Blower assembly

Abstract

The gas trailer assembly has an intake conduit for receiving gas from the well. The gas is communicated from the intake conduit to a blower and into an exhaust pipe. Gas exiting the blower passes through the exhaust pipe and into a pipeline. At least a portion of the intake conduit is disposed in the exhaust pipe so that gas in the exhaust pipe is cooled by contact with the outer surface of the intake conduit.

Description

BACKGROUND OF THE INVENTION

The present disclosure pertains to a blower assembly for gas wells.

Gas wells are common in the United States and gas is produced from a variety of sources. In many cases, gas wells lack sufficient pressure to lift the gas to the surface. For example, in coal bed methane recovery and in recovery of gas from shale reservoirs, the gas often must be artificially lifted and delivered to a pipeline or gathering system. A blower assembly may be used in such circumstances to pull gas from the well and then to blow or push the gas into the gathering system. The gathering system delivers gas from several wells to a single location, for example, to a compressor, where the gas is then delivered into a sales pipeline.

The pipeline leading from the well, which is a part of the gathering system may be a plastic pipe, for example, a polyethylene pipe. Gas delivered from the blower assembly may be heated by the blower to as much as 300°, which may be unacceptable for the plastic pipe receiving the gas. For example, polyethylene pipe in the ground utilized to deliver the gas may be rated at 150° F. or less. In order to accommodate gas at higher temperatures, it is common practice to replace a significant length of the polyethylene pipe with steel pipe. The gas will cool as it passes underground in the steel pipe until it reaches a temperature low enough that it will not distort, melt or otherwise damage the polyethylene pipe. It is costly and time-consuming to replace polyethylene pipe with steel pipe and in addition, steel pipe is much more expensive than polyethylene pipe. A blower assembly which would cool the gas prior to entry into the pipeline that delivers the gas to the gathering system and would eliminate or at least lessen the amount of steel pipe needed is desired.

SUMMARY

A blower assembly for communicating gas from a well to a pipeline has an intake conduit for receiving gas from the well. A blower inlet conduit communicates gas from the intake conduit to a blower. A separator may be connected in the blower inlet conduit for separating liquid from the gas prior to the time it enters the blower. A blower outlet conduit is connected at one end to the blower and at a second end to an exhaust pipe. The blower outlet conduit communicates gas from the blower into the exhaust pipe and gas in the exhaust pipe is communicated into the pipeline. The gas will be heated by the blower as it passes therethrough. At least a portion of the intake conduit is disposed in the exhaust pipe and preferably is concentrically disposed in the exhaust pipe so that the intake conduit and exhaust pipe have a common longitudinal axis.

The exhaust pipe has an internal diameter larger than that of the blower outlet conduit so that gas exiting the blower outlet pipe into the exhaust pipe will expand therein. In addition, gas in the exhaust pipe will contact an outer surface of the intake conduit. Because gas in the intake conduit is cooler than gas exiting the blower, gas in the exhaust pipe will be cooled by contact with the outer surface of the intake conduit and by the expansion of the gas in the exhaust pipe. The blower is driven by a motor which may have a variable speed drive, and the blower and the motor are supported on a support table. The blower assembly may be mounted to a skid that can be pulled along the ground or can be placed on a trailer and transported along roads from well site to well site. Thus, the blower assembly is completely mobile and can be operated simply by connecting to an external power source.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left-side perspective view of the blower assembly of the current disclosure.

FIG. 2 is a right-side view of the blower assembly showing an intake conduit and exhaust pipe.

FIG. 3 is a right-side perspective view of the blower assembly showing the intake pipe and the exhaust conduit.

FIG. 4 is a top view of the blower assembly.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now to the drawings, FIG. 1 is a representation of a blower assembly 10. Blower assembly 10 will receive gas from the wellhead of a gas well (not shown) through a well outlet pipeline 15. Well outlet pipeline 15 may be above ground or as shown in FIG. 2 may be above ground for a portion of its length but may also extend underground below ground surface 11 from the well until it reaches a point at which it is to be connected to blower assembly 10. Gas from a well will be communicated to a gas pipeline 20 which may comprise a part of a gathering system. Pipeline 20 may likewise be above ground or in many cases will be connected to blower assembly 10, and will extend downwardly so that it is below ground surface 11 as is shown in FIG. 2. Blower assembly 10 may be mounted on a skid 12. Skid 12 is movable along the ground 1 1, and may be placed on a trailer, so that the blower assembly 10 is a mobile, or transportable unit that may be pulled behind a vehicle on a roadway, moved and used at a number of different well sites.

Blower assembly 10 includes an intake pipe, or intake conduit 22. Gas flows through intake conduit 22 in the direction shown by arrow 22a. Intake pipe 22 has outer surface 21 that defines outer diameter 23 and has first end 24 and second end 25. An elbow connector 26 is connected to second end 25 and extends therefrom through the exhaust pipe of blower assembly 10 which will be explained in more detail hereinbelow. Intake pipe 22 will receive gas from well outlet line 15 and is adapted to be connected thereto in a manner known in the art, for example, with a flanged and bolted connection or with other connections. A blower inlet pipe 28 has a first end 30 that is connected to elbow connector 26 and has a second end 32 connected to a blower 34. Blower 34 is of a type utilized to pull gas from wells when there is insufficient pressure to lift the gas. Blower 34 has a blower inlet 36 and a blower outlet 38 and is driven by an electric motor 39 of a type known in the art. Motor 39 and blower 34 may be supported on a support table 40. Support table 40 may comprise a support platform 42 with a plurality of legs 44 extending therefrom. Support table 40 is mounted on skid 12 so as to provide a space between platform 42 and skid 12. A separator 46 may be connected in blower inlet pipe 28. Separator 46 may be of a type known in the art adapted to separate liquid and solid from the gas communicated through blower inlet pipe 28. Separating as much liquid as possible from the incoming gas may extend the life of and prevent damage to the blower 34 which can be caused by liquid passing therethrough. Separator 46 may have a popoff valve 47 that will open if pressure in separator 46 exceeds a predetermined maximum pressure.

A blower outlet pipe 48 is connected to blower outlet 38 of blower 34 at a first end 50 thereof. A second end 52 of blower outlet pipe, or conduit, 48 is connected to an exhaust pipe 54. Exhaust pipe 54 has inner surface 56 which defines inner diameter 58. Inner diameter 58 has a magnitude greater than outer diameter 23 of intake pipe 22. Gas exiting blower outlet pipe 48 will enter exhaust pipe 54 and will expand therein. The exiting gas will pass into and through exhaust pipe 54 into pipeline 20. Gas travels in exhaust pipe 54 in the direction shown by arrow 54a, which is the same direction as gas traveling in intake pipe 22. The connections between pipe sections in the blower assembly 10 may be welded, flanged and bolted connections, threaded connections or other connections known in the art that will provide sufficient structural integrity and a sufficient seal to prevent leakage.

Blower assembly 10 may include a bypass line 60, with a first end 62 connected to blower inlet pipe 28 and a second end 64 connected to blower outlet pipe 48. Bypass line 60 may be utilized to bypass blower 34 if desired. Bypass line 60 may have a bypass valve 66 connected therein, and blower inlet pipe 28 and blower outlet pipe 48 may have inlet and outlet valves 68 and 70 connected therein, respectively. Valves 66, 68 and 70 may be manually operated valves, for example, butterfly valves, movable between open and closed positions. In normal operation, valves 68 and 70 will be open, and valve 66 will be closed. If it is desired to bypass blower 34, valves 68 and 70 are closed, and valve 66 is open. A check valve 72 may be located in blower outlet line 48 and will allow flow in a direction towards second end 52 of blower outlet pipe 48 and will prevent flow in the opposite direction. Check valve 72 will prevent pressure from the gathering system from pushing back on blower 34. Blower assembly 10 may also include filters connected in the blower inlet and outlet pipes to filter particles from gas flowing therein.

In operation, gas from the wellhead will be communicated from well outlet line 15 to intake pipe 22. As is shown in the drawings, intake pipe 22 is at least partially disposed in exhaust pipe 54. Gas will pass through intake pipe 22 into blower inlet pipe 28 and then into blower 34. Gas will pass through separator 46, which is connected in blower inlet pipe 28, and which will remove liquid particles from the gas passing therethrough. Gas passes through blower 34 into blower outlet pipe 48 and then into exhaust pipe 54. Gas exiting blower outlet pipe 48 will expand in exhaust pipe 54 and will contact the outer surface 21 of intake pipe 22. Intake pipe 22 has a longitudinal central axis 76 while exhaust pipe 54 has a longitudinal axis 78. Preferably, longitudinal axes 76 and 78 are colinear such that intake pipe 22 is coaxially, or concentrically disposed in exhaust pipe 54.

A control box 80 mounted to skid 12 may be connected to a power source and will provide power to drive motor 39. Control box 80 may include a variable speed drive for motor 39, so that blower 34 can be automatically maintained at the speed necessary to provide the desired flow. For example, the control box may contain a keypad on which the desired amount of pull, for example 0.5 psi, can be entered. A pressure transducer 82 may be mounted on separator 46 and a temperature sensor 84 may be mounted in blower outlet pipe 48 on the discharge side of blower 34. A pressure transducer 86 may be mounted to the exhaust pipe 54 to measure the pressure on the outlet side of the blower. The pressure at transducers 82 and 86 may be communicated to a variable speed drive in control box 80, which will vary the speed of the motor based on the sensed pressures. The blower is therefore automatically controlled and automatically moves the motor to the speed necessary to achieve the desired pull on the well. Temperature sensor 84 will measure temperature, and in the event the temperature exceeds a predetermined maximum temperature, blower 34 will shut down. Sensor 84 will send a signal to the blower drive, which will shut blower 34 off if the sensed temperature is too high.

Gas passing through a blower will often be heated significantly to a temperature much greater than the temperature of the gas prior to reaching the blower. In some cases, the temperature of the gas may reach 300° F. Generally, gas from coal bed methane, shale reservoirs and other gas sources may be delivered to an underground pipeline which in many cases comprises a polyethylene pipe. Because polyethylene pipe may not be temperature rated for the high temperatures that can be generated by a blower, it is often necessary to replace some of the polyethylene pipe with an underground steel pipe. Oftentimes, significant lengths of steel pipe must be used to replace polyethylene pipe so that the gas exiting a blower will pass through the steel pipe for a significant length until it is cooled to meet the rating of the polyethylene pipe which may be, for example, 150°.

Blower assembly 10 of the current disclosure will cool the gas prior to the time gas exits exhaust pipe 54 so that much shorter lengths of steel pipe will be needed and in some cases no steel pipe is necessary. Gas exiting outlet pipe 48 will expand in exhaust pipe 54 and will contact intake pipe 22 so that gas exiting exhaust pipe 54 will be significantly cooler than the temperature at which the gas exits blower 34. Gas exiting the blower will be cooled both by expansion in exhaust pipe 54, and by contact with intake pipe 22. The cooling by contact is essentially a heat exchanger arrangement, since the hotter gas is contacting the intake pipe which has cooler gas from the well passing therethrough.

For example, tests have shown that gas exiting the blower at 180-200° which is communicated into exhaust pipe 54 exits exhaust pipe 54 at a temperature of about 110°. Gas at that temperature may be communicated into polyethylene pipe having a temperature rating of 150° or less. As such, no steel pipe is necessary. Thus, use of blower assembly 10 is economic both in terms of cost and efficiency since it alleviates, and in some cases eliminates the need to use steel pipe to cool gas exiting the blower 34. Blower assembly 10 is movable from site to site, since skid 12 may be trailered and transported for use at a plurality of well sites.

Thus, it is seen that the apparatus and methods of the present invention readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred embodiments of the invention have been illustrated and described for purposes of the present disclosure, numerous changes in the arrangement and construction of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present invention as defined by the appended claims.

Claims

1. Apparatus for communicating gas from a well to a pipeline comprising:

an intake conduit for receiving gas from the well;

a blower inlet conduit communicated with the intake conduit;

a blower connected to the blower inlet conduit;

a blower outlet conduit connected to the blower and connected to an exhaust pipe for communicating gas from the blower into the exhaust pipe, wherein at least a portion of the intake conduit is disposed in the exhaust pipe, and wherein the exhaust pipe communicates gas exiting the blower into the pipeline.

2. The apparatus of claim 1, wherein the intake conduit is concentrically disposed in the exhaust pipe.

3. The apparatus of claim 1, further comprising a support table, the blower being mounted to and supported by the support table.

4. The apparatus of claim 1 further comprising a separator connected in the blower inlet conduit for separating liquid from the gas.

5. The apparatus of claim 1, further comprising a bypass conduit connected at one end to the blower inlet conduit and at a second end to the blower outlet conduit for bypassing the blower and communicating gas from the blower inlet conduit to the blower outlet conduit.

6. Apparatus for delivering gas from a well to a pipeline comprising:

an intake conduit;

a gas blower;

a blower inlet conduit having a first end communicated with the intake conduit and a second end connected to the gas blower;

a separator for separating liquids from the gas connected in the blower inlet conduit between the first and second ends thereof;

an exhaust pipe for delivering the gas to the gas pipeline; and

a blower outlet conduit having a first end connected to the blower and a second end connected to the exhaust pipe, wherein gas communicated into the exhaust pipe from the blower outlet conduit contacts an outer surface of the intake conduit.

7. The apparatus of claim 6, wherein the gas in the exhaust pipe is cooled by contact with the intake conduit.

8. The apparatus of claim 6 wherein the intake conduit and the exhaust pipe are coaxial.

9. The apparatus of claim 8, wherein gas in the exhaust pipe and the intake conduit travel in the same direction.

10. The apparatus of claim 6, wherein the internal diameter of the exhaust pipe is larger than the internal diameter of the blower outlet conduit.

11. A method of communicating gas from a wellhead to a pipeline comprising:

delivering gas from the wellhead to an intake pipe;

communicating gas from the intake pipe through a blower; and

contacting an outer surface of the intake pipe with gas exiting the blower to cool the exiting gas.

12. The method of claim 11, further comprising communicating the gas exiting the blower into an exhaust pipe, the at least a portion of the intake conduit being disposed in the exhaust pipe.

13. The method of claim 12, further comprising communicating the gas exiting the blower from the exhaust pipe into the pipeline.

14. The method of claim 11, further comprising separating liquid from the gas prior to communicating the gas into the blower.

15. The method of claim 11, further comprising communicating the gas exiting the blower into an exhaust pipe.

16. The method of claim 15, wherein at least a portion of the intake pipe is disposed in the exhaust pipe.

17. The method of claim 15, further comprising communicating gas from the exhaust pipe to the pipeline.

18. Apparatus for communicating gas from a well to a pipeline comprising:

an intake conduit for receiving gas from the well; and

an exhaust pipe for communicating gas from the intake conduit to the pipeline, wherein at least a portion of the intake pipe is disposed in the exhaust pipe.

19. The apparatus of claim 18, further comprising a blower, wherein gas is communicated from the intake conduit through the blower into the exhaust pipe.

20. The apparatus of claim 18 further comprising a separator for separating liquid from the gas before gas is communicated into the exhaust pipe.

21. The apparatus of claim 18 further comprising:

a blower;

a blower inlet pipe connected to the intake conduit and to the blower; and

a blower outlet pipe connected to the blower and the exhaust pipe.

22. The apparatus of claim 21 further comprising a separator connected in the blower inlet pipe for removing liquid from the gas.

23. The apparatus of claim 21, wherein the intake conduit is concentrically disposed in the exhaust pipe.