US3461977A

US3461977A - Casing perforating and screen plug setting device

Info

Publication number: US3461977A
Application number: US732351A
Authority: US
Inventors: Harriet A Taggart
Original assignee: HARRIET A TAGGART
Current assignee: HARRIET A TAGGART
Priority date: 1968-05-27
Filing date: 1968-05-27
Publication date: 1969-08-19
Anticipated expiration: 1986-08-19

Description

Filed lay 27, 1968 H. A.'TAGGART CASING PERFORAAIING AND SCREEN PLUG SETTING DEVICE 4 Sheets-Sheet 2 26 i. l ss ,2e

\ 52 f se 59 w//SI 3? 1/ 4 se 4s s?l 25 FIG. 4 [NVENTOR MMM' Q CASING rma my 27.,.1968

PERFORATING -AND SCREEN PLUG SETTING DIEIVIGE.A

4 sheets-sheet. s

vmvmrToR Filed Au@ 19,1959 L AJM-:GAM l y* 43.461,97?

' CASI TI'NG AND SCREEN PLU SETTING 'DEVIGE v 4 Sheetsi-Sheet 4* l FIG. 12 1 A y u NTO INVE. R'

' v HM us. ci.

' L ABSTRACT or THE mscLosURE IThe invention relates to a device which Awill selectively perforate a well casing, and at the same time insert a filter plug in the perforation which will be held fast, and

prevent sand and other unconsolidated materials from entering the casing.

In` current well completion practice, a steel casing is lowered in the hole and 'cemented into place. The cement is forced down vthe casing and up between the casing and the |bore hole. In doing this the formation is completely shut offfrom the casing, and in order to produce the uids' from the formation, the casing and cement must be perforated. The usual practice is to set the casing in cement as described above and then selectively perforate "the casing and cement opposite oil or gas sands. This prevents the production of water, since the Water sands are left shut oi behind the cement.

Many times the producing sands are unconsolidated vand flow into the well with the fluids being produced 'and cause sanding up in the well, and damage to the equipment. When this occurs the production equipment inust be pulled and the well cleaned out. Many different `approaches have been taken to solve the problem of sand production. The approach taken here is to plug the perforation with a fluid permeable filter plug, and

thus prevent the sand from entering the well bore. The

procedure of selectively perforating cemented casing precludes the possibility of placing lters or screen plugs `in the casing before the casing is set in the' well, because theV cement must also be perforated after it has set up in the hole.

" 'The device disclosed herein is by necessity designed to operate in the limited space of the casing, and therefore the utilization of available space becomes an impor'tant'factor. The design must also take into account fhydrostatic pressures of the drilling fluid in the xwell bore. With these factors in mind, an object of the present invention is to present a Well casing perforating and screen plug setting device which is'compact in design, 'and which will perform the function setforth in fthyis specification under relatively great hydrostatic pres- Slll'eS.

y .Another object is to provide a perforating and screen plug setting device which may be lowered into a well and perform' the above mentioned functions after the casingjhas been lowered and cementedinto place.

j Another object of the invention is to provide a device which will permit standard well completion and water fshut off practices, and at the same time eliminate theneed United Sme Pff for setting screens, gravel packs and the like. The screen A setting process will instead be combined with theusual Vof the invention is tol create a and at' any selected point, be locked in position in the casing by electric means from the surface. lAlso upon command from the surface the' casing may be perforated `and theA screen plug set in the perforation. Subsequent e 3,461,977; Patented Aug. 19, 19,69

to thislthe device may be freed from its position in the casing and retrieved from the well.I

A further object is to offer an oilwell casing perforating and screen plug setting device which contains multiple units as described above and which willperform the perforating and screen plug setting operation' at `selected ICC ,points in the casing a number of times without necessitating the removal of the device from the Well bore.

Yet, another object of this invention is to provide a casing perforating and screen plug setting device with the versatility described and yet relatively simple in design, freel from operating failure and inexpensive to fabricate. l

The novel features and functions of the present invention can best be understood by reference to the followingspecification in conjunction with the accompanying drawinginwhich:

FIG. 1 is a longitudinal cross-section view of the casing perforating and screen plug setting device in free suspension in the well casing.

FIG. Z is also a view in longitudinal cross-section, but locked in rigid position in the well casing.

FIG. 3 is a top view of the device showing an individual tiring cylinder and part of its electrical apparatus.

FIG. 4 is a longitudinal cross-section view of an individual firing cylinder taken along line 4-4 of FIG. 3.

FIG. 5 shows an exploded view of an individual firing cylinder, its placement in the main housing and its spring and retaining ring.

FIG. 6 is an illustration of a iilter plug with helical fins after it has been fired into the casing perforation.

FIG. 7 shows .the forward end of a filter plug.

FIG. 8 is a longitudinal section view of a filter plug showing the filtering granules and screens.

FIG. 9 is a longitudinal cross-section of one of the hydraulic positioning jacks holding the device rigid in the wellcasing.

FIGS. 10 and 11 are cross-sectional views of a firing cylinder taken along line 10-10 of FIG. 3. FIG. 10 shows the position of the tiring cylinder before firing. FIG. 11 shows the position of the firing cylinder after the perforating bullet has been red, the tiring cylinder rotated and the lter plug fired into the casing perforation.

FIG. 12 is a top view of the cylinder position shown in FIG. 11, showing that the terminals in this position are in electrical contact. l

Referring now to the drawings, FIG. 1 shows a cross section view of the device suspended in the Well casing 13 on the electrical conductor-core cable 12. The casing traverses the earth formation 14, and has been set in the cement 15. It can be seen at this point that the formation 14 is completely shut olf by the cement 15 and the casing 13. l

The positioning jacks 16 are hydraulically operated and are used to forcethe device against the casing and hold it rigid while the perforating and plugging operation takes place (FIGURE 2). When the motor 17 is started, the threaded shaft 18 begins to unscrew from its matching threaded member'19 and causes the piston 20 to expel the hydraulic uid from the chamber 21 and into the hydraulic system which activates the positioning jacks. The pressure sensitive switch 22 shuts off the motor when a suicient pressure is built up in the system to hold the device rigid in the casing. After the perforating and plugging operation the motor is reversed, drawing the fluid back into the chamber 21 and retracting the jacks 16. FIGURE 2 shows the device after it has been positioned by the jacks. 'Ihe switch 23 shuts off the motor when the threaded member 19 is brought down in contact with it, as in FIGURE 1 The firing cylinders 24 have two chambers; one fires a bullet which perforates the casing and the other fires a filter or screen plug into the perforation (see FIGURES 4 and 5 The firing cylinder rotates within the main housing 25. After the perforating bullet has been fired through the casing, the filter plug chamber is rotated into alignment with the perforation and the filter plug is then fired into the perforation.

FIGURE 3 is a top detail view of a firing cylinder, and FIGURE 4 is a section view taken along line 4--4 of FIGURE 3. The hydraulic line 26 carries fluid to the positioning jacks 16. The wire 27 runs from cylinder to cylinder for the electrical firing of the perforating bullets. In FIG. 4 the terminal 28 makes contact with the firing element 29 which employs a Nichrome wire 30 in contact with the gun powder 31, and grounded to the device to complete the circuit. When a current is passed through it, the Nichrome wire 30 burns, and ignites the powder 31. When the bullet 32 is fired the explosive pressure drives the pin 33 back, which in turn drives back the spring loaded catch 34 and releases the firing cylinder. The firing cylinder is under spring tension by virtue of the spring 35. The spring 35 is held on the firingcylinder shaft 36 by the snap ring 37 (see FIGURE 5). As the bullet 32 is fired through the bullet firing chamber 38 and the catch is released, the firing cylinder spins 180, aligning the filter plug chamber 39 with the perforation made by the bullet. FIGURE shows the position of the firing cylinder 24 before the bullet is fired. FIGURE ll shows the firing cylinder 24 after the bullet 32 has been fired and the cylinder has spun 180. The spring loaded member 40 drops into the slot 41 in the firing chamber 24 and fires the primer cap 42 and ignites the powder charge 43 which drives the filter plug 44 into the perforation. FIGURE 4 shows the packing 60 which serves as a gas seal and pushes the filter plug 44 ahead of it as the charge 43 explodes.

FIGURE 6 is a detail of the filter plug 44 after it has been driven into the casing 13. The helical fins 45 are made of hardened steel and cause the plug to spin through the casing 13. As the fins cut through the other side of the casing 13, they spin out of the grooves 46 which they have cut, and thereby lock the plug in place. It should be noted in the enclV view of the plug (FIGURE 7) that the fins 45 are not spaced at equal angles from each other, so the plug cannot come out unless it has turned exactly 360, exactly the way it has entered. FIGURE 8 is a longitudinal section view of the filter plug. The screens 47 enclose the filtering granules 48. The screens are held in place by the retainer plates 49a and 49b. The shoulder 50 holds the rearward retainer plate 49a in place While the snap ring 51 holds in the forward retainer plate 49b.

FIGURE 9 is a detail section of one of the positioning jacks 16. This is a simple telescoping hydraulic jack. It has been activated by fluid from the lines 26 and has forced the main housing 25 against the well casing 13. The jack 16 is held in the main housing 25 by the snap ring 52.

The explanation of the wiring system is as follows: FIGURE 3 shows the electrical terminal 28 connected to the incoming wire 27a and it, in turn, is resting on the firing element 29 which is seen in FIGURE 4. The other terminal 53 in FIGURE 3 is connected to wire 27b and is resting on a strip of insulating material 54. Both terminals are mounted on the insulator 55, so a broken connection exists between the two terminals. FIGURE l2 shows the two terminals resting on a conducting material 56 after the firing cylinder has fired and rotated 180 as in FIGURE 11. The wires 27a and 27b are now in electrical contact and wire 27b leads to the next firing cylinder, making it ready for firing. This can be repeated for any number of cylinders.

FIGURES 4 and 6 show the placement of the gasket 57 on the filter plug. The gasket 58 in FIGURE 4 seals the device and prevents leakage of well fluids into the electrical conductor-core cable containing two wires for the hydraulic system motor and one wire for firing the perforating bullets. When the desired point is reached for perforating, the positioning jacks are activated and the device is forced against the casing with the firing chamber muzzles `against the casing. The firing element is then activated. The perforating bullet is fired through the casing, the catch is released and the firing cylinder spins around to a point aligning the filter plug chamber with the perforation. At this point the primer cap is fired, driving the filter plug in the perforation. Thefiring cylinder in this position has left the next firing cylinder in electrical contact and ready for firing. After the operation is completed the hydraulic system motor is reversed, the jacks retracted and the device retrieved from the well, or moved to the next selected interval to be perforated.

Although I have illustrated and described a specific embodiment of my invention it should be understood that many substitutions and modifications may be made with'- out departing from the true spirit of the invention.

What I claim is:

1. A casing perforating and screen plug setting device for oil wells and the like consisting of a tubular housing suspended in a well casing on an electrical conductor-core cable; said tubular housing containing a plurality of cylinders, the longitudinal axis of said cylinders disposed tlasversely to the longitudinal axis of said tubular housing; said cylinders rotatable relative to said tubular housing with spring means urging said rotation; a releasable catch between said cylinders and said tubular housing to prevent relative rotation, said cylinders having two diametrically opposed chambers along said cylinders longitudinal axis, one chamber vhaving a charge driven projectile suitable for perforating a steel casing; the other chamber having a charge driven filter plug equipped with helical fins suitable for holding fast when driven into a casing perforation; said tubular housing equipped with hydraulic jacks which may be activated to force said tubular housing against said casing and hold said tubular housing stationary within said casing; said component parts being so arranged that the tubular housing may be lowered into the larger tubular casing and locked in rigid position in said casing, said projectile may then be fired through the casing by electric means through the electrical conductor-core cable; said catch may then be released, allowing the cylinder to rotate to a point aligning the filter plug with the perforation made by the projectile, said filter plug may then be red into said perforation; said jacks may then be retracted and said tubular housing retrieved from said casing.

2. The casing perforating and screen plug setting device of claim 1 wherein said cylinders are equipped with circular gaskets to prevent drilling fiuids from enten ing said tubular housing.

3'. A casing perforating and filter plug setting device for oil wells and the like consisting of a tubul-ar housing suspended in a well casing on a line from the surface; said tubular housing containing a plurality of cylinders, the longitudinal axis of said cylinders disposed transversly to the longitudinal axis of said tubular housing; said cylinders being rotatable relative to said tubular housing with spring means urging said rotation; a releasable catch between said cylinders and said tubular housing to prevent relative rotation, said lcylinders having two chambers along said cylinders longitudinal axis, one chamber having a projectile and means for driving said projectile through a steel casing; the other chamber having a filter plug and means for driving said filter plug into a casing perforation; said tubular housing equipped with clutches which may be activated to hold said tubular housing stationary within said well casing; said component parts being so arranged that the tubular housing may be lowered into the well casing and locked in rigid position in the casing, the projectile may then be driven through the casing on command from the surface, said catch may then be released, allowing the cylinder to rotate to a point aligning the iilter plug with the perforation made by the projectile, said lilter plug may then be driven into said perforation; said clutches m-ay then be retracted and the tubular housing retrieved from the well casing.

4. A casing perforating and screen plug setting device as described comprising; a tubular member suspended in a well casing on -a cable from above; said tubular member having a plurality of rotatable cylinders disposed transversly to the longitudinal axis of said tubular member; spring tension urging said cylinders to rotate relative to said tubular member, a releasable catch between said tubular member and said rotatable cylinders preventing relative motion therebetween; each of said cylinders having two chambers, one of which chambers employs a projectile and means of propelling said projectile through said well casing; the other chamber employs a filter plug 20 and means of driving said filter plug into a perforation in said casing: said device equipped with clutches which 6 may be activated to hold said device stationary in said casing: said parts being so arranged that the clutching process as well as the perforating and plugging operations may be activated from the upper end of said cable.

References Cited UNITED STATES PATENTS 2,210,983 8/1940I MacClatchie 175-4.5 2,426,517 8/1947 McWhorter 175-4.5 2,482,913 9/1949 Jobe 166-55.1 2,559,687 7/1951 Thomas 166--55.1 X 2,587,723 3/ 1952 Githens et `al 175-4.5 2,614,633 10/1952 Broyles a 166-55.1 3,245,472 4/1966 Zandmer 166-100 3,318,393 5/1967 Brown 166--100 X DAVID H. BROWN, Primary Examiner U.S. Cl. X.R.