US3366074A - Device for removing liquids from gas wells - Google Patents

Description

Jan. 30, 1968 B. J. SHIRLEY 3,366,074

DEVICE FOR REMOVING LIQUIDS FROM GAS-WELLS Filed July 8, 1966 2 Sheets-Sheet 1 ITOPA/FKS Jan. 30, 1968 B. J. SHIRLEY DEVICE FOR REMOVING LIQUIDS FROM GAS WELLS 2 Sheets-Sheet 2 Filed July 8, 1966 INVENTOR. 9 p I 6/1.; /E' 4/0 SH/ LEY United States Patent 3,366,074 DEVICE FOR REMOVING LIQUIDS FROM GAS WELLS Billie J. Shirley, P.O. Box 33, Woodward, Okla. 73801 Filed July 8, 1966, Ser. No. 563,915 12 Claims. (Cl. 103232) This invention relates to oil and gas well tools, and more particularly, to well tools used in the removal of liquids from the bores of predominantly gas wells by the use of gas pressure.

A great number of so-called intermitter or differential pressure actuated devices have been proposed for use in removing substantially all of the liquid from the annulus of a well into which connate liquids, such as oil and water, have entered and built up a sufiicient hydrostatic head to prevent flow of gas from the well into the production tubing. All of these tools have as their object, the reduction of the water or oil level in the gas Well to the point where the gas can be produced with such removal being accomplished without substantial loss of gas pressure or undesirably large quantities of gas. Many of the intermitter devices which have heretofore been proposed and which operate on the basis of differential pressure have been complicated in operating principles and expensive to manufacture. Others have functioned imperfectly and have been restricted in their usefulness to certain types of wells and prevailing conditions. One of the undesirable characteristics which has frequently been encountered in some of the devices previously used is that certain valve elements used in the device and operated by differential pressure do not seat smoothly and easily, but instead, tend to bounce to reverberate on the seat due to the sudden impact of closing or opening, and such chattering and vibration soon destroys the effectiveness of the tool and requires its repair or replacement.

The present invention provides a down hole tool for removing liquids from a gas well in an efiicient and predictable manner. The tool is operated by differential pressure in accordance with general principles heretofore well known, but achieves improved performance, and is substantially simpler in its construction and more economical to manufacture than tools of this general type which have been heretofore provided. Broadly described, the present invention comprises an elongated tubular element having first and second ends and a bore extending therethrough, the tubular element further having a capillary orifice extending through the wall to the bore and preferably positioned adjacent one end of the tubular element. An annular seat is located in the bore of the elongated tubular element, and is spaced from the capillary orifice toward the other end of the tubular element. The opening through the seat is aligned with the bore of the tubular element. At least one opening of substantially larger size than the capillary orifice is provided through the wall of the tubular element with such openings being located on the opposite side of the seat from the capillary orifice.

A valve closure member which is dimensioned to mate with the seat to prevent fluid flow therethrough is provided in the bore of the tubular element and is positioned on the opposite side of the seat from the capillary orifice. An elongated valve stem is used for interconnecting the valve closure member with a piston element which is secured to the opposite end of the elongated valve stem from the valve closure member and is slidingly positioned in the bore of the tubular element. Plug means is provided for obstructing and sealing the bore through the tubular element, and sealingly and slidingly engages the elongated valve stem so that the stem can be reciprocated through this plug means. Positive stop means is provided 3,366,974 Patented Jan. 30, 1968 in the tool for limiting the movement of the piston element, the valve stem and the valve closure member away from the seat. An adjustable control means is located externally of the tubular element and cooperates with a portion of the piston element which projects from one end of the tubular element for resiliently biasing the piston element against the positive stop means with a predetermined force. Finally, by-pass conduit means is provided and communicates with the bore at a point in the tubular member which is on the same side of the seat asthe capillary orifice. The by-pass conduit means extends around the plug means to a point in the bore of the tubular member which is between the piston element and the plug means.

In a preferred embodiment of the invention, the tool is further provided with pneumo-hydraulic cushioning means which functions to prevent the moving parts within the bore of the tubular element from chattering as they engage the positive stop means and the valve seat during different phases of the operation of the tool.

The number of moving parts which are provided in the tool of the present invention is relatively small as compared with a number of such elements which have been utilized in many previous types of tool. Moreover, the construction which is employed assures minimization of opportunity for malfunctioning to occur so that the tool is characterized in having a long and trouble-free operating life. The liquid removing device of the invention will effectively remove substantially all of the liquid which has accumulated in the annulus of the well bore and is preventing production of gas by the well. The gas pressure in the well is not reduced to any significant degree when using the device, and very little of the gas is produced during the operation of the tool for removing liquid from the well bore.

From the foregoing description of the invention, it will be apparent that a major object of the invention is to provide an improved intermitter or pressure differential actuated tool for removing liquid from a well.

A more specific object of the invention is to provide a tool for removing water or oil from a gas well so that the well may produce more efiiciently, which tool does not chatter or vibrate excessively during its cycle of operation.

An additional object of the invention is to provide a relatively simple, compact tool which can be placed on the end of conventional gas well production tubing strings and used to reduce a liquid head accumulated in the annulus of the well and thus permit gas to be more efficiently produced therefrom.

An additional object of the invention is to provide a mechanically rugged, yet relatively simply constructed well tool which is characterized in having a long and trouble-free operating life, and which can be employed for removing liquids from gas wells.

In addition to the foregoing described objects and advantages, a number of additional objects and advantages characterize the present invention and will become apparent as the following detailed description of the invention is read in conjunction with the accompanying drawings which illustrate the invention.

In the drawings:

FIGURE 1 is a vertical sectional view through a typical gas well and depicting the present invention secured to the lower end of a string of production tubing.

FIGURE 2 is a vertical sectional view through the center of the liquid removing tool of the present invention.

FIGURE 3 is a sectional View taken along line 33 of FIGURE 2.

FIGURE 4 is a sectional view taken along line 4-4 of FIGURE 2.

FIGURE 5 is a sectional view taken along line S5 of FIGURE 2.

FIGURE 6 is a horizontal sectional view taken along line 66 of FIGURE 2.

FIGURE 7 is a horizontal sectional view taken along line 77 of FIGURE 2.

Referring initially to FIGURE 1 of the drawings, the environment in which the tool of the invention is typically used is illustrated, and includes a well casing 10 which extends downwardly into the earth 12 and terminates in an open hole completion providing an uucascd portion of the hole 14 at the lower end of the well. The casing 10 extends to a wellhead 16 and is provided with an outlet pipe 20 through which gas produced from a producing formation 22 may be conducted to a reservoir or point of use. A production tubing string 24 is extended downwardly into the well concentrically in the casing 10 and terminates in the uncased portion of the well adjacent the lower end thereof. An outlet pipe 26 is provided for conducting to an open tank or to a gas liquid separator fluids forced to the surface through the production tubing 24. Secured to the lower end of the production tubing 24 by a typical box and pin connection 28 is the well tool of the present invention, designated generally by reference numeral 30 and illustrated in greater detail in FIGURES 2-7.

In referring to FIGURE 2, it will be noted that the tool may be described as a three sectioned hollow body, or may be differently characterized as an elongated tubular element. Adhering for the moment to the former description, the tool includes an upper body section 32, a central body section 34, and a lower body section 36. Each of the body sections is provided with a bore extending therethrough with the bores of the three body sections coaxially aligned to form the elongated tubular element of the tool. The upper body section 32 carries an externally threaded tapered neck portion 38 which forms the pin of a typical box and pin connection.

Immediately below the threaded tapered neck portion 38 of the upper body section 32, a capillary orifice 40 is provided and extends through the wall of the elongated tubular element of the tool and communicates with the bore which extends through the upper body section 32. A second orifice 42 substantially larger than the capillary orifice 40 is provided through the wall of the tool on the opposite side of the bore from the capillary orifice for a purpose hereinafter described. A counterbore 44 is formed in the lower end of the upper body section 32 to define a downwardly facing shoulder 46. A seat 48 carrying a sealing O-ring 50 bears against the shoulder 46 and is provided with a central, frusto conically tapered aperture 52.

A hollow cage 54 is connected to the seat 52 and is characterized in having a plurality of circumferentially spaced, relatively large ports 56 therein. The ports 56 are much larger than the capillary orifice 40 and are placed in communication with the exterior of the tool through a large opening 58 formed in the wall of the tool. It will be noticed that the cage is of smaller diameter than the diameter of the counterbore 44 so that an annular spac exists between the outer periphery of the cage 54 and the interior wall of the upper body section 32. The cage 54 threadedly engages plug means 60 which includes an elongated, externally threaded tubular body 62 having a relatively large bore 64 formed in the upper end thereof adjacent the cage 54 and an intermediate diameter, first counterbore 66 and a relatively small diameter second counterbore 68. The lower face of the plug means 60 is recessed as indicated by reference numeral 70 and receives an annular packing element 72 and suitable retaining rings 74.

Positioned within the first counterbore 66 of the plug means 60 is a tubular sleeve 76 which is preferably constructed of a relatively high density, low coefficient of friction synthetic resin, such as nylon or Teflon. The sleeve 76 is provided with a radially outwardly extending annular flange 78 adjacent its upper end with such flange extending to the defining walls of the counterbore 66. Be-

neath the flange 78 in the annular space between the shank portion of the sleeve 76 and the wall of the counterbore 66 are a plurality of packing rings 80 which are placed in compression by the flange 78 when the sleev 76 is fully seated as hereinafter described. An annular retaining ring 82 bears against the flange 78 and is biased thereagainst in a resilient manner by a compression spring 84 which extends between the retaining ring 82 and the lower end of the valve cage 54 which is threaded into the upper end of the plug means 60.

The tubular body 62 of the plug means 60 is provided with an annular groove 85 adjacent its upper end and with a sealing ring 86 which is positioned in the annular groove and bears against the internal wall of the upper body section 32. Below the annular groove 84 and sealing ring 86, the external peripheral surface of the body 62 is threaded and engages the internally threaded lower end of the upper body section 32. The lower end of the tubular body 62 of the plug means 60 is also threaded, and threadedly engages the upper end of the central body section 34 of the tool. A pair of sealing rings 90 and 92 are provided in accommodating annular grooves intermediate the threaded portions of the body 62 which engage the upper body section 32 and the central body section 34 of the tool so as to form a seal connection between these body sections when the plug means 60 is used for interlocking them in the manner illustrated in FIGURE 2.

An elongated valve stem 94 extends upwardly in the bore through the elongated tubular element of the tool, passing through the packing 70, the sleeve 76 and the compression spring 84 positioned in the bore 64. The valve stem 94 has its upper end extended through a central aperture 95 in the lower end of the valve cage 54. A valve closure member 96 is formed integrally with or secured to the upper end of the valve stem 94, and is dimensioned to engage the valve seat 48 as it moves into the frusto-conical tapered aperture 52. The lower end of the valve stem 94 carries a plurality of annular ribs 98 which project into, or interlock with, mating grooves 100 formed in a connecting collar 102. The interlock formed between the ribs 98 and grooves 100 is relatively loose to provide a flexible connection. The grooves 100 of the connecting collar 102 also interlock loosely with annular ribs 104 provided on an upwardly projecting piston neck 106. It will be noted that a space or gap is provided between the upper end of the piston neck 106 and the lower end of the valve stem 94, again for the purpose of providing a flexible, universal movement connection between the piston neck and the valve stem.

Approximately midway of the length of the central body section 34, an aperture 107 extends through the body section to place the bore of the tool in communication with an elongated, small diameter tubing 109 which is also in communication with orifice 42 in the upper body section 32. The purpose of this arrangement will be hereinafter explained.

The piston neck 106 projects from the upper end of a piston cap element 108 which is screwed into and closes the upper end of an elongated hollow piston body 110 which extends downwardly in the bore of the central body section 34 of the tool. An annular sealing ring 112 is carried in a groove 114 formed around the outer periphery of the hollow piston body 110 and forms a sliding seal between the piston body and the internal wall of the central body section 34. It will be noted in examining FIGURE 2, and specifically, the configuration of the piston body 110, that an annuar downwardly facing shoulder is formed on the piston body and functions as a positive stop element in a manner hereinafter described. The hollow interior of the piston body 110 extends to a point near the lower end of the piston body. A relatively small diameter first conduit 116 extends from outside the piston body 110 through the wall thereof to a point adjacent the lower end of the hollow interior of the piston body. An air bleed tube 118 also extends from the exterior of the piston body 110 into the hollow interior thereof with the air bleedtube terminating at a point spaced vertically above the lower end of the first conduit 116.

The lower body section 36 of the tool is threadedly connected to the lower end of the central body section 34 and a suitable sealing ring 122 is provided to assure sealing engagement between these two sections of the tool. The lower body section 36, in addition to a relatively large, threaded bore 124 formed in the upper end thereof for receiving the threaded lower end of the central body section 34, also has a relatively smaller diameter counterbore 126 formed in the lower end thereof which more closely surrounds, but yet is slightly spaced from, the external periphery of the piston body 110. By this construction, an upwardly facing shoulder 128 is formed in the lower body section 36, and this shoulder cooperates with the downwardly facing shoulder 120 carried by the piston body 110 to limit movement of the piston in the bore of the tool during its operation as hereinafter described. The extreme lower end of the piston body 110 is externally threaded and receives an adjusting nut 130 which can be threaded on the lower end of the piston body to any desired axial location therealong. A compression spring 132 is interposed between the adjusting nut 130 and an annular, spring receiving detent 134 formed on the lower end of the lower body section 36.

Operation In use, the tool 30 of the invention is secured to the lower end of a production tubing string 24 by a conventional box and pin connection in which the threaded neck portion 38 of the upper body section 32 is threaded into the lower end of the tubing string. The tool 36 has been assembled with the body sections 32, 34 and 36 threadedly engaged in the manner illustrated in FIGURE 2. As the tubing string is initially lowered in the well, the resilient biasing action of the compression spring 132 extends the piston body 110 from the lower body section 36 so that the downwardly facing shoulder 120 bears against the upwardly facing shoulder 128. It should be pointed out that the spring 132 is selected, and the adjusting nut 130 is set in a selected axial position on the lower end of the piston body 110, so that the spring exerts a predetermined downward bias on the piston body. Thus, for example, let it be assumed that the spring exerts a downward force on the piston body of 300 p.s.i.g.

As the tubing string moves downwardly in the well bore and approaches the position depicted in FIGURE 1, the bottom hole pressure exerted through the liquid located in the well acts upwardly on the lower end of the piston body 110 and against the total cross sectional area of the piston which is sealed against the internal wall of the bore of the central body section 34. This upwardly acting pressure which, say, is 800 p.s.i.g., overcomes the downward bias of the compression spring 132 and thus causes the piston body to slide upwardly in the central and lower body sections 34 and 36, respectively. It should :be noted that, even though prior to the upward movement of the piston body 110, the liquid standing in the well bore can enter the tool through the large opening 56, this liquid is isolated from the piston body in the plug means 60. The liquid which enters the opening 58 thus exerts no force on the piston which tends to counteract the upwardly acting force exerted by the liquid on the lower side of the piston.

Once the tool is in position in the bottom of the well bore as illustrated in FIGURE 1, the upwardly acting bottom hole pressure has overcome the downward bias of the compression spring 132, and has forced the piston body 110 upwardly until the valve closure member 96 engages the frusto-conical tapered aperture 52 through the seat 48 and closes this aperture. At this time, no liquid can flow via the opening 58 through the aperture 52 and upwardly into the tubing string. Flow of the liquid into the tubing string, which is open to the atmosphere at the top, can occur, however, through the capillary orifice 4i). The liquid thus gradually builds up in the tubing string 24 above the valve seat 48, being forced through the capillary orifice 40 by the pressure of gas accumulated in the annulus between the casing 10 and the tubing string. The liquid continues to rise in the tubing string 24 and simultaneously with the introduction of liquid into the tubing string via the capillary orifice 46, liquid is permitted to pass downwardly through the small diameter tubing 109 from the orifice 42 to the aperture 107. Liquid thus commences to accumulate in the bore of the central body section 34 above the sealing ring 112.

As liquid continues to rise in the tubing string 24, the force exerted by the increasing hydrostatic head increases and is transmitted through the small diameter tubing 109 into the space within the central tubing section 34 above! the sealing ring 112. In the hypothetical example under discussion, when the hydrostatic head developed by the rise of liquid in the tubing string 24 reaches a magnitude such that a force of 300 p.s.i.g. is exerted on the upper side of the piston (above the sealing ring 112), the combined forces of this hydrostatic head and the downwardly biasing influence of the spring 132 balance or counteract the upwardly acting bottom hole pressure tending to force the piston body upwardly so that the piston is balanced. Further flow of water under the gas pressure existing in the well annulus through the capillary orifice 4t] and into the tubing string 24 will thus result in a sufficient downwardly acting force being developed to cause the piston body 110 to reciprocate downwardly in the body sections 34 and 36 so that the valve closure member 96 moves off the seat 48, and the tapered aperture 52 is opened. This opening of the valve formed by.the seat 48 and closure member 96 permits a relatively large volumetric fiow of liquid to occur through the opening 58 and thence through the tapered aperture 52 into the tubing string 24. The result is a rapid decrease in the accumulated head of liquid in the annulus surrounding the pro duction tubing string 24 and soon the level of the water in this annulus reaches the horizontal level of the capillary orifice 46. As the water moves below this level, the gas accumulated in the annulus is free to pass through the capillary orifice 40 and into the bore of the tubing string 24. The inrush of gas then forms a pneumatic piston under the head of water accumulated in the tubing string 24 with the result that this water is rapidly blown or lifted to the surface through the tubing string 24 and is discharged through the pipe 26. A substantial amount of water is thus unloaded by a relatively small amount of gas and without any significant decrease in the total gas pressure of the reservoir.

As gas replaces the liquid in the tubing string 24 above the tool 39, the weight of the liquid is replaced by the weight of the gas in the tubing string and consequently no hydrostatic force continues to act downwardly on the piston body 110 except for the very small amount which results from liquid accumulated in the bore of the central body section 34 and in the small diameter tubing 109. Thus, the bottom hole pressure again becomes suificient to close the valve by moving the piston body 110 upwardly, and the cycle of operation is ready to be repeated.

At this point, it should be pointed out that the construction of the piston means used in the invention permits closure of the valve member 96 on the seat 48 without chattering or vibration. The smooth seating action described is effected by the operation of the small diameter first conduit 116 and the air bleed tube 118 which extends from outside the piston body 110 to the hollow interior thereof. Thus, during the influx of water via the capillary orifice 40 into the tubing string 24 with the resultant gravitation of water through the small diameter tubing 109 into the space above the sealing ring 112, the liquid also passes through the conduit 116 and accumulates in the bottom of the hollow interior of the piston body 110. Simultaneously, air contained Within the hollow interior of the piston body 116 is displaced therefrom through the air ejection tubing 118 or is at least placed in compression by the increasing hydrostatic head.

At such time as the gas enters the tubing string through the capillary orifice 40, and frequently also through the relatively large opening 58, the acting hydrostatic head is suddenly removed by the pneumatic piston formed by the entering gas with the result that the piston body 1H) suddenly moves upwardly in the tool, and the valve formed by the seat 48 and closure member 96 is closed. This upward movement of the piston body 110 is opposed by the gas which has been placed in compression by the introduction of water through the small diameter tubing 1059 into the bore of the central body section 34 in the manner hereinbefore described. This entrapped, compressed gas tends to cushion the seating stroke of the piston body 110 and the valve stem 94 since the gas becomes more compressed as the piston body moves upwardly in the bore through the central body section 34. Once the air bleed tube 118 moves upwardly so that its open upper end is above the level of liquid accumulated in the bore through the central body section 34, the compressed air located above this liquid is free to enter this tube with the result that water accumulated in the bottom of tie hollow interior of the piston body 110 is forced upwardly through the first conduit 116 and can then be ejected under air pressure through the small diameter tubing 16? into the space above the valve seat 48. The small diameter of the first conduit 116 and the tubing 109 assure that a dashpot action will be obtained in the ejection of liquid and air through these tubings.

At such time during the operation of the tool as water has accumulated in the tubing string 24 to a height such that the piston body 110 will be moved downwardly and the valve opened, the movement of the piston body tends to enlarge the space existing within the central body section 3 above the sealing ring 112 and the result is that a partial vacuum is created in the bore of the central body section. This evacuation provides a pneumatic spring cushioning the downward movement of the piston body 110 and preventing chattering or bouncing as the downwardly facing shoulder 112 contacts the upwardly facing shoulder 128. Gas or liquid to fill the partial vacuum created by this downward movement of the piston body 110 must be drawn either from the hollow interior of the piston body 110, or through the small diameter tubing 109, and since both the conduit 116 and air bleed tube 118 are of relatively small diameter, they again provide a dashpot effect preventing rapid filling of the partial vacuum by liquid or gas drawn from within the hollow interior of the cylinder of the piston body 110.

After one complete cycle of the tool 30 in which a substantial amount of accumulated liquid is unloaded in the manner described, the valve constituted by the seat 48 and the valve closure member 96 will remain closed until such time as enough liquid has re-entered the annulus of the well to build up a liquid column within the tubing string 24 providing sufficient hydrostatic head to again open the valve. When this condition has been attained, the valve again opens, permitting rapid influx of liquid, followed by a charge of gas from the annulus sufficient to force the accumulated liquid to the surface.

The provision of the compression spring 132 and the adjusting nut 130 permits the tool to be adapted for use under differing well conditions so that the tool responds to different liquid columns in the tubing string. The cycle of operation can also be adjusted to any period which may be desired by proper sizing of the capillary orifice 40 and the relatively large opening 58. Preferably, the capillary orifice 40 is of sufiiciently small size that grains of sand or other foreign materials entrained in the liquid in the well bore will not plug or stop the orifice. As a preferred alternative, a fine mesh screen or wire cloth is placed across the orifice 40 in an aperture or a recess 140 provided in the Wall of the upper tubing section 32 and functions to prevent deleterious materials from entering and choking the orifice. The relatively simple construction of the tool insures a minimum of malfunction during its use, and it is characterized in having a long and relatively trouble-free operating life. The flexible connection afforded by the engagement of the connecting collar 102 with the ribbed lower end of the valve stem 94 and the upwardly projecting piston neck 106 also assures that forces of large magnitude which may be imposed on the tool by unanticipated well conditions or improper use will not render the tool inoperative.

As an example of the use of the invention, a non-commercial well, when completed, had a potential of 200M cf. of natural gas per day and was thus considered infeasible to produce. The well was drilled in an extremely tight rock and was acidized during completion stages. When an effort was made to produce the well, it would load up with liquid and kill the gas volume. The well was tested for two months for its production capabilities. barrels of oil were recovered during the testing period.

The tool of the present invention was placed in the well for the purpose of unloading the water and oil without exhausting the gas supply. The bias of the resilient spring was set for 500 p.s.i.g. by adjustment of the adjusting nut. An an 8-day shut-in test, 98 barrels of oil was produced and 70 barrels of water and over this period, the gas pressure in the annulus dropped from 1550 p.s.i.g. to 1260 p.s.i.g. No gas was passed through the annulus. Since relatively little liquid was produced on the last two days of the test, it is believed that the tool successfully dried up the area around the well bore. The casing pressure stabilized at 1260 pounds upon completion of the test.

From the foregoing description of the invention, it will have become apparent that the present invention provides a highly efiicient and useful tool for unloading liquid from a gas well in an economical and reliable manner. The tool is ruggedly constructed and is reliable over long periods of operating life.

Although a specific embodiment of the invention has been herein illustrated in order to provide an example of the manner in which it is constructed, it will be readily apparent that various changes and modifications can be made in the depicted structure without departing from the basic principles which underlie the invention. All such changes and modifications are therefore deemed to be circumscribed by the spirit and scope of the present invention except as the same may be necessarily limited by the appended claims or reasonable equivalents thereof.

What is claimed is:

1. A device for removing liquids from a gas well comprising:

an elongated tubular element having first and second ends, and having a bore extending therethrough between the ends, said tubular element including upper, central and lower body sections, said upper body section having a capillary orifice extending through the wall thereof into the bore of said elongated tubular element and having a second orifice extending through the wall thereof, said upper body section further having an opening through said wall and spaced along said bore from said capillary orifice and said second orifice;

an annular seat positioned in the upper body section below said capillary orifice and said second orifice and above said opening and having a central aperture therethrough;

a valve closure member dimensioned to mate with said seat to prevent fiuid flow therethrough;

an elongated valve stem connected at one of its ends to said valve closure member and extending in the bore of said tubular element;

a piston element secured to the opposite end of said valve stem from said valve closure member and slidingly positioned in the bore of said tubular element, a portion of said piston element projecting from an end of said tubular element;

plug means sealingly surrounding and slidingly engaging said valve stem, said plug means being positioned in the bore of said tubular element in said central body portion and obstructing and sealing the bore around said valve stem;

stop means in said tubular element for limiting the movement of the piston element, valve stem and valve closure member away from the seat;

adjustable control means located externally of the tubular element and cooperating with the projecting portion of the piston element for resiliently biasing the piston element against the stop means with a predetermined force; and

by-pass conduit means connected to said second orifice, by-passing said plug means and communicating with the bore through said tubular element at a point between said piston element and said plug means.

2. A device as defined in claim 1 wherein said piston element includes an elongated, hollow piston body;

a sealing element around said piston body and sealingly engaging the internal wall of said central body section; and

means for gradually admitting fluid from said bore above said sealing element into the hollow interior of said piston body.

3. A device as defined in claim 1 wherein said valve closure member comprises a spherical metallic member.

4. A device as defined in claim 1 wherein said plug means includes a synthetic resin sleeve surrounding and sealingly engaging said valve stem.

5. A device as defined in claim 1 wherein said piston element includes an elongated, hollow piston body having a downwardly facing shoulder formed thereon and positioned in the bore of said tubular element; and

said stop means comprises an upwardly facing shoulder positioned in the line of movement of said downwardly facing shoulder.

6. A device as defined in claim 1 wherein said adjustable control means comprises:

an adjusting nut threaded on the portion of said piston element which projects from the end of said tubular element; and

a compression spring positioned between said adjusting nut and said lower body section.

7. A device as defined in claim 1 wherein said central body section has an opening through the wall thereof into said bore at a point above said piston element, and said by-pass conduit means comprises a small diameter tubing extending from said second orifice to said last mentioned opening for conveying fluid from a point in the bore above said valve seat to a point in the bore above said piston element.

8. A device as defined in claim 2 wherein said means for gradually admitting fluid comprises:

a first small diameter tubing extending through the wall 10 of said hollow piston body at a point above said sealing element and terminating adjacent the lower end of the hollow interior of said piston body; and

a second small diameter tubing extending through the wall of said hollow piston body at a point above said sealing element and terminating in the hollow interior of said body portion at a point spaced above the lower end of said first mentioned small diameter tubmg.

9. A device as defined in claim 1 and further characterized to include a flexible connection between said piston element and said elongated valve stem.

10. A device as defined in claim 1 and further characterized to include a hollow cage positioned between and spacing said plug means and said seat, said cage having a plurality of openings therein in coplanar alignment with said opening through the wall of the upper body section.

11. A device as defined in claim 10 wherein said cage threadedly engages the upper end of said plug means, and said seat is pressed into said cage.

12. A device as defined in claim 11 wherein said piston element includes:

an elongated hollow piston body having a downwardly facing shoulder formed thereon;

a sealing element around said piston body and sealingly and slidingly engaging the internal wall of said central body section;

a first tubing extending through the wall of said hollow piston body at a point above said sealing element and terminating adjacent the lower end of the hollow interior of said piston body;

a second tubing extending through the wall of said hollow piston body at a point above said sealing element and terminating in the hollow interior of said body portion at a point spaced above the lower end of said first mentioned tubing;

and wherein said stop means comprises an upwardly facing shoulder positioned in the line of movement of said downwardly facing shoulder.

References Cited UNITED STATES PATENTS 2,061,289 11/1936 Phipps 103232 2,128,475 8/1938 Rodgers 10340 2,192,945 3/1940 Toney 103-232 X 2,291,902 8/ 1942 Kelley 103-40 2,356,423 8/1944 OLeary 103-232 2,368,999 2/1945 OLeary 103-232 2,865,305 12/ 1958 Vincent 103-232 3,075,475 1/ 1963 Otis 103-232 3,212,517 10/1965 Canalizo 103232 ROBERT A. OLEARY, Primary Examiner,

J KRAUSS, Assistant Examiner.

Claims (1)

1. A DEVICE FOR REMOVING LIQUIDS FROM A GAS WELL COMPRISING: AN ELONGATED TUBULAR ELEMENT HAVING FIRST AND SECOND ENDS, AND HAVING A BORE EXTENDING THERETHROUGH BETWEEN THE ENDS, SAID TUBULAR ELEMENT INCLUDING UPPER, CENTRAL AND LOWER BODY SECTIONS, SAID UPPER BODY SECTION HAVING A CAPILLARY ORIFICE EXTENDING THROUGH THE WALL THEREOF INTO THE BORE OF SAID ELONGATED TUBULAR ELEMENT AND HAVING A SECOND ORIFICE EXTENDING THROUGH THE WALL THEREOF, SAID UPPER BODY SECTION FURTHER HAVING AN OPENING THROUGH SAID WALL AND SPACED ALONG SAID BORE FROM SAID CAPILLARY ORIFICE AND SAID SECOND ORIFICE; AN ANNULAR SEAT POSITIONED IN THE UPPER BODY SECTION BELOW SAID CAPILLARY ORIFICE AND SAID SECOND ORIFICE AND ABOVE SAID OPENING AND HAVING A CENTRAL APERTURE THERETHROUGH; A VALVE CLOSURE MEMBER DIMENSIONED TO MATE WITH SAID SEAT TO PREVENT FLUID FLOW THERETHROUGH; AN ELONGATED VALVE STEM CONNECTED AT ONE OF ITS ENDS TO SAID VALVE CLOSURE MEMBER AND EXTENDING IN THE BORE OF SAID TUBULAR ELEMENT; A PISTON ELEMENT SECURED TO THE OPPOSITE END OF SAID VALVE STEM FROM SAID VALVE CLOSURE MEMBER AND SLIDINGLY POSITIONED IN THE BORE OF SAID TUBULAR ELEMENT, A PORTION OF SAID PISTON ELEMENT PROJECTING FROM AN END OF SAID TUBULAR ELEMENT; PLUG MEANS SEALINGLY SURROUNDING AND SLIDING ENGAGING SAID VALVE STEM, SAID PLUG MEANS BEING POSITIONED IN THE BORE OF SAID TUBULAR ELEMENT IN SAID CENTRAL BODY PORTION AND OBSTRUCTING AND SEALING THE BORE AROUND SAID VALVE STEM; STOP MEANS IN SAID TUBULAR ELEMENT FOR LIMITING THE MOVEMENT OF THE PISTON ELEMENT, VALVE STEM AND VALVE CLOSURE MEMBER AWAY FROM THE SEAT; ADJUSTABLE CONTROL MEANS LOCATED EXTERNALLY OF THE TUBULAR ELEMENT AND COOPERATING WITH THE PROJECTING PORTION OF THE PISTON ELEMENT FOR RESILIENTLY BIASING THE PISTON ELEMENT AGAINST THE STOP MEANS WITH A PREDETERMINED FORCE; AND BY-PASS CONDUIT MEANS CONNECTED TO SAID SECOND ORIFICE, BY-PASSING SAID PLUG MEANS AND COMMUNICATING WITH THE BORE THROUGH SAID TUBULAR ELEMENT AT A POINT BETWEEN SAID PISTON ELEMENT AND SAID PLUG MEANS.

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