US3391744A - Removable tubing stop - Google Patents

Description

J. G. BURCH July 9, 1968 REMOVABLE TUB ING STOP 4 Sheets-Sheet 1 Filed Jan. 15, 1968 INVENTOR. JG BURCH %T.To RNEY July 9, 1968 J. G. BURCH REMOVABLE TUBING STOP 4 Sheets-Sheet 2 Filed Jan. l5, 1968 m u R Tow 5% L 1 mm 3. W F 02 mo.

2 am 8. y m9 8 Q R E 5 v N. Mb 8 3 w INVENTOR. L]. G BURCH ATTORNEY July 9, 1968 J.G.BURCH REMOVABLE TUB ING STOP Filed Jan. 15, 1968 F/G. IO

TTORNEY July 9, 1968 J- G. BURCH REMOVABLE TUBING STOP 4 Sheets-Sheet 4 Filed Jan. 15, 1968 Ur l lm ATTORNEY United States Patent ()1 lice 3,391,744 Patented July 9, 1968 3,391,744 REMOVABLE TUBING STOP Julius Gordon Burch, 822 S. McGee St., Borger, Tex. 79007 Filed Jan. 15, 1968, Ser. No. 697,929 7 Claims. (Cl. 166-214) ABSTRACT OF THE DISCLOSURE A thin flat well landing platform has projecting from one vertical edge thereof, spring loaded, pivotally supported, downwardly directed, rigid pawls and a pivotally supported spring loaded, upwardly directed, resilient pawl.

Locking means keep the pawls in contracted running position within the outline of the platform until the platform is located at proper depth in well and then are released by light mechanical and/or solvent action to bring the pawls to a locking position. The upwardly directed resilient pawl action may be overcome by light fishing tool operation to move the platform upward.

Cross-reference to related applications In the preferred embodiment of operation of this apparatus it is used with a specially developed drop swab such as shown in my U.S. Patent 3,265,133 and supplements the methods shown in my US. Patent 3,302,581.

Background of the invention (1) The field of the invention is a device with several latch means attached to a casing member which is run into a well conduit already in fixed position in a well, the latch means being movable outwardly to engage and jam against the surrounding conduit wall, the latch means functioning to attach the member in the well so as to resist the action of gravity and a lifting force.

(2) Description of the prior art.-Prior art devices required heavy complex equipment for setting of a landing platform in a well and do not provide for perfect alignment in dirty or in perforated casing and do provide substantial restriction of the normal production of the well.

This device is easily exactly set in operative position in the well with a light measuring line and is easily removed from its locked position in the well with a light measuring line.

Summary of the invention The invention provides a well landing platform of sufiiciently low transverse cross-section to not interfere with the passage of gas therepast and yet is sufficiently firmly locatable in a well to control the action of plugs that travel up and down the well.

The gist of the inventive concept is the use of members and assemblies providing adequate force to locate the apparatus against the forces of gravity and apparatuses applied thereto from above and enough force in a lower resilient locking pawl assembly, so that the pawl in one position permits the apparatus to run freely down through the well, and in another position prevents the platform moving upward in the well, and in a third position, permits the apparatus to be moved up the well, all with only very readily applied amounts of force to effect these changes in position of that pawl.

Description of the drawings FIGURES 1 and 2 are broken away views at level of zone of FIGURE 11; FIGURE 1 is a side view of the landing platform and travel and release unit 24 in its downward running position as viewed from the direction of arrow 1A of FIGURE 2.; FIGURE 2 is an end view of the landing platform 20 and unit 24 in its running position as seen in the direction of the arrow 2A of FIGURE 1.

FIGURES 3 and 4 are broken away views at level 16 of FIGURE 11 when apparatus 20 is near to its located position. FIGURE 3 is a side view of the landing platform below the aqueous phase of a gas producing formation in its set or located position with unit 24 released therefrom. FIGURE 4 is a side view of the landing platform 20 in its upward running position with a catch and travel unit 25 attached thereto.

FIGURE 5 is a vertical sectional view of the apparatus 20 in the downward running orientation of parts thereof shown in FIGURE 6; FIGURE 5 is taken along a section shown by the vertical sectional line 5A-5A of FIGURE '6.

FIGURE 6 is a sectional view of the apparatus shown in FIGURE 2 in the downward running position of parts thereof wherein the pawls thereof are in closed position. This view is shown as seen along the vertical section 6A--6A of FIGURE 5.

FIGURE 7 is a side and broken away sectional view of apparatus 20 viewed generally in the same manner as shown in FIGURE 6, but the components of the apparatus 20 are here shown in the stable located position of the landing platform shown in FIGURE 3 with unit 25 shown in perspective view when it is about to engage the apparatus 20 prior to upward movement to the position of apparatus 20 shown in FIGURE 4.

FIGURE 8 is an end view of the apparatuses 20 and 24 viewed along the vertical plane 8A--8A of FIGURE 7 when pawl locking means of apparatus 20 have been released immediately prior to its location as shown in FIGURE 3 to provide the orientation of parts as shown in FIGURE 7.

FIGURE 9 is a side view, partly broken away below bolt 101 to plane '6A- 6A of FIGURE 5, when the apparatus 20 is in its running position as shown in FIG- URE 4 for upward travel.

FIGURE 10 is a horizontal transverse cross-sectional view of the apparatus 20 along the horizontal plane 10A10A of FIGURE 7 in the disposition of parts shown in FIGURE 7.

FIGURES 6, 7 and 9 are gene-rally shown to the same scale. FIGURES 8 and 10 exaggerate the thickness of elements of apparatus 20 for clarity of their representation.

FIGURES l1 and 12 are diagrammatic and show the operation of a well unloading process using the apparatus of this invention; FIGURE 11 shows a movable plug travelling into position on top of the landing plat form 20 of this invention; FIGURE 12 shows the plu discharging the water load from the well wherein is located the landing platform 20 of this invention.

FIGURE 5 is drawn to scale from an operative embodiment.

The sequence of operation shown by the FIGURES 1 through 12 is that:

(a) FIGURES l and 2 show the initial stages of operation of the apparatus. Elaboration of the details of structure during that stage of operation are shown in FIG- URES 5 and 6.

(b) FIGURE 3 is the result of operation shown in FIGURE 8 in detail. FIGURE 8 shows details of the release mechanism of apparatus 20 following which the overall orientation of the apparatus 20 is generally shown in FIGURE 3. FIGURES 7 and 10 show details of the apparatus 20 as shown in FIGURE 3.

(0) Following the location of the apparatus 20 in its desired location, as shown in FIGURE 3, the operation shown in FIGURES 11 and 12 is performed.

(d) On completion of the operation using the apparahis 20 located as shown in FIGURES 3, 11 and 12 prior to upward movement of apparatus 20 as shown in FIG- URE 4, FIGURE 7 shows the first stages in the upward movement of apparatus 20, followed by the structural relations shown in FIGURE 9, and FIGURE 4- shows the overall result of the release of the pawl point 107 and an early stage in upward movement of the apparatus 20.

Description of the preferred embodiment The landing platform 20 according to this invention apparatus 20 is used in a combination 18 of apparatus 20 and a travel release unit 24, and in a combination 19 of apparatus 20 with a catch and travel unit 25. Appara tus 20 and the combinations 13 and 19 are designed to operate in the interior cavity 23 of a casing 27 a well 26. The casing 27 extends into a gas producing formation 28 from the ground level 21.

The landing platform 20 is an apparatus comprising, in operative combination, a casing assembly 31, a top gravity resistant pawl assembly 34 and a bottom gravity pawl assembly 35; a fiow resistant pawl assembly 36, a bail and landing plate assembly 37 and a pawl locking assembly 39. Assemblies 34, 35, and 36 are firmly supported on and pivotally located in assembly 31.

While the apparatus 20 is described as formed of several sub-assemblies this is an artificial sub-division for purposes of description; as shown by the drawings and the inter-relationships of the various parts, the apparatus 20 is an organized combination of cooperating parts, eg. the casing assembly supports parts of the pawl sub-as semblies; the pawl sub-assemblies react with and cooperate with the elements of the casing and other assemblies of the apparatus 20 within the casing 27.

The top pawl assembly 34 comprises an upper gravity resistant pawl 44, an upper pawl pin 45, an upper pawl spring 46, and an upper pawl spring bolt 47 to fix one end of the upper pawl spring. The pawl 44 is a rigid steel element shown in FIGURES 5, 6 and 7 which has a sharp hard curved locking edge 50, a fiat lower face 51, an upper fiat face 52, a flat front face 53, a rear face 54 and a cylindrical spring hole 55, a flat left face 57, a flat right face 58 and a cylindrical pivot pin support hole 56. The lower face 51 and the outer face 53 meet to form the sharp locking edge 50. The lower face 51 and the upper face 52 are parallel to each other as are faces '7 and 58. The outer face 53 is flat and the faces 51, 52, 53, 54, 57 and 58 are all fiat.

The pin 45 is a rigid solid cylindrical shaft, the ends of which are firmly fixed into the cheek plates of casing assembly 31 and the central portion of which is located in hole 56 in the upper pawl 44 with a smooth pivotal fit.

The bolt 47 is firmly attached at its ends to plates 121 and 122 of assembly 31; its central portion is attached to the spring 46 at the lower end of that spring. The upper end of the spring 46 is firmly attached to the hole 55, hole 55 is located in the pawl 44 near to the junction of the inner face 54 with the lower face 51 thereof. The length of the pawl 44 from the center of pivot support hole 56 to locking edge 50 is chosen so that the locking edge 50 will, when all of the rear edge of assembly 31 contacts the rear portion 41 of surface 29 of casing 27, as shown in FIGURES 7 and 10, be a slightly greater (MW) distance than the distance from the center of pivot support hole 56 and pin 45 to the front portion 42 of inner surface 29 of the casing 27, portion 42 being the portion of wall surface 39 near to edges 126 and 136 of plates 121 and 122 of assembly 31.

The lower pawl assembly 35 comprises a lower gravity resistant pawl 64, a lower pawl pin 65, a lower pawl spring 66, and a lower pawl spring bolt 67 to fix the lower pawl spring. The pawl 64 is a rigid steel element shown in FIGURES 5, 6 and 7 which has a sharp hard curved locking edge 70, a lower face 71, an upper fiat face 72, a flat front face 73, a rear face 74 and a spring hole 75, a left face 77, a right face 78 and a pivot support hole 76. The lower face 71 and the outer face 73 meet to form the locking edge 70. The lower face 71 and the upper face 72 are parallel to each other as are faces 77 and 78. The outer face 73 is fiat and the faces 71, 72, 73, 74, 77 and 78 are all fiat.

The pin 65 is a rigid solid cylindrical shaft, the ends of which are firmly fixed into the cheek plates 121 and 122 of casing assembly 31 and the central portion of which is located in hole 76 in the lower pawl 64 with a smooth pivotal The bolt 67 is firmly attached at its ends to plates 121 and 122 of assembly 31; its central portion is attached to the spring 66 at the lower end of that spring. The upper end of the spring 66 is firmly attached to the hole 75, hole 75 is located in the pawl 64 near to the junction of the inner face 74 with the lower face 71 thereof. The length along pawl 64 from the center of pivot support hole 76 to locking edge 70 is chosen so that the locking edge 70 will, when all of the rear edge of assembly 31 contacts the rear portion 41 of surface 29 of casing 27, as shown in FIGURES 7 and 10, be a slightly greater distance than the distance from the center of pivot support hole 76 and pin 65 to the front portion 42 of inner surface 29 of the casing 27.

The curvature of locking edges 50 and 70 are chosen so that both will meet the inner surface 29 of casing 27 along a curved line of contact in the locked or set position of the apparatus 20 as shown in FIGURES 7 and 10.

The spring pawl lock and release assembly 39 comprises a tension spring 100, a tension spring bolt 101, a spring pawl assembly 102, in operative connection. The spring bolt 101 is firmly attached at its ends to the plates 121 and 122 of the casing assembly 31. The spring pawl assembly comprising a spring pawl lever arm 104 which is continuous with a resilient spring pawl point arm 106 at the end of which arm is a spring pawl point 107. The spring pawl point 107 is formed of harder material than the interior surface 29 of the casing 27. The ring 105 has an inner portion 103 and an outer portion 109 and is wrapped once lightly yet rotatably around a spring pawl pivot shaft 108. The spring pawl pivot shaft is a rigid cylindrical bolt; its ends are firmly located in the lower front corners of plates 121 and 122 of the casing assembly 31. The lower end of the tension spring 100 is attached to the rear end of the spring pawl lever arm 104 and urges that rear end upwardly and thereby urges the spring pawl point arm to rotate in a clockwise direction as shown in FIGURES 6, 7 and 3 as well as in FIG- URE 9.

The spring pawl point arm is of a sufi icient length that, in the operation of the apparatus 20 the distance from the center of the spring pawl pivot shaft 108 to the outer edge of the spring pawl point 107 is greater than the distance from that shaft 108 to the inner surface 29 of the casing 27 in the position of parts shown in FIG- URES 7 and 3.

The pawl locking and release assembly comprises an upper lock wire which is provided with a passage-way 81 in the left casing cheek plate 121 and a lower pass-age 32 in the right casing cheek plate 122.

A lower locking portion 84 of the upper lock wire 80 extends through the passage 81 and, in the downward traveling position of the apparatus 20 passes in front of and in contact with the face 53 of the upper pawl 44. Portion 84 restrains pawl 44, as shown in FIGURES 5 and 6, from rotating outwardly to the position shown in FIGURE 7.

An upper end loop 86 of wire 80 joins to the arm 111 of the travel release assembly 24. An upper left shoulder 87 prevents the outward or frontward movement of the wire 00 from its position in the passage 81 and an upper right shoulder 88 in the right cheek 122 of casing 31 prevents the escape of the end of the Wire from the passage 82 in the right cheek 122 in the casing 31.

The casing 31 comprises a rigid left cheek plate 121, a rigid right cheek plate 122 and a casing cavity 123 therebetween. Oheek plate 121 has a rear edge 125 (left in FIGURES 3 and 9) a right side edge 126, an upper edge 127 and lower edge 128. Cheek plate 121 also has an outer face 129 and an inner face 130 and adjustment holes 131, 132 and 133 therethrough.

The right cheek plate 122 is provided with a rear edge, 135, a front edge 136, an upper edge 137, and a lower edge 138. The right cheek plate has an outer face 139 and an inner face 140. The faces 129, 130, 139 and 140 are all flat and parallel to each other. The faces 129 and 139 are firmly and permanently joined to each other as by welds W, W along the top edges 127 and 137 and W" at lower rear corners 151 and 152. Shaft 108 is firmly attached to corners 153 and 154 of plates 121 and 122 respectively and fixes those corners with respect to each other.

The assembly 31 provides for firm yet pivotal support for various elements of the other assemblies 33, 36 and 39. The plates 121 and 122 are rigid, corrosion resist-ant steel of rectangular outline.

The overall horizontal transverse cross-sectional area of the assembly 31 is less than 10% of the transverse cross-sectional area encompassed by the inner wall 29 of the casing 27. The length of the cheeks 121 and 122 is greater than the width thereof.

The cavity 123 is a rectangular cavity as viewed in horizontal or transverse as well as vertical longitudinal section and is bounded on its left side by the inner face 130 of the left cheek plate 121 and on its right side by the inner face 140 of the right cheek plate 122.

The spring pawl pivot shaft 108 is located near to the lower front corner 153 of the casing 31 near to the edges 128 and 126 of plate 121 and similarly near to corner 154 near to the edges 138 and 136 of the plate 122 and there fixed to plates 121 and 122. The pins 45, 65 and the shaft 108 are all cylindrical and the axes thereof are parallel to each other and perpendicular to the plane of the inner faces as 140 and 130 of the cheek plates 121 and 122. Near to edges 136 and 126 and above the upper faces 52 and 72 of the pawls 44 and 64 in the contracted position thereof shown in FIGURES 5 and 6, plate 122 is provided with candy bar holes 156 and 158 and plate 121 is provided with corresponding candy bar holes 155 and 157. Holes 156 and 158 may be used to support a horizontal top candy bar lock 168, holes 155 and 157 may be used to support a horizontal bottom candy bar lock 169. The below description of operation applies where no candy bar (as 168 or 169) is used in holes 155 -158.

Apparatus 20 is arranged with the pawl assemblies 34 and 35 and 39 in their retracted position in the stage of operation shown in FIGURES 1, 5 and 6: in this position the lock wire 80 passes through the passageways 81 and 82 and in front of the front outer face 53 of pawl 44. The stilf locking portion 84 of the wire 80 is in contact with the flat outer face 53 of the pawl 44 and prevents the pawl 44 from swinging outwardly of the front edges 126 and 136 of the plates 121 and 122. The face 53 is urged into contact with the lock portion 84 by the spring 46 as spring 46 is under a substantial amount of tension in the position shown in FIGURES l and 6, one end of that spring being attached to the bolt 47 and the other end of that spring 46 being attached to the spring hole 55 in pawl 44.

In the position of parts shown in FIGURES 1 and 6 the lower pawl 64 is located with its front, outer, face 73 in contact with the lock portion 94 of the lock wire 90; the lock wire 90 is located with a lower portion in the passage 91 of the left cheek plate 121 and the lowest end, portion 93 of that wire in the right passage 92. The lock portion 94 of wire 90 is in direct contact with the outer face 73 of the pawl 64. The pawl 64 is pivotally located on the pin 65 and the spring 66 is, in the position of parts shown in FIGURES 1 and 6, under tension, one end of that spring being attached to the lower gravity spring pawl bolt 67 which bolt is firmly attached to plates 121 and 122 and the other end of that spring is attached to the hole close to the inner face 74 of the pawl 64.

In the position of parts shown in FIGURES l and 6, the spring point arm 106 is located under the lower face 71 of the lower gravity pawl 64 and the spring pawl ring, 105, is wrapped around the spring pawl pivot shaft 108 and the spring pawl lever arm 104, is attached at its rear (left as shown in FIGURE 6) to the tension spring 100. The tension spring is attached at one end to the left end of the lever arm 104 and the other end to the spring bolt 101, the spring bolt 101 being firmly attached to the cheek plates 121 and 122 of the assembly 31.

The upper end loop 86 of the upper lock wire is attached to the hole 118 in the left arm 111 of the travel and release assembly 24 and the upper loop 96 of the lower lock wire is attached to a hole 119 therefor also located in the arm 111 of the assembly 24. The length of the wire 80 is such that in the downward travel position of the apparatus 20 shown. in FIGURES 1, 2, 5 and 6, the wire 80 extends through the upper, left lock passage 81 of the plate 121, and lower right passage 82 in plate 122, but does not extend therebeyond and the wire is held against the upper left shoulder 87 and upper right shoulder 88 of the grooves 81 and 82 respectively.

The length of the wire 90 is such that in downwardly travelling position of the apparatus 20 with the travel release assembly 24 as shown in FIGURES 1 and 2, the lower portion of the wire 90 extends through the upper left passage 91 in plate 121 and past the shoulder 97 of that passageway into the lower right passage 92 of the right plate 122 and is there held against the lower right shoulder 98 of the passage 92 but the lower end 93 does not extend beyond the outer face 139 of the cheek plate 122. Accordingly, as below described, on upward movement of the travel release assembly 24 relative to the apparatus 20 the wires 80 and 90 are concurrently drawn out of the passages therefor and away from their locking relationships in the front, faces 53 and 73 of the pawls 44 and 64 respectively as the upward motion of the travel release assembly 24 thusremoves the locking wires 80 and 90 completely from their locking relationship with the gravity resistant pawl assemblies 34 and 35 of the apparatus 20.

On removal of the locking wire elements 80 and 90 from the apparatus 20 (unless there are candy bars used as below described) the pawls 44 and 64 rotate counterclockwise about their pins 45 and 65 respectively, being urged so to do by their springs 46 and 66 respectively. In the position of parts shown in FIGURES 3 and 7, the locking edges 50 and 70 of the pawls 44 and 64 then engage the inner wall 29 of the casing 27 and form a locking engagement therewith. In the preferred embodiment of the invention the distance from the center of pin 45 to the locking edge 50 is A" greater than the distance from the center of pin 45 to the portion of the inner wall 29 of the casing 27 closest to the edges 126 and 136 of the plates 121 and 122, when the rear edges 125 and of the plates 121 and 122 are in contact with the opposite side of the inner wall 29 of the casing 27, as shown in FIGURE 10. Accordingly, there is a very large acute angle made between the bottom face 51 of the pawl 44 and the surface of the inner wall 29 of the casing 27 measured in a vertical plane passing through the pin 45, lock edge 50 and the surface of the inner wall 29 during the locking engagement of the pawl 44 with the inner wall 29 of the casing 27.

The edge 50 is a Stellite edge and is substantially harder than the surface of the inner wall 29 of the casing 27. This is readily observed by that the pawl edge 50 may be made to scratch the inner surface 29 when the apparatus 20 is disassembled and the pawl is used to demon- 7 strate this difference in hardness between the edge 50 and the surface 29.

On release of the pawl 64 by removal of the locking wire 90 from grooves 91 and 92 in front of the face 73, the pawl 64 springs in a counter clockwise manner (as shown in FIGURES 6 and 7) which motion moves the locking edge 70 upward and into engagement with the inner wall 29 of the casing 27. In the preferred embodiment for purposes of expediency the pawls 44 and 64 are made of the same size and the pin 65 is located vertically below the pin 45 when the left edges 125 and 135 of the plates 121 and 122 are vertical. Here also the length of the pawl from the center of pin 65 to the locking edge 7 is /s greater than the distance from the center of pin 65 to the inner wall 29 of the casing 27 in the locked (FIGURE 7) position of the apparatus 20.

On release of the lower gravity pawl 64, the point arm 106 of the pawl 102 is urged to rotate about shaft 108 in a clockwise direction as shown in FIGURES 6 and 7, not only by the spring 100 but also by the resiliency of the pawl material in the region of the spring pawl ring 105.

The length of the point arm 106 from the center of the shaft 108 is chosen to be above A longer than the distance from the center of the pivot shaft 108 to the portion 42 of inner wall 29 of the casing 27 near to the front edges 126 and 136 of the cheek plates 121 and 122 respectively when the rear edges 125 and 135 of the cheek plates 121 and 122 are flush against, i.c. in contact with the opposite side, 41, of inner wall 29 of the casing 27.

In operation to move apparatus downward in a well and locate it, the apparatus '20 is placed within the interior 23 of the casing 27 of the well 26 and supported by the travel release assembly 24 and the support line 30 thereabove. The support line 3% is attached to the eye 110 of the apparatus 24. The spring 114 of the apparatus 24 passes below the top portion of the bail 37; the wires 80 and 90 are attached at their top to the holes 118 and 119 respectively. The lower end of the wire 80 passes through the passages 81 and 82 and the locking portion 84 of the wire 80 contacts the front face 53 of the pawl 44, the lower locking portion 94 of the wire 90 contacts the face 73 of the pawl 64 with the lower portion of the wire 90 passing through the passages 91 and 92.

Accordingly, on movement of the components of apparatus 2.0 to the locking position shown in FIGURE 7 and release of the wire locking element as 94 for the lower gravity pawl 64, the spring pawl point 107 engages the inner face 29 of the casing 27 and arm 106 forms a large acute angle below the contact of point 107 with surface 29. The point 167 is much harder than the steel which the casing 27 is made from. The point 107 is hardened by rapid quenching using a suitable alloy steel for the point material.

When the spring 100 urges the arm 104 upward about the pivot shaft 108 the loop portion 109 of ring 108, (which loop is to the right of the pivot shaft, as shown in FIGURE 7) to which portion arm 106, via left ring portion 103 is firmly attached, resiliently yet firmly serves to prevent displacement of the point 107 and the point arm and the pivot shaft away from the surface 29 of the casing 27. The spring pawl in its extended position shown in FIGURES 7 and 11 prevents upward motion of the apparatus 20 against any upward thrust that might be aplied to the apparatus 20 as by rapid gas and oil liquid flow.

The catch and travel sub-assembly comprises a rigid left vertical arm 161, a rigid right vertical arm 162, both vertically extending from the rigid horizontal shoulder 163 at the top of which is located the eye 160. A rigid pivotal link 164 is pivotally located on a horizontal pin 165 firmly located on the left arm 161. Arm 164 is shorter than the distances from pin 165 to top of space 159 and longer than width of space 159. Spring 166 also on arm 161 urges the link 164 lightly downward against 8 the link rest 167. The space 159 between arms 161 and 162 embraces bail 37 and is wider and taller than that bail.

In operation, as shown in FIGURE 4, to move apparatus 2.0 upward, unit 25 contacts the firmly located apparatus 20 and the link 164 is urged upwardly by the bail plate 38 and snaps into place below the bail plate as the assembly 25 is lowered relative to casing 31 and unit 35 is supported by line 30. This provides for applying a firm attachment of assembly 25 to the apparatus 20. To move apparatus 20 upward, with assembly 25 joined to bail 27 the operator applies a firm pull in excess of 30 lbs. to the apparatus 20 through line 30 and the unit 25 and link 164. This upward movement is not at all resisted by the pawls 44 and 64 nor by the engagement of those pawls with the inner Wall 29 of the casing 27. However, this sharp upward force does cause the spring pawl ring 105 to expand and the portion 103 thereof to be moved leftward (left as shown in FIGURES 6 and 7) as that ring expands somewhat due to resiliency of arm 102, this causes a release of the contact of the point 107 contact with the wall surface 29.

The point arm 106, urged by spring 100, then snaps over to the release position thereof shown in FIGURE 9 completely out of contact with wall 29. In this position, there is no resistance by the spring pawl 102 to the upward motion of the apparatus 20 and the support line 30, firmly attached to the catch and travel assembly 25, may readily move the apparatus upward of and through the cavity 23 of the casing 27.

Broadly the operation of the apparatus 20 in the structure 27 in which it is intended to operate, is that apparatus 20 is brought to the depth at which it is desired to be located. The apparatus 20 is supported by the wire 30 and travel and release unit 24 of which the spring 114 engages the bail 27. On arrival at the desired depth of location of apparatus 20 a sharp upward motion at the top end of the line 30 causes the assembly 24 to move upward, the spring 114 bends downward to the dotted position thereof shown in FIGURE 8, the bail is released and the spring 114 returns to the full line position shown in FIGURE 8. The upward motion of the assembly 24 draws the locking wires and from their locking engagement position in passages 81 and 82 and 91 and 92 as above described.

The location of the apparatus 20 below the aqueous phase as shown in FIGURE 3 is to illustrate the operation of the candy locking bars 168 and 169. The locking wires 80 and 90 operate with or without the presence of water in the cavity 23. The use of the wires 80 and 90 permit the location of the apparatus 20 at any level in casing 27. This location at any point permits the apparatus 20 to be used to locate a plug thereabove for purpose of cementing the interior of the well or to locate a cutting, cleaning or perforating tool as well as to provide for the well unloading operation described in relation to FIGURES 11 and 12.

It is within the scope of this invention that a cylindrical rigid yet watersoluble bar such as rock candy in the form of a cylindrical bar 168 may be located in the holes 156 and 158 and a similar bar 169, identical in shape and sizeto bar 168 for purposes of manufacturing convenience, may be located in the holes and 157. Bar 168 is a rigid and cylindrical rock and candy bar and, when located in the holes provided therefor and in the contracted position of the pawl 44 as shown in FIGURE 6, it contacts the upper face 52 of pawl 44. In this position the candy bar 168 serves to hold the pawl 44 in the position shown therefore in FIGURE 6.

Bar 169 is also a rigid and cylindrical rock candy bar and, when located in the holes provided therefor and in the contracted position of the pawl 44 as shown in FIG- URE 6, it contacts the upper face 72 of the pawl 64. In this position the candy bar 169 serves to hold the pawl 9 64 in the position shown therefor in FIGURE 6. The same operation of the candy bars 168 and 169 serves to maintain the relationship of parts shown also in FIG- URES 1, 2 and 5.

When, according to the manipulation of the apparatus 20 above described, the apparatus 20 is brought to an aqueous zone as shown in FIGURE 3, the bar of candy will dissolve and then release the pawls 64 and 44. This release of the pawls 44 and 64 is, accordingly, automatic on the location of the apparatus 20 in a zone where water is located and surrounds the casing 31.

Accordingly, when release in an aqueous zone is desired the apparatus 20 may be lowered to such zone and the water may provide a solution or solvent action to release the pawls from the position shown in FIG- URES 6 and 3 .to the positions shown in FIGURES 7 and 10. The release of the lower pawl 64 provides release of the resilient pawl 102 which prevents the upward motion of the apparatus 20 until the apparatus 20 is sufiiciently forecfully jarred upward as above described by an apparatus such as 25 to bring the arm 106 to the position shown in FIGURE 9 which then permits the apparatus 20 drawn up the casing as above described.

This method shown in FIGURES l1 and 12 uses a specially developed Drop-Swab assembly 170 with a swab 172 made of natural rubber in the shape of a bull-plug, or an inverted U. It is used with the dome up. The dome only is reinforced with tire cord. It is hollow and flexible with Mr" thick walls. For use in /2" casing the overall length of the swab is 7". The outside diameter is the ID. of the production casing 27 and it weighs little more than one pound. It is described in my US. Patent 3,265,133.

The flexible swab 172 is folded vertically generally in the form of the letters S to one-half the interior diameter of the production casing 27 and placed inside a watersoluble retaining tube .171. This tube has a closed hemispherical bottom with one to two pounds of soluble ballast at bottom of 171 to help in the gravity drop. The assembled tube is placed in the connection nipple 178 resting on the closed master valve 176. The lubricator top is re-sealed and the assembly 170 dropped into the well by opening the master valve 176.

To assure that the swab will be set accurately at a point above the wells lowest gas formation 28 and below the accumlated liquids, 174, to be removed, the landing platform 20 is preset as above described in the casing at the desired depth therein.

When the swab assembly 170 reaches the plate 38, the tube automatically releases the swab 172; the swab then springs back to its original size and shape and seals tightly against the casing. The gas is confined below the swab. The differential between the true rock pressure and the producing pressure of the well lifts the swab and the liquid, as 174 then trapped above it. The liquids rise to the surface 21 in a solid, vaporless column. The outward pressure on the swab skirt wipes the casing clean and stops downward leakage. The well liquids lubricate the swab, which can be used repeatedly.

When the swab is dropped by opening the master valve, the well is immediately returned to production. The quarter-inch bleeder valve 180 on the lubricator is cracked open to determine when the first liquids as .174 reach the well head. When the first liquid is visible the valve 179 to be conventional meter is closed and the waste control valve 177 opened to the disposal outlet. This valve gives complete control of the volume of flow of the waste liquids and makes it possible to discharge with complete safety. For example, even into a truck through 50 feet of 2 hose. When the liquids as 174 are removed from the well, the master valve 176 is closed, and the swab 172 is removed from the lubricator, together with any recoverable swab-container tube alttached to it. The much improved well is put back on production immediately.

Gas wells with higher pressures than line pressure produce their liquids to the surface because their liquids weight has already been deducted from their flow pressure.

In gas wells Where the liquids have lowered pressures equal or below line pressure, the same procedure is used, other than relieving to some degree back pressure above the swab and the wells liquids to develop suflicient pressure dilferential to lift the swab 170 and the liquids as 174 therea'bove. Usually as long as a well makes gas all its liquids can be lifted in one running, the swab works perfectly if the landing platform 20 is properly placed.

The bail 37 is a portion of assembly 31. It comprises an upper rigid horizontal yoke 190 attached at its ends to a left rigid vertical arm 191 and a right rigid vertical arm 192; arm .191 is firmly attached to weld W, arm 192 is firmly attached to weld W. Welds W and W respectively bridge the space between the rear and front edges of plates 121 and 122. A rear triangular web plate 193 joined to arms 191 and 193 and a front web plate 194, joined to arms 192 and 193, each such web formed of a rigid plate, in cooperation with the top edges of plates 121 and 122 outline an isosceles triangular space j95 slightly truncated, below yoke 190, the center of which space is located vertically over the center pins 45 and 65 in the position of parts shown in FIGURE 7. The space is large enough to permit the arm 164 of unit 25 to be readily located therein in the operation of unit 25 above described as well as to hold wire 114 of unit 24; a rigid horizontal fiat landing plate 38 is firmly fixed to the top of arm 190 and extends the full length thereof.

The sloped portion of wire 114 serves to hold bail arm 190 of apparatus 20 against arm 112 of unit 24 in the position of parts shown in FIGURES 1, 2, 5 and 6. Details thereof are shown in the scale drawing of FIGURE 5. As there shown arm .111 holds ends 86 and 96 of wires and at a distance from the plate 121 (about /8" in the embodiment shown); this distance is about the thickness of the assembly 31 at point of the passages 81 and S2 and 91 and 92 therethrough so that the relatively stiif wires 80 and 90 may be readily removed from their passages on upward movement of the unit 24 from the unit 20 as above described.

Generally it is preferred that the transverse crosssection of the apparatus 20 is only about 10% of the total horizontal transverse cross-sectional area of the interior of the casing. Not only is this a small percentage of the total cross-sectional area, but, because of the flat surfaces of the apparatus 20, there is a minimum disturbance of gas flow therepast; yet, as above described the apparatus 20 operates entirely satisfactorily for the intended purpose as a landing platform.

Stellite is a trademark for a conventionally available, very hard facing alloy containing 75-90% cobalt, 10- 25% chromium and 0-25 tungsten and 040% molybdenum.

Although in accordance with the provisions of the patent statutes, particular preferred embodiments of this invention have been described and the principles of the lnvention have been described in the best mode in which it is now contemplated applying such principles, it will be understood that the operations, constructions and compositions shown and described are merely illustrative and that my invention is not limited thereto.

I claim:

1. A well landing platform comprising, in operative combination, a casing assembly: a first, upward motion resistant, pawl assembly; a second, downward motion resistant, pawl assembly; and a pawl holding means;

said casing assembly comprising a bail and a flat rigid plate therebelow, said bail comprising an upper horizontally extending landing plate element, and said vertical plate extending in a vertical plane and having a front edge and a rear edge, said vertical plate and said landing plate being fimly joined together;

11 said first, upward motion resistant, pawl assembly comprising a first elongated pivotal pawl means with a first locking edge at one end of said pawl means, a first pivotal pawl support means, a first pawl spring means, said first pawl means pivotally supported on said first pivotal pawlsupport means, said first pawl spring means operatively connected at one end to said first pawl means and at another end to said casing assembly, the said first pivotal pawl support means being operatively attached to and supported on said casing assembly, said first locking edge being located at a first distance from said first pivotal pawl' support means that is greater than the distance of said first pivotal pawl support means from said one edge of said vertical plate of said casing assembly;

said second, downward motion resistant, pawl assembly comprising a second pivotal pawl means with a second locking edge thereon, a second pivotal pawl support means, a second pivotal pawl spring means, said second pawl means being supported pivotally on said second pivotal pawl support means, said second pawl spring means being operatively connected to said second pivotal pawl means at one end, and, at its other end, to said casing assembly, said second locking edge being located at a second distance from said second support means that is greater than the distance of said second pivotal pawl support means from said one edge of said vertical plate of said casing assembly; said first spring means urging said first pawl means .to rotate in one direction about said first pivotal pawl support means and said second spring means urging said second pawl to rotate in the other direction about said second pivotal pawl support means;

releasable means attached to said casing means and holding such first and second pawl assemblies in contracted position against the action of said first and second spring means respectively.

2. Apparatus as in claim 1 wherein said apparatus is used in a well casing, said first locking edge engages an interior surface of said well casing and said first distance of said first locking edge from said first pivotal support means is more than the distance of said first pivotal pawl support means from said interior surface of said well casing engaged by said first locking edge and,

said second locking edge engages an interior surface of said well casing and the said second distance of said second locking edge from said second pivotal pawl support means is more than the distance of said second pivotal pawl support means from said interior surface of said well casing engaged by said second locking edge.

3. Apparatus as in claim 2 wherein the second pawl means is pivotally and resiliently supported on said second pivotal pawl support means and, on urging said apparatus in the direction of said rotation of said locking edge of said second pawl means said second spring means urges and holds said locking edge away from engagement with said interior surface of said well casing.

4. Apparatus as in claim 3 wherein said casing assembly comprises a plurality of like parallel cheek plates and said casing assembly has a passageway extending across said one edge of each of said cheek plates of said casing assembly and said locking means extends through said passageways and contact one of said pawl means and opposes the action of one of the spring means attached thereto.

5. Apparatus as in claim 4 wherein line carrying means attached to the top of said apparatus is permanently attached to said locking means and said locking means is releasable from said passageways in said cheek plates, and said passageway extends downwardly as well as across said edge of said cheek plates of said casing assembly and downwardly and across a face of said pawl means.

6. Apparatus as in claim 4 wherein a water-soluble rigid material is carried in said passageway and serves as locking means in contact with said pawl means.

7. Apparatus as in claim 5 wherein the second of said pawl means engages the first of said pawl means when said first locking means engages said first pawl means.

References Cited UNITED STATES PATENTS 2,229,581 1/1941 McLaughlin 166-2l4 2,539,353 1/1951 Minyard l662l4 2,569,457 10/1951 Dale et -al. l66134 X 2,965,031 12/1960 Johns l662l4 X DAVID H. BROWN, Primary Examiner.

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