US3543848A

US3543848A - Intermitter

Info

Publication number: US3543848A
Application number: US819608A
Authority: US
Inventors: Henry U Garrett
Original assignee: UDELL GARRETT Inc
Current assignee: UDELL GARRETT Inc
Priority date: 1969-04-28
Filing date: 1969-04-28
Publication date: 1970-12-01
Anticipated expiration: 1987-12-01

Description

United States Patent lnventor Henry U. Garrett [56] References Cited Housmna Texas UNITED STATES PATENTS P 8191608 2,882,832 4/1959 Swink 103/233 Fled mm/1969 2,982,226 5/l96l Peters et al. 103/232x pattfmed 1,197" 3,213,806 10/1965 Walton 103/232 Ass'gnee 3,363,581 1/1968 Kelley et al. 103/232 Texas 3,415,199 12/1968 Elliott et a]. 103/232 a corporation of Texas Primary Examiner-James A. Leppink Attorney-J. Vincent Martin, Joe E. Edwards and M. H. Gay INTERMITTER 7 Claims, 25 Drawing Figs.

US. Cl 166/53,

166/224; 103/232, 103/233 ABSTRACT: This patent discloses a diverter for use in Int. Cl E21b petroleum wells in which liquids are permitted to accumulate E2 1 b 33/00; E09f [/00 from a well formation and are then lifted to the surface by gas, Field of Search 166/224, either introduced from the surface or obtained from the same or another formation penetrated by the well.

Patented Dec. 1, 1970 3,543,848

Sheet 5 are) HH-uhlhwmn mi llll {I ll'lll l ilil Hll IIF HEA/RXU. GARRETT 1 N VENTOR.

Patented Dec. 1,1970 3,543,848

Sheet 2 of 9 HENRY u. GARRETT V R; i

Patented Dec. 1, 1970 I TM 1 a M a H E N /Z m Patented Dec. 1, 1970 Sheet 5- of 9 l HENRYU.

ATTORA/E y Patent ed Dec. 1,1910 4 3,543,848

Sheet 6 01'9 HENRYU. GARRET v Patented Dec. 1,1970 3,543,848

Sheet 7 of 9 ATTORNEYS j INTERMITTER In petroleum wells it is frequently desirable to control the lifting of liquids in the well in a manner such that liquids are permitted to accumulate until they reach a desired volume and then are automatically lifted to the surface in response to reaching the desired volume.

It is an object of this invention to provide a diverter for petroleum wells in which liquids are permitted to accumulate in the tubing until they have reached a desired volume, and then inflowing liquids arepositively stopped and gas is automatically admitted to the tubing to lift the accumulated liquid.

Upon sufficient gas being admitted to the tubing to lift the liquid, the gas port into the tubing is closed and the fluid entry port into the tubing is reopened.

Another object is to provide a diverter for use in petroleum wells in which the gas entry port and the fluid entry port are alternately opened and closed in response to the liquid levelin the tubing accumulating to a selected volume and being lifted from the well.

Another object is to provide a diverter as in the preceding object in which the valves are opened and closed by maintaining or venting pressures on valve operators.

Another object is to provide a diverter for positively admitting liquid into a tubing until a selected volume has been reached and then positively closing the liquid. inletand opening a gas lift inlet to lift the liquid and thenclosing the gas'inlet and reopening the liquid inlet in which one of the valves is opened in response to closing ofthe'other valve and vice ver- Another object is to provide .a diverter for lifting liquids from a well with gas in which liquid and gas entry into the tubing are positively controlled by alternately opening and closing valves in combination with a packoff assembly, which combination may be run into and landed in a well at any selected point without pulling the tubing.

Other objects, features and advantages of this invention will be apparent from the drawings, the specification and the claims.

In the drawings wherein illustrative embodiments of this invention are shown and wherein like numerals indicate like parts:

FIG. I is a view partly in vertical cross section and partly in elevation, showing the intermitter of this invention'in place in a well where gas from a lower formation is utilized to lift fluid from an upper formation with the valves in a position permitting liquid to flow from the formation into the tubing;

FIG. 2 is a view similar to FIG. 1 with the valves positioned to lift the fluid using gas from the lower formation as alifting medium; FIG. 3 is a view partially in elevation and partially in cross section, showing the intermitter of thisinventionin a well in which gas from the surface is used to lift fluid;

FIG. 4 is a view partially in elevation and partially in cross section of a well, showing the intermitter of this invention used to dewater a gas well;

FIGS. 5A through 5D are continuation views,'partially in cross section and partially in quarter-section, illustrating an intermitter constructed in accordance with this invention;

FIG. 6 is a view along the lines 6-6 of FIG. 5C;

FIG. 7 is a view along the lines 7-7 of FIG. 5C;

FIG. Sis a view along the lines 8-8 ofFIG. 5C;

FIG. 9 is a view along the lines 9-9 of-FIG.'5D;

FIG. 10 is a fragmentary view, showing a different construction of slide valve which may be substituted for the slide valve shown in FIG. 5C;

FIG. II is a view, partially in elevation and partially in cross section, illustrating the use of another form of intermitter where an anchor has been run in a well, the tubing perforated above the anchor and the intermitter landed in the anchor;

FIG. 12A through 1213 are continuation views,partially in cross section and partially in quarter-section, illustrating a modified form of diverter;

FIG. 13 is a diagrammatic illustration of the intermitter in simplified form for purposes of illustration; and

FIG. 14 through 18 are line drawings showing the successive steps in utilizing the intermitter illustrated in FIGS. 12A through 12E.

Reference is first made to FIG. 13 where the operation of the intermitter is illustrated. The intermitter is provided with a pair of control valves, indicated generally at 20 and 21, for controlling flow of fluid through the intermitter. The valves are alternately opened and closed by a control valve 22 which is shifted in response to pressure conditions on the bellows 23. With the valves in the position illustrated, it may be assumed that liquid from below the intermitter is passing valve 20 and rising in the tubing. Upon asufficient amount of liquid passing into the tubing, the pressure exerted by this liquid on the bellows 23 will shift the control valve 22 upwardly to effect closing of the valve '20 and opening of valve 21. Valve 21 would be connected with a source of gas under pressure, and this gas would be utilized .to lift the liquid in the tubing to the surface. Upon the pressure in the tubing dropping to aselected level during the lift cycle, the control valve 22 will again shift to the position shown to open the valve 20 and permit entry of additional liquid.

While it :will be appreciated'that the control valve 22-might admit or vent pressure from the valves 20 and 21, it is preferred for simplicity to provide bleeds in the valves which will permit the upstream fluid to bleed past the valve. Then this fluid is either maintained on the valves or vented to effect shifting of'the valves 20 and 21.

In the illustrated form, the valve 20 has a bleed passageway .24 therethrough. Carried on the valve stem is a pressure responsive member or piston 25 which sealingly engages cylinder 26. A spring '27 is provided to positively urge the \valve toward its seat. Thus with the control valve in the position illustrated, the cylinder 26 is connected through passageway28 and passageway'29 to the upper end of the intermitter. With the control valve,22 in theposition shown. the two

passageways

28 and 29 are in communication and the .cylinder 26 is vented andthe valve 20 is permitted to open under thepressure of formation fluid entering the lower end of below thevalve 21 is identical. As'the cylinder is larger in diameter than the valveseat and-the spring urges the valve member downwardly, it will remain seated.

Uponthe bellows 23 being subjectedto asufficient pressure, it-willmoveupwardly shiftingthe control valve'22 to a position where the lower O-

rings

33 and 34 straddle the passageway, 28 to close valve20. Passageway 31 will be placed in communication with passageway 29 -to thus vent passageway 32 and establish a pressure differential across the valve 21. This willresult in opening of the valve-21 to permit gas to lift thefluid above the intermitter, As will appear more fully hereinafter, the liquid'mayenter' through valve 21 and the-gas through valve 20.'ln this case the seals on the valve 22 are rearranged so'that the intermitter will function as explained.

Reference is now made to FIG. 3 and to FIGS. 5A through 5D which show the system and intermitter for lifting fluid with gas from the surface. The intennitter 40 is positioned in tubing 41 and-communicates with the casing annulus 42 through a suitable perforation 43 in the tubing. The tubing casing annulus is closed by the packer indicated at 44. Liquid from the production sand 45 rises through the intermitter and gas introduced through conduit 46 is utilized to lift liquid through tubing 41 in theconventional manner.

The intermitter FIGS. 5A-5D) includes an elongate outer body carried by tubing 41. The body ismadeup of several generally

tubular sections

47, 48 and 49 which are secured together as by the thread systems shown. If desired, the tubing may extend downwardly from the body section 49 to the desired depth as indicated by the length of tubing 51. The

tubular body sections

47, 48 and 49 are made up as a part of the tubing string when the string is run.

In order to provide for flow of gas into the intermitter, the body section 48 is perforated as at 50.

To provide for flow of liquid from the lower end of the intermitter past the perforation 50, the body section 48 is provided with bypass passageways 48a.

The remainder of the body of the intermitter is preferably adapted to be run on a wire line and includes

body sections

52, 53, 54, 55, 56, 56a, 57, 58, 59 and 60, all suitably secured together to provide the elongate tool shown as by the thread systems and seals illustrated.

Suitable seals are provided about the body sections 56 and 56a to seal with the bypass section of body section 48 and confine fluid entering through port 50. These seals are shown at 61 and 62. When the wire line portion of the body is run, the seals are positioned to straddle port 50 by the latch mechanism indicated generally at 63. (FIG A) As the latch mechanism 63 forms no part of this invention and any desired latch may be used, it is not described in detail. The latch should by be of the type permitting running and retrieving of the tool by wire line.

A first passageway through the body is provided for flow of liquids from the bottom to the top of the intermitter. The passageway may be provided by the annulus 64 (FIG. 5C) and the bore 65 (F 16. 51)) which extends through the

body sections

58, 59 and the upper slotted portions of the body section 60. Ports 70 connect the annulus 64 and bore 65.

A first valve means indicated generally at 66 controls the flow through the first passageway. The first passageway communicates with the interior of the tubing at the outlet of the passageway and with the exterior of the tubing at a point which is spaced below the perforation 50. Thus, well fluids from sand 45 (P16. 3) being confined by a packer 44 will flow upwardly through the first passageway into the tubing above the intermitter when the valve 66 is open.

The valve indicated generally at 66 includes a resilient seal 67, providing a sliding seal with seat 68. The valve member also includes a metal-to-metal seat provided by the surface 69 on the valve member and the surface 71 on the valve seat. The use of the resilient seal 67 will provide a bubble-tight seal. The valve member includes a mandrel 72 on which the seal 67 is mounted and on which the ring 73, which provides the metal seat surface 69, is positioned. The snap ring 74 holds the resilient seat member 67 and the ring 73 in position.

A first pressure responsive member indicated generally at 75 controls the opening and closing of the first valve member. The pressure responsive member is provided by a piston which includes two ring-shaped

parts

76 and 77 with resilient packing 78 therebetween. The packing 78 has a sliding seal with the cylinder wall 79. A pair of O-

rings

81 and 82 are also provided with O-ring 81 sealing between the piston and the mandrel '72 and O-ring se 82 sealing between the piston and cylinder wall 79.

Resilient means provided by compression spring 83 urges the piston downwardly relative to the valve 66 to maintain it in position and to provide for positive closing of the first valve when the pressure differential across the valve is not such as to keep it in open position.

A stinger 84 extends through the valve 66 and the annulus 85 between the stinger, and the valve mandrel 72 provides a bleed passage for pressure fluid from below the intermitter to rise through the valve and into the chamber 86. The stinger 84 within the chamber 86 has been bled down to equal the pressure in the first passageway, the first valve member 66 will move to open position under the influence of the pressure of fluid rising from the formation 45.

A second passageway is provided through the body and begins at the inlet port 50 which communicates with bore 93, port 94 and the annulus 64 which is opened to the top of the intermitter. As this is the gas passageway, a suitable backcheck valve indicated generally at 95 is provided in bore 93.

A second valve means indicated generally at 96 controls flow through the second passageway. This valve includes a mandrel section 97 on 'which a resilient packing 98 is mounted. The packing is held in place by a combination piston and valve member 99. The lower beveled surface 101 on this member provides a metal surface for engagement with the metal seat 102. Thus a metal-to-metal and a bubble-tight seat are provided. The member 99 has suitable O-

rings

103 and 104 which slidably engage respectively the cylinder 105 and the mandrel 97 to provide a pressure responsive member for opening and closing the second valve means. The combined piston and valve member 99 are held in place on the mandrel by a snap ring 106. A suitable spring guide 107 is provided on the mandrel above the snap ring.

ln order to provide for positive closing of the valve when pressures thereacross are equal, it will be noted as in the case of the first valve member, the cylinder 105 is of greater'diamd ter than the valve seat and also a compression spring 108 urges the pressure responsive member and valve downwardly toward its seat.

A bleed is provided by the annulus 109 between the valve mandrel section 97 and the stinger 110 to permit gas to rise through the valve and the piston when the valve is closed.

The chamber above the second pressure responsive member is connected to the control valve through the passageway 111.

The shifting valve means indicated generally at 91 includes a slide valve member 112 which has spaced O-

rings

113, 114, and 1 16 thereon.

The O-

rings

113 and 114 straddle the outlet from passageway 111 and contain pressure on the second piston to hold the second valve closed. When the shifting valve is raised, the O-rings 115 and 116 straddle passageway 89 to contain pressure on the first pressure responsive member and maintain the first valve closed while connecting the passageway 111 with the passageway 92 to vent the second pressure responsive member and thus permit the second valve to open.

The shifting valve 112 is carried on a suitable valve stem 117 which is operated by a means responsive to changing pressures at the outlet of the passageways controlled by the first and second valves, such as the bellows 118. The bellows 118 are associated with a pressure dome 119. While not shown for clarity, the bellows will be entirely filled with an incompressible medium such as liquid which will fill the bellows to a point above the bellows protective valve 121. Valve 121 is provided with an O-ring 122 on its upper face and an O-ring 123 on its prevents blocking of the bleed passageway through the first valve by any solids which might be present in the rising fluid.

The chamber 86 is connected to the control valve through a passageway provided by

bores

87, 88 and 89. Thus with the control valve indicated generally at 91 in the position shown in FIG. 5C, the

vent passageway

87, 88 and 89 is placed in cornmunication with the first passageway through the port 92 associated with the control valve, and as soon as the pressure lower face. These O-rings respectively engage seat 124 and seat 125 to limit the flow of pressure fluid past the seat. This protects the bellows against an excess pressure differential. Thus, upon a rise in tubing pressure, the bellows 118 contracts until the valve stem 117 moves valve 121 up into engagement with seat 124. At this time the substantially incompressible medium within the bellows prevents further contraction of the bellows, and any increase in pressure externally of the bellows will not injure the bellows, as the bellows will be protected by the incompressible liquid therein. The bellows is also protected against the pressure within the pressure within the pressure dome by the valve 121 seating on surface 125 when the pressure in the tubing or ambient pressure at the surface of the well before the tool is run is present on the exterior of the bellows. Dome pressure will force the bellows to extend until the valve 121 seats on seat 125. The stem 117 will have moved down to permit valve 121 to seat. At this time, any additional reduction in pressure externally of the bellows will permit the bellows to further extend to relieve the trapped dome pressure within the bellows. This further extension is permitted by=the fact that the valve 121 is not connected to the stem 117, and the valve member 112 is a sliding valve member so that further travel of the valve stem and valve member is permitted after valve 121 has seated. Thus, in FIG. 5C it is apparent that the valve member can move downwardly a slight distance to permit further extension of the bellows to relieve the pressure of the incompressible medium trapped therein.

The upper end of the dome 119 is closed by the plug 126 which has means indicated generally at 127 for introducing gas under pressure into the dome.

In operation the tubing string is run with the outer section of the intermitter body made up as a part of the tubing string. The packer 44 (FIG. 3), which may be any desired type of packer, is set. The inner body section would normally be in place in the tubing when the tubing was originally run. It could, however, be run later. In any event, the inner body section is such that it can be removed by wire line for replacement or repair of component parts and rerun by wire line with the tubing in place in the well. After the intermitter is in place, the well is unloaded in any desired manner. For instance, th the well may be unloaded by swabbing or as is well known, unloading valves may be provided in the tubing string above the intermitter to unload the tubing. It is noted that when the tubing is run with the inner body section in place, liquid will be permitted to rise in the tubing through the lower valve until the selected pressure at which the bellows is set is reached at which the valve 112 moves upwardly to trap the pressure above the first valve piston and thus the lower valve will close. At this time the upper valve 96 will open and additional liquid will flow into the tubing through this valve. After the excess liquid in the tubing has been unloaded, a gas will be introduced into the casing tubing annulus if such were not used during the unloading procedure. This gas will pass through the open valve 96 and gas lift the liquid in the tubing. As the liquid is lifted, the pressure in the tubing above the intermitter will drop, and the dome pressure will force the shifting valve 91 to its down position as shown in FIG. 5C. This will trap pressure behind the operating piston for the upper valve 96 and vent pressure from the piston for the lower valve 66. The upper valve will close. The lower valve will open, admitting formation fluid which will rise in the tubing until a sufficient level of fluid is reached, at which time the bellows moves upwardly and the shifting valve 91 moves to its upper position. It will be appreciated that the pressures at which the shifting valve will move between upper and lower position may by selected by the selection of dome pressure.

Liquid rising in the intermitter is confined to the first passageway by a seal member between the inner body member 58 and outer body member 49, such as the seal shown at 128. (FIG. 5D)

In come some instances, particularly where the intermitter is used to dewater a gaswell, it is desirable to control the velocity of flow of liquid through the intermitter. For this purpose, a choke 129 may be used in the inner body member 59. (FIG. 5D) When the intermitter is to be used to dewater a well, the system is run in the manner shown in FIG. 4. It will be noted that there is no packing between the tubing 131 and the casing 132. The intermitter indicated generally at 133 is positioned in the tubing at a point relative to the level of the gas sand which will depend upon well conditions. In the illustrated embodiment, it is shown immediately opposite the gas sand. Liquids will fall out of the gas as it rises up the casing tubing annulus and will collect in the bottom of the well. The tubing will normally be open to atmospheric pressure, and thus the tubing casing annulus pressure will U-tube liquid up into the tubing as shown in FIG. 4.

I will be appreciated that when the liquid rises in the tubing to a sufficient level to shift the shifting valve 112, the lower valve will close and the upper valveadjacent the gas sand will open. Gas from the tubing casing annulus will then enter the tubing and lift the liquid-to the surface, after which the gas valve will close and the liquid valve will reopen. If flow through the lower valve were permitted under wide-open, unrestricted conditions, the gas would aerate the liquid, and substantial gas might be lost through the tubing. For this purpose, when dewatering, the choke 129 of FIG. 5D is utilized to insure that liquid flows through the first passageway at a suffciently slow rate that gas entrained in the liquid and escaping after the liquid passes the lower valve 66 will not be capable of lifting the liquid to the surface. In other words, the entrained gas will rise in the tubing, but it will not have sufficient power to take the liquids with it. The liquids will fall out of the gas stream and collect in the tubing so that the intermitter may operate as hereinabove explained.

When it is desired to utilize the intermitter to lift an upper formation with gas from a lower formation such as illustrated in FIGS. 1 and 2, the shifting valve member 112 is changed to the form shown in FIG. 10. Thus the shifting valve member 112a has three O-rings 134, I35 and 136 spaced along its length. With the shifting valve member in lower position, 0-

rings

134 and 135 provide for communication between passageway Ill and port 92. O-rings I35 and 136 straddle passageway 89, and thus when pressure in the tubing above the intermitter is low, the upper valve 96 is open to permit flow of liquid from the formation into the tubing. Upon accumulation of a sufficient amount of fluid to collapse the bellows and raise the shifting valve, communication between port 92 and passageway 111 is interrupted by the O-ring 135 and communication is established between port 92 and passageway 89 to permit entry of gas from the lower formation.

Referring to FIGS. 1 and 2, the well is provided with casing 137 which is perforated as at 138 and 139 at the upper and lower sands. The tubing 141 is run into place, with the intermitter shown generally at 142 providing a part of the tubing. A packer 143 is set between the two sands. In FIG. 1 the upper valve 96 is open, and liquids from the upper formation are flowing into the tubing and casing. As soon as a sufficient level of liquid has accumulated in the tubing, the upper valve 96 will be closed, and the lower valve 66 will open and gas from the lower formation will lift the liquid out of the tubing as shown in F IG. 2. The cycle will then be repeated.

In certain circumstances, it is desirable to be able to go into an existing well without pulling the tubing and position an intermitter. FIGS. 11 and 14 through 18 illustrate such a system. A stop of any desired type as indicated schematically at 144 is positioned in the well. Preferably, this is a type of stop which lands in a collar and when landed, is held against movement in either direction. (FIG. 14) A perforating gun is then utilized to perforate the tubing as at 145. (FIG. 15) A straddle packer assembly, indicated generally at 146, is run in the well and landed on the stop with

seals

147 and 148 straddling the tubing perforation 145. (FIG. 16) This straddle packer is specially designed, as will be explained hereinafter, to form a part of an intermitter. The remainder of the intermitter 150 is then run into the well and landed in the straddle packer assembly (FIG. 17) to provide an intermitter which will be operated in the manner hereinabove explained. FIG. 18 illustrates the removability of the inner section of the intermitter to permit repairs.

Reference is now made to FIGS. 12A through 12E, wherein the intermitter of FIG. 11 is shown in detail.

Referring first to FIG. 12E, a conventional collar stop, indicated generally at 144, is shown. This stop has

fingers

245 and 246 which extend out into a collar and prevent movement of the collar in either direction in the tubing.

At 145a perforation is shown in tubing 151. (FIG. 12D) This perforation would have been made by a suitable perforating gun 140. (FIG. 15)

The straddle packer assembly, indicated generally at 146, provides a part of the intermitter body. The assembly is generally tubular in form and is made up of a plurality of tubular sections I52, 153, I54, and 156, suitably secured together as by thread systems as shown. Any desired type of straddle packers may be used. In the illustrated embodiment and the pressure from the higher side passes through the holes in the middle of the packer and is exerted behind the packer on the low pressure side thereof. The body section 154 (FIG. 12B) is provided with a port 157 extending therethrough. A back-check valve 158 is provided in this port to prevent reverse flow through the port.

A suitable bypass is'provided through this section of the body as by a plurality of passageways, one of which is shown at 159 to permit fluid from thelower valve to bypass the upper valve as was true in the previously described embodiment.

The inner body section of the intermitter includes a plurality of tubular sections 161 through 175, suitably secured together as by the thread systems shown.

The inner body section 166 carries a plurality of straddle packing elements, indicated generally at 176 and 1.77, which seal with the outer body section 154 to separate fluid entering through port" 157 from fluid passing through the bypass passageways 159.

Fluid from the production sand rises through the bore 178 in the collar stop and enters into the bore 1750 through body section .175 and through

bores

174a, 173a, 172a and 171a to the lower valve member indicated generally at 179. The just enumerated bores form a part of a first passageway. Downstream from the lower valve 179, the annulus between the inner and outer bodies, as previously defined, and the bypass passageways 159 provide the remainder of a first passageway for fluids from the formation to rise through the intermitter when the valve 179, which controls this passageway, is open. A metal-to-metal seat between the valve member and valve seat is indicated generally at 181, and the annular valve member 182 has a sliding seal with a resilient seal member 183 to thus give a metal-to-metal and resilient seal for a bubble-tight performance. A stinger 184 extends through the valve member and the annular passageway between the valve member 182 and the probe 184 provides a bleed passageway for formation fluid to pass to the chamber passage through the lower valve by suitable seals between the inner and outer bodies indicated generally at 192. (FIG. 12D) To control operation of the lower valve 179, the chamber 185 is in communication with port 193 through a bore 194 in inner body member 168. The port is straddled by O-

rings

195 and 196 and communicates with the annulus between the inner and outer bodies through a series of

ports

197 and 198. A slide valve member 199, having a port 201 therein, cooperates with the ported upper section of the inner body member 168 and when in the position shown, closes flow through the port 193 to confine'pressure in the chamber 185 and maintain the lower or first valve member in seated position. When the slide valve member 199 is in lower position to establish communication between ports 193 and 201, the pressure in chamber 185 is vented, and the lower valve member may move to open position.

The slide valve member 199 is moved to open and close position in response to opening and closing of the second valve member.

Fluid entering the intermitter through the port 157 (FIG. 12B) flows through port 202 and bore 166a to the upper valve member 204. Fluid flowing past the upper valve member exits through port 203 into the annulus between the inner and outer body and thence to the upper end of the intermitter. These flow passageways provide the second passageway which is controlled by opening and closing of the second valve indicated generally at 204. The upper valve member 205 has a metal seat 206 which seats on the seat member 207 and a cylindrical section 208 which has a sliding seal with the resilient seal member 209 to provide a metal-to-rnetal and a resilient seat. I

Fluid from passageway 166a enters through port 211 into the annulus between the stinger 212 and the bore 213 through the valve member. This annulus provides a bleed passageway. The upper end of the valve member is surrounded by a sleeve 214, and suitable O-

rings

215 and 216 seal between the valve member 205 and sleeve 214 and between the sleeve 214 and body section respectively to provide a pressure responsive member or piston. A suitable spring 217 urges the valve member toward seated position.

The chamber 219 above the second valve member commu nicates through bore 164a with port 221. The inner body member 164 is provided with straddle packing 222 and 223 on either side of the port 221. This structure, together with the cooperating valve member 224, provides the shifting valve for controlling opening and closing of the first and second valve members. I

A suitable pressure responsive member, such as the bellows 225, controls shifting of the valve member 224 to interrupt or provide communication between port 221 and port 226 in the valve member. The port 226 communicates with the annulus between the inner and outer body parts through a plurality of ports 227.

In operation the collar locator is first run and positioned in the well as shown. The tubing is then perforated, using the collar locator as a bench mark. The outer body section of the intermitter is then run, and upwardly facing dogs, indicated generally at 228, (FIG. 12D), on the lower end of the outer body section engage shoulder 229 in the collar anchor to hold the outer body section against upward movement. The dogs are urged to the position shown by springs which are not shown. The collar anchor is provided with a shoulder 231, (FIG. 1215.), which may be engaged by the lower end of the body section 156 to prevent downward movement of the outer body section. Thus the outer section of the intermitter is positively located in position in the well. The latch assembly, which includes the fingers 228, may be provided by any desired form of latch assembly.

The inner body section of the intermitter is then run and landed in the outer body section of the intermitter. section.

Any desired latch assembly may be utilized to latch the two sections of the intermitter body together. In the illustrated form the lower end of outer body section 155 has a small diameter section 230. The lower inner body section carries thereon a slidably mounted collar 232, having a plurality of split fingers 233. in the unstressed form they are as shown in the drawings. While being run into the well, the collar and tingers would be in the up position and would engage the lower end of a collar 234 which is pinned to inner body section 175 by a shear pin 235. Thus the enlarged head of the spring fingers 233 will overlie the groove 236 in the inner body member 175 and will spring inwardly to pass the flange 231. When the inner body lands on shelf 237, the operator knows that the inner body is in position and picks up on the inner body to disengage the wire line. The enlarged ends of fingers 233 engage the lower end of the flange 231, and the inner body slides under the fingers until the fingers are held in position by surface 238 on the lower body member 175.

When coming out of the hole, the inner body is jarred downwardly until the collar 232 engages the sleeve 234 and continued jarring shears pin 235 to permit the inner body to move downwardly relative to sleeve 234. The collar 232 then moves over a segmented catching assembly 240 in groove 250 by radially contracting assembly 240 and confining it in groove. Inner-engaging shelves on the assembly 240 and within collar 232 lockand hold the collar 232 in upper position so that the fingers 233overlie the groove 236 to permit the inner assembly to be pulled from the body. During the downward jarring action just referred to the detent 239 would be sprung inwardly to allow the inner body section 172 to move downwardly relative to inner body section 173 and aline the two

ports

251 and 252 to equalize pressure across the inner body section to permit it to be freely removed from the outer body section.

After the inner body section is removed, a suitable pulling tool is introduced to disengage the dog assembly 228 and pull the outer body section of the intermitter.

In operation fluid flows from the production sand below the packer and through the lower passage to the lower valve 179. Fluid from the casing tubing annulus will enter through port 157 past the back-check valve 158 and be present at the upper valve 204 controlling flow through the upper or second passageway. As the tool is illustrated, there is a substantial pressure in the tubing due to a slug of fluid which is being lifted by gas from the casing tubing annulus and the bellows 225 is in its collapsed position with the bellows protecting valve 241 in upper position. The

ports

221 and 226 are alined to vent the chamber 219 above the upper valve member, and this valve member is in open position as shown so that flow through the second passageway from the casing tubing annulus to the tubing is permitted to provide gas for lifting liquid in the tubing. As soon as the tubing pressure drops, the bellows will extend and the port 226 will pass O-ring 223 to close the vent from the piston for the upper valve member. As pressure builds up above the piston, the upper valve will close as the effective diameter of the piston is greater than the effective diameter of the valve seat and also due to the spring 217.

As the valve member moves downwardly to close, it carries with it the valve member 199 which is carried on an extension 242 on the valve member. The downward movement will aline the ports 201 and 193 to vent the chamber 185 above the lower valve member, and the lower valve member will open to permit formation fluid to pass through the first passageway controlled by the lower valve 179 into the tubing. Thereafter the cycle will be repeated.

From the above it will be seen that an intermitter has been provided in which flow is positively controlledfrom a liquid source and from a gas source. Such flow is positively in the alternative, and when liquid is flowing, no gas' is flowing and vice versa. From the different forms illustrated, it is apparent that the bellows or other means responsive to tubing pressure may apply and relieve pressure from the pistons controlling operation of the two valves in any desired manner.

While pressure fluid from one source, such as a gas source, could be utilized to pressure each of the pistons for the two valves, it is preferred that the pressure fluid control be utilized as the controlling pressure for the operating pistons.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

I claim:

1. An intermitter comprising:

a body adapted to be secured to a well tubing;

first and second passageways through the body with their.

outlets adapted to communicate with the interior of a well tubing and their inlets adapted to communicate with the exterior of a well tubing at spaced points therealong;

first and second valve means controlling flow through said first and second passageways respectively;

means including shifting valve means for alternatively opening and closing said first and second valve means; and

means responsive to changing pressure at the outlets ofsaid passageways for shifting said shifting valve means to alternately open and close said first and second valve means in response to an increase or decrease of pressure at the outlets of said passageways to selected values.

2. An intermitter comprising:

a body adapted to be secured to a well tubing,

first and second passageways through the body with their outlets adapted to communicate with the interior of a well tubing and their inlets adapted to communicate with the exterior of a well tubing at spaced points therealong;

first and second valve, means controlling flow through said first and second passageways respectively;

first and second pressure responsive means controlling opening and closing of said first and second valve means respectively;

means including shifting valve means for alternately maintaining fluid pressure from the inlet of at least on of said passageways on one face of said first pressure responsive member while venting one face of said second pressure responsive member and maintaining such pressure on said one face of said second pressure responsive member while venting said one face of said first pressure responsive member to alternatively open and close said first and second valve means; and

means responsive to changing pressure at the outlets of said passageways for shifting said shifting valve means to alternatively maintain pressure on one pressure responsive member while venting the other in response to an increase or decrease of pressure at the outlets of said passageways to selected values.

3. An intermitter comprising:

a body adapted to be secured to a well tubing,

first and second valve means controlling flow through said first and second passageways respectively; I

first and second pistons connected to and controlling opening and closing of said first and second valve means respectively;

bleed means through each valve means and piston for supplying inlet pressure fluid to a face of each piston;

shifting valve means for alternately venting and maintaining inlet pressure on said face of each piston; and

means responsive to changing pressure at the outlets of said passageways for shifting said shifting valve means to alternatively maintain pressure on one piston while venting the other in response to an increase or decrease of pressure at the outlets of said passageways to selected values.

4. The intermitter of claim 3 wherein a choke is provided in the inlet of one of the passageways to regulate flow therethrough.

5. An intermitter comprising:

a body adapted to be secured to a well tubing;

means including shifting valve means for alternately opening and closing said first valve means;

means responsive to opening of said first valve means for closing said second valve means and to closing of said first valve means for opening said second valve means; and

means responsive to changing pressure at the outlets of said passageways for shifting said shifting valve means to open and close said first valve means in response to changes in pressure at the outlets of said passageways to selected high and low values.

6. An intermitter comprising:

, a body adapted to be secured to a well tubing;

'first and second pressure responsive members connected to and controlling opening and closing of said first and second valves respectively;

means including shifting valve means for alternately maintaining fluid pressure from the inlet of the first passage on a face of said first pressure responsive member and venting said pressure from said face;

means responsive to opening of said first valve means for maintaining pressure on a face of said second pressure responsive member to close said second valve in response to closing of said first valve means for venting pressure from said face of said second pressure responsive member to open said second valve means; and

7. In combination, a packoff assembly comprising:

an annular body;

spaced packers on the exterior of said body adapted to engage a tubing and seal therewith;

port means through the wall of said body intermediate said packers;

a bypass passageway in the wall of said body extending to points on either side of said port means;

' latch means on said body adapted to engage a complementary latch means in the tubing for holding the assembly in a selected position in a tubing;

second latch means on said body adapted to latch a tool in a selected position within the packoff assembly, an apparatus in said packoff comprising;

a body adapted to be positioned within the annular body of said packoff assembly,

latch means adapted to cooperate with said second latch means of said packoff assembly for latching said two bodies together;

first and second passageways through the apparatus body with their outlets communicating with the interior of one end of said annular body and the inlet of the second passageway communicating with the port means of said packoff assembly and the inlet of the first passageway communicating with the other end of said annular body;

straddle packing between the apparatus body and packoff assembly body on either side of said port means and inlet of said second passageway and inwardly of the ends of said bypass passageway in the packoff assembly body,

first and second valve means controlling flow through said first and second passageways;

means responsive to changing pressure at the outlets of said passageways for shifting said shifting valve means to alternately open and close said first and second valve means in response to an increase or decrease of pressure at the outlets of said first and second passageways to I selected values.