Patent Application
20090260817
The present invention broadly relates to well cementing. More particularly the invention relates to servicing apparatus for completing downhole wells from a subterranean reservoir, such as for instance an oil and gas reservoir or a water reservoir.
After a well has been drilled, the conventional practice in the oil industry consists in filing the well with a metal casing. The casing is lowered down the hole and cement is pumped inside the casing and returns through the annulus where it is allowed to set. Lining the well aims at a dual purpose: preventing the bore walls from collapsing and isolating the various geological strata and thus, avoiding exchange of fluids between them. Furthermore, it can be useful also for different reasons to fill the well with a permeable screen (meaning not impermeable as metal casing) as perforated tubular, tubular with other openings, slotted liner or expandable screen. Use of such permeable screen aims for example in allowing the oil to pass the bore walls from production zones into the hole by retaining debris. However, when a permeable screen is present downhole, there is no simple way to cement the annulus. Effectively, conventional technique where cement is pumped inside the permeable screen to be returned through the annulus will not work, because the cement will pass through the first openings of the permeable screen and no cement will be pumped at the other extremity. Further cement would fill the inside of the permeable screen and extra drilling, which is costly and time consuming, will be required after the cement is set. Even this conventional technique does not apply to other types of fluids and there is no simple way to make a treatment to a zone of the borehole behind a permeable screen.
Hence, it remains the need for a method of cementing the annulus or a method of treatment of the earth formation, behind a perforated casing, a slotted liner or an expandable and permeable screen.
According to one aspect of the invention, the invention provides a method of treatment of a near zone and/or a far zone of a well comprising a wellbore and wherein the method comprises the steps of: (i) placing inside the wellbore a tube which is permeable to a material, so that the tube forms an annulus with the wellbore, the first zone being inside the annulus and the second zone being beyond the wellbore; (ii) placing inside the tube a setting section surrounded by a sleeve, the sleeve being expandable and impermeable to the material; (iii) inflating the sleeve so that the sleeve is in contact with the tube, ensuring for a first zone of the tube impermeability to the material, but leaving a second zone permeable to the material; (iv) pumping a treatment fluid to the zones, the treatment fluid passing through the second zone still permeable to the material; and (v) treating the near zone and/or the far zone with the treatment fluid.
According to a second aspect of the invention, the invention provides a method to consolidate a near zone and/or a far zone of a well comprising a wellbore and wherein the method comprises the steps of: (i) placing inside the wellbore a tube which is permeable to a material, so that the tube forms an annulus with the wellbore, the first zone being inside the annulus and the second zone being beyond the wellbore; (ii) placing inside the tube a setting section surrounded by a sleeve, the sleeve being expandable and impermeable to the material; (iii) inflating the sleeve so that the sleeve is in contact with the tube, ensuring for a first zone of the tube impermeability to the material, but leaving a second zone permeable to the material; (iv) pumping a treatment fluid to the zones, the treatment fluid passing through the second zone still permeable to the material; and (v) treating the near zone and/or the far zone with the treatment fluid.
According to a third aspect of the invention, the invention provides a method to isolate a near zone and/or a far zone of a well comprising a wellbore and wherein the method comprises the steps of: (i) placing inside the wellbore a tube which is permeable to a material, so that the tube forms an annulus with the wellbore, the first zone being inside the annulus and the second zone being beyond the wellbore; (ii) placing inside the tube a setting section surrounded by a sleeve, the sleeve being expandable and impermeable to the material; (iii) inflating the sleeve so that the sleeve is in contact with the tube, ensuring for a first zone of the tube impermeability to the material, but leaving a second zone permeable to the material; (iv) pumping a treatment fluid to the zones, the treatment fluid passing through the second zone still permeable to the material; and (v) treating the near zone and/or the far zone with the treatment fluid.
There are possible uses of the methods, in one case, the second zone is a void making communication with the zones: this configuration can appear when the zones is at the bottom of the well and when the tube ends leaving direct communication between the inside of the well and the earth formation; this configuration can also appear in the well when an unconsolidated zone is in direct communication with the earth formation. In a second case, the second zone is an element permeable to the material, for example the permeable element can be the tube: this configuration can appear when a part the tube is made impermeable and another part of the same tube is used to ensure flow of the treatment fluid from the inside of the well to the annulus and to the zones.
Preferably, the method according to the invention further comprises the step of deflating the sleeve so that the sleeve is no more in contact with the tube near the zones; also preferably, the invention further comprises the step of removing the setting section surrounded by the sleeve from the zones. The inside of the tube is left unchanged after the zones have been treated or consolidated or isolated.
In a first embodiment, the step of placing the setting section surrounded by a sleeve is done by placing first the sleeve inside the tube and after the setting section inside the sleeve. The sleeve can be lowered in the well first, positioned near the zones; and after the setting section can be positioned inside the sleeve so the step of inflating can begin. In a second embodiment, the step of placing the setting section surrounded by a sleeve is done by placing into the tube the setting section already surrounded by the sleeve. The sleeve can be positioned on the setting section before to be positioned near the zones. Preferably, in a configuration where the well has a longitudinal axis (A), the step of placing the setting section surrounded by a sleeve further comprises the step of deploying the sleeve longitudinally to the axis (A). The sleeve is arranged like a fan on the setting section and can be deployed on its length to cover the part of the tube or all the tube to be impermeabilized.
In one example of realization, the setting section has an upper part and a lower part, the setting section being connected to a delivery section going on surface at the upper part, and being in communication with the inside of the well at the lower part through a delivery opening, and the step of pumping a treatment fluid to the zones is done by: (i) delivering the treatment fluid inside of the well through the delivery section, through the setting section and through the delivery opening; (ii) filling the inside of the well located downhole from the lower part with the treatment fluid, until the treatment fluid passes into the annulus via the second zone still permeable to the material; and (iii) rising said treatment fluid into the zones.
In a second example of realization, the setting section has an upper part and a lower part, the setting section being connected to a delivery section going on surface at the upper part, and being in communication with the inside of the well at the lower part through a delivery opening, and wherein the step of pumping a treatment fluid to the zones is done by: (i) delivering a first fluid inside of the well through the delivery section, through the setting section and through the delivery opening; (ii) filling the inside of the well located downhole from the lower part with the first fluid, until the first fluid realized a plug inside of the well; (iii) delivering the treatment fluid inside of the well through the delivery section, through the setting section and through the delivery opening; (iv) filling the inside of the well located downhole from the lower part and uphole from the plug, with the treatment fluid, until the treatment fluid passes into the annulus via the second zone still permeable to the material; and (v) rising the treatment fluid into the zones. The first fluid can be a viscous bentonite fluid, a delayed-gel fluid, or a reactive fluids system.
In a third example of realization, the setting section has an upper part and a lower part, the setting section being connected to a delivery section going on surface at the upper part, and being in communication with the inside of the well at the lower part through a delivery opening, and wherein the step of pumping a treatment fluid to the zones is done by: (i) deploying a plug inside of the well; (ii) plugging the inside of the well located downhole from the lower part with the plug; (iii) delivering the treatment fluid inside of the well through the delivery section, through the setting section and through the delivery opening; (iv) filling the inside of the well located downhole from the lower part and uphole from the plug, with the treatment fluid, until the treatment fluid passes into the annulus via the second zone still permeable to the material; and rising the treatment fluid into the zones. The plug is a device with an expandable sleeve which acts as a plug when the expandable sleeve is inflated. The plug can be deployed inside the well with the apparatus of the invention or with another apparatus.
In various possible examples of realization, the methods of the invention work when the tube is taken in the list constituted by: perforated casing, perforated tubing, perforated pipe, perforated conduit, slotted liner, screen, expandable casing, expandable screen, tube comprising opening, tube comprising permeable component, and permeable component; when the material is taken in the list constituted by: oil, water, cement, sand, gravel, gas; when the setting section is taken in the list constituted by: coiled tubing, drill pipe; when the delivery section is taken in the list constituted by: coiled tubing, drill pipe; when the sleeve is made of rubber; when the treatment fluid is a settable fluid or a non settable fluid; when the settable fluid is taken in the list constituted by: conventional cement, remedial cement, permeable cement, phosphate cement, special cement, inorganic and organic sealants, remedial resin, permeable resin, geopolymer materials; when the non settable fluid is taken in the list constituted by: acid, washer.
In the case where the treatment fluid is a settable fluid, the method further comprises the steps of: (v) allowing the treatment fluid to set; (vi) deflating the sleeve so that the sleeve is no more in contact with the tube near the zones; and (vii) removing the setting section with the sleeve from the zones by putting it out. In a preferred embodiment, the method further comprises the step of: (viii) drilling the well with a drilling tool.
According to a fourth aspect of the invention, the invention provides an apparatus for treatment or to consolidate or to isolate a near zone and/or a far zone of a well, comprising a wellbore, and the apparatus comprising: (i) a setting section surrounded by a sleeve, the sleeve being expandable and impermeable to a material; (ii) a tube which is permeable to the material, wherein the tube surrounds the sleeve; (iii) an inflating means for inflating the sleeve, the inflating means ensuring that the sleeve is in contact with a first zone of the tube so that the first zone of the tube becomes impermeable to the material; and (iv) a delivery opening for delivering a treatment fluid to the zones, the delivery opening ensuring that the treatment fluid passes, via a second zone still permeable to the material, into an annulus formed between the tube and the wellbore.
There are possible configurations of the delivery opening, in a first configuration they ensure that the treatment fluid passes into the annulus via a void making communication with the zones to treat; in a second configuration, they ensure that the treatment fluid passes into the annulus via an element permeable to the material, preferably the permeable element is a part of the tube.
Preferably also, the apparatus comprises: a deflating means for deflating the sleeve, the deflating means ensuring that the sleeve is no more in contact with the tube.
Preferably, the sleeve is attached to the tube with connecting means at the upper part and/or with connecting means at the lower part. In one embodiment, the connecting means are connected permanently to the tube; in a second embodiment the connecting means are removable connecting means; in a third embodiment the connecting means are floating means.
Preferably, the sleeve is attached to the setting section with connecting means at the upper part and/or with connecting means at the lower part. In one embodiment, the connecting means are connected permanently to the setting section; in a second embodiment the connecting means are removable connecting means; in a third embodiment the connecting means are floating means.
Preferably, the tube is attached to the setting section with connecting means at the upper part and/or with connecting means at the lower part. In one embodiment, the connecting means are connected permanently to the setting section; in a second embodiment the connecting means are removable connecting means; in a third embodiment the connecting means are floating means.
In another configuration, the setting section has an upper part and a lower part and the apparatus further comprises a delivery section going on the surface connected to the upper part.
In various possible examples of realization, the apparatus of the invention works when the tube is taken in the list constituted by: perforated casing, perforated tubing, perforated pipe, perforated conduit, slotted liner, screen, expandable casing, expandable screen, tube comprising opening, tube comprising permeable component, and permeable component; when the material is taken in the list constituted by: oil, water, cement, sand, gravel, gas; when the setting section is taken in the list constituted by: coiled tubing, drill pipe; when the delivery section is taken in the list constituted by: coiled tubing, drill pipe; when the sleeve is made of rubber; when the treatment fluid is a settable fluid or a non settable fluid; when the settable fluid is taken in the list constituted by: conventional cement, remedial cement, permeable cement, phosphate cement, special cement, inorganic and organic sealants, remedial resin, permeable resin, geopolymer materials; when the non settable fluid is taken in the list constituted by: acid, washer.
In examples of realization, the inflating means is a device delivering a gas and/or a liquid inside the sleeve; is a check valve delivering mud into the inside of the sleeve; is a pump delivering mud into the inside of the sleeve.
In other examples of realization, the apparatus further comprises a deflating means for deflating the sleeve, the deflating means ensuring that the sleeve is no more in contact with the tube and wherein the deflating means is a device releasing the gas and/or the liquid from the sleeve.
According to a fifth aspect of the invention, the invention provides an apparatus for treatment or to consolidate or to isolate a near zone and/or a far zone of a well, comprising a wellbore, and the apparatus comprising: (i) a stinger assembly comprising a stinger mandrel at the lower part, and a seal and a first thread at the upper part; (ii) a bladder assembly comprising a bladder which is expandable and impermeable to a material, a check valve for inflating the bladder, a lower attachment assembly and an upper attachment assembly, wherein the stinger mandrel fits in the lower attachment assembly and the seal fits in the upper attachment assembly; (iii) a liner string comprising a tube which is permeable to the material and comprising a delivery opening for delivering a treatment fluid, a guide, a seat and a second thread, wherein the lower attachment assembly fits in the guide, the upper attachment assembly fits in the seat and the first thread fits in the second thread; and (iv) a running tool going to surface and connected to the stinger assembly at the upper part; wherein, the check valve ensures inflation so that the sleeve is in contact with a first zone of the tube so that the first zone of the tube becomes impermeable to the material; and the delivery opening ensures delivery so that the treatment fluid passes, via a second zone still permeable to the material, into an annulus formed between the stinger assembly and the wellbore and into the zones.
In various possible examples of realization, the apparatus of the invention works when the tube is taken in the list constituted by: perforated casing, perforated tubing, perforated pipe, perforated conduit, slotted liner, screen, expandable casing, expandable screen, tube comprising opening, tube comprising permeable component, and permeable component; when the material is taken in the list constituted by: oil, water, cement, sand, gravel, gas; when the running tool is made of part of elements taken in the list constituted by: coiled tubing, drill pipe; when the bladder is made of rubber; when the treatment fluid is a settable fluid or a non settable fluid; when the settable fluid is taken in the list constituted by: conventional cement, remedial cement, permeable cement, phosphate cement, special cement, inorganic and organic sealants, remedial resin, permeable resin, geopolymer materials; when the non settable fluid is taken in the list constituted by: acid, washer.
Preferably, the check valve delivers a gas and/or a liquid inside the bladder; the liquid can be mud.
Further embodiments of the present invention can be understood with the appended drawings:
The present invention involves the use of an expanding sleeve that selectively isolates a portion of a permeable tube such as a perforated casing, or a slotted liner or an expandable and permeable screen, this isolation allowing the further treatment of the annulus zone between the permeable tube and the borehole, such treatment can be a cementing operation. The typical applications for which the apparatus and method of the invention can be used include sand control and support of wellbore producing formations, in water, oil and/or gas wells. The apparatus and method of the invention can be used also in all type of geometry of wellbores, as highly deviated and horizontal wellbores.
The method of the invention is a method of treatment of a zone of the well which is located below the placed tube 20. Zone is defined as a part of the well or a region of the well which is delimited, but which can be quite small—from one cubic meter to ten cubic meters—and which can also be quite large—from hundred cubic meters to ten thousand cubic meters—.
The sleeve 50 is positioned inside the tube 20 in a zone 60. The zone 60 delimits the location where the sleeve 50 has to be positioned to ensure an efficient method of treatment. The zone 60 is defined by a cylinder inside the well, wherein the external surface of the cylinder is delimited by the tube 20. The zone of treatment can be delimited by a near zone 60B and a far zone 60C. The near zone 60B is defined by an annulus surrounding the zone 60, delimited by the tube 20 and the wellbore 10. The far zone 60C is defined by an annulus also surrounding the zone 60B, delimited at one side by the wellbore 10 and stretching into the earth formation from a fixed length L, varying from few centimeters to few meters, preferably the length L is between 2 centimeters to 15 meters and more preferably between 10 centimeters to 5 meters.
Aim of the impermeabilisation of the zone 60A allows the treatment fluid 70 to rise into the zone 60B instead of rising into the inside of the well via zone 60. Once the entire zone 60B to be treated is filled with the treatment fluid, the pumping of the treatment fluid is stopped. Advantageously, depending on the composition of the treatment fluid 70 and on the composition of the earth formation beyond the wellbore (in the zone 60C), the treatment fluid can, after having filled the zone 60B, flow into the zone 60C. The pumping of the treatment fluid can be re-launched if needed to compensate for the fluid treatment flowing into the zone 60C and re-stopped when required. This step can be further re-executed a number of times, as needed. All along this time, the sleeve 50 is left inflated, ensuring impermeability of zone 60A, the time needed that the treatment fluid 70 makes its action in zone 60B and/or in zone 60C. As a first example of realization, the treatment fluid can be an acid for acid fracturing of the zone 60C or a chemical activator for activating zone 60C. As a second example of realization, the treatment fluid can be a settable fluid to set in zone 60B and/or in zone 60C, the settable fluid can be a permeable cement, a remedial cement or any type of cement or other sealant e.g. epoxy or furan resin. Further type of treatments can also be combined.
After the zone 60B and/or the zone 60C is treated, the sleeve 50 is deflated (
In a first embodiment, the method and the apparatus according to the invention are deployed at the bottomhole of the well, all the volume of the zone 70A left downhole of the apparatus 40 can be filled with the treatment fluid. After the treatment is finished, if a settable fluid is used, the set fluid remained in zone 70A can be drilled with a drilling tool lowered into the well from the surface.
In a second embodiment, the method and the apparatus according to the invention are deployed anywhere in the well, the volume of the zone 70A left downhole of the apparatus 40 is unknown and considered big. If the treatment fluid 70 has the same density as the fluid 700 already in the well, there is no risk that the treatment fluid fills first the zone 70A. However, if the treatment fluid 70 has not the same density as the fluid 700 already in the well two solutions can be used. One solution can be to pump few barrels of a viscous fluid into a part of said zone 70A, for example viscous fluid can be viscous bentonite pill, a delayed-gel, a reactive fluids system (RFS). If this is not sufficient, a second solution can be to mechanically isolate a part of said zone 70A with a second apparatus. Said second apparatus will be deployed first and will act as a plug so to limit the zone 70A to a smallest volume. An example of such a second apparatus can be found in U.S. Pat. No. 3,460,625; U.S. Pat. No. 2,922,478 and preferably in the co-pending European patent application from the Applicants under application number 05291785.3. Preferably, said second apparatus is deployed with the apparatus 40 and is positioned downhole compared to the apparatus 40; the second apparatus acts as a plug and the apparatus 40 can be used as described from
In a further step, a permeable tube can be placed in another zone of the well and said another zone can be treated with the method according to the invention by deploying the apparatus, if for example there are multiple and separated zones in the well or if the zone to be treated is too long to be treated with a single treatment.
The upper attachment assembly is composed of a similar fixation of the bladder between an upper mandrel 412 and an upper sleeve 413, comprising a male profile 420A and a female profile 420B. The upper mandrel 412 has an external shoulder 414 whose diameter is slightly larger that the diameter of the seat 310 (part of the liner string 300,
The stinger assembly has an upper part 500B and a lower part 500A. The lower part 500A is made of a stinger mandrel 501 with a seal assembly 502 to fit into the mandrel 404 (part of the bladder assembly 400,
A coupling 507 is connected on top of the stinger mandrel 501. A check valve assembly 507A, made of a puppet valve 508 pushed by a spring 509 and a nut 510, is installed in the thickness of the coupling. The check valve 507A ensures that the pressure inside the bladder 50 will never be lower than the pressure inside the stinger assembly. The drawing shows a very basic check valve located in the thickness of the coupling. However a concentric design with a sliding sleeve would be preferred to provide a larger flow area within the geometry of the tool. At the beginning of the job, the bladder 50 is filled with water at a very low pressure and the check valve 507A is closed. While the bladder is lowered downhole, the hydrostatic pressure increases and the bladder 50 is collapsed to increase its internal pressure. When the fluid is pumped through the drill pipes and the stinger assembly, the pressure inside the stinger assembly is slightly higher than the pressure inside the well, due to friction losses. So some fluid enters into the bladder 50 to increase its pressure, maintaining the bladder against the permeable tube 20.
Above the coupling 507, several tubular joints 511 are connected to obtain the same length as the permeable tube 20. The overall length can be adjusted by selecting short joints and/or an adjustable joint, so that the seals 502 engage the mandrel 404 (part of the bladder assembly 400,
Alternatively, the attachment of the liner hanger running tool 515 on the upper attachment assembly 400B (
The liner hanger running tool 515 shown in details on
The apparatus 40 according to this second embodiment can be used for various types of permeable tubes as: perforated casing, perforated tubular, a tubular with other openings, a slotted liner or a screen (standalone or prepacked). The apparatus 40 can also be used for expandable permeable tubes as expandable tubular. However, the difference is that the expandable tubular is run and expanded first. Then the bladder is hanged at the rig floor level while the stinger assembly is made up. Finally the upper attachment assembly is secured on the stinger assembly. In order to bleed off the bladder at the top, a second telescopic latch tube, similar to the one in the lower attachment assembly, can be added to disengage the seals and vent the bladder.
In the first step, the permeable tube 20 is made up with the guide 302 above the shoe 301 and the nipple 307 on top. External centralizers 305 are installed all along the permeable tube 20. The running tool is used to connect it to drill pipes. Optionally, the liner hanger running tool and/or a packer is made up.
In the second step, the bladder 50 is run inside the permeable tube 20. It is made of a flexible hose connected to two attachment assemblies (400A of the lower and 400B for the upper). The bladder is spooled on a reel and a pulley is guiding it during deployment in the permeable tube, until the upper attachment assembly seats into the nipple 307.
In the step three, the apparatus 40 is prepared: the stinger assembly 500 is assembled inside the bladder 50. The stinger mandrel 501 fits into the lower attachment assembly 400A. Then the running tool 600 is secured in the nipple 307 at the top of the permeable tube 20 and at this moment, the several seals 514 engage into the upper attachment assembly 400B.
In the step four, the bladder 50 can now be inflated with any liquid for test purpose, through the filling ports 308 and 417. The check valve 51-52 prevents the bladder to deflate into the well.
In the step five, the apparatus 40 is run in the well with drill pipes. The pressure in the bladder automatically raises up to the hydrostatic pressure, thanks to the check valve. In the step six, once the lower section 42 is at the desired depth, the liner hanger running tool (if any) is set and the running tool disconnected (but left in place) for safety reasons. In the step seven, the cement slurry 70 can be pumped through the drill pipes and the stinger assembly 500. It is circulating through the shoe 301 and back up the annulus 2. The stinger assembly pressure is always slightly higher than the annulus pressure. As the bladder is inflated by the stinger assembly pressure, it is maintained against the permeable tube thanks to the check valve 51-52, so it prevents the cement slurry 70 to circulate between the outside of the bladder and the inside of the permeable tube. In the step eight, the apparatus is left in place until the cement is set. In the step nine, by pulling on the drill pipe, the stinger assembly pulls on the stinger mandrel 501 and the fingers 504 which finally disengage latch tube 406 to create a path for fluid circulation so to vent the bladder.
In the step ten, by pulling more on the drill pipe, the running tool 600, the stinger assembly 500 and the lower attachment assembly 400A are coming out of the well, while the bladder bleeds off and turns inside out, hanging below the lower attachment assembly 400A. The whole apparatus can be retrieved, except the permeable tube. No cement is located inside the permeable tube.
In the above sequence, the bladder was pre-inflated at surface on the step four for test purposes. Alternatively, that test can be eliminated to save time, and the bladder will inflate by circulating the mud through the check valve 51-52, once it is arrived at desired depth. Optionally, a ball or a dart can be pumped down to close the bottom of the stinger assembly and to apply some pressure into the bladder. Then the ball seat can shear to establish the free circulation, but the bladder stays pressurized because the check valve is now closed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 06290518.7 | Mar 2006 | EP | regional |
| 06290700.1 | Apr 2006 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP07/01560 | 2/16/2007 | WO | 00 | 3/13/2009 |
