GB2334286A - Plugging a well - Google Patents

Abstract

In a one-trip method of plugging a well in which a packer and perforating gun are run into the well-bore together, the packer is set by a setting tool, the tool is released from the packer and the gun is positioned, set off and removed, the setting tool S includes a support 74 for collets 78 which secure the tool to the packer P while they are being run into the well-bore. On setting of the packer an assembly 26,30 is displaced, e.g. under the action of pistons, resulting in breakage of a tensile element 84 which releases the tool from the packer.

Description

2334286 _- 11 1 PLUGGING A WELL This invention relates to plugging a well,

and may be azolied to the placement of: a bridge plug or packer in L-he wellbore prior to perforating.

In the past,'packers or bridge plugs have been run into the wellbore on wireline to facilitate rapid positioning and setting. wMe = of an electric line or wireline packer or plug allows for rapid placement and deployment of such equipment, it requires the use of wreline equipment at the surface which is costly and which creates logistical concerns, particularly in offshore applications.

According to methods used in the past, after running and setting the packer with a wireline, a separate trip has to be made into the wellbore with the tubingconveyed perforating gun. The need to run the perforating gim on rigid or coiled tubing has, in the past, necessitated this two-trip system when used in combination with packers which are run in on wireline.

Accordingly, it is one of the objects of the present invention to provide a simple system to run in one trip a packer and tubingconveyed perforating gunThe packer can be easily set in the preferred manner hydraulically such that the s,dtting mechanism releases from the packer, whick in turn allows for simple positioning of the perforating gun for subsequent actuation.

2 Valcus signiling mechanisms for actuation of downhole tools hive been dcvclopci U.S. Patent 5,226,494 indicates a signaling method using pressureinduc.rA strains in tubing suspending a dow-ahole tool to trigger an,lez+.ronic ciicjit to aciate the tool. U.S. Putent 5,343, 963 also relates to me-isifing prcwur,-inductA stmin in the conveying tubing to trigger the operation of a downhole tool. Yet other devices hive been developed that = acoustical signals or press= pulses transmitted downhole which are received and converted to an clectrical signal to actuate a downhole tool.

Creation of a motive pressure forcz to drive downhole components by initiatina a chemical reaction is described in U.S. Patent 5,396,951.

The prior techniques hive not approached the simplicity and reliability of the present inventioii which facilitates a one-trip operation and allows for considerable savings of rig time and surface equipment.

The inventlon -is set out in claim 1 and various ootional features are set out Ln the subsidiary claims.

Examples o_f the invention will now be described with reference to the accompany.Ling drawings in which:

1 3 Fizures la-Ib are a split view of the setting tool for the packer in two positions. illustrating hlow the perforating gun is mounted thereto.

Fieures 2a-2c are a view of the scaing mechanism prior to its insertion into the packer for an embodiment triggered by hydraulic pressure which initiates a reaction creating a pressure to set the packer.

Fi(_,ures 3a-3d and 4a-4c are sectional elevational views of the apparatus of the present invention. showing, an embodiment xvhere rupture disks are broken to initiate the setting o the packer. with Figure ') showing, the assembly with the packer and Figure 4 illustrating, the assembly in a split view showinQ the run-in and set positions of the running tool.

Figures Sa-5d and 6a-6c in sectional elevation indicate -another embodiment or Ficures 1-4 wherein a strain cyuace si2naI trizeers the pressure-creating reaction to set the packer and release therefrom, as shown in split view in Figures 5a-5d, with the packer assembly and without the packer in the run-in position for the setting tool in Figures 6a-6c.

Ile apparatus A of the present invention is shown in Figure 1. At the upper end a perforating gun is schematically illustrated as G. Below the perforating gun G is a top sub 10, which has a series of ports 12. Ports U are in communication, with a rupture disk 14 which, when it breaks, activates ha=er 16 to initiate a reaction between a contmonly known initiator material 18, which reacts with a commonly known charge 20. This method of initiating a reaction in response to a mechanical movement is also fflustrated in U.S. Application Serial No. 08j233,368 filed April 25, 1994, entitled "Downhole Signal-Conveying System', 4 which issued on 10th Octobel, 1995 as U.S. Patent No. 5 456 J16. and which is incorporated by refer=w herein as if fully set fortbL T1he charge 20 is housed in body 24, which is made up of several components. Slidably mounted at the lower end of body 24 is an outer sleeve 26, which has a lower end 25, wbich in t= be= on the setting sleeve 30 of a typical packer P. It should be noted that the design of packer P is of a type weU-known in the art, and its internal construction per se is not a part of the invention. As Olustrated in Figure 1, the packer P has lower slips 32 and uppe&- slips 34. In between is a selling element assembly 36 which, in the top portion of Figure 1, is shown in the relazed position and in the bottom portion of Fig= 1 is shown in the e.Tpanded position for sealing against a casing or a wellbore (not shown). Below lower sEps 32 is bottom sub 38, which is conncclxd to inner mandrel 40. Inner mandrel 40 of the packer P is sc,ur:d to setting tool 5 at thread 47.

Those skAffied in the art can see that the packer P is set by downward move ment of settin. sl=ve 30 which is driven by the setting tool S, as will be described below, while at the s=e time setting tool S retains bottom sub 38 against down ward movement by virtue of a connection through inner mandrel 40.

The setting tool 5, as previously indicated, has a body 24 within which is disposed an initial piston 44. When the charge 20 is set off due to mixing with the initiator 18, pressure develops above piston 44. As seen in the split view of Figure 1, piston 44 is driven downwardly. The pressure developed by the reaction be tween the initiator 18 and the charge 20 is prevented ftorn escaping anywhere by a series of seals 46, 48, and 50. Seals 50 are on piston 44, while seals 48 are an body 24, and seals 46 are on internal sub 52- Accordingly, the pres=e developed by the reaction between the initiator 13 and the charge 20 creates a force that moves piston 44. Piston 44 c=presses oil through restriction 54. This meters (or slows) the setting force, preventing damage or a partial set of the packer. 71C restriction 54 is downstream of piston 44 and upstream of secondary piston 56.

Secondary piston 56 has a piston rod 58 connected thereto. Piston rod 58 is ultimately connected to outer sleeve 26 for tandem movement through ring 60.

Piston rod 58 is sealed with respezt to body 24 through seals 62 on hub 64. Seals 66 seal the piston 56 against the body 24. The restriction 54 prevents overly rapid acceleration of piston 44. Movement of piston 44 ultimately results in a build-up of a force acting on piston 56 which causes piston 56 to shift downwardly. Once piston 56 moves downwardly, taking with it piston rod 58, the lower end 28 of outer sleeve 26 shifts downwardly, as can be seen in Figure 1 by comparing one segment of the drawing to the other. The shifted position of the outer sleeve 26 results in displacement of the setting sleeve 30. At the same time, the lower ring 38 on packer P is restrained from downward movement because it is being retained by inner mandrel 40 which is connected to the setting tool S at thread 42. The not is result is that the slips 32 and 34 are driven outwardly, as is the scaling element assembly 36 on packer P to set the packer.

The apparatus A of the present invention is set to automatically release from the packer P upon setting packer P. The mechanism of how the setting of the packer P results in release therefrom by the setting tool S will now be dcscn-oed.

71e setting tool S has a release rod 70. Ring 72 is mounted on rod 70 and sup ports wedge ring 74. As shown in Figure 1,'wedge ring 74 has a tapered surface 76 which, in the run-in position shown in Figure 1, is wedged under collets 78, which are externally threaded so that they can be engaged via thread 42 to inandrel 40. Those skilled in the art will appreciate that the wedging action of tapered surface 76 helps to retain the setting tool S to the mandrel 40. Additionally, there is no other connection to packer P other than a bearing by outer sleeve 26 setting 1 6 on setting sleeve 30. Accordingly, when the collets 78 become undermined, as occurs when the packer P is set, the setting tool S can be removed from the packer.

As previously described, body 24 supports a hub 64, which in turn supports sleeve 80. Hub 82 is connected to sleeve 80. Tensile member 84 is connected to hub 82 by rod 86. In the preferred embodiment, tensile member 84 breaks at approx-imateiv a 22,800 kg for-ce.

Shaft 70, apart from its initial function of supporting the ring 74 with tapered surface 76 against the collets 78, further extends upwardly into contact with tensile member 84 throuah rod 88. Tensile member 84 can be threadedly con nected to hub 82 and shaft 70. Hub 82 is connected to sleeve 90, which has a Jug 92 to eventually catch shoulder 94 of the collet assembly 42.

When the tensile member 84 is subjected to a predetermined stress during the procedure for setting the packer P, a tensile for= is transmitted to the tensile member 84 through tapered surface 76. Eventually, when the predetermined force, such as 2 2, 8 0 0 k, is exceeded, the tensile member 84 breaks because it is firmly supported from above through sleeve 80 wlule it is being pulled at from below through ring 74. Upon separation of shearing member 84, shoulder 96 is caught on lug 98. This allows tapered surface 76 to back away from collets 78 and leave them unsupported. The entire assembly of the collets 78 is then retained on lug 92 of sleeve 90. An upward pull on the tubing string (not shown) which is connected above the perforating gun G results in removal of the setting tool S. M is because the collets 78 are no longer supported by tapered surface 76, allowing the collets 78 to flex radially inwardly to disengage the threaded connection 42.

Alternatively, the setting tool S can be disengaged from the packer P by rotation, which will release the connection at thread 42. However, in deviated wellbores, it may be difficult to disengage by rotation and the rotational means of disengage- 1.1 7 ment is intended to be used as a back-up if the components do not properly move to Mly remove the support for collets 78. Once the setting tool S is disengaged from the packer P, the perforating gun G can be set at the desired location without another trip into the hole and fired.

Figure 2 is an illustration of the setting tool 5 shown separately from the packer P. Noted in dashed line 100 on Figure 2 is the manner in which the tensile member 84 breaks after being subjected to the predetermined force.

Figure 3 is in all ways identical to the embodiment shown in Fig= 1; however, the actuating mechanism to move the outer sleeve 26' is a little bit different. In Figure 3, an initial rupture disk 102 communicates into cavity 104, which is directly above the initial piston 44'. In this embodiment, the initial piston 44' is connected to the secondary piston 56' by a piston rod 106. Rod 106 extends through seal 108 to define cavity 110. A second rupture disk 112 is in communication with cavity 110 and is set to burst preferably at the same pressure as rupture disk 102, but different pressures can also be used. As before, seals SO' seal initial piston 44' against body 24'. Accordingly, seals 50% 108, and 114 seal off cavity 116 through which the piston rod 106 extends. Cavity 116 is initially filed with a compressible fluid such as air so that it can have its volume reduced as piston 44' moves in response to built-up pressure when rupture disk 102 breaks. Similarly, at the same or a higher pressure when rupture disk 112 breaks, seals 66, 108, and 118 seal off cavity 110 to allow pressure to build up on sec ondary piston 56'. Cavity 120 is sealed off by seals 62' and 66', and contains ible fluid such as air to allow pistons 44' and 56' to advance under the a compressi initial force when rupture disk 102 breaks and the subsequent boost force applied when rupture disk 112 breaks. Those skilled in the art wW appreciate that in the embodiment shown in Figure 3 and 4, the primary and secondary pistons 44' and 8 56' are rigidly connected to each other by rod 106 for tandem movement. Ulti mately, a rod 58' extends from piston 56' to operate the outer sl=ve 26' and the other components in the s=e manne.. as previously dese.nbed for Figures 1 and 2.

Figure 5 and 6 bear a great resemblanw to the embodiment shown in Figures 1 and 2, exczpt Ithe method for actuation of the pressurizing reaction for the initial piston 4.V is some,.vhat different- T7he construction of the packer P and the setting tool S bellew the initial pis-ton 44" is othcrwi-,z the s=c. as the em bodiment in Figwes 1 and 2_ In this embodiment, a similar setting systern, akin:o ffiat shown in U.S. Patents 5,343,963, and 5,396,9151, is schematically illustrated to initiate the initial reaction to create pressure above initial piston 44".

As in two of the rcfc=nwd patents, a strain gauge or g:iugr-s 11-1, responsive to the stresses measu=d at body 24", signals a control circuit L24 to initiate a signal to a heating element 1-16. The heat generated by element 126 initiates a reaction which creates pressure in cavity 20' when materials, such as de=-bed in U. S.

Patent 5,396,951, react, causing the pressure build-up. Thereafter, the operation of the embodiment of Figure.

g 5 is the same as that of Fig= I. It should be noted that the configuration of Figures 5 and 6 is intended to be in part schematic and is amenable to related m6ans of initiatino, a pressurizing reaction in ch=ber 2T, such as by the sending from the surface of an acousdcal signal or a pressure-puLee signal and its r=ipt at the control circuit 124 via means alternative to the strain gauges 122. Instead, a signal receiver of the type known in the art can accept an incoming acoustical signal, pressure pulse, or a physical movement signal, and convert 11 to an output electrical signal by using the control circuit 124 to in tura actuate a mechanism not n=ssarfly limited to a heater 126 to Initiate a reaction or to otherwise initiate or liberate a force sufficient to move piston 44, '. Thus, in lieu of strain gauges 1212, the circuit 1-14 can be sensitized to a predetermined 9 pattern of movement of the entire assembly to set and reAle= from packer P and/or to fire gun G.

Tlose skilled in the art will appreziate that what is disclosed in the apparatus and method of the present invendon is a one-trip system where, on coiled or rigid tubing, the perforating gun G can be lowered and located in the wellbore along with the packer P in one trip. The setting tool S, already connected and supporting the packer P, can be actuated in a variety of ways as dc=-bcd above. Having set the packer P, the setting tool 5 is released automatically from the packer P and retrieved therefrom by manipulation of the rigid or coiled tubing which supports the gun G. nereafter, having removed the setting assembly from the packer, the gun G is properly positioned and set off to complete the perforating procedum 71creafter, to conclude the one trip, the assembly of the gun and the setting tool is removable from the wellbore.

CLAMS A one-trip well completion method, comprising: running in a packer and perforating gun into the wellbore togethersetting the packer with a hydraulically actuated setting tool usincy a tensile element to secure the settina, tool to said packer; securing su 1 1 g pport for at least one collet with said tensile element., usincr said collet when supported to secure said setting tool to said packer., 0 - 1 releasing the setting tool from the packer.

positioning the perforating gun.

W c setting offthe Sun. and removing the gun.

0 2. The method as claimed in claim 1, further comprising breaking said tensile element while setting said packer; undermining support of said collet by said 0 breakina. and releasina from said packer by said undermining.

0,:1 - 1 J. The method as claimed in claim 1, further comprising initiating pressure building in said setting tool. creating differential movement due to said pressure CP 0 1 1_) building; and setting the packer with said differential movement.

4. The method as claimed in claim 3, further comprising using hydraulic pressure to initiate said pressure building and moving at least one piston by said pressure building 5. The method as claimed in claim 3, further comprisinal Z_ using connected pistons in said setting tool. applying an initial force to said pistons; and applying a boost force to said pistons.

6. The method as claimed in claim 4, further comprising using a first rupture disk to provide a hydraulic force above said pistons. and using a second rupture disk to provide a boost force between said pistons.

7. The method as claimed in claim 3, further comprising using a pressure pulse or pulses as a signal to said setting tool, converting said pressure pulse or pulses into an output signal, and using said output signal to initiate said pressure building.

3 The method as claimed in claim, further comprising physically movine, 1 0 s'd setfing tool in a predetermined pattern, sensing said predetermined pattern or al 1 0 d sett'nR tool, and convertina said sensed pattern into an output movement at sal 1 signal that initiates said pressure building.

9. The method as claimed in claim 3, further comprising transmitting an acoustic signal to said setting tool, converting said acoustic signal to an output signal, and initiating said pressure building with said output signal.

1) 0 0 1Q The method as claimed in any one of claims 3 to 9 further comprising using sid differential movement to break a tensile member on said setting tool, and al 1 0 releasing said setting tool from said packer by said breaking IP 01 11.

The method as claimed in claim 10, further comprising moving an initial piston by said pressure building, using movement of said first piston to build pressure on a second piston and controlling the speed of said first piston.

12. The method as claimed in claim 11, further comprising using a restriction 0 1 between said pistons and forcing said first piston to push fluid through said restriction to control its speed.

1 1.

The method as claimed in claim 12 further comprising connecting said second piston to a settincr sleeve on the packer for actuation thereof and supporting 0 12 another portion of the packer by a mandrel on said setting tool which is circumscribed by said second piston.

14. The method as claimed in claim 13 ffirther comprising using, a tensile element in said mandrel.

15. A well completion method substantially as herein described with reference to the accompanying drawings.

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