Patent Application
20230279732
The field of the invention is the creation of a mounting location in a tubular mounted in a borehole at a desired location and delivering an adaptive support to the mounting location for selective isolation of a portion of the borehole for pressure formation treatment outside the isolated portion of the borehole.
Adaptive supports and devices to deliver them to a groove or a recess in a tubular or in a similar support location between tubulars have been described in U.S. Pat. Nos. 10,287,835 and 10,273,769. The method to deliver such devices was limited to pre-existing grooves or recesses in the tubular between joints or in similar recesses defined at tool joints. However, there are occasions where flexibility of mounting location is determined at a time well after the tubular string is run into the hole. Having to rely on pre-existing support locations in tubulars or between them, limits flexibility of locating the adaptive supports. In some applications, the applied pressures for formation treatment, after an object is landed on the adaptive support, can be high enough that frictional or even penetrating contact with the surrounding tubular by the adaptive support will not keep the adaptive support in place.
To address this condition, the present method provides a recess or groove or similar ledge support location added to the tubular after it is run in the hole in a desired tubular preferably between its ends. The adaptive support can be located in the created structure in the tubular in the same trip as milling or removing wall structure to create the support structure. The mill can include features to centralize and anchor within the tubular to be milled if it is desired to create a ledge for support that extends as much as 360 degrees although support locations that extend less than 360 degrees are envisioned. There are tubulars that can have an inside out of round shape and centralizing optimizes the angular extent of the support location to be milled. Another issue with tubulars can be uneven wall thickness. A uniform milling diameter in a location of thinner wall thickness can undermine the pressure rating of the tubular string. The mill can include sensing devices for the circumferential wall thickness where the milling is to occur that integrates with the centralized position of the mill so that an optimal milling depth can be computed that will not materially alter the pressure rating of the tubular at the milled location, while providing enough overlap with the adaptive support to hold the adaptive support in position with pressure applied to an object landed on the adaptive support. Different milled profiles are envisioned, for example, square, rectangular or arcuate. The mill as well as the adaptive support delivery tool can then be pulled out of the hole to allow an object to land on the adaptive support for pressure treatment of any kind into the surrounding formation. The adaptive support can have a variety of shapes with a coil design released with stored potential energy from a delivery tool being preferred.
In the past milling in a tubular string has been combined with setting an anchor in a procedure for creating a lateral. The milling is through the tubular wall and the packer or anchor is set below the milled window to support a whipstock to force the drill or mill through the tubular wall so that a lateral can be created. The mill or drill is typically run in attached to the whipstock with an anchor and an MWD tool below the whipstock for orienting the whipstock ramp before setting the anchor and milling the window. This procedure was done in a single trip as illustrated in U.S. Pat. Nos. 6,454,007; 9,062,508 and US2020 0318435.
Another application involving milling a downhole tubular and running in an anchor or packer is in the process of section milling. In section milling, the mill cuts through the tubular wall for 360 degrees so that the anchor or packer can be set in the cut section and the cut section of the string can be pulled out of the hole. This method is shown in U.S. Pat. No. 10,151,154.
During drilling and before a tubular string is run in, a borehole can be enlarged with an underreamer as illustrated in U.S. Pat. Nos. 2,879,038 and 8,448,724.
Preformed grooves in tubulars for whipstock locating when milling a window are illustrated in U.S. Pat. No. 8,505,621.
Of general relevance is U.S. Pat. No. 8,936,077 which illustrates creation of an end bell in a tubular using an expansion swage so that a monobore string can be created in a borehole.
What is lacking in the art mentioned above is a method to create a support location within a tubular that is in a borehole without milling completely through its wall for the purpose of supporting an adaptive support for subsequent formation pressure treatment with pressure against an object landed on the properly supported adaptive support that is properly located with respect to the formation of interest at a time determined after the string is run in the hole. In other applications a variety of tools can be landed in the support location for a variety of purposes such as isolation or formation treatment, for example. Those skilled in the art will more readily appreciate additional aspects of the present in vetion from a review of the descriptions below while recognizing that the full scope of the invention is to be determined from the appended claims.
A method of preparing a mounting location in a tubular disposed in a borehole features milling a support location and then releasing an adaptive support to position it in the mounting location directly or indirectly by releasing the adaptive support offset from the mounting location and then translating the adaptive support to the mounting location or directly into the support location without translating. A mill centralizing anchor compensates for internal out of roundness of the tubular. Uniformity of the wall thickness at the milling location is determined in conjunction with the centralizing feature to obtain a mounting location that extends circumferentially for as much as 360 degrees, without materially reducing the pressure integrity of the tubular being milled. The recess, groove or equivalent that is the mounting location can have planar or/and arcuate surfaces. The adaptive support can be released using stored potential energy in the adaptive support.
A tubular 5 has been run into a borehole as a part of a tubular string that is not shown. The portion of the tubular 5 where a support location 6 is to be formed is illustrated. The bottom hole assembly of
Mill 2 has articulated cutting structure 16 that is retracted for running in and extended when the desired bore depth is achieved for the cutting structure 16. An anchoring and centralizing system 18 is schematically illustrated on or adjacent to the structure of mill 2. Since the inside diameter of the tubular 5 may be out of round the system 18 comprises telescoping anchor pistons that can be extended to contact the inside wall at circumferentially spaced locations. These pistons can serve a dual purpose of anchoring and centralizing or a separate centralizer like a bow spring structure can be used for centralizing while pistons can then be expended for fixation of the mill 2. A sensor system 20 measures the distance between the mill 2 center and the inside wall of tubular 5 at spaced circumferential locations. The sensor system controls the extension and retraction of the telescoping anchor pistons in conjunction with a processor to minimize or eliminate the differences in distance readings created by out of roundness of the inside wall of the tubular 5. The anchor pistons are not necessarily extended the same length for proper anchoring while holding the optimized centering position with the aid of the sensor system 20. The sensor system 20 also measures the wall thickness of the tubular 5 at or near where the degrees, without distance to the inside wall measurements are taken. It is possible for the tubular 5 to have variations in wall thickness around its circumference. The goal is to create a support location 6 in the inside wall of the tubular 5 that covers as close as possible to a full 360 degrees. The centralizing aspect of the telescoping pistons or a separate centralizer in conjunction with anchoring pistons, addresses this issue. At the same time, the depth of the support location 6 with the mill 2 centralized is controlled by the measured wall thickness data with the goal of leaving sufficient wall thickness 22 to safely handle the anticipated treatment pressures within tubular 5 as the surrounding formation is treated. At the same time, the depth of surface 24 needs to be sufficient to resist shear forces on the adaptive support 7 when an object 8 has landed and pressure from uphole is applied during a treatment operation of the surrounding formation. Depending on the shape of the adaptive support 7 the support location 6 can be continuous or segmented over the circumference of the inside wall of the tubular 5. For a continuous groove, the lower supporting surface 24 is preferably planar but may be slightly arcuate depending on the shape of the cutting structure on mill 2 or the way the cutting structure is articulated into the milling position. Surface 26 is curved and is spaced from surface 24 further than the height of the adaptive support 7 so that the adaptive support can easily enter the support location 6 which is preferably a groove, channel or equivalent recess that can extend preferably continuously for at least 180 degrees to provide enough support against shear forces when pressure is applied to object 8 landed on adaptive support 7. Surface 24 can be in a single plane transverse or skewed to the longitudinal axis of the tubular string 5 or it may be a spiral shape, as shown in
The adaptive support 7 can be released directly into the support location 6 as shown in
Preferably, the bottom hole assembly is run into the tubular 5 in a single trip but a separate trip for just milling with mill 2 is contemplated. A separate trip for the mill 2 makes cuttings removal more effective but incurs additional costs associated with rig time.
Those skilled in the art will appreciate that the methods described above allow the flexibility to create support locations 6 after a tubular 5 which is part of a longer string is in the hole and more data about the surrounding formation(s) is known. One or more support locations 6 can be milled in a single run, although milling a single support location 6 is shown. Although a single placement of an adaptive support 7 is shown, the delivery tool 4 can carry multiple adaptive supports 7 that have progressively larger opening dimension to accept objects of progressively larger dimension as a formation zone or zones are treated. The delivery of multiple adaptive supports 7 can be accomplished with a single delivery tool 4 equipped to selectively release one adaptive support at a time by regulating movement of a release sleeve on the tool 4 or by including multiple delivery tools 4 in the bottom hole assembly 14. Either way objects 8 of progressively larger diameter can be sequentially dropped to isolate portions of a single formation or to treat multiple formations that are spaced apart.
The ability to get real time data when selecting a given milling location optimizes the dimensions of the groove(s) or recess(es) that form the support location 6. Out of roundness of inside diameter and variations in wall thickness about the circumference are determined prior to milling. The depth of cut can also be monitored in real time and the processor 20 that takes in such data in real time can control the radial movement of the cutting structure as well as providing a depth profile of the groove or recess as it is being milled. In this manner, the pressure integrity of the tubular 5 is maintained as a support location 6 is milled deep enough to support the applied pressures on an object 8 landed on an adaptive support 7 while, at the same time, guarding against removal of too much wall that can affect the pressure rating of the tubular 5.
Although removal of wall material by milling is described, the method, when the term milling is used, envisions other techniques of wall removal such as chemical reaction or lasers, to name a few known examples.
The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below:
