Patent Application
20210002976
Embodiments taught herein are related to apparatus, systems, and methods for use in wellbore completion operations, and, more particularly, to shiftable sleeves for opening and closing ports located along a tubular, such as wellbore casing.
It is known to position shifting sleeve assemblies axially along a wellbore casing string for opening and closing ports therealong to facilitate treatment of an underground formation, such as in a fracturing operation. The sleeve assemblies typically comprise a generally tubular sleeve housing having a sleeve releasably retained therein. The sleeve can be actuated to axially slide within the housing to selectably open and block housing ports extending radially through the housing. Sleeve assemblies are spaced along the casing string such that they are adjacent to respective treatment zones, or other zones of interest, once the casing has been set in the wellbore.
The sleeve assemblies can be actuated using an actuating tool run into the wellbore from surface. For example, the actuating tool can be run-in-hole to below the downhole-most sleeve assembly and operated to actuate the sleeve to the open position. At least one sealing means, such as a packer, is employed by the actuating tool to isolate the balance of the wellbore from the treatment fluids, such as the wellbore downhole of the sleeve being actuated. Fluid is then introduced into the wellbore and directed into the formation through the open housing ports for treatment of the treatment zone adjacent to the sleeve assembly. Once treatment is complete, the actuating tool can be repositioned to the next sleeve assembly, uphole of the just-actuated sleeve assembly, and operated to actuate the next sleeve assembly to the open position, the process continuing until all desired treatment zones have been treated.
Many different types of sleeves and actuating tools are known in the industry. Applicant's U.S. Pat. No. 10,472,928 discloses a downhole actuator tool for locating and actuating one or more sleeve valves spaced along a completion string. Applicant's U.S. patent application Ser. No. 16/515,881 discloses a shift uphole-to-open sleeve assembly for insertion along a tubular string for multi-stage, selectable wellbore treatment.
Existing sleeve assemblies permit binary control of flow through the housing ports thereof. In other words, the sleeves of the sleeve assemblies can only be actuated between fully open and fully closed positions, with no ability to modulate or meter flow through the housing ports. There is interest in sleeve assemblies having the ability to meter the amount of flow through the ports thereof, and that are suitable for manipulation using downhole actuator tools.
Embodiments of a multi-position sleeve assembly having an additional metering position, for use when less than maximum flow through the ports of the sleeve assembly is desired, are described herein. The sleeve assembly can be positioned along a casing string extending into a wellbore from surface and located adjacent a corresponding treatment zone of a subterranean formation.
In embodiments, the sleeve assembly is a three-position sleeve assembly comprising a housing and two sliding sleeves slidably retained therein. The housing has one or more housing ports for permitting fluid communication between a bore of the housing and the surrounding formation. The first sliding sleeve is movable between an open position, wherein the one or more housing ports are exposed for permitting fluid communication between the bore of the housing and the surrounding treatment zone, and a closed position, wherein the first sliding sleeve obstructs the one or more housing ports, thereby preventing fluid communication between the housing bore and the treatment area. The second sliding sleeve has at least one metering orifice and is actuable between a metering position, wherein the at least one metering orifice is aligned with the one or more housing ports, and an inactive position wherein the second sliding sleeve is clear of the one or more housing ports. The dimensions of the at least one metering orifice are selected to maintain fluid flow into the treatment zone at a desired flow rate.
The three-position sleeve assembly can therefore have three operational modes: a closed mode wherein the first sleeve is in the closed position and the second sleeve is in the inactive position, an open more wherein the first sleeve is in the open position and the second sleeve is in the inactive position, and a metering mode wherein the first sleeve is in the open position and the second sleeve is in the metering position. The sleeve assembly can be actuated to its various modes using a bottom hole actuator tool configured to actuate both the first and second sleeves in a single run, or by running the bottom hole actuator downhole in a first run to actuating the first sleeve, and then reconfiguring the bottom hole actuator and actuating the second sleeve in a second run.
In an exemplary operation, the three-position sleeve assembly can be actuated to the open position to permit treatment of the surrounding formation, and then actuated to the metering position when it is desired to convert the well from a producer well to an injector well, wherein water is injected into the formation at a metered rate determined by the dimensions of the one or more metering orifices.
Embodiments of multi-position sleeve assemblies are provided herein for installation along a casing string extending from surface into a wellbore to control fluid flow between a bore of the casing string and corresponding treatment zones surrounding the sleeve assemblies.
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The metered flow rate through the metering orifices of the second sleeve is determined by the dimensions of the one or more metering orifices. In embodiments, the metering orifice is a single 1/16″ diameter orifice that allows flow at a fixed injection rate into a formation when the second sleeve shifted into the open metering position. The 1/16″ diameter orifice allows the flow of 20 cubic meters of fluid per day.
Both the first sliding sleeve and the second sliding sleeve are “pull to open” from the housing, such that they are pulled uphole by the actuating tool to the open/metering positions, respectively. In embodiments, the first and second sleeves can have radially outwardly protruding annular rings or detents paired with corresponding annular grooves of the sleeve housing to lock the sleeves at each end of their strokes to prevent accidental shifting thereof. When the rings of the first and second sleeves reside within a corresponding groove, a shifting force must first be overcome before the sleeves can be actuated to a new position. In some embodiments, an annular ring can protrude radially inwardly from the housing, axially retained in one or more ring grooves, toward the first or second sleeve, and the sleeves can have corresponding annular grooves on their outer surfaces to engage the annular ring to retain the sleeves in their terminal positions. In some embodiments, shear screws may be used to retain the first and/or second sleeves in their initial positions, such as retaining the first sleeve in the closed position, and the second sleeve in the non-metering inactive position, until a requisite shear force is overcome to break the shear screws and shift the first or second sleeve to the open and metering positions, respectively.
The sleeve assembly is therefore capable of being actuated to three operational modes: a closed mode wherein the first sleeve is in the closed position and the second sleeve is in the inactive position (
The first and second sleeves can be actuated using any suitable downhole actuator tool. For example, Applicant's U.S. Pat. No. 10,472,928 ('928), incorporated herein in its entirety by reference, discloses a bottom hole actuator tool for locating and actuating one or more sleeve valves spaced along a completion string. Applicant's U.S. patent application Ser. No. 16/515,881 ('881), incorporated herein in its entirety by reference, discloses a downhole tool including a biased repositioning sub to reduce the number of tool cycles required to open a sleeve and treat the adjacent treatment zone. Applicant's U.S. patent application Ser. No. 16/921,696 ('696), incorporated herein in its entirety by reference, discloses a downhole tool having a dual J-Mechanism also for reducing the number of required tool cycles. The bottom hole actuators of '928, '881, and '696 comprise dog arms, capable of locating the first sliding sleeve and the second sliding sleeve.
As mentioned above, an actuating tool can be used to actuate the first and second sleeves in a single run, the first and second sleeves can be actuated in separate runs. In the latter case, the actuating tool can be fit with first sleeve-engaging elements sized to correspond to the first tool-engaging profiles of the first sleeves. As the second tool-engaging profiles of the second sleeves have a shorter axial length than that of the first profiles, the first sleeve-engaging elements of the actuating tool cannot inadvertently engage the second profiles. After the first sleeves have been actuated, the actuating tool can be fit with second sleeve-engaging elements sized to correspond to the second tool-engaging profiles of the second sleeves. The first sleeve-engaging elements may or may not need to be removed.
If both the first and second sleeves are actuated in a single run, the actuating tool can be fit with both the first and second sleeve-engaging elements and selectively activate first and second sleeve-engaging elements to respectively engage the first and second sleeve profiles, depending on which sleeves are to be shifted.
In an embodiment, the second sleeves are located downhole of the first sleeves. As described in further detail below, the actuating tool can be located below a target sleeve assembly, and therefore below the first and second sleeves thereof, and pulled uphole to locate the desired sleeve. As the first sleeve-engaging elements are configured such that they cannot fit into and engage with the second profiles of the second sleeve, when the actuating tool is configured to locate and shift the first sleeve, the first sleeve-engaging elements will pass over the second profile of the second sleeve without engaging therewith as the tool is pulled towards the first sleeve.
In an exemplary embodiment of the operation of the three-position sleeve assemblies, a plurality of sleeve assemblies are located along the casing of the wellbore. In a first run, the bottom hole actuator tool is fit with first sleeve-engaging elements, such as dogs, configured to engage the first sleeve profiles and sized be too large to fit into the second sleeve profiles of the second sleeves. The actuator tool is run in hole below a target sleeve assembly. The actuating tool is then actuated to a locate mode to bias the dogs radially outwards, and the tool is pulled uphole to locate the first sleeve profile. The dogs pass over the second sleeve profile of the second sleeve, as they are too large to fit into the second profile, and continue uphole until reaching the first sleeve profile of the first sleeve, at which point the dogs engage with the first sleeve profile. While the dogs are engaged with the first sleeve profile, the actuating tool continues to be pulled upward such that the first sliding sleeve is pulled to the open position by the first dogs. The sleeve assembly is now in the open mode. After the first sliding sleeve is actuated to the open position, the actuating tool can be actuated to a set mode wherein a packer of the actuating tool is positioned and set below the housing bores of the target sleeve assembly. Fracturing fluid is then provided into the casing bore and flows out of the housing ports to the treatment area. Once the treatment with fracturing fluid is complete, the first sliding sleeve of the sleeve assembly can be closed by the actuating tool or left open. The actuating tool can then be positioned below a subsequent sleeve assembly uphole of the present sleeve assembly, and the above process is repeated to actuate the subsequent sleeve assembly to the open position. This process can be repeated until all desired sleeves assemblies are actuated to the open position.
As discussed above, the sleeve assembly is in the metering mode when the second sleeve is in the metering position while the first sleeve is in the open position. The metering position is generally used when a well is converted from a producing well to an injector well, or in any other situation wherein it is desired to introduce fluid into the formation in a metered manner.
To actuate the sleeve assemblies to the metering mode, the actuating tool can be pulled back up to surface and fit with second sleeve-engaging members, such as dogs, for engaging the second sleeve profiles. Such second sleeve-engaging members can be axially shorter than the first sleeve-engaging members such that they can fit into the second sleeve profiles. The actuating tool can then be run back downhole to a target sleeve assembly to actuate the assembly to the metering position in the same manner as for the first sleeves. Since the second sleeve is downhole of the first sleeve, when the actuating tool is actuated to the locate mode and pulled uphole, the dogs will first encounter the second sleeve and engage with the second sleeve profile. The process above can be followed to pull the actuating tool uphole to actuate the second sleeve to the metering position. Subsequent sleeve assemblies can be located and shifted to metering positions in the same manner.
In other embodiments, the first and second sliding sleeves can both be respectively shifted to the open and metering positions on the initial run. For example, the actuating tool can be fit with both first and second sleeve-engaging elements and is capable of selectively actuating the elements to locate and open the first and second sleeves of the sleeve assemblies.
While various embodiments and examples have been described herein, it should be understood that this is by way of illustration only and the apparatus, system and method are not intended to be limited to these embodiments. On the contrary, this disclosure is intended to cover alternatives, modifications, and equivalents which will become apparent to those skilled in the art in view of this disclosure.
