Patent Description:
A <NUM>,<NUM> (<NUM>-<NUM>/<NUM>") "Stronghold Barricade System" - or more generalized, an annulus wash tool (<NUM>) also used for annulus cementing.

A <NUM>,<NUM> (<NUM>-<NUM>/<NUM>") "SAMURAI MF Cutter" - or more generally a casing cutter tool (<NUM>) which has a through bore which may also be cemented through.

A <NUM>,<NUM> (<NUM>-<NUM>/<NUM>") "Spearhead Plug" - a spear and plug tool which is enabled to hang off drill pipe string below, or more generalized, a spear tool (<NUM>) which has a main through bore which may be circulated through the main bore.

According to regulations for abandoning a petroleum well, a dual barrier is required. In an example, illustrated in the left column of Fig. A1, B1, and C1, Please also see Fig. A2, B2, and C2, <NUM>,<NUM> (254ft) of perforations will be made and a <NUM>,<NUM> (600ft) cased hole cement plug will be placed within a <NUM>,<NUM> (<NUM>-<NUM>/<NUM>") casing. This is for a well called BC-<NUM>, and other depths may be relevant for other wells, but the example illustrates the problem to be solved.

The geological formation to be plugged in the example is the Shetland formation between depths: <NUM>,<NUM> - <NUM>,<NUM> (<NUM>,831ft - <NUM>,436ft) BHR MD at <NUM>° inclination.

The top of the completion packer is at <NUM>,<NUM> (<NUM>,700ft) BHR MD.

The planned perforation depth is <NUM>,<NUM> -<NUM>,<NUM> (<NUM>,027ft - <NUM>,281ft) BHR MD (<NUM>,<NUM>) (254ft) with a further <NUM>,<NUM> (346ft) internal cased hole plug covering <NUM>,<NUM> - <NUM>,<NUM> (<NUM>,681ft - <NUM>,027ft) MD to ensure the combined plug (<NUM>,<NUM>) (600ft) covers the parts of the Shetland Group formation that needs be plug cemented.

In an embodiment of the invention a wireline set plug is set at <NUM>,<NUM> (<NUM>,578ft) BHR to allow a sump to drop the TCP BHA into.

Drill string to be used is <NUM>,<NUM> (<NUM>") NC50 drill pipe to surface.

<CIT> relates to a casing retrieval drill pipe string conveyed tool string assembly for a well comprising one or more casings, said tool string assembly comprising:.

<CIT> relates to a method for pulling casing pipes/liner in a petroleum well, comprising the steps of: a) perforating an actual section of said casing pipe in said well by means of a perforating gun, and then b) washing, by means of a washing tool in at least one casing pipe annulus outside the perforated section of said casing pipe for removing debris material, particles, cement or other bonding substances which otherwise hold said casing pipe section stuck, c) cutting, by means of a cutting tool said casing pipe within or below the perforated section for releasing it from the deeper residing, remaining portion of said casing pipe in said well, d) pulling said released, washed-out section of said casing pipe out of said well.

The invention is defined in the attached set of claims.

The invention is illustrated in the attached Drawing Figures. The Figures have been drawn in three corresponding series A1 - A11, B1 - B11, and C1 - C11, which differ in the following aspects:.

The invention provides a well intervention toolstring as defined in claim <NUM>.

The through bore spear plug tool (<NUM>, <NUM>') is arranged for engaging and pulling on casing pipe, in this case a casing pipe section having been severed at a desired depth, as illustrated in Figs. A4, B4, C4.

In an embodiment the through bore spear plug tool (<NUM>, <NUM>') is a drill-pipe conveyed spear tool (<NUM>) with slips setting in a casing pipe, please see Figs. In that embodiment the through bore spear plug tool (<NUM>, <NUM>') may be in the original drill pipe string, a casing spear (<NUM>).

In an embodiment the through bore spear plug tool (<NUM>, <NUM>') is not in the original tool string first run into the well, please see Figs. but inserted after the cut has been made, please see Fig. B6.

In another embodiment the through bore spear plug tool (<NUM>, <NUM>') is in the form of a casing hanger running tool.

In yet another embodiment the through bore spear plug tool (<NUM>, <NUM>') is in the form of a spear plug tool (<NUM>') with capacity for holding the remaining toolstring of cutter tool (<NUM>), swivel (<NUM>) and swab cup wash tool (<NUM>) below the spear. Such a spear plug tool (<NUM>') which has a packer may be used for, in addition to pulling on the severed-off casing section, also to be set under pressure via the drill pipe string, the pressure now directed upwardly from below, also via the cut, in order to create a piston effect from below on the severed-off casing section.

In an embodiment of the invention the through bore cutter tool (<NUM>) has a fourth ball seat (<NUM>) arranged for receiving a fourth ball (22B) arranged for building up pressure in the through bore cutter tool (<NUM>) in order to extend knives (<NUM>), please see Figs. A4, B4, and C4. The reason for naming it the fourth ball seat (<NUM>) is that there are three ball seats arranged below, one in the perforation gun (<NUM>), and two in the swab cup wash tool (<NUM>), which are utilized before the cutter tool ball seat.

In an embodiment of the invention the swab cup wash tool (<NUM>) further has a bypass line (<NUM>) across the wash tool (<NUM>) swab cups (<NUM>).

The wash tool (<NUM>) is arranged for washing the perforated annulus.

The wash tool (<NUM>) is arranged for subsequently cementing the perforated casing annulus, cement passing back in through the perforations and passing through the bypass line (<NUM>) to cement the casing main bore, as described in Sverre Bakken's patent <CIT> on a combined annulus wash and cementing method.

In an embodiment of the invention there is a second and third ball seat (<NUM>, <NUM>) below the swab cup wash tool (<NUM>). The second and third ball seat (<NUM>, <NUM>) are arranged for receiving a second and third ball (42B, 43B). The second ball seat (<NUM>) may be sheared out at a predetermined pressure after the annulus washing procedure, and the third ball seat (<NUM>) is sheared out after the cementing circulation procedure for cementing the annulus of the perforated casing, and also for cementing the main bore below the washing tool during the pump and pull operation. Details of the washing and cementing procedures are given in the below appendix.

In an embodiment of the invention the well intervention, the toolstring further comprises a first ball seat (<NUM>) in a firing head (<NUM>) and an automatic gun release AGR (<NUM>) for the perforation gun (<NUM>). A first ball (52B) is dropped to the first ball seat (<NUM>), landed, and pressure is set to trigger the firing head (<NUM>) which sets off all the guns (<NUM>) in common, and activates the automatic gun release (<NUM>) to drop the guns into the below rathole above the wireline set plug or other basis for the cementing operation.

In an embodiment shown in Figs C1 - C11, the through bore spear (<NUM>) is a spear plug tool (<NUM>') which comprises a packer and further comprises a switchable ball valve having a bore of relatively large diameter to allow circulation through.

The method provides a method for pulling a casing as illustrated in Figs. A1, B1, C1 to A11, B11, C11. The method comprises the steps of:.

(In case said spear tool (<NUM>) was not inserted in the toolstring initially, such as in Fig. A1 to A5, after the cutting, pull up and insert said spear tool (<NUM>) into the toolstring as illustrated in Fig. B6 and A6) (In case the spear tool (<NUM>) already was inserted in the toolstring, such as in Figs. A1 to A5, it is not necessary to pull up and insert the spear tool (<NUM>), and then the steps of Fig. A6 and A7 have been indicated by "X" as not required, and we may proceed to the test pulling of Fig. A8.

Test pull the severed-off casing section using said spear tool (<NUM>) as illustrated in Fig. A8, B8, and C8.

If the test pulling is successful, pull up and remove the spear tool (<NUM>), the cutter tool (<NUM>) and the swab cup wash tool (<NUM>).

(If the test pulling is not successful, if using a spear plug (<NUM>') as in Fig. C8, pressure up on the drill pipe string to add piston pressure force from below on the severed-off casing section, and try also to wash out the annulus via the cut. If still not successful in test pulling, pull up and reinsert the cutter tool and make a shallower cut and repeat the test pulling, until successful test pull.

Then reinsert spear tool (<NUM>), run it into the well and engage with the severed-off casing section, please see Figs. A10, B10, and C10, and pull said severed casing out of hole, as illustrated in Fig. A11, B11, and C11.

In an embodiment of the invention, after running into hole and placing the perforation gun (<NUM>) at the predetermined perforation depth,.

In an embodiment of the invention, wash the perforated casing section annulus by.

Due to the fact that the second ball seat has been sheared out, we may pump wash fluid through the wash tool axially, and back up through the bypass line (<NUM>) across the swab cups, and thus circulate out the debris.

In an embodiment the method for pulling a casing further comprising.

In an embodiment of the invention, one shall now wait on cement, i.e. until the cement plug has set and hardened sufficiently to conduct a pressure test, increase the pressure in the casing to pressure test the formed cement plug. We are now at the stage of Fig. A3, B3, and C3, and before the cutting in Fig. A4, B4, C4. If the pressure test, which tests sealing from above, is OK, we are sure that the plug, which is of more than <NUM>, <NUM> (250ft) length in the example, has sealed from rock to rock across and along the perforated section, and forms one permanent fluid barrier.

In an embodiment of the invention, the method further comprises to cut the casing by.

Now the cut-off casing section, the severed casing section, should be tested for whether it is possible to pull out and lay out of hole.

According to an embodiment of the invention the method further comprises to test pull said severed-off casing section by.

There are two possible situations before the test pull can take place:.

Thus, in an embodiment of the invention, in case said spear tool (<NUM>, <NUM>') was not inserted in the toolstring initially, after the cutting, pull up and insert said spear tool (<NUM>, <NUM>') into the toolstring above the cutter tool (<NUM>), please see Fig. B6 and C6, and run in said spear tool (<NUM>, <NUM>') into the well and engage with said severed-off casing section, please see Fig. B7, B8, and C7, C8, and test pull the severed-off casing section using said spear tool (<NUM>, <NUM>'). Please see Fig. B8 and C8.

In case the test pull is not OK, and the severed-off casing section is stuck, we still have the cutter tool in the well, and may repeat the cutting process with cutting higher up and test pulling until free.

In case the test pull is OK, we may now pull out the severed-off casing section. But at the surface the drill pipe string with the spear tool (<NUM>, <NUM>'), the cutter tool (<NUM>), the swivel (<NUM>) and the swab cup wash tool (<NUM>) will usually be in the way of the process of removing the severed-off casing section and lay it out; in an embodiment of the invention we have to remove the spear tool (<NUM>, <NUM>'), the cutter tool (<NUM>), the swivel (<NUM>) and the swab cup wash tool (<NUM>) before pulling the severed-off casing section out of hole.

In the embodiment we pull out said severed-out casing section by.

In an embodiment of the invention, if the top of the casing is a casing hanger, engaging said spear tool (<NUM>, <NUM>') in the casing hanger, please see Fig. A8, B8, C8, of said severed-off casing, before pulling it out.

This concludes the embodiments of the method and the severed-off casing section has been laid out of the well.

The invention is in this appendix lined out with details of the below planned operation on a well. The present invention relates to a plug and abandon operation with a pulling out of a casing from the well. The Perforate, Wash and Cementing operation utilises the applicant's so-called Barricade system, a single trip system to perforate a casing wall, wash the casing annulus, and circulate in cement to the annulus to establish a cement barrier across a geological formation, here the Shetland Group formation.

Some of the essential tools used in the operation according to the invention are:.

According to regulations for abandoning a petroleum well, a dual barrier is required, therefore <NUM>, <NUM> (254ft) of perforations will be made and a <NUM>, <NUM> (600ft) cased hole cement plug will be placed within the <NUM>,<NUM> (<NUM>-<NUM>/<NUM>") casing.

Pump and pull rates are based on <NUM>,<NUM> (15ft) stroke of the HWO Unit.

BHR Height used has been <NUM>,<NUM> (<NUM>.

Planned perforation depth will be2. <NUM>,<NUM> - <NUM>,<NUM> (<NUM>,027ft - <NUM>,281ft) BHR MD (<NUM>,<NUM>) (254ft) with a further <NUM>,<NUM> (346ft) internal cased hole plug covering <NUM>. <NUM> - <NUM>,<NUM> (<NUM>,681ft - <NUM>,027ft) MD to ensure the combined plug (<NUM>,<NUM>) (600ft) covers the Shetland Group formation.

A wireline set plug may be set at <NUM>,<NUM> (<NUM>,578ft) BHR to allow a sump to drop the TCP BHA into.

Drill string to be used will be <NUM>,<NUM> (<NUM>") NC50 drill pipe to surface.

As part of the pre-job planning at a minimum the following should be carried out to ensure flawless execution.

Fluids to be sent out pre-mixed where possible.

Below is described embodiments of the invention. The invention is in one aspect a method as defined by claim <NUM>.

The invention is, in another aspect, a toolstring, as defined by claim <NUM>, arranged for conducting the method. We describe the entire operation beginning with preparations and ending with the situation wherein all sections of the severed-off casing section have been laid-out on deck. The below description of embodiments of the invention is based on the inventor's "Archer Oiltools' Shell BC07 Operation Procedure" for conducting the entire perforate-wash-cement operation for plugging the well in the Shetland Formation before cutting the casing at a shallower depth and pulling out the severed-off casing section. The method may be employed for other wells in the same Shetland Formation, of course adapted to the local relevant depths, but may also be employed in other similar wells wherein the well shall be subject to casing perforation, washing and cementing before cutting the casing at a shallower depth and pulling out the casing. During the procedure the bottom-hole assembly generally comprises a casing perforation gun (which is dropped automatically after perforating), a casing annulus wash and cementing tool, a casing cutter tool, and a spear tool, possibly a combined spear and plug tool is applied, although the spear and plug tool is in some embodiments inserted into the toolstring after the cutter tool has been employed. The scope of protection of the current invention is defined by the appended claims.

Below is described the exemplary operation procedure in minute detail.

Check if rig monitoring system for recording flow rate and pump pressure is running. Carry out circulation "fingerprint" and record below.

Stop pumping and break out swivel and insert the second ball (42B), which is a <NUM>,<NUM> (<NUM>") OD Steel Ball. M/U swivel. Circulate the second ball (42B), the <NUM>,<NUM> (<NUM>") ball, to the second ball seat (<NUM>) below the swab cup wash tool at maximum <NUM>,<NUM> I/min (1bbl/min). Now the swab cup wash tool (<NUM>) main bore is closed and the swab cups may be pressure tested against blank casing. Note: Max running speed across perforations is <NUM> per <NUM>,<NUM> (15ft) stroke. P/U into blank casing and confirm swab cup integrity to <NUM>,<NUM> bar (<NUM>,000psi). Hold <NUM>,<NUM> bar (300psi) on the string and slowly RIH the swab cup wash tool (<NUM>) to locate top of perforations indicated by pressure bleed off. We may now assume that the fluid enters into the perforations. Continue to RIH a further <NUM>,<NUM> (2ft) to place the swab cup wash tool (<NUM>) swab cups in perforations. Now we start washing. Start pumping to circulate out to the annulus between the swab cup wash tool (<NUM>) swab cups and increase rate to a maximum loss free rate aiming for a minimum <NUM>,<NUM>/min (<NUM>. 7bbl/min) aiming for <NUM>,<NUM>/min (12bbl/min).

Move the swab cup wash tool (<NUM>) and wash downwardly: Once stable rate has been achieved wash downwards at <NUM>,<NUM>/min (1ft/min) monitoring for blank sections from TCP BHA. Ensure connections are made quickly and efficiently.

At bottom of perforations continue to pump a string volume while stationary. Switch off pumps and - pull up to top of perforations and repeat the wash down pass while monitoring for a decrease in washing pressure. We now reach the bottom perforations. The washing procedure is now finished and we prepare for primer and cementing of the washed-out casing annulus. But first we must circulate out the washed-out debris from the tool annulus. RIH the swab cup wash tool (<NUM>) into blank casing below perforated zone and verify swab cup wash tool (<NUM>) swab cups pressure integrity to <NUM>,<NUM> bar (<NUM>,000psi) and continue to pressure up to <NUM>,<NUM> bar (<NUM>,000psi) shearing out the second ball seat (<NUM>) <NUM>,<NUM> (<NUM>") ball seat and regain circulation through the bottom of the swab cup wash tool (<NUM>).

In order to circulate out the washed-out debris, circulate min <NUM> x B/U at max allowable rate rotating the string above the swivel (<NUM>) above the swab cup wash tool (<NUM>) at max allowable rpm continuing to monitor debris returns over shakers. The swab cup wash tool (<NUM>) is not rotated.

P/U to straddle bottom of perforations with the swab cup wash tool (<NUM>) swab cups and drop and circulate a third ball (43B) , a <NUM>,<NUM> (<NUM>") ball to the third ball seat (<NUM>) which is arranged below the swab cup wash tool (<NUM>), at maximum <NUM>,<NUM>/min (1bbl/min). This third ball (43B), when landed, closes the central bore of the swab cup wash tool (<NUM>) to re-enable circulation out to the perforated casing annulus. RIH to blank casing and verify integrity to <NUM>,<NUM> bar (<NUM>,000psi) to verify swab cup wash tool (<NUM>) integrity. When OK, spacer circulation may commence.

Hold TBT for cementing operations. Have a review to capture any lessons learned or improvements from the preceding spacer section. Ensure all communications are clear. Discuss the Archer displacement plan. RIH to straddle the bottom of perforations. Note: Ensure Cementer is aware of the plan and does not start to fill the tanks while displacing down the string. Pump the following volumes down the string as per displacement plan of the appendix below.

This will displace 10bbl of cement out of the wash tool (<NUM>) while stationary prior to starting Pump + Pull operations. Cement will be circulated into the perforated casing annulus and rise above the upper swab cups and back into the toolstring annulus and the upper bypass line (<NUM>) port. Pulling up while pumping will now also guide cement down through the bypass and cement the main bore of the casing below the lower bypass port. Start picking up to carry out Pump and Pull operations as per cement calculation parameters. Pumping at <NUM>,<NUM>/min (3bbl/min) and pulling at <NUM> per <NUM>,<NUM> (15ft) stroke. Note: Monitor maximum volume pumped allowed as per displacement plan. At the top of the perforations continue to P/U into blank casing and shear out the third ball seat (<NUM>) with the third ball (43B), the <NUM>,<NUM> (<NUM>") ball seat pinned to <NUM>,<NUM> bar <NUM>,000psi. <IMG>
<NUM>. Continue to pump cement as a balanced plug as per displacement plan for the remaining internal cement plug in the main bore. Pumping at 1bpm. TTOC at approximately <NUM>,<NUM> (<NUM>,681ft). POOH (Pull up) until clear above worst-case top of cement TOC at <NUM>,<NUM> (<NUM>,112ft). Carry out minimum <NUM> x string volume B/U circulation at minimum <NUM>,<NUM>/min (<NUM>. Note: If a sponge ball is to be pumped recommended to only pump <NUM> sponge ball as pumping <NUM> could lead to the tool being partially plugged. The toolstring should now be free of cement and spacer fluid. POOH, i.e. pull up the toolstring and position the cutter tool (<NUM>) knives at cutting depth <NUM>,<NUM> (<NUM>,227ft) where the cut shall be made. Wait on cement WOC and pressure test the formed cement plug formed with the above perforation, washing, and cementing procedure, the so-called "Shetland plug". Note: Shell to advise timings and parameters
<NUM>. Drop a fourth ball (22B), a <NUM>,<NUM> (<NUM><NUM>/<NUM>") activation ball for a ball seat (<NUM>) of a flow controller valve of the cutter tool (<NUM>) and record parameters without pumps.

Chase the activation ball (22B) to land in the seat (<NUM>) of the cutter tool (<NUM>) with maximum <NUM>. 5bpm
<NUM>. Watch for pressure build up to indicate that the fourth ball (22B) has landed in seat (<NUM>). Increase pressure to shear a pin which activates the longitudinal movement of a piston and piston rod controlled by a flow controller, activating the knife assembly of the cutter tool (<NUM>), and watch for pressure drop.

Stop pumps. Increase flow until torque increase is observed
<NUM>. Increase pressure to achieve a cutting pressure drop of <NUM>,<NUM> - <NUM>,<NUM> bar (<NUM>-<NUM>,160psi) in 2mins until stable pressure is witnessed
<IMG>
Note: If pressure and flow rate deviated from table below, pressure should be used as reference.

USing the cutter tool (<NUM>), cut the casing at <NUM>,<NUM> (<NUM>,227ft) BHR MD according to Archer rep. An increase in torque may be observed during the cutting process. Subject to centralisation, the torque may become erratic as the cut proceeds.

When the cutter tool's (<NUM>) knife arms reach their pre-set diameter a pressure drop, due to the end position of the cutter tool's flow regulator, will be observed and the pre-determined knife opening is reached. Immediately increase pump rate to chase the required cutting pressure. A reduction in torque is expected. Note: Cutting a casing which is in compression can reduce the visibility of the reduction in torque and surface pressure drop. Maintain cutting pressure and continue cutting for a short duration (<NUM>). The knife arms will continue to the maximum knife sweep. To ensure a clean cut. Stop circulation, bleed of pressure and stop rotation. Note: Bleed off pressure thru the standpipe to prevent hydraulic locking
<NUM>. P/U pick up string weight and POOH to bit depth <NUM>,<NUM> (<NUM>,973ft) BHR MD, which is <NUM>,<NUM> (<NUM>") above the cut made at <NUM>,<NUM> (<NUM>,<NUM>").

P/U the spear tool (<NUM>) assembly and remove the Safety Clamp from the spear tool (<NUM>) Running Tool. In case of using a spear plug tool (<NUM>'), Make sure the ball valve of the spear plug tool (<NUM>') is open. M/U the spear tool (<NUM>) assembly to the drill pipe set in the slips
<NUM>. Remove inner bushing and lower the spear tool (<NUM>) through the rotary
<NUM>. M/U to NC50 drill pipe and RIH to engage the spear tool (<NUM>) in the casing hanger of the severed-off casing section.

Record up/down weights and DP stretch
<IMG>
<NUM>. Start circulating and condition mud in order to clean the spear tool (<NUM>) and the internal casing wall of the setting area. In case of using a spear plug tool (<NUM>') , start circulating and condition mud in order to clean the lips, drag blocks of the spear plug tool (<NUM>') and the internal casing wall of the setting area. Depending on the well condition, circulate for <NUM>. with maximum rate.

Make sure to space out in a manner so that you have some room to work with during setting, ideally <NUM>,<NUM> (30ft) above RKB. Note: should be to place mid-joint of single across BOP's to prevent connection being immediately below or at blind shear rams of the BOP when the spear tool (<NUM>) is set. Move DP down to 6ft above desired setting depth and pick up to neutral weight. Activate the slips of the spear tool (<NUM>). In case of using a spear plug tool (<NUM>'), Establish right hand RH rotation at <NUM>-20RPM. Confirm stationary wind-up torque by rotating the drill pipe string slowly until break-over torque of the spear tool (<NUM>) is reached & weight is confirmed, minimum <NUM> turns. This will activate the slips and the packer of the spear plug tool (<NUM>'). Record number of turn to achieve free rotation torque (FRT), and weight(FRW):
<IMG>
<NUM>. Set the slips of the spear tool (<NUM>). In case of using a spear plug tool (<NUM>'),move the string down at approximately 1ft/s in order to engage and set the slips of the spear plug tool (<NUM>'). When the spear plug tool (<NUM>') starts to take weight, stop rotation, release torque and set down minimum <NUM>,<NUM> (44klbs) below slack off weight (SOW), holding weight 2mins
<NUM>. Pick up, in order to have <NUM>,<NUM> (22klbs) tension on the spear tool (<NUM>), compared to Pick up weight (PUW)
<IMG>
<NUM>. Release torque in the string and verify that the spear tool (<NUM>) is set according to Archer rep. Now the spear tool (<NUM>) is ready to pull the casing. Pull the severed-off casing section according to Archer rep.

If the severed-off casing section is not free, follow the below steps:.

If the severed-off casing section is free and possible to move, release the spear tool (<NUM>), because we will now lay out the cutter tool (<NUM>) and the swab cup wash tool (<NUM>) before pulling out the severed-off casing:
<NUM>. Slack off to have <NUM>,<NUM> (5klbs) above free rotation weight (FRW). Release the spear tool (<NUM>). In case of using a spear plug tool (<NUM>'), still with <NUM>,<NUM> (5klbs) above the free rotation weight (FRW), start RH rotation at <NUM>-<NUM> RPM, in order to release spear plug tool (<NUM>'). In case of using a spear plug tool (<NUM>'), when spear plug tool (<NUM>) is free, pull the string slowly as you rotate another <NUM> turns. Then stop rotation gently as you continue pulling the string another <NUM>,<NUM> - <NUM>,<NUM> (<NUM>-<NUM> ft). In case of using a spear plug tool (<NUM>'),If no indication that spear plug tool (<NUM>) has released after <NUM> turns, increase over pull in steps towards pick up weight. Once spear plug tool (<NUM>) releases pull the string slowly as you rotate another <NUM> turns. Then stop rotation gently as you continue pulling the string another <NUM>,<NUM> - <NUM>,<NUM> (<NUM>-<NUM> ft). NOTE: Make sure that while operating spear tool (<NUM>), the TD must at all times be positioned so that spear tool (<NUM>) can be released and DP made up/broken with the Iron Rough Neck
<NUM>. Stop pulling and wait <NUM> minutes to allow elements to fully retract. If possible, run spear tool (<NUM>) in-hole to below setting depth, to ensure that spear tool (<NUM>) is retrieved and free. POOH and lay out the spear tool (<NUM>) assembly. We shall now get rid of the cutter tool and wash tool before pulling the severed-off casing section. POOH and lay out the Archer cutter tool (<NUM>) and swab cup wash tool (<NUM>). The reason for having kept the cutter tool (<NUM>) in the work-string until now is due to the fact that if the severed-off casing section remained stuck and impossible to poll, we could now make a new cut and try to pull the new, shorter severed-off casing section in order to proceed. P/U the spear tool (<NUM>) assembly and M/U to NC50 drill pipe. RIH to engage the casing hanger of the severed-off casing section.

Repeat steps <NUM>-<NUM> for setting the spear tool (<NUM>) in the severed-off casing section, now without the cutter tool (<NUM>) and swab cup wash tool (<NUM>), and to determine that the severed-off casing section is free. Apply overpull to lift casing and break circulation to wash old mud from behind the casing
<NUM>. POOH Pull the casing hanger out of hole and lay out the casing hanger
<NUM>. Release the spear tool (<NUM>) as per steps <NUM>-<NUM>. L/O Spear tool (<NUM>) assembly
<NUM>. L/O lay out the severed-off casing section using casing handling equipment.

The severed-off casing has now been removed from the well, subsequent to the well having been plugged.

Claim 1:
A method for pulling a casing, comprising the steps of:
- assembling a toolstring, from top to bottom, of
- a drill pipe string,
- a spear tool (<NUM>, <NUM>')
- a space-out drill pipe string above a cutter tool (<NUM>)
- a through bore cutter tool (<NUM>),
- a swivel (<NUM>) below the cutter tool (<NUM>),
- a swab cup wash tool (<NUM>),
- a perforation gun (<NUM>),
- run in hole and place the perforation gun (<NUM>) at a predetermined perforation depth,
- perforate the casing using the perforation gun (<NUM>),
- wash the perforated casing annulus using the swab cup wash tool (<NUM>),
- circulate in cement into the washed casing annulus and the casing bore using the swab cup wash tool (<NUM>),
- wait on cement and pressure test the cement plug so formed,
- pull up and cut the casing at a shallower depth using said casing cutter tool (<NUM>),
- test pull the severed-off casing section using said spear tool (<NUM>),
- if test pull successful, pull up and remove said spear tool (<NUM>), said cutter tool (<NUM>) and said wash tool (<NUM>),
- reinsert said spear tool (<NUM>) and run in to engage the severed-off casing section, and pull said severed casing section out of hole.