Patent ID: 12209482

DETAILED DESCRIPTION OF THE DRAWINGS

FIG.1illustrates a single zone abandonment tool10which can be used to install a cement plug in a well. The abandonment tool10can be used when the well has a single zone to place a cement plug above the single zone to prevent fluids, such as gas and/or oil, from the zone migrating into the water table or out into the atmosphere. The single zone abandonment tool10can include: a cement tool20; an upper shear joint40; a setting tool50; exhaust ports67; a shear stud70; a bridge plug80; and a dart90.

The cement tool20can be connected to coiled tubing that will be run down a well to be abandoned. The setting tool50can be connected by the upper shear joint40to the cement tool20so that the setting tool50is positioned below the cement tool20when the tool10is run down a well and cement slurry flowing out of the cement tool20can flow through the upper shear joint40to the setting tool50. The setting tool50can be used to set the bridge plug80that is connected to the setting tool50by the shear stud70. The dart90is placed in the coiled tubing before an amount of cement slurry, based on the amount of cement that is desired for the cement plug in the well, so that the dart90enters the cement tool20behind the cement slurry as it passes through the cement tool20and seats inside the cement tool20, blocking the cement tool20when the desired amount of cement slurry has been placed in the well to form the cement plug.

The cement tool20is on the upper end of the abandonment tool10and the cement tool20is used to control the flow of cement slurry from the coiled tubing so that the cement slurry initially flows into the setting tool50, that sets the bridge plug80in place in the well, using this flow of cement slurry and then the cement tool20can change the flow of the cement slurry so that the cement slurry flows on top of the set bridge plug80to form a cement plug in the well. Referring toFIGS.3and4, the cement tool20can have: an upper end22; a lower end24; an inner passage25; a circulation sleeve26; a circulation sub30; circulation ports31; a cement piston33; cement drains34; cement ports35; a check valve36; an annulus37; an outer sleeve38; a cement drain sleeve39; a dart seat95.

The upper end22of the cement tool20is connected to coiled tubing that is run down the well so that cement slurry can flown down the coiled tubing and into the cement tool20. At the upper end22of the cement tool20the circulation sub30can be provided. Below the circulation sub30, the cement drains34can be provided, with the check valve36positioned below the cement drains34.

The outer sleeve38surrounds the components of the cement tool20and forms an outer surface of the cement tool20.

The inner passage25of the cement tool20can pass axially through the cement tool20from the upper end22of the cement tool20with the inner passage25having an inlet21at the upper end22of the cement tool20. The cement piston33can be provided in the inner passage25so that cement that flows into the inner passage25from the top end22of the cement tool20through the inlet21will flow up against the cement piston33. Cement introduced by coiled tubing connected to the upper end22of the cement tool20can flow through this inner passage25in the cement tool20and up against the cement piston33.

The check valve36is provided within inner passage25of the cement tool20to stop cement flowing through the inner passage25and out the lower end24of the cement tool20. The check valve36is used so that cement slurry can be pumped into the lower end24of the cement tool20so this cement slurry can flow up the cement tool20and into the lower end of coiled tubing connected to upper end22of the cement tool20. The check valve36allows the cement slurry to be pumped into and up the cement tool20. However, when the desired amount of cement slurry has been pumped up the cement tool20and into the bottom of the coiled tubing, the check valve36will close and prevent the cement slurry from sliding back down and out of the lower end24of the cement tool20.

The cement drains34can allow cement in the inner passage25of the cement tool20to flow from the inner passage25, through the cement ports35in the walls of the cement piston33, out of the cement drains34and into an annulus37formed between the exterior of the cement drain sleeve39and the inner surface of the outer sleeve38when the cement ports35are aligned with the cement drains34. The annulus37is in fluid communication with the lower end24of the cement tool20and an outlet23at the lower end24of the cement tool20. The cement ports35are provided passing out of inner passage25and covered with the cement drain sleeve39when the cement piston33is in an upper position. When the cement slurry in the inner passage25is placing enough downward force on the cement piston33, the cement piston33can be displaced downwards to a lower position, which in turn will displace the cement ports35downwards. At the bottom position of the downwardly displaced cement piston33, the downwardly displaced cement ports35can align with cement drains34in the cement drain sleeve39; exposing the cement ports35. This will place the inner passage25of the cement tool20in fluid communication with the annulus37through the cement ports35and the cement drains34.

The circulation sub30at the upper end22of the cement tool20is used to pressurize the well to test the cement plug after it has been set in the well. The inner passage25in the cement tool20is sized to receive the dart90in a dart seat95, when the dart90is forced into the inner passage25of the cement tool20.

The circulation sub30can have circulation ports31exiting out of the inner passage25that are covered with a circulation sleeve26. However, by applying pressure to the dart90when it is seated in the dart seat95, the circulation sleeve26can be shifted or displaced downwards, exposing the circulation ports31and placing the inner passage25in fluid communication with the annulus37through the circulation ports31. With the inner passage25in fluid communication with the annulus37, the coiled tubing can be pressurized, which will pressurize the annulus37and the well above the cement plug.

Referring again toFIGS.1and2, the setting tool50is connected below the cement tool20by the upper shear joint40. This upper shear joint40can be designed to shear at a first force so that if force greater than this first force is applied to the upper shear joint40, the upper shear joint40will separate causing the setting tool50to separate from the cement tool20. In one aspect, this first force that the upper shear joint40will shear and separate at is 20,000 lbs.

Referring again toFIGS.1and2, the setting tool50is used to set the bridge plug80in place in the well so that cement slurry can be flowed on top of the set bride plug80to set in place in the well and form a cement plug. Referring toFIGS.5and6, the setting tool50can have: an upper end52; a lower end54; an inner passage55; a series of pistons including a first piston62and additional pistons64; setting sleeve66; exhaust ports67; an outer wall68; and the shear stud70.

The inner passage55can be oriented to pass generally axially through the setting tool50, from an inlet53in the upper end52of the setting tool50. A series of pistons62,64can be provided in the inner passage55of the setting tool50. These pistons62,64can create the force on the setting sleeve66to set the bridge plug80in place in the well and then to shear the shear stud70to separate the bridge plug80that has been set in the well from the setting tool50.

The upper end52of the setting tool50can be connected by the upper shear joint40to the cement tool20so that cement slurry that flows down from the cement tool20enters the inner passage55of the setting tool50at the upper end52of the setting tool50.

A first piston62is positioned in the inner passage55of the setting tool50upstream from the additional pistons64so that cement slurry that enters the inner passage55of the setting tool50from the cement tool20will flow against this first piston62. This first piston62will press against the additional pistons64in the series of pistons, displacing the first piston62and therefore the additional pistons64downwards as more and more cement slurry builds up against the first piston62.

The series of pistons62,64will be displaced downwards; engaging the setting sleeve66to press against the bridge plug80, setting the bridge plug80and then eventually shearing the shear stud70to separate the bridge plug80from the setting tool50.

Exhaust ports67can be provided in an outer wall68of the setting tool50to allow the inner passage55of the setting tool50to be in fluid communication with an annulus formed in between the outer wall68of the setting tool50and the bore of the well. These exhaust ports67can be provided in the inner passage55below where the first piston62will be in an initial top position of its stroke, but above where the first piston62will be in a bottom position of the stroke of the first piston62.

In this manner, when the first piston62is initially its top position at the top of its stroke, the exhaust ports67are fluidly separated from cement in the inner passage55of the setting tool50. However, when the first piston62is displaced downwards to its bottom position of its stroke, the exhaust ports67are uncovered by the first piston62and the inner passage55of the setting tool50is placed in fluid communication with the annulus between the setting tool50and the well bore. This will allow cement in the inner passage55of the setting tool50to flow out of the inner passage55of the setting tool50through the exhaust ports67and flow into the annulus of the well between the abandonment tool10and the well bore.

The setting tool50is connected to the bridge plug80by the shear stud70. This shear stud70can be designed to shear at a second force so that if more force than this second force is applied to this shear stud70, the shear stud70will separate causing the bridge plug80to separate from the setting tool50. In one aspect, this second force that the shear stud70will shear and separate at is 18,000 lbs.

When the setting sleeve66of the setting tool50has been displaced downward enough to set the bridge plug80in the well bore, continued downward movement of the setting sleeve66can reach this second force and shear the shear stud70; separating the bridge plug80, that is now set in the well bore, from the setting tool50.

By making the second force required to shear the shear stud70lower than the first force required to shear the upper shear joint40, if the bridge plug80gets stuck in the well before it is in its desired position (i.e. snagged on the trip down the well), the abandonment tool10can be pulled up by the coiled tubing attached to the upper end of the cement tool20and the shear stud70will shear before the upper shear joint40, allowing the setting tool50to remain with the abandonment tool10while the bridge plug80is separated while the setting tool50is pulled back up the well with the rest of the abandonment tool10instead of the setting tool50remaining with the stuck bridge plug80downhole in the well.

The bridge plug80is connected to the setting tool50the shear stud70. The bridge plug80is set in the bore of the well by the setting tool50to bridge the bore of the well so that cement slurry poured on top of the bridge plug80will remain in place on top of the bridge plug80while the cement slurry sets and forms a cement plug in the well bore.

Referring toFIG.7, the dart90can have a latching mechanism92in the form of tabs to lock the dart90into place in the cement tool20and seals94to seal the inner passage25of the cement tool20.

In operation, the dart90can be inserted in an end of coiled tubing and the upper end22of the cement tool20connected to a bottom end of the coiled tubing. Cement slurry can then be pumped up into the lower end24of the cement tool20, up through the inner passage25of the cement tool20and into the coiled tubing behind the dart90. The amount of cement slurry pumped into the coiled tubing can be based on the amount of cement needed for the cement plug. With the cement slurry in the coiled tubing and the cement plug20, the setting tool50can be attached below the cement tool20by the upper shear joint40and the bridge plug80can be attached below the setting tool50by the shear stud70to form the abandonment tool10.

The check valve36will allow cement slurry to be pumped up the inner passage25in the cement tool20, but will stop the cement slurry from falling out of the coiled tubing and the cement tool20, allowing the setting tool50to be attached to the cement tool20and preventing the cement slurry in the coiled tubing and inner passage25of the cement tool20from flowing into the inner passage55of the setting tool50.

The entire abandonment tool10, attached to the coiled tubing, can be lowered downhole in the well by the coiled tubing, until the abandonment tool10reaches the depth where the cement plug is desired. Once the abandonment tool10is in the desired position down the well, the coiled tubing can be pressurized so that the cement slurry in the bottom of the coiled tubing and the inner passage25of the cement tool20can be forced against the cement piston33.

Referring toFIG.4, when the cement tool20is attached to the coiled tubing, cement can flow down the coiled tubing and into the cement tool20, where it will flow through the inner passage25in the cement tool20until it comes into contact with the cement piston33. This cement piston33will prevent the cement slurry from flowing downwards into the rest of the abandonment tool10. However, to allow the cement slurry to start flowing through the cement tool20, the coiled tubing can be pressurized to a predetermined pressure, forcing the cement slurry in the inner passage25of the cement tool20against the cement piston33with enough force that the cement piston33will be forced downwards and, in turn, forcing the cement ports35to be displaced downwards.

When the pressurized cement slurry in the inner passage25of the cement tool20has displaced the cement piston33and therefore the cement ports35downwards enough that the cement ports35align with the cement drains34in the cement drain sleeve39. Cement slurry in the coiled and the inner passage25of the cement tool20can now flow out of the inner passage25of the cement tool20and into the annulus37formed between the exterior of the cement drain sleeve39and the inner surface of the outer sleeve38of the cement tool20. This cement slurry will flow out the cement ports35, through the annulus37and out the lower end24of the cement tool20.

Referring again toFIGS.1and2, the cement slurry that flows out of the lower end24of the cement tool20will flow through the upper shear joint40and into the upper end52of the setting tool50. Referring toFIG.8, the cement slurry inside the setting tool50will flow through the inner passage55of the setting tool50and up against the first piston62in the series of pistons62,64in the setting tool50.

When the force of the cement slurry against the first piston62reaches a predetermined force, the force of the cement against the first piston62will start stroking the setting tool50. As the first piston62continues to be displaced downwards with the force of the cement slurry against the first piston62, the first piston62will be displaced downwards from its initial top position and will in turn displace downwards the additional pistons64in the series of pistons. As the series of pistons all move downwards, the setting sleeve66will be forced against the bridge plug80, which the shear stud70will pull back on the bridge plug80causing the bridge plug80to bridge the well bore. As the setting sleeve66continues to be forced downwards by the displacement of the series of the pistons62,64in the setting tool50, the force of the setting sleeve66on the bridge plug80will eventually be greater than the second force for the shear stud70and the shear stud70will shear, separating the bridge plug80from the setting tool50.

With the bridge plug80separated from the setting tool50, the series of pistons62,64and specifically the first piston62can be displaced to its bottom position, exposing the exhaust ports67in the setting tool50and allowing cement slurry in the inner passage55of the setting tool50to flow out of the setting tool50and into the annulus formed between the setting tool50and the bore of the well. In this annulus, the cement slurry can flow downwards around the outside of the setting tool50and on top of the bridge plug80that is set in the well.

The bridge plug80can hold this cement in place in the well until it sets forming a cement plug to permanently seal the well.

Referring again toFIG.2, as the cement drains out of the abandonment tool10and the coiled tubing, the dart90will move down the coiled tubing and eventually into the cement tool20. Referring toFIG.4, the dart90can follow the cement slurry into the abandonment tool10and specifically the cement tool20until the dart seats in the inner passage25of the cement tool20in the dart seat95. With the dart90seated in the dart seat95of the cement tool20, the dart90will isolate the cement ports35from the inner passage25of the cement tool20allowing the coiled tubing to be pressurized. As the pressure in the coiled tubing builds, the force on the dart90can shift the circulation sleeve26downwards when the pressure reaches a predetermined force on the dart90. In one aspect, this predetermined force might be 900 psi.

When the circulation sleeve26has shifted far enough downwards, the circulation sleeve26can expose the circulation ports31passing through the circulation sub30. The exposed circulation ports31will place the interior passage25of the cement tool20in fluid communication with the annulus37. From this annulus37, the pressurized fluid from the coiled tubing can flow into the setting tool50and out through the exhaust ports67in the setting tool50and into the well bore.

With the interior of the coiled tubing now being in fluid communication with the annulus of the well bore surrounding the abandonment tool10, the cement plug can be tested. The coiled tubing and therefore the well bore can be pressurized to 1000 psi for 10 minutes to test the cement plug.

Once the testing is done, the pressure can be bled off, the dart90is latched into the cement tool20by the dart seat95and the latching mechanism92to prevent the dart90travelling back up the well with the pressure bleed off.

Once the pressure is bled off, the abandonment is done and the abandonment tool10can be pulled back up the well. The cement plug will eventually set, permanently sealing the well.

The abandonment tool10can be used when there are no zones in the well above where the cement plug will be installed so that the bore of the entire well can be pressurized above the installed cement plug to test it. However, if there are zones above the location where the cement plug will be placed in the well, the abandonment tool10may not be able to pressurize the well to test the newly placed cement plug without the pressure being bled off into these higher zones. Instead, a different abandonment tool provided with a packer can be used to install a cement plug below a zone in a well.

Referring toFIG.12, an abandonment tool200can be used that includes a tubing drain200used to cover the exhaust ports. The abandonment tool200can be similar to abandonment tool10, however, the tubing drain310is used to cover the exhaust ports, similar to the exhaust ports67of the abandonment tool10. After the bridge plug80is set and separated from the setting tool50, the cement in the inner passage of the setting tool20must be pressurized to place enough force on the tubing drain310before the tubing drain310will uncover the exhaust ports and allow cement to flow from the inner passage and out into the annulus of the well.

In this manner, the after the bridge plug80is set in the well, the bridge plug80can be pressure tested before the cement slurry is dumped on top of the bridge plug80to create the concrete plug. The well can be filled with water in the annulus and pressure tested from the surface. If the bridge plug80withstands the pressure testing, the water can be bled off and the cement slurry in the coiled tubing can be pressurized until it has enough force on the tubing drain310for the tubing drain310to uncover the exhaust ports. With the exhaust ports uncovered, cement slurry from the inner passage can flow out of the exhaust ports on the setting tool50and cover the bridge plug80to dry and set; creating a cement plug.

FIGS.8and9illustrate an abandonment tool100that can be used when there are multiple zones in a well that are to be sealed off with different cement plugs at different heights in the well. The abandonment tool100can be similar to abandonment tool10, however, a packer150is added to fluidly isolated a section of the well so that a cement plug that has been paced in the well by the abandonment tool100can be pressure tested without the pressurized fluid escaping into a higher zone. The abandonment tool100can be used to set the lowest cement plug first, with the packer used to isolate the portion of the well above the cement plug from a higher reservoir. When this lowest cement plug is in place, this abandonment tool100can be used to set a higher cement plug above the next highest zone. When there are no more zones above the well, the abandonment tool10shown inFIGS.1and2can be used to set the last cement plug above the highest zone.

The abandonment tool100contains similar components to abandonment tool10, in that the abandonment tool100can contain: a cement tool20; an upper shear joint40; a setting tool50; a stud70; a bridge plug80; and a dart90. However, the abandonment tool100also contains a packer150.

Referring toFIGS.10and11, the packer150can be used to isolate the well bore above the cement plug to the packer150from any zones above the packer150. The packer150can have an equalizer mandrel152; slips154; a cone156; a flow passage158and a packer element170.

The equalizer mandrel152carries the other elements of the packer150and has a flow passage158passing axially through the equalizer mandrel152.

The slips154are provided on the outside of the equalizer mandrel152with outward facing teeth155for gripping a casing wall of a well and holding the packer150and therefore the abandonment tool100in place in the well. The cone156is angled to match the back of the slips154and force the slips154outwards against the wall of the well as the cone156and packer element170move towards the slips154.

When the slips154are in place, anchoring the packer element170in place in the well, the packer element170can be energized and the packer element170expanded against the walls of the casing to isolate the annulus of the well below the packer element170from the annuls of the well above the packer element170.

In this manner, the annulus in the well between the packer element170and the cement plug installed in the well can be isolated so that this section of the well can be pressurized using the circulation sub30of the cement tool20to test the cement plug that was just installed in the well by the abandonment tool100.

In operation, the abandonment tool100can operate similar to the abandonment tool10, but the packer150can be used after the cement slurry is placed on top of the bridge plug80by the abandonment tool100to isolate the annulus of the well around the abandonment tool100and the well bore.

To use the abandonment tool100, the dart90can be inserted in an end of coiled tubing and cement slurry pumped up into the coiled tubing behind the dart90. The amount of cement slurry pumped into the coiled tubing can be based on the amount of cement needed for the cement plug. With the cement slurry in the coiled tubing, the abandonment tool100can be attached to the end of coiled tubing by attaching the upper end22of the cement tool20to the end of the coiled tubing so that the hollow inner passage of the coiled tubing is in fluid communication with the inner passage25of the cement tool20.

The packer150can be attached below the cement tool20by the upper shear joint40and the packer150attached to the upper shear joint40. The setting tool50can be attached below the packer150. The bridge plug80can be connected to the bottom of the setting tool50by the shear stud70.

The entire abandonment tool100, attached to the coiled tubing, can be lowered downhole in the well by the coiled tubing, until the abandonment tool100reaches the depth where the cement plug is desired. Referring toFIG.4, the coiled tubing can be pressurized so that the cement slurry in the bottom of the coiled tubing and in the cement tool20can be forced against the cement piston33until the cement piston33is forced downwards exposing the cement ports35.

With the cement ports35exposed, cement slurry can flow out of the inner passage25of the cement tool20and flow into the annulus37formed between the exterior of the cement drains34and the outer sleeve38of the cement tool20. This cement slurry will flow out the cement ports35, through the annulus37and out the lower end24of the cement tool20and into the packer150.

Referring again toFIGS.8and9, the cement slurry that flows out of the lower end24of the cement tool20will flow through the flow passage158in the packer150and into the setting tool50. Referring toFIG.6, the cement slurry inside the setting tool50will flow through the inner passage55of the setting tool50and up against the first piston62in the series of pistons in the setting tool50.

The cement slurry will set the bridge plug80and then the bridge plug80is sheared off from the bottom of the abandonment tool100by the shear stud70.

With the bridge plug80sheared off the bottom of the setting tool50, the series of pistons in the setting tool50can continue to be displaced downwards by the cement slurry until the exhaust ports67in the setting tool50are exposed and the cement slurry can exit the setting tool50to flow down the annulus formed between the setting tool50and the bore of the well to the top of the bridge plug80that is set in the well.

The bridge plug80can hold this cement in place in the well until it sets; forming a cement plug to permanently seal the well.

Referring again toFIG.9, as the cement drains out of the abandonment tool10and the coiled tubing, the dart90will move down the coiled tubing and eventually into the cement tool20.

Referring again toFIGS.10and11, the packer150can be used to set the packer element170against the walls of the well and isolate the annulus of the well around the lower portion of the abandonment tool100between the packer150and the packer element170and the newly placed cement plug.

With the well isolated between the packer150of the abandonment tool100and the newly placed cement plug, the pressure in the coiled tubing can force on the dart90and shift the circulation sleeve26downwards until the circulation ports31passing through the circulation sub30are exposed. The exposed circulation ports31will place the interior passage25of the cement tool20in fluid communication with the annulus37. From this annulus37, the pressurized fluid from the coiled tubing can flow into the packer150, through the packer150and into the setting tool50where the pressurized fluid can exit the setting tool50through the exhaust ports67and into the annulus of the well surrounding the bottom of the abandonment tool100.

Because the packer element170of the packer150will fluidly isolate the well between the packer150and the newly placed cement plug, preventing the pressurized fluid from travelling up the well and escaping into a higher zone, this pressurized fluid can pressurize this portion of the well and allow the newly placed cement plug to be tested. The coiled tubing and therefore the well bore between the packer150and the newly placed cement plug can be pressurized to 1000 psi for 10 minutes to test the cement plug.

Once the testing is done, the pressure can be bled off, the dart90is latched into the cement tool20by the dart seat95and the latching mechanism92to prevent the dart90travelling back up the well with the pressure bleed off.

Once the pressure is bled off, the packer150can be disengaged with the walls of the well. The abandonment tool100can be pulled back up the well and the cement plug will eventually set, permanently sealing the well. The abandonment tool100can then be used to set the next higher cement plug, of if there is only one more cement plug to be set, the abandonment tool10can be used to set the last cement plug.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.