The present invention relates to methods and devices for treating multiple interval well bores and more particularly, the use of an isolation assembly to provide zonal isolation to allow selected treatment of productive or previously producing intervals in multiple interval well bores.
Oil and gas wells often produce hydrocarbons from more than one subterranean zone or well bore interval. Occasionally, it is desired to treat or retreat one or more intervals of a well bore. Reasons for treating or retreating intervals of a well bore include the need to stimulate or restimulate an interval as a result of declining productivity during the life of the well. Examples of stimulation treatments include fracturing treatments and acid stimulation. Other treating operations include conformance treatments, sand control treatments, blocking or isolating intervals, consolidating treatments, sealing treatments, or any combination thereof.
One difficulty in treating a selected interval of an already producing well bore is the lack of zonal isolation between intervals. That is, each of the selected intervals to be treated may be in fluid communication with other intervals of the well bore. This lack of isolation between intervals can prevent targeted treatments to selected intervals because treatments intended for one selected interval may inadvertently flow into a nonintended interval. Thus, before treating or retreating a selected interval of a well bore, the selected interval will often be isolated from the other intervals of the well bore. In this way, treatments may be targeted to specific intervals.
Conventional methods for reisolation of well bore intervals include the use of isolation devices such as, for example, straddle packers, packers with sand plugs, packers with bridge plugs, isolation via cementing, and combinations thereof. Such conventional methods, however, can suffer from a number of disadvantages including lower rate throughputs due to additional well bore restrictions inherent in such methods, poor isolation between intervals, and depletion between intervals.
Thus, a need exists for an improved method for providing isolation between well bore intervals to allow treatment or retreatment of selected intervals in multiple interval well bores.
The present invention relates to methods and devices for treating multiple interval well bores and more particularly, the use of an isolation assembly to provide zonal isolation to allow selected treatment of productive or previously producing intervals in a multiple interval well bore.
One example of a method for multi-interval fracturing completion comprises the steps of: introducing an isolation assembly to a well bore, the isolation assembly comprising a liner, one or more sleeves, one or more screen-wrapped sleeves and a plurality of swellable packers, wherein the plurality of swellable packers are disposed around the liner at one or more selected spacings; swelling at least one of the plurality of swellable packers so as to provide zonal isolation one or more selected intervals; wherein the one or more sleeves and the one or more screen-wrapped sleeves are disposed around the liner at selected spacings so as to provide at least one of the one or more sleeves and at least one of the one or more screen-wrapped sleeves within at least one of the one or more selected intervals; deploying a shifting tool inside the liner, wherein the shifting tool is adapted to adjust positioning of each of the one or more sleeves and each of the one or more screen-wrapped sleeves; actuating the shifting tool to adjust positioning of the at least one of the one or more sleeves to an open position so as to stimulate the at least one of the one or more selected intervals by flowing fluid through one or more openings of the liner and through one or more openings in the at least one of the one or more sleeves; actuating the shifting tool to adjust positioning of the at least one of the one or more sleeves to a closed position so as to reestablish zonal isolation of the at least one of the one or more selected intervals; and actuating the shifting tool to adjust positioning of the at least one of the one or more screen-wrapped sleeves to an open position so as to allow flow of production fluid from the at least one of the one or more selected intervals through one or more openings in the liner and through a plurality of openings in the at least one of the one or more screen-wrapped sleeves.
Another example of a method for multi-interval fracturing completion comprises the steps of: introducing an isolation assembly to a well bore, the isolation assembly comprising a liner, one or more sleeves and a plurality of swellable packers, wherein the plurality of swellable packers are disposed around the liner at one or more selected spacings; swelling at least one of the plurality of swellable packers so as to provide zonal isolation of one or more selected intervals; wherein the one or more sleeves are disposed around the liner at selected spacings so as to provide at least one of the one or more sleeves within at least one of the one or more selected intervals and wherein the one or more sleeves are configured so as to provide a closed position, an open position and an open to screen position; actuating the shifting tool to adjust positioning of the at least one of the one or more sleeves to an open position; pumping fluid through one or more openings in the liner and through one or more openings of the at least one of the one or more sleeves within the at least one of the one or more selected intervals so as to stimulate the at least one of the one or more selected intervals; actuating the shifting tool to adjust positioning of the at least one of the one or more sleeves to an open to screen position so as to allow flow of production fluid from the at least one of the one or more selected intervals through one or more openings in the liner and through one or more openings in the at least one of the one or more sleeves.
An example isolation assembly tool adapted to provide multi-interval fracturing completion comprises: a liner; one or more sleeves, wherein the one or more sleeves are disposed around the liner; one or more screen-wrapped sleeves, wherein the one or more screen-wrapped sleeves are disposed around the liner, wherein the one or more sleeves and the one or more screen-wrapped sleeves are disposed around the liner at selected spacings and wherein a shifting tool is adapted to adjust positioning of each of the one or more sleeves and each of the one or more screen-wrapped sleeves to an open position and a closed position.
Another example isolation assembly tool adapted to provided multi-interval fracturing completion comprises: a liner; one or more sleeves, wherein the one or more sleeves are disposed around the liner; wherein a shifting tool is adapted to adjust positioning of each of the one or more sleeves to an open position, a closed position and an open to screen position and wherein a shifting tool is adapted to adjust positioning of each of the one or more sleeves to an open position, a closed position and an open to screen position and wherein the one or more sleeves is disposed around the liner at selected spacing to cover selected perforations of the liner.
The features and advantages of the present invention will be apparent to those skilled in the art. While numerous changes may be made by those skilled in the art, such changes are within the spirit of the invention.
These drawings illustrate certain aspects of some of the embodiments of the present invention, and should not be used to limit or define the invention.
The present invention relates to methods and devices for treating multiple interval well bores and more particularly, the use of an isolation assembly to provide zonal isolation to allow selected treatment of productive or previously producing intervals in a multiple interval well bore.
The methods and devices of the present invention may allow for reestablishing zonal isolation of producing intervals, bypassed, or non-producing intervals, or previously producing intervals in multiple interval well bores through the use of an isolation assembly. In certain embodiments, isolation assemblies of the present invention may comprise a liner and a plurality of swellable packers, the swellable packers being disposed about the liner at selected spacings.
To facilitate a better understanding of the present invention, the following examples of certain embodiments are given. In no way should the following examples be read to limit, or define, the scope of the invention.
In particular,
In certain embodiments, liner 110 may be installed permanently in a well bore, in which case, liner 110 may be made of any material compatible with the anticipated downhole conditions in which liner 110 is intended to be used. In other embodiments, liner 110 may be temporary and may be made of any drillable or degradable material. Suitable liner materials include, but are not limited to, metals known in the art (e.g. aluminum, cast iron), various alloys known in the art (e.g. stainless steel), composite materials, degradable materials, or any combination thereof. The terms “degradable,” “degrade,” “degradation,” and the like, as used herein, refer to degradation, which may be the result of, inter alia, a chemical or thermal reaction or a reaction induced by radiation. Degradable materials include, but are not limited to dissolvable materials, materials that deform or melt upon heating such as thermoplastic materials, hydralytically degradable materials, materials degradable by exposure to radiation, materials reactive to acidic fluids, or any combination thereof. Further examples of suitable degradable materials are disclosed in U.S. Pat. No. 7,036,587, which is herein incorporated by reference in full.
Swellable packers 120 may be any elastomeric sleeve, ring, or band suitable for creating a fluid tight seal between liner 110 and an outer tubing, casing, or well bore in which liner 110 is disposed. Suitable swellable packers include, but are not limited, to the swellable packers disclosed in U.S. Publication No. 2004/0020662, which is herein incorporated by reference in full.
It is recognized that each of the swellable packers 120 may be made of different materials, shapes, and sizes. That is, nothing herein should be construed to require that all of the swellable packers 120 be of the identical material, shape, or size. In certain embodiments, each of the swellable packers 120 may be individually designed for the conditions anticipated at each selected interval, taking into account the expected temperatures and pressures for example. Suitable swellable materials include ethylene-propylene-copolymer rubber, ethylene-propylene-diene terpolymer rubber, butyl rubber, halogenated butyl rubber, brominated butyl rubber, chlorinated butyl rubber, chlorinated polyethylene, styrene butadiene, ethylene propylene monomer rubber, natural rubber, ethylene propylene diene monomer rubber, hydragenized acrylonitrile-butadiene rubber, isoprene rubber, chloroprene rubber, and polynorbornene. In certain embodiments, only a portion of the swellable packer may comprise a swellable material.
As is evident from
The swelling of plurality of swellable packers 220 may cause an interference fit between liner 210 and casing string 205 so as to provide fluidic isolation between selected intervals along the length of the well bore. The fluidic isolation may provide zonal isolation between intervals that were previously not fluidly isolated from one another. In this way, integrity of a previously perforated casing may be reestablished. That is, the isolation assembly can reisolate intervals from one another as desired. By reestablishing the integrity of the well bore in this way, selected intervals may be treated as desired as described more fully below.
The swelling of the swellable packers may be initiated by allowing a reactive fluid, such as for example, a hydrocarbon to contact the swellable packer. In certain embodiments, the swelling of the swellable packers may be initiated by spotting the reactive fluid across the swellable packers with a suitable fluid. The reactive fluid may be placed in contact with the swellable material in a number of ways, the most common being placement of the reactive fluid into the well bore prior to installing the liner. The selection of the reactive fluid depends on the composition of the swellable material as well as the well bore environment. Suitable reaction fluids include any hydrocarbon based fluids such as crude oil, natural gas, oil based solvents, diesel, condensate, aqueous fluids, gases, or any combination thereof. U.S. Publication No. 2004/0020662 describes a hydrocarbon swellable packer, and U.S. Pat. No. 4,137,970 describes a water swellable packer, both of which are hereby incorporated by reference. Norwegian Patent 20042134, which is hereby incorporated by reference, describes a swellable packer, which expands upon exposure to gas. The spotting of the swellable packers may occur before, after, or during the introduction of the isolation assembly into the well bore. In some cases, a reservoir fluid may be allowed to contact the swellable packers to initiate swelling of the swellable packers.
After fluidic isolation of selected intervals of the well bore has been achieved, fluidic connectivity may be established to selected intervals of the well bore. Any number of methods may be used to establish fluidic connectivity to a selected interval including, but not limited to, perforating the liner at selected intervals as desired.
Selected intervals may then be treated with a treatment fluid as desired. Selected intervals may include bypassed intervals sandwiched between previously producing intervals and thus packers should be positioned to isolate this interval even though the interval may not be open prior to the installation of liner 210. Further, packers may be positioned to isolate intervals that will no longer be produced such as intervals producing excessive water.
As used herein, the terms “treated,” “treatment,” “treating,” and the like refer to any subterranean operation that uses a fluid in conjunction with a desired function and/or for a desired purpose. The terms “treated,” “treatment,” “treating,” and the like as used herein, do not imply any particular action by the fluid or any particular component thereof. In certain embodiments, treating of a selected interval of the well bore may include any number of subterranean operations including, but not limited to, a conformance treatment, a consolidation treatment, a sand control treatment, a sealing treatment, or a stimulation treatment to the selected interval. Stimulation treatments may include, for example, fracturing treatments or acid stimulation treatments.
Liner 310 may be introduced into well bore 340 by any suitable method for disposing liner 310 into well bore 340 including, but not limited to, deploying liner 310 with jointed pipe or setting with coiled tubing. If used, any liner hanging device may be sheared so as to remove the coiled tubing or jointed pipe while leaving the previously producing intervals isolated. Optionally, liner 340 can include a bit and scraper run on the end of the liner for the purpose of removing restrictions in the casing while running liner 310. In certain embodiments, liner 310 may be set on the bottom of well bore 340 until swellable packers 320 have swollen to provide an interference fit or fluidic seal sufficient to hold liner 310 in place. Alternatively, liner 310 may set on bridge plug 355 correlated to depth, or any suitable casing restriction of known depth. Here, liner 305 is depicted as sitting on bridge plug 355, which may be set via a wireline. In this way, bridge plug 355 may serve as a correlation point upon which liner 310 is placed when it is run into the casing. In certain embodiments, liner 310 may a full string of pipe to the surface, effectively isolating the entire casing string 310, or in other embodiments, liner 310 may only isolate a longitudinal portion of casing string 310.
As previously described, once liner 310 is in place and the swellable packers have expanded to provide fluidic isolation between the intervals, selected intervals may be isolated and perforated as desired to allow treatment of the selected intervals. Any suitable isolation method may be used to isolate selected intervals of the liner including, but not limited to, a ball and baffle method, packers, nipple and slickline plugs, bridge plugs, sliding sleeves, particulate or proppant plugs, or any combination thereof.
Before treatment of selected intervals, liner 310 may be perforated to allow treating of one or more selected intervals. The term “perforated” as used herein means that the member or liner has holes or openings through it. The holes can have any shape, e.g. round, rectangular, slotted, etc. The term is not intended to limit the manner in which the holes are made, i.e. it does not require that they be made by perforating, or the arrangement of the holes.
Any suitable method of perforating liner 310 may be used to perforate liner 310 including but not limited to, conventional perforation such as through the use of perforation charges, preperforated liner, sliding sleeves or windows, frangible discs, rupture disc panels, panels made of a degradable material, soluble plugs, perforations formed via chemical cutting, or any combination thereof. In certain embodiments, a hydrajetting tool may be used to perforate the liner. In this way, fluidic connectivity may be reestablished to each selected interval as desired. Here, in
In certain embodiments, sliding sleeves 360 may comprise a fines mitigation device such that sliding sleeve 360 may function so as to include an open position, a closed position, and/or a position that allows for a fines mitigation device such as a sand screen or a gravel pack to reduce fines or proppant flowback through the aperture of sliding sleeve 360.
Certain embodiments may include umbilical line, wirelines, or tubes to the surface could be incorporated to provide for monitoring downhole sensors, electrically activated controls of subsurface equipment, for injecting chemicals, or any combination thereof. For example, in
Although liner 310 and swellable packers 320 are shown as providing isolation along casing string 305, it is expressly recognized that liner 310 and swellable packers 320 may provide isolation to an openhole without a casing string or to a gravel pack as desired. Thus, casing string 305 is not a required feature in all embodiments of the present invention. In other words, the depiction of casing string 305 in the figures is merely illustrative and should in no way require the presence of casing string 305 in all embodiments of the present invention.
As selected intervals are appropriately isolated and perforated using the isolation assembly, selected intervals may be treated as desired.
Examples of suitable treatments that may be apply to each selected interval include, but are not limited to, stimulation treatments (e.g. a fracturing treatment or an acid stimulation treatment), conformance treatments, sand control treatments, consolidating treatments, sealing treatments, or any combination thereof. Additionally, whereas these treating steps are often performed as to previously treated intervals, it is expressly recognized that previously bypassed intervals may be treated in a similar manner.
Once attachment 575 is sheared or otherwise disconnected, hydrajetting tool 585 may be lowered to a well bore interval to be treated, in this case, first well bore interval 591 as illustrated in
After removal of the excess proppant, hydrajetting tool 585 may be used to perforate casing string 505 and initiate or enhance perforations into second well bore interval 592 as illustrated in
As a final step in the process the tubing may be lowered while reverse circulating to remove the proppant plug diversion and allow production from the newly perforated and stimulated intervals.
Traditionally fracturing relies on sophisticated and complex bottomhole assemblies. Associated with this traditional method of fracturing are some high risk processes in order to achieve multi-interval fracturing. One major risk factor associated with traditional fracturing is early screen-outs. By implementing the sleeves and isolation assembly depicted in
To prevent the walls of the well bore from damaging the screens 650, one or more centralizers 620 may be disposed about the screen-wrapped sleeve 660 or liner 610. As shown in
Screen-wrapped sleeve 660 is disposed around a liner 610 as part of an isolation assembly discussed below with respect to
As indicated in
To prevent the walls of the well bore from damaging the screens of screen-wrapped sleeves (not shown) such as screen-wrapped sleeves 660 of
As indicated in
In certain embodiments and as shown in
In certain embodiments the functionality of screen-wrapped sleeve 660 and the sleeve 770 may be combined as illustrated in
In certain embodiments, liner 810 may have preformed ports 830. In other embodiments, ports 830 may be formed after the liner 810 has been inserted into the well bore. To prevent the walls of the well bore from damaging the screens 850, one or more centralizers 820 may be disposed about the sleeve 880 or liner 810. As shown in
In certain embodiments and as shown in
One or more swellable packers 1090 are also disposed around liner 1010. Also, to prevent the walls of the well bore from damaging the screens 1050, one or more centralizers 1020 may be disposed about the sleeve 1060 or liner 1010. As shown in
The method of selecting, stimulating, and producing hydrocarbons from an interval or zone using an isolation assembly will now be described with reference to
Next, a shifting tool 1015 may be introduced into liner 1010. As depicted here, the shifting tool 1015 may be actuated to displace the sleeves 1070 and screen-wrapped sleeves 1060 about the liner 1010. Displacement or adjustment of position of sleeves 1070 and screen-wrapped sleeves 1060 may occur longitudinally along the liner 1010 or rotationally about the liner 1010 as described in
Once a selected interval has been isolated, the shifting tool 1015 actuates the sleeve 1070 to adjust positioning of the sleeve 1070 to an open position. Screen-wrapped sleeves 1060 are in a closed position to prevent any fluid from flowing back into the liner 1010. The well bore is treated with fluid that flows down the liner 1010, through ports 1030 and 1040 and out into the well bore. In one example embodiment, the selected intervals are treated with fracturing fluid so as to stimulate the well bore.
The swellable packers 1090 prevent any fluid from flowing outside the selected interval so as to form zonal isolation of the selected interval. After treatment, the sleeve 1070 is actuated by the shifting tool 1015 to a closed position. Fluid treatments may then be applied to other selected intervals in like manner. In another embodiment, multiple selected intervals isolated by multiple swellable packers 1090 may be treated simultaneously by actuating multiple sleeves 1070 in the multiple selected intervals to an open position and then flowing the treatment fluid. Multiple selected intervals may be contiguous, non-contiguous or a combination thereof.
Once the selected intervals have been treated, sleeves 1070 may be actuated to a closed position in order to reestablish zonal isolation of the selected interval and to allow for further operations of the well bore. For instance, the shifting tool 1015 may actuate screen-wrapped sleeves 1060 to an open or open to screen position in a selected interval as depicted in
Screen-wrapped sleeves 1060 may be actuated to a closed position to allow for further operations of the well bore. In one example embodiment, refracturing of the well bore may be initiated by actuating the sleeves 1070 to an open position so as to allow treatment of the well bore. In another embodiment, new selected intervals may be chosen for stimulation and receipt of production fluids.
Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee.
This application is a continuation of U.S. patent application Ser. No. 11/746,656 filed on May 10, 2007 which is a continuation in part of U.S. patent application Ser. No. 11/450,654 filed on Jun. 9, 2006, and issued as U.S. Pat. No. 7,478,676, both of which are hereby incorporated by reference as if fully reproduced herein.
Number | Date | Country | |
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Parent | 11746656 | May 2007 | US |
Child | 12435128 | US |
Number | Date | Country | |
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Parent | 11450654 | Jun 2006 | US |
Child | 11746656 | US |