Self-contained portable, automated blow down apparatus

Abstract

A blow down apparatus for a well has a tank for receiving an emulsion of water and natural gas, a piping connectable to a well from which the emulsion is supplied and connected to the tank so as to direct a flow of the suspension from the well into the tank, a control valve provided in the piping for closing and opening the piping, a vent for venting the gas from the vessel to atmosphere, and a transporting structure for transporting the apparatus to and from the well, the tank and the piping unit being mounted on the transporting unit.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a self-contained portable, automated blow down apparatus.

[0002] A process of blowing, unloading or pulling a well has been always accomplished manually, and by allowing a reservoir water to fall onto the ground. Also, the vented gas has never been accurately measured for reporting.

[0003] Some methods for increasing flow out of a natural gas well by the reducing the restriction caused by the presence of formation water in a tubing string are known. One of them uses a coil tubing unit which involves attaching a lubricator to the wellhead and running down coil tubing into the well. Compressed air is forced down the tubing and out the end of an upward vector, causing the water to be lifted up the tubing and into a portable tank. This requires a large unit and a two-man crew and is costly. However, the process is effective, especially in wells that have loaded up with water and died completely. On low pressure, low volume wells it is uneconomical as the production realized may not pay off the cost before the well loads up and stops flowing again.

[0004] The other processes include installation of 1¼″ coil tubing, the use of a gas recompression unit with a screw compressor suction line drawing the tubing pressure down through a separator and then discharging back into the casing, a plunger lift or vertical pig process with a plunger traveling from the bottom of the well to the surface lifting the fluid with it as it goes, and a manual method which is time consuming, environmentally unsound and regularly left undone due to demands for operational personnel time.

[0005] U.S. Pat. Nos. 5,707,214; 5,979,549; 5,282,263; 4,589,488; and 4,113,017 disclose some solutions in this field.

[0006] It is therefore believed to be clear that there is a continuous need for a practical system for removal of the reservoir water from a tubing string in a reliable, cost effective, and environmentally friendly way, for low pressure, low production, wet gas wells.

SUMMARY OF THE INVENTION

[0007] Accordingly, it is an object of present invention to provide a self-contained portable, automated blow down apparatus which avoids the disadvantages of the prior art methods.

[0008] In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated in an apparatus which has a tank for receiving an emulsion of water and natural gas; piping means connectable to a well from which the emulsion is supplied and connected to said tank so as to direct a flow of the suspension from the well into said tank; a control valve provided in said piping means for closing and opening said piping means; means for venting the gas from said vessel to atmosphere; means for emptying liquid removed from suspension from tank; and means for transporting the apparatus to and from the well, said tank and said piping means being mounted on said transporting means.

[0009] When the apparatus is designed in accordance with the present invention, it is formed as a mobile, automated blow down apparatus, to accomplish the highest pressure differential between the formation pressure and the pressure into which it must flow. Especially for shallow low pressure, sweet, natural gas wells which require only liters of water to be removed in order for the flow to be significantly increased, which is characteristic for many wells in Canada and the United States, some of which are abandoned or shut due to the economics of producing, the inventive apparatus will allow these wells to operate and allow the owners of the wells to enjoy revenues from these wells once again.

[0010] The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a perspective view of a self-contained portable, automated blow down apparatus in accordance with the present invention;

[0012] FIG. 2 is a schematic view of the inventive apparatus;

[0013] FIGS. 3 and 4 are a side view and a plan view of the inventive apparatus; and

[0014] FIG. 5 is a perspective view showing a detail of the apparatus from the opposite side.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0015] A self-contained portable, automated blow down apparatus is mounted on a wheeled trailer 9 for easy portability to and from a well site. The apparatus includes a water tank identified as a whole with reference numeral 1 and mounted on the trailer 9. A piping system 8 has one end connectable to a well and another end connected to the water tank 1. The piping system is provided with a full port control valve 4, a meter run and orifice plate changer 5, a gas metering device 6, and a controller 7. The plate changer 5 changes a flow cross-section of the piping system 8. The gas metering device determines differential pressure, pressure and temperature of gas. A load line 13 is used for emptying liquid from the water tank.

[0016] Natural gas separated from water exits the tank from the top through two goose neck vents 2, and the level of water in the tank will be allowed to reach a level no higher than permitted by a high level shut off switch 10. The heating means which can include one or several heaters 11 are supplied with a casing gas, which is directed through a fuel gas scrubber 12 after the pressure has been regulated down. The control valve is operated pneumatically by gas supplied from compressed gas (such as propane) bottles 3 at the rear of the trailer. The supplied pressurized gas is preferred, in order that sufficient pressure is available in the event that the well is incapable of supplying enough pressure to operate the control valve.

[0017] The control valve is operated by a battery operated-pneumatic timer associated with the controller 7, generally set to open for 30 minutes per 24 hour period. It is to be understood that other timing arrangements are possible.

[0018] The apparatus is attachable to the well by means of a flexible hose or piped in directly with steel piping and swivel joints. When the control valve opens, the gas takes the path of least resistance (to atmospheric pressure in the tank) and the check valve on the flow line closes preventing gas in the pipeline from entering the flow to the tank. The velocity of the gas increases as the formation gas no longer has to fight the pipeline pressure and begins lifting the water in the tubing string. The emulsion of water and natural gas flows through the meter run which measures approximately the amount of gas passing through it to enter the tank. The free water drops out of the gas stream and is collected in the tank, while the gas is vented to the atmosphere through the goose neck vents on the top of the tank. When the control valve closes, the gas is returned to the pipeline where it flows less restricted, due to the removal of the formation water from the tubing string.

[0019] As shown in the drawings, the equipment is permanently mounted on the trailer, but also can be mounted on a small skid and the like, for portability. It is covered with an insulated enclosure or panel building 13 of such a construction as to tolerate the conditions experienced during 5 towing. The tank 1 or a different vessel is fastened directly to the trailer platform which forms simultaneously a floor of the enclosure, by means of brackets, tie downs and/or guides. The vents extend outwardly through the top wall of the enclosure. The piping which directs the flow is of suitable pressure rating to tolerate expected pressures upstream of the control valve. It is attached to the trailer or skid by appropriate brackets and supports.

[0020] As explained herein above, the control valve and the gas measuring device are self-contained, and operate by propane, or another gas which supplies adequate pressure to operate the control valve. The shut down device in the water tank discontinues the flow of instrument gas to the control valve, preventing the valve from opening in the event the tank reaches a certain level which is considered undesirable. The heaters heat the apparatus inside the enclosure and prevent the tank content from freezing in cold weather. The heaters can be formed as catadyne or other flameless heaters which are safe for the application. Fuel for the heater can be supplied from the well, on which the apparatus is attached, or can be supplied in bottles.

[0021] It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

[0022] While the invention has been illustrated and described as embodied in self-contained portable, automated blow down apparatus, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

[0023] Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.

Claims

1. A blow down apparatus for a well, comprising a tank for receiving an emulsion of water and natural gas; piping means connectable to a well from which the emulsion is supplied and connected to said tank so as to direct a flow of the suspension from the well into said tank; a control valve provided in said piping means for closing and opening said piping means; means for venting the gas from said vessel to atmosphere; and means for transporting the apparatus to and from the well, said tank and said piping means being mounted on said transporting means.

2. A gas blow down apparatus as defined in claim 1; and further comprising means for mounting said tank and said piping means on said transporting means.

3. A gas blow down apparatus as defined in claim 1; and further comprising a gas metering device for determination of parameters of the flow of the suspension.

4. A gas blow down apparatus as defined in claim 1; and further comprising a controller for controlling opening and closing of said valve.

5. A gas blow down apparatus as defined in claim 1; and further comprising a shut off switch provided in said tank for controlling a maximum level in said tank.

6. A gas blow down apparatus as defined in claim 1; and further comprising heating means for heating said tank and said piping system.

7. A gas blow down apparatus as defined in claim 1, wherein said control valve is a pneumatically operated control valve; and further comprising means for operating said control valve with compressed gas.

8. A gas blow down apparatus as defined in claim 1; and further comprising an enclosure which accommodates said tank and said piping means.

9. A gas blow down apparatus as defined in claim 8; and further comprising heating means for heating an interior of said enclosure.

10. A gas blow down apparatus as defined in claim 8, wherein said transporting means have a platform which forms a floor of said enclosure.

11. A gas blow down apparatus as defined in claim 10, wherein tank and said piping means are mounted on said platform.

12. A gas blow down apparatus as defined in claim 8; and further comprising gas venting means extending from said tank through and outwardly of said enclosure.