the second outlet 113 of the V-groove 11 and the solids filter.

In one embodiment, the gas-liquid separation membrane 322 is axially within the first outlet 112 of the V-shaped channel 11. Thus, the underground fluid in the V-shaped diversion trench 11 can fully enter the separation bin 32 through the gas-liquid separation membrane 322, so that only gas can be ensured to enter the separation bin 32, and the accuracy of the detection result of the while-drilling detection device 100 is improved.

In one embodiment of the present utility model, both the gas-liquid separation membrane 322 and the solid filter have good resistance to high temperature, high pressure and impact. Meanwhile, the gas-liquid separation membrane 322 and the solid filter can be effectively protected by the first nipple 1, so compared with the prior art, the utility model has good underground safety measures, thereby obtaining more accurate detection results.

In one embodiment, as shown in fig. 2, the gas injection mechanism 41 includes a cylinder 411 mounted within the second sub 2. Preferably, the cylinder 411 is a high-pressure cylinder, so that it can be filled with a sufficient amount of compressed air (generally, 500h of supply air can be ensured). In addition, the air in the cylinder 411 can be checked and replenished after each trip for the next long time gas detection downhole.

In one embodiment, as shown in FIG. 2, the gas injection mechanism 41 further includes a flow controller 412. Wherein a flow controller 412 is provided at the outlet end of the cylinder 411 and is capable of controlling the flow rate of the gas flowing into the separation chamber 32 by the cylinder 411. The flow controller 412 is connected to the control mechanism 2. Therefore, when the piston member 311 is operated, the control mechanism 2 can control the flow rate of the gas flowing to the separation chamber 32 from the cylinder 411 by controlling the flow rate controller 412, thereby further improving the stability of the gas flow rate and the sufficiency of mixing the carrier gas with the downhole gas.

In one embodiment, as shown in fig. 2, the gas injection mechanism 41 further includes a sealing connector 413 disposed within the second sub 2. The upstream end of the sealing connector 413 can sealingly interface with the downstream end of the separation chamber 32 to ensure that the cylinder 411 can flow sufficiently and safely into the separation chamber 32.

In one embodiment of the present utility model, the gas injection mechanism 41 further includes a second one-way valve (not shown). The second check valve is installed at the outlet end of the cylinder 411, so that the gas flow direction of the gas injection mechanism 41 is only from the cylinder 411 to the separation bin 32, thereby effectively avoiding the problem that the accuracy of the detection result is affected due to reverse circulation.

According to one embodiment of the present utility model, as shown in FIG. 2, the while drilling test apparatus 100 further includes a roller centralizer block 42. The roller type centralizing blocks 42 are provided in a plurality, and are all circumferentially disposed in the annulus between the second nipple 4 and the gas injection mechanism 41. Therefore, during the downhole drilling process, the gas injection mechanism 41 can always maintain a fixed posture and cannot rotate along with the second nipple 2, so that the safety of the cylinder 411 and the stability of the output carrier gas are effectively improved.

In addition, since the gas injection mechanism 41 can be always in a fixed posture, a good supporting effect can be provided for the control mechanism 2 and the detection mechanism 3 which are positioned upstream of the gas injection mechanism 41, so as to ensure that the detection bin 31 and the separation bin 32 have stable working environments.

In one embodiment, as shown in fig. 1, the control mechanism 2 includes a circuit module 21. The circuit module 21 communicates with the regulating assembly 33 and the gas injection mechanism 41, respectively, so that both can be controlled more precisely so that the gas injection mechanism 41 can deliver the carrier gas to the separation chamber 32 according to the operating state of the piston member 331 in the regulating assembly 33.

In one embodiment, as shown in FIG. 1, the control mechanism 2 further includes a memory module 22. The storage module 22 communicates with the gas sensor array 311, and can record the detection result presented by the gas sensor array 311 in real time.

In one embodiment, as shown in FIG. 1, the control mechanism 2 further includes an interface module 23. The first end of the interface module 23 is directly connected with the upstream MWD, and the second end of the interface module 23 is connected with the storage module 22, so that the detection result information in the storage module 22 can be transmitted to the ground in real time through the MWD, and the accuracy and the effectiveness of information acquisition are improved.

In one embodiment, as shown in FIG. 1, the control mechanism 2 further includes an electrical energy conditioning module (not shown). The power conditioning module includes a first battery pack 241 that individually powers the storage module 22, a second battery pack 242 that integrally powers the while-drilling test apparatus 100, and a conditioning element. Wherein, the adjusting member can reasonably distribute the electric energy, thereby intelligently adjusting the power supply relation between the first battery pack 241 and the second battery pack 242.

According to a second aspect of the present utility model, a method of detecting downhole gas using a detection while drilling device 100 for downhole gas as described above is presented, comprising the following steps.

First, the control mechanism 2 and the detection mechanism 3 are threadedly mounted within the first sub 1, and the position of the separation cartridge 32 is adjusted to radially align the through-hole with the first outlet 111.

Then, the gas injection mechanism 41 is mounted into the second sub 2 by the roller type centering block 42 and is sealingly connected to the downstream end of the separation cartridge 32 by the sealing connector 413.

The assembled while drilling test device 100 is then connected at its upstream end to the MWD and at its downstream end to the downhole motor and is run downhole.

Then, the carrier gas in the downhole gas and gas injection mechanism 41 is caused to flow into the separation bin 32 and the detection bin 31 in sequence by the adjusting assembly 33,

specifically, the fluid in the annulus enters the V-shaped diversion trench 11 through the inlet 111 and the solid filter under the action of flow pressure difference; the control mechanism 2 controls the operation of the piston member 331 so as to promote the environment in which the negative pressure is generated in the separation chamber 32 (i.e., the pressure in the separation chamber 32 gradually decreases). Thus, the downhole gas in the V-shaped flow guide groove 11 enters the separation chamber 32 through the gas-liquid separation membrane 322, and the carrier gas in the gas injection mechanism 41 enters the separation chamber 32 through the flow controller 412 and the second check valve. The downhole gas and carrier gas at this point are thoroughly mixed within the separation chamber 32;

specifically, the control mechanism 2 controls the first check valve 332 to open, so that the mixed gas in the separation chamber 32 enters the detection chamber 31. The piston member 331 at this time is reset.

Thereafter, the downhole gas is sufficiently detected by the gas sensor array 311 in the detection bin 31, and the detected data is stored into the memory module 22.

Finally, the detected data in the storage module 22 is signal compiled and transmitted to the MWD in real time through the interface module 23, and then transmitted to the surface through the MWD, so that the downhole situation can be judged in real time.

It will be readily appreciated that after each inspection operation, the inspection chamber 31 is required to discharge the gas mixture therein, and the above operations are repeated to perform a new round of inspection operation for the gas under the well.

The utility model provides a while-drilling detection device for underground gas, which utilizes the good high temperature and high pressure resistance of a gas sensor array in the underground and the capability of more accurately detecting the components and the concentration of the gas sensor array when facing complex mixed gas, thereby ensuring the accuracy and the authority of detection results, further enabling ground personnel to master the information of underground stratum oil and gas in real time, and further accurately judging the property and the productivity of a reservoir. In addition, the gas sensor array has higher sensitivity in the underground and smaller overall volume, so that the gas sensor array can be lowered into the well along with the drilling tool. Thus, the present utility model is still more readily adaptable to situations where space within the drill string is small and with uncertainty when in a "three-high" well or well where formation properties are less known.

The above is only a preferred embodiment of the present utility model, but the scope of the present utility model is not limited thereto. Modifications and variations may readily be made by those skilled in the art within the scope of the present disclosure, and such modifications and variations are intended to be included within the scope of the present utility model. Therefore, the protection scope of the utility model is subject to the protection scope of the claims.

Claims (9)

1. A while-drilling detection device for downhole gas, comprising:

a first nipple (1);

a control mechanism (2) arranged in the first short section (1);

a detection mechanism (3) arranged between the first nipple (1) and the control mechanism (2), comprising a separation bin (32) for receiving downhole gas, a detection bin (31) arranged upstream of the separation bin (32), and an adjustment assembly (33) arranged between the separation bin (32) and the detection bin (31); and

a second nipple (4) arranged at the downstream of the first nipple (1), a gas injection mechanism (41) communicated with the separation bin (32) and used for injecting carrier gas is arranged in the second nipple (4),

the control mechanism (2) is connected with the adjusting assembly (33) so as to enable the underground gas and the carrier gas to flow into the separation bin (32) and the detection bin (31) in sequence through the adjusting assembly (33), and therefore the underground condition is evaluated through detection devices in the detection bin (31).

2. A detection apparatus while drilling for downhole gas according to claim 1, comprising a V-shaped channel (11) arranged in an outer wall inside the first sub (1), and a solid filter arranged on the V-shaped channel (11), wherein the V-shaped channel (11) comprises an inlet (111) radially outside, a first outlet (112) radially inside, and a second outlet (113) radially outside and axially upstream of the inlet (111), and is configured to be able to receive downhole fluid through the inlet (111) and the solid filter.

3. The while-drilling detection device for downhole gases according to claim 2, wherein the adjustment assembly (33) comprises a piston member (331) in communication with the separation chamber (32), and a first one-way valve (332) arranged upstream of the piston member (331) and in communication with the detection chamber (31),

wherein the control mechanism (2) is configured to cause the downhole gas in the V-shaped diversion trench (11) and the carrier gas in the gas injection mechanism (41) to flow into the separation bin (32) and mix by controlling the piston member (331), and to cause the mixed gas to flow into the detection bin (31) by controlling the first one-way valve (332).

4. A downhole gas while drilling detection device according to claim 3, wherein the separation bin (32) comprises at least one through hole, and a gas-liquid separation membrane (322) arranged in the through hole, wherein the gas-liquid separation membrane (322) is axially in the range of the first outlet (112) of the V-shaped channel (11), thereby separating the downhole fluid flowing through the V-shaped channel (11) and allowing the separated gas to enter the separation bin (32), while the separated liquid is returned downhole through the second outlet (113) of the V-shaped channel (11) and the solid filter.

5. A downhole gas while drilling detection apparatus according to claim 4, wherein the detection means comprises a gas sensor array (311) consisting of a number of metal semiconductor wafers circumferentially arranged within the detection chamber (31).

6. The while-drilling detection device for downhole gas according to claim 5, wherein the gas injection mechanism (41) comprises a cylinder (411) in communication with the separation chamber (32), a flow controller (412) arranged at an outlet end of the cylinder (411), and a sealing connector (413) for connection with a downstream end of the separation chamber (32), wherein the control mechanism (2) is in communication with the flow controller (412).

7. The while drilling detection apparatus for downhole gases according to claim 6, wherein the gas injection mechanism (41) further comprises a second one-way valve arranged at the outlet end of the cylinder (411) allowing the gas within the cylinder (411) to flow towards the separation bin (32).

8. The while-drilling detection device for downhole gas according to claim 7, further comprising a number of roller-type centralizers (42) circumferentially arranged in the annulus between the second sub (4) and the gas injection mechanism (41), the gas injection mechanism (41) being configured to be able to maintain a fixed attitude under the influence of the roller-type centralizers (42).

9. A downhole gas while drilling detection device according to claim 8, wherein the control mechanism (2) comprises a circuit module (21) connected to the conditioning assembly (33) and the gas injection mechanism (41), respectively, a memory module (22) in communication with the gas sensor array (311) and recording the detection results in real time, and an interface module (23) in communication with the upstream MWD, wherein the interface module (23) is configured to signal the data within the memory module (22) and transmit to the MWD (5) in real time.

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