Patent Description:
It is referred to <FIG>, where it is shown an oil and gas well bore WB, wherein a production liner or production tubing PT is installed for the purpose of transferring oil/gas to the top of the well. A screen SC is often installed outside of the production tubing PT, wherein oil/gas flows (indicated with dashed arrows) into the screen and further via holes or perforations H into the production tubing PT and further topside.

The screen is typically used in sand control applications to support the gravel pack.

The well bore WB may have more than one screen where oil/gas is flowing into the production tubing PT from different zones of the oil/gas containing formations. It is not uncommon that one or more such zones starts to produce water. In such wells, it is desired to stop or at least considerably reduce the amount of produced water, while maintaining produced oil/gas.

It is known to use straddles or straddle packers to isolate such water producing zones. One disadvantage of such straddles is that they form a restriction within the production tubing, as the inner diameter of the straddle is smaller than the inner diameter of the production tubing.

<CIT> discloses a wellbore intervention tool comprising a mandrel, an upper centralizer/sealing device, a lower centralizer/sealing device spaced apart from the upper centralizer/sealing device. Fluid may flow through the wellbore intervention tool toward the surface via fluid communication ports in the housing. It should be noted that these communication ports are located between the upper centralizer/sealing device and the lower centralizer/sealing device. During injection, the well bore between the upper centralizer/sealing device and the lower centralizer/sealing device will be filled with the injection fluid.

From NO329699 (Cannseal AS) it is known a well tool and method for in situ introduction of a fluid or treatment means into a region of an annulus, comprising: an anchoring body; a perforation device for making a hole through a pipe structure; a storage chamber for the treatment means; a driving means for the treatment means; and a flow-through connection device for injection of the treatment means. The distinctive characteristic is that the anchoring body is disposed in an anchoring module; wherein the storage chamber, the driving means and the connection device are operatively connected to an injection module; wherein the injection module can be moved axially relative to the anchoring module for moving the connection device in vicinity of the hole; and wherein the well tool comprises at least one alignment means for alignment and connection of the connection device vis-à-vis the hole.

Here, the exact location of the hole made by the perforation device is known and it is therefore easy to inject fluid into the hole.

<CIT> discloses an apparatus for withdrawing fluid from an earth formation comprising an elongated housing, a first inflatable elastomeric seal adapted to expansively fill an annular space between the housing and the wall of a wellbore. The seal includes axially spaced seal lips protruding from a surface of the seal. The seal lips circumscribe the seal and define a flow channel therebetween. The flow channel includes radially spaced filler blocks which divide the channel into radial segments. Each segment further includes a flow port. The apparatus includes means for inflating the seal. The apparatus includes valves connected to each of the flow ports for connecting selected flow ports to an intake of a fluid pump and connecting selected other flow ports to a discharge port of the pump. The pump is operable in conjunction with the valves to withdraw fluid from selected flow ports and to discharge fluid into other flow ports. The apparatus includes a fluid discharge port connected to the valves, and in hydraulic communication with the wellbore so that fluid withdrawn from the flow ports can be discharged into the wellbore, and fluid withdrawn from the wellbore can be discharged through the flow ports. The apparatus includes a pressure transducer connected to the pump intake so that a pressure of the fluid withdrawn is determined. A preferred embodiment includes a second pressure transducer connected to the pump discharge and differential pressure transducers interconnected between adjacent flow ports to measure radial differences in pressure.

One object of the invention is to inject fluid into a hole in the well bore, where the exact location of the hole is not known.

A further object of the invention is to be able to inject fluid into several holes in the well bore in one single run.

One object of the invention is to provide an improved well tool device for injecting a fluid through a hole in a well bore, where the inner diameter of the well bore is not considerably reduced after the injection process.

A further object of the invention is to provide a well tool device which may pass through a section of the well bore with relatively small inner diameter and further inject the fluid into a hole in an section of the well bore with relatively larger inner diameter, the hole being located below the small inner diameter section.

The present invention relates to a well tool device for injecting an injection fluid through a hole in a well bore, comprising:.

In one aspect, the injection fluid is a treatment fluid, a sealing fluid, a chemical heating mixture, a hydraulic fluid etc. In one aspect, the fluid is a liquid, a gel etc. In one aspect, the fluid comprises granulates dissolved in a liquid. In one aspect, the injection fluid is a molten metal, which becomes cooled down and solidifies in the hole in the well bore.

The hole in the well bore may be one hole or several holes. The hole may be a hole of a screen in the well bore, one or a plurality of perforation holes in the well bore, cracks in a cemented area of a well bore, cracks or apertures in the formation etc. The may also be an interval or length of holes, such as a predrilled base pipe or a perforated interval of a well bore.

The hole may also refer to leaks in the well pipe, for example leaks in threaded joints of casing or production tubing.

In one aspect, the fluid in the control fluid system is a control fluid, for example a hydraulic fluid. Hence, the first fluid compartment may be referred to as a control fluid compartment.

In one aspect, the expandable sleeve is in a radially expanded state when the first fluid compartment is filled with control fluid and wherein the expandable sleeve is in a radially retracted state when the first fluid compartment is emptied of control fluid.

In one aspect, a second fluid compartment is defined radially outside of the expandable sleeve and axially between the first expanding device and the second expanding device when the first expanding device and the second expanding device are in their radially expanded states, wherein the second fluid compartment is configured to be supplied with injection fluid from the injection fluid system.

The second fluid compartment may be referred to as an injection fluid compartment.

In one aspect, the second fluid compartment is defined radially outside of the expandable sleeve and radially inside of the well bore.

In one aspect, the injection fluid line is provided as a bore in the mandrel, wherein a first end of the nozzle element is movably connected to the injection fluid line.

In one aspect, the first end of the nozzle element is displaceably arranged within the injection fluid line. In one aspect, the first end of the nozzle element is sealingly engaged within the injection fluid line.

In one aspect, the nozzle element is secured to the expandable sleeve.

In one aspect, a second end of the nozzle element is secured to the expandable sleeve. The outlet is also provided in the second end of the nozzle element.

In one aspect, the nozzle element will be pulled a distance out from the injection fluid line when the expandable sleeve is brought to its expanded state and the nozzle element will be pushed into the injection fluid line when the expandable sleeve is brought to its retracted state. Hence, movement of the nozzle element will either shorten or lengthen the fluid path of the injection fluid.

In one aspect, the injection fluid system comprises an injection fluid supply unit. The injection fluid supply unit may comprise a fluid source and a pump for pumping the injection fluid from the fluid source and into the injection fluid line.

Alternatively, the injection fluid supply unit is located topside, and the well tool device is connected to the fluid supply unit via fluid lines.

In one aspect, the control fluid system comprises a control fluid supply unit. The control fluid supply unit may comprise a fluid source and a pump for controlling the fluid pressure in the first fluid compartment.

In one aspect, the control fluid system comprises a control fluid sensor for measuring a parameter representative of the fluid pressure of the control fluid in the first fluid compartment.

In one aspect, the injection fluid system comprises an injection fluid sensor for measuring a parameter representative of the fluid pressure radially outside of the sleeve.

In one aspect, the injection fluid sensor and the control fluid sensor are connected to a control system configured to control the injection fluid supply unit and the control fluid supply unit.

In one aspect, the first expander and/or the second expander comprises:.

wherein the expander ring is radially expanded by axial movement of the actuator in a first direction and wherein the expander ring is radially retracted by axial movement of the actuator in a second direction.

In one aspect, the first direction is a direction towards the middle of the expandable sleeve. Hence, the actuator of the first expander and the actuator of the second expander are moved towards each other for radially expanding the expander rings.

In one aspect, the second direction is a direction away from the middle of the expandable sleeve. Hence, the actuator of the first expander and the actuator of the second expander are moved away from each other for radially retracting the expander rings.

In one aspect, the actuator is moved towards a wedge-shaped surface of the mandrel during its movement in the first direction and/or wherein the actuator comprises a wedge-shaped surface.

In one aspect, the expander ring comprises a plurality of thimble-shaped elements inserted into each other, and an elastic ring/spring inserted into an opening of each of the plurality of thimble-shaped elements.

In one aspect, the actuator comprises a piston element, wherein the mandrel comprises a piston compartment in which the piston element is sealingly engaged; wherein the well tool device comprises an expander fluid system for controlling the fluid supplied to the piston compartment.

In one aspect, the actuator comprises a connection interface to which an end of the expandable sleeve is secured.

Alternatively, the ends of the expandable sleeve are secured to the mandrel.

In one aspect, the central area of the expandable sleeve comprises guiding grooves in its outwardly facing surface for guiding the injection fluid in the axial direction.

The first and second side areas do not comprise such guiding grooves, as such guiding grooves will reduce the sealing efficiency when pressed towards the well bore by the first and second expanders.

The present invention also relates to a method for injecting an injection fluid through a hole in a well bore, comprising the steps of:.

In one aspect, the step of injecting is performed before the step of expanding.

In one aspect, the step of expanding the expandable sleeve comprises:.

In one aspect, the method comprises following steps prior to the step of injecting the injection fluid:.

Hence, if a hole is present in the well bore, the reduced volume caused by the expanding sleeve will not have caused an increase in pressure. However, if a hole is not present, the reduced volume caused by the expanding sleeve will have caused an increased pressure.

In one aspect, the above well tool device is deployed by e-line.

As the well tool device is deployed via e-line, coiled tubing and drill pipe can be avoided, thereby reducing the costs of the operation. As us known, e-line is corresponding to wireline with the addition of a signal conductor for providing communication between the well tool device and topside.

The present invention also relates to a well tool device for receiving a fluid from a confined section of a well bore, wherein the well tool device comprises:.

In one aspect, also the above well tool device is deployed by e-line.

In one aspect, the well tool device further comprises:.

In one aspect, the confined section is defined as the area of the well bore between the first side and the second side of the expandable sleeve in the expanded state.

According to the invention, it is possible to seal off a water zones in an efficient way, and hence avoid the considerably reduced inner diameter of a straddle.

According to the above, the amount of injection fluid present in the wellbore after the injection process is may be considerably reduced. Hence, it is still possible to retrieve the tool from the wellbore after the injection fluid has solidified.

Embodiments of the present invention will now be described in detail with reference to the enclosed drawings, wherein:.

It is now referred to <FIG> and <FIG>, where a well tool device <NUM> for injecting an injection fluid through a hole H in a well bore WB is shown. First, the well tool device <NUM> will be described in detail, and then, the operation of the well tool device will be described in detail.

The well tool device <NUM> comprises a mandrel <NUM>, indicated in <FIG> with its nose or lower end 10a and its upper end 10b. It should be noted that only parts of the upper end 10b are shown in comprises the drawings.

The well tool device <NUM> comprises an expandable sleeve <NUM> provided circumferentially outside of the mandrel <NUM>, and axially between the lower end 10a and upper end 10b. The central axial direction or central longitudinal direction is indicated as a dashed axis I-I in <FIG>. The expandable sleeve <NUM> is also indicated with its lower side 15a and its upper side 15b.

It should be noted that terms "upper", "above" etc. should be interpreted as "closer to the topside of the well", while the terms "lower", "below", etc. should be interpreted as "closer to the bottom of the well". It should further be noted that even though the well tool device in many situations will be oriented vertically, with the upper end 10b provided above the lower end 10a, the well tool device <NUM> may also be used in inclining and/or horizontal well bores WB.

Between the lower end 15a and the upper end 15b, an outlet 51a is provided in the expandable sleeve <NUM>. It is further indicated a pressure sensor <NUM> for measuring a parameter representative of the pressure outside of the expandable sleeve <NUM>.

It is now referred to <FIG>. Here it is shown that the well tool device <NUM> comprises a first expander <NUM> and a second expander <NUM>. The first expander <NUM> is configured to move the lower side 15a of the expandable sleeve <NUM> between a radially retracted state (<FIG>) and a radially expanded state (<FIG>). The second expander <NUM> is configured to move the upper side 15b of the expandable sleeve <NUM> between a radially retracted state and a radially expanded state.

In <FIG>, it is also shown that the well tool device <NUM> comprises a first fluid compartment <NUM> radially between the expandable sleeve <NUM> and the mandrel <NUM>.

The well tool device <NUM> further comprises an injection fluid system <NUM>, a control fluid system <NUM>, an expander fluid system <NUM> and a control system CS, as indicated in <FIG>. As described above, only parts of the upper end 10b of the mandrel <NUM> is shown in the drawings. The upper end 10b of the mandrel <NUM> is connected to, or is forming, a housing <NUM> (<FIG>) with a compartment <NUM>, in which the injection fluid system <NUM>, the control fluid system <NUM>, the expander fluid system <NUM> and the control system CS are provided. Hence, the compartment <NUM> is forming a fluid system compartment <NUM>. In the upper end of the housing <NUM>, a connection interface 14a is shown. The connection interface 14a may be a wireline interface.

It should be noted that the fluid system compartment <NUM> in <FIG> is considerably larger than indicated in <FIG>.

The well tool device <NUM> is configured to be in the following main states:.

As will be apparent from the description below, the control fluid system <NUM> is used to supply control fluid to and to retract fluid from the first compartment <NUM>, while the expander fluid system <NUM> is used to expand and retract the first expander <NUM> and the second expander <NUM>.

The injection fluid system <NUM> will typically be used in the first and second set states, but not in the run state.

During retraction, i.e. when bringing the well tool device <NUM> from the second set state and back to the run state again, the retracting state is used to avoid that injection fluid is flowing back to the second compartment <NUM> when the first compartment <NUM> is emptied. If the first expander <NUM> and the second expander <NUM> were expanded, the emptying of the first compartment <NUM> would produce a vacuum in the second compartment <NUM>, which could cause injection fluid to flow back. Hence, the first expander <NUM> and the second expander <NUM> are radially retracted, allowing fluid from the well bore WB to flow to the second compartment <NUM> during emptying of the first compartment <NUM>.

It is now referred to <FIG>. Here, it is shown that a second fluid compartment <NUM> is defined radially outside of the expandable sleeve <NUM> and axially between the first expanding device <NUM> and the second expanding device <NUM> when the first expanding device <NUM> and the second expanding device <NUM> are in their radially expanded states towards the wellbore. The second fluid compartment <NUM> is defined radially outside of the expandable sleeve <NUM> and radially inside of the well bore WB. This compartment has a relatively large volume when the centre of the expandable sleeve is radially retracted (<FIG>) and has a relatively low volume when the centre of the sleeve <NUM> is radially expanded. This second fluid compartment <NUM> is configured to be supplied with injection fluid from the injection fluid system <NUM>.

The second fluid compartment <NUM> may be referred to as an injection fluid compartment <NUM>.

It is referred to <FIG>, where it is shown that the injection fluid system <NUM> comprises an injection fluid supply unit <NUM> for supplying fluid to the injection fluid outlet 51a via an injection fluid line <NUM> and a nozzle element <NUM>. The nozzle element <NUM> is a rigid element, for example made of metal, plastics etc..

The injection fluid supply unit <NUM> may comprise a fluid source and a pump for pumping the injection fluid from the fluid source and into the injection fluid line <NUM>. It should be noted that the injection fluid supply unit <NUM> may comprise a heater for heating the injection fluid before the injection process. The injection fluid supply unit <NUM> may also comprise two or more fluid sources, which are mixed before the injection process. The injection fluid supply unit <NUM> may also inject two different injection fluids, i.e. the process starts by injecting a first fluid and then a second fluid is injected.

The injection fluid line <NUM> is provided as a bore within the mandrel <NUM>. At the location of the outlet 51a, a section 53a of the injection fluid line <NUM> is oriented in a radial direction. Here, a first, inner end of the nozzle element <NUM> is displaceably and sealingly arranged within the section 53a of the injection fluid line <NUM>. The second, outer end of the nozzle element <NUM> is secured to the expandable sleeve <NUM>. The outlet 51a is provided in this second, outer end of the nozzle element <NUM>.

When comparing <FIG> with <FIG>, it can be seen that the expandable sleeve <NUM> is radially expanded with respect to the mandrel <NUM>. Here, the nozzle element <NUM> will be pulled a distance out from the section 53a of the injection fluid line <NUM> when the expandable sleeve <NUM> is brought to its expanded state and the nozzle element <NUM> will be pushed into the injection fluid line <NUM> when the expandable sleeve <NUM> is brought to its retracted state. Hence, movement of the nozzle element <NUM> will either shorten or lengthen the fluid path of the injection fluid.

The control fluid system <NUM> is controlling the fluid pressure within the first fluid compartment <NUM>, i.e. the control fluid system <NUM> is supplying fluid into and is retracting fluid out from the compartment <NUM>.

It is referred to <FIG>, where it is shown that the control fluid system <NUM> comprises a control fluid supply unit <NUM> for supplying fluid to and from the control fluid outlet 61a via a control fluid line <NUM>. The control fluid outlet 61a is provided in the end of the control fluid line <NUM> on the outer surface of the mandrel <NUM> and inside of the expandable sleeve <NUM>.

The control fluid supply unit <NUM> may comprise a control fluid source and a pump for pumping the control fluid between the control fluid source and the first fluid compartment <NUM>. Hence, the control fluid is used to expand and retract the expandable sleeve <NUM>, as will be described in detail further below.

The first expander <NUM> and the second expander <NUM>.

The first expander <NUM> will now be described with reference to <FIG>. The first expander <NUM> comprises an expander ring <NUM> provided circumferentially outside the mandrel <NUM> and an actuator <NUM> axially displaceable relative to the mandrel <NUM>.

The expander ring <NUM> may comprise a torus-shaped spiral spring, or it may comprise several torus-shaped spiral springs located inside each other. In the present embodiment, the expander ring <NUM> comprises a plurality of thimble-shaped elements inserted into each other to form a torus. A torus-shaped ring made of thimble-shaped elements are known from <CIT>. Consequently, as this expander ring per se is considered prior art, it will not be described further in detail herein. In the above prior art document, it is described that a wire can inserted through respective openings of the thimble-shaped elements and hence to join the elements together. In the expander ring <NUM>, a spiral spring may be inserted though the respective openings of the thimble-shaped elements. This spiral spring will help bringing the expander <NUM> from the expanded state to the retracted state.

The actuator <NUM> comprises a piston element <NUM> sealingly engaged within a piston compartment 13a of the mandrel <NUM>. Recesses 33a for O-rings are provided on the piston element <NUM>. As shown, a fluid line <NUM> is provided through the mandrel <NUM> between the piston compartment 13a and the expander fluid system <NUM>, which will be described below.

The expander ring <NUM> is located between a wedge-shaped or inclining surface 12a of the mandrel <NUM> and a wedge-shaped or inclined surface <NUM> of the piston element <NUM>. The two surfaces 12a, <NUM> together form a V-shape, causing the expander ring <NUM> to be pushed outwardly when the wedge-shaped surface <NUM> of the piston element <NUM> is pushed towards the wedge-shaped surface 12a of the mandrel <NUM>, as shown in <FIG>. The expanding expander ring <NUM> will expand the first side 15a of the expandable sleeve <NUM> in a radial direction. When comparing <FIG>, it is apparent that there is more fluid in the piston compartment 13a in the expanded state (<FIG>) than in the retracted state (<FIG>).

The actuator <NUM> further comprises a connection interface <NUM> to which a lower end 15c of the expandable sleeve <NUM> is secured and sealingly engaged. Hence, in this embodiment, the O-rings of the actuator <NUM> also form a seal for the first fluid compartment <NUM>.

The second expander <NUM> is identical to the first expander <NUM>, and the parts 4x of the second expander <NUM> (shown in <FIG>) have the same reference number as their counterpart 3x of the first expander <NUM>, where x indicates a number and/or a number plus a character. The second expander <NUM> will therefore not be described further in detail herein. One exception is the inclining surface of the mandrel, which has reference number 12a for the first expander <NUM> and reference number 12b for the second expander <NUM>. A second exception is the end of the expandable sleeve, which has reference number 15c for the first expander <NUM> and reference number 15d for the second expander <NUM>. A third exception is piston compartment, which has reference number 13a for the first expander <NUM> and reference number 13b for the second expander <NUM>.

In the present embodiment, the same expander fluid line <NUM> supplies expander fluid to both piston compartments 13a, 13b.

It should be noted that in the present embodiment, the piston elements <NUM>, <NUM> both moves towards a middle M of the expandable sleeve <NUM> when moving from their retracted state to their expanded state, i.e. they move towards each other as indicated by arrows D1 shown in <FIG>. One effect of this is less tension in the expandable sleeve <NUM>, making it easier to radially expand the expandable sleeve <NUM>.

The piston elements <NUM>, <NUM> both moves away from the middle M of the expandable sleeve <NUM> when moving from their expanded state to their retracted state, i.e. they move away from each other as indicated by arrows D2 shown in <FIG>. Here, the expandable sleeve <NUM> becomes tensioned again, making it easier to radially retract the expandable sleeve <NUM>.

It is referred to <FIG>, where it is shown that the expander fluid system <NUM> comprises an expander fluid supply unit <NUM> for supplying fluid to the piston compartments 13a, 13b via the expander fluid line <NUM>.

The expander fluid supply unit <NUM> may comprise a fluid source and a pump for pumping the expander fluid between the fluid source and the respective piston compartments 13a, 13b.

The expander fluid line <NUM> is provided as a bore within the mandrel <NUM>.

The expander fluid system <NUM> will typically be considered as a hydraulic fluid system where hydraulic fluid is used as the expander fluid.

It is now referred to <FIG> again, where two sensors are shown, the first being the above-mentioned pressure sensor <NUM> for measuring a parameter representative of the pressure outside of the expandable sleeve <NUM>. In addition, a second pressure sensor <NUM> is shown, for measuring a parameter representative of the pressure in the first compartment <NUM> (i.e. inside of the sleeve <NUM>).

The pressure sensors <NUM>, <NUM> are connected to the control system CS as indicated by dashed lines. The control system CS is controlling the pumps of the units <NUM>, <NUM>, <NUM> based on signals from the sensors <NUM>, <NUM> and based on predetermined control parameters. It should be noted that the control system CS may be connected to a topside user interface, to manually control at least some of the operations of the well tool device <NUM>.

In the above embodiment, the fluid supply units <NUM>, <NUM>, <NUM> are all located within the well tool device <NUM>. At least parts of the control system CS may be located within the well tool device <NUM>, where the user interface is connected to the control system CS via e-line.

The operation of the well tool device <NUM> will now be described with reference to <FIG>. The purpose of the operation is here to seal off a water-producing screen SC by injecting a sealing fluid into the hole H of the screen SC. The sealing fluid is here an epoxy, which will harden after injection into the hole H.

In step a) in <FIG>, the well tool device <NUM> is in the run state. The exact location of the hole H may or may not be known accurately, for the present well tool device <NUM> to work, it is sufficient that the hole H is located somewhere between the first expander <NUM> and the second expander <NUM> when initiating the setting of the well tool device <NUM>.

Initially, a hole detection process is performed.

In step b) in <FIG>, the first expander <NUM> is expanded for moving a first side 15a of the expandable sleeve <NUM> into contact with the well bore WB on a first side of the hole H and the second expander <NUM> are expanded for moving a second side 15a of the expandable sleeve <NUM> into contact with the well bore WB on a second side of the hole H. This is done by controlling the expander fluid system <NUM> to pump fluid into the piston compartments 13a, 13b. As described above, this will move the piston elements <NUM>, <NUM> in the direction D1, i.e. towards the middle M of the expandable sleeve <NUM>.

In step c) and d) in <FIG>, the initial pressure radially outside of the expandable sleeve <NUM> is measured by means of the pressure sensor <NUM>. The expandable sleeve <NUM> is now expanded towards the well bore WB. This is done by controlling the control fluid system <NUM> to pump fluid into the first compartment <NUM>. <FIG> shows a partially expanded sleeve <NUM>. <FIG> shows an entirely expanded sleeve <NUM>.

A post expanding pressure radially outside of the expandable sleeve <NUM> (i.e. the pressure after expansion of the sleeve <NUM>) is measured by means of the pressure sensor <NUM>.

If a hole H is present in the well bore WB axially between the first and second expander <NUM>, <NUM>, the post expanding pressure is expected to be approximately equal to the initial pressure, as the decreased volume caused by the expansion of the expandable sleeve <NUM> is small compared with the total volume (including the volume on the opposite side of the hole). However, if the difference between the post expanding pressure and the initial pressure is higher than a predetermined threshold value, i.e. a substantial pressure increase is measured by the pressure sensor <NUM>, then it is assumed that no hole is present.

If it is confirmed that no hole H is detected, then the well tool device can be configured to its run state again, and then axially moved to a different position and the hole detection process is performed again in this different position.

If it is confirmed that a hole H is detected, the injection process may start.

In step e), <FIG>, the expandable sleeve <NUM> is at least partially retracted by reducing the amount of fluid in the first compartment <NUM>, hence increasing the volume of the second compartment <NUM>.

In step f), <FIG>, the injection fluid <NUM> is injected through the outlet port 51b by means of the injection fluid system <NUM>. As shown, the volume in the first compartment <NUM> inside the sleeve <NUM> has been reduced, while the volume in the second compartment <NUM> outside of the sleeve has been increased, allowing a relatively large amount of injection fluid in the second compartment <NUM>. It is assumed that this will increase the efficiency of injecting fluid into the hole H, as the exact location of the hole H is not known.

It is also shown in <FIG> that the injection fluid <NUM> has entered the hole H and has partially filled the rear side of the well bore WB or screen SC.

In step g), <FIG>, the injection of the injection fluid <NUM> by the injection fluid system <NUM> has stopped. Now, the control fluid system <NUM> is used to increase the volume in the first compartment <NUM> inside the sleeve <NUM>, causing the volume in the second compartment <NUM> outside of the sleeve to decrease. Remnants of injection fluid <NUM> in the second compartment <NUM> will now be pressed from the second compartment <NUM> outside of the sleeve and into the hole H.

It is shown that a central area 15c of the expandable sleeve <NUM> defined as the area between, but not including the side areas 15a, 15b expanded by the first and second expanders <NUM>, <NUM>, comprises guiding grooves <NUM> in its outwardly facing surface. The purpose of these grooves <NUM> is to guide injection fluid in the axial direction towards the hole H during step g). It should be noted that the first and second side areas 15a, 15b do not comprise such guiding grooves <NUM>, as such guiding grooves will reduce the sealing efficiency when pressed towards the well bore by the first and second expanders <NUM>, <NUM>.

Step h), <FIG>, is a continuation of step g), wherein the control fluid system <NUM> is used to increase the volume in the first compartment <NUM> inside the sleeve <NUM> further out into contact with the well bore WB. Here, the volume in the second compartment <NUM> outside of the sleeve <NUM> will be zero, or close to zero.

The well tool device <NUM> may be held in the state shown in <FIG>, for example to allow the injection fluid to solidify, to harden etc..

In step i), <FIG>, the first and second expanders <NUM>, <NUM> are radially retracted by controlling the expander fluid system <NUM> to pump fluid out from the piston compartments 13a, 13b and hence moving the piston elements <NUM>, <NUM> in the direction D2 as shown in <FIG>, i.e. away from the middle M.

As described above, this is done to avoid that injection fluid is sucked out from the hole H again due to a vacuum being created by emptying the first compartment <NUM> if the first and second expanders <NUM>, <NUM> were not radially retracted.

Then, also in step i), first compartment <NUM> will be emptied.

In step j), <FIG>, the well tool device <NUM> is in run state again and can be moved to a new hole at a different location in the well. As shown, the inner diameter of the well bore is as before the injection process started.

Above, the well tool device <NUM> was used to inject a sealing fluid, epoxy, into the hole H in the screen SC.

In a further example, the injection fluid may be a heat generation mixture which will generate heat when ignited. One example of such a heat generation mixture is thermite, which may be used during a plugging and abandonment operation, or which may be used to remove a well element by melting it. The heat generation mixture may be in the form of powder or granules mixed into a fluid.

In a further example, the injection fluid may be a molten metal. The metal may be a metal with low melting point (to avoid that the expandable sleeve becomes damaged by the molten metal) and/or it may be a metal which expands during cooling. One such metal is bismuth (Bi).

In a further example, the injection fluid may be a sealing fluid used to seal a threaded connection, for example a threaded connection between two tubing string sections. Occasionally, such threaded connections may leak, which is not desirable.

In a further example, the injection fluid is an actuation fluid (which may be a hydraulic fluid or any other type of suitable fluid) for local pressure actuation of well equipment, such as production regulating valves or other smart production regulating devices. Such well equipment is typically controlled via hydraulic fluid lines from topside. If one piece of equipment or a section of such equipment is malfunctioning, then this typically will affect the complete control system. By using the present tool, the malfunctioning piece of equipment may be locked in its position and sealed off with for example epoxy. In many wells, this will restore the function of the remaining control system.

In a further example, the injection fluid is an actuating fluid for actuating a production packer. Some production packers are actuated by applying a pressure to the inside of the well bore (here typically the production tubing). In some examples of prior art, the entire well bore is pressurized to achieve this. By using the well tool device <NUM>, only the area necessary for the production packer to be actuated is pressurized.

In a further example, the injection fluid is epoxy. Here, the well tool device <NUM> is used to fill an open hole packer with epoxy. It is also possible to use the well tool device <NUM> to fill/expand a swell packer with epoxy.

In a further example, the injection fluid is a sealing fluid for sealing perforation channels in a cemented production tubing in which the water cut is high, to reduce the water production from the well. The injection fluid may seal perforations and cracks in the cement and may seal perforations and cracks in the formation outside of the cement.

It is now referred to <FIG>. Here, the purpose is not to inject a fluid into a hole of the well bore. Instead, the purpose is to bring a treatment fluid <NUM> into contact with a confined section S of a well bore WB. The confined section S is defined as the area of the well bore WB between the first side 15a and the second side 15b of the expandable sleeve <NUM> in the expanded state. The confined section S may comprise a restriction R. As shown, both sides of the restriction, and the restriction itself, may be threated as long as the inner diameter of the restriction allows the lower expander <NUM> of the well tool device <NUM> to be run past the restriction.

Here, the confined section S may comprise a sliding sleeve which has been stuck due to scaling, where the treatment fluid is an acid or other type of scale-removing fluid. After the treatment, the well tool device can be retrieved, and the sliding sleeve may be operated again.

It should be noted that in this last example, the control fluid system <NUM> for controlling fluid supply to and from the first fluid compartment <NUM> are not essential, only the first expander <NUM> and the lower expander <NUM> are needed to restrict the area of the well bore from which fluid should be received from. Hence, also the nozzle element allowing radial expansion of the fluid line is not essential.

It should be noted that the well tool device of <FIG> may also work if the restriction R of <FIG> is present in the area of the hole H in <FIG>.

Typically, this is an operation which today requires coiled tubing or drill pipe. According to the present well tool device, this may be performed by e-line.

It is now referred to <FIG>. Here, the well tool device <NUM> can be used to receive a fluid <NUM> from a confined section S of a well bore WB. In <FIG>, the confined section S is a perforated section of the well bore (typically production tubing), where fluids are allowed to enter the well bore from the formation. The above-described fluid supply unit may here form a fluid receiving unit <NUM> for receiving fluid, alternatively, the fluid may be transported to surface via fluid lines. The analysis may be performed topside. Alternatively, the well tool device <NUM> itself may comprise sensors for measuring desired parameters, such as fluid constituents (weight percentage or volume percentage) such as water cut, H2S content etc..

It should be noted that in <FIG>, the control fluid system <NUM> for controlling fluid supply to and from the first fluid compartment <NUM> are not essential, only the first expander <NUM> and the lower expander <NUM> are needed to restrict the confined section S. Hence, also the nozzle element allowing radial expansion of the fluid line is not essential.

It is now referred to <FIG>. This embodiment of the well tool device <NUM> is almost identical to the above embodiments, the one difference being the length of the well tool device being shorter. It should be noted that only one of the fluid lines are indicated in the drawing.

In the embodiments described above, parts of the fluid systems <NUM>, <NUM>, <NUM> are located in the fluid system compartment <NUM>. In an alternative embodiment, the injection fluid supply unit <NUM>, the control fluid supply unit <NUM> and/or the expander fluid supply unit <NUM> may be located topside wherein their respective fluid lines <NUM>, <NUM>, <NUM> are extending between the well tool device and the topside.

In the embodiments described above, the nozzle element <NUM> is pushed radially into and out from the radial section 53a of the injection fluid line <NUM>. In an alternative embodiment, the nozzle element <NUM> itself is a flexible element connected between the injection fluid line <NUM> in the mandrel <NUM> and the expandable sleeve <NUM>, for example a bellows, a flexible plastic tube etc..

In the embodiments described above, the injection fluid system <NUM> will typically be used in the first and second set states, but not in the run state. However, in some situations, it may be desired to flush away or clean excessive injection fluid from the outside of the expandable sleeve <NUM>. In this case, the first and second expanders may be retracted or partially retracted after the injection process has finished. Then, a flushing or cleaning fluid may be flushed through the injection fluid line <NUM> and the nozzle element <NUM> to the outside of the expandable sleeve <NUM>. In this state, the hole in the well bore has been filled by the initial injection fluid, and the flushing/cleaning fluid will typically not enter the hole H.

Claim 1:
Well tool device (<NUM>) for injecting an injection fluid (<NUM>) through a hole (H) in a well bore (WB), wherein the well tool device (<NUM>) comprises:
- a mandrel (<NUM>);
- an expandable sleeve (<NUM>) provided circumferentially outside of the mandrel (<NUM>);
characterized in that the well tool device (<NUM>) further comprises:
- a first expander (<NUM>) for moving a first side (15a) of the expandable sleeve (<NUM>) between a radially retracted state and a radially expanded state;
- a second expander (<NUM>) for moving a second side (15b) of the expandable sleeve (<NUM>) between a radially retracted state and a radially expanded state;
- an injection fluid system (<NUM>) comprising an injection fluid line (<NUM>) and a nozzle element (<NUM>), wherein the nozzle element (<NUM>) is providing fluid communication between the injection fluid line (<NUM>) and an outlet (51a) provided on the outside of the expandable sleeve (<NUM>);
- a control fluid system (<NUM>) for controlling the fluid pressure in a first fluid compartment (<NUM>) provided radially between the expandable sleeve (<NUM>) and the mandrel (<NUM>).