Patent Application
20230228163
Hydrocarbon resources are typically located below the earth's surface in subterranean porous rock formations, often called reservoirs. These hydrocarbon-bearing reservoirs can be found in depths of tens of thousands of feet below the surface. In order to extract the hydrocarbon fluids, also referred to as oil and/or gas, wells may be drilled to gain access to the reservoirs. Wells may be drilled vertically from the surface, deviated from vertical, or vertical to horizontal in order to most effectively access the subsurface hydrocarbon reservoirs.
A step in the drilling operations, or well construction, involves casing the wellbore with tubulars and cementing the tubulars in place. This isolates the internal conduit or well from the surrounding formations that may be prone to collapse or have undesirable hazards present such as shallow gas. Each section of the well is typically drilled with a drill bit that is attached to a length of drill string that extends from the bottom of the wellbore to a drilling rig at surface. Upon completion of drilling a section of well bore, the drill string and the drill bit are pulled out of the wellbore and a section of casing is deployed and cemented into place to create the desired isolation from the newly drilled formation.
In well construction it is often necessary to alter an existing wellbore trajectory. This is typically known as “sidetracking”. Scenarios that may require sidetracking include, but are not limited to, a need to avoid subsurface hazards (faults, shallow gas, etc.), planned multi-lateral wells, failure of an existing wellbore, missed geological targets, and reuse of an existing wellbore that has depleted reservoir production. A whipstock is a device that is commonly deployed to facilitate the altering of a wellbore trajectory. The whipstock has a longitudinal tubular body with an inclined plane that when deployed into the wellbore can serve as a deflection surface or ramp to alter the trajectory of the drill bit and, thus, the wellbore.
Conventionally, sidetracking involves a complex series of steps. Normally, a whipstock is deployed and set at a predetermined “casing window” or “side-track” depth inside the wellbore, and within a casing section. A window is typically milled in the casing, following the setting of the whipstock. Typically, at least two mills are required for ensuring that a window can be fully cut and the resultant edges smoothed. A well cleanout assembly is then run to retrieve metal cuttings, and finally the whipstock needs to be retrieved after the task of actually drilling a lateral is complete.
Conventional operations as noted can clearly be time-consuming and expensive, especially in connection with certain rig locations. On the other hand, operational difficulties can often be encountered such as mechanical problems with the mills, human error in the course of shaping the window, and problems with setting and retrieving the whipstocks.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
In one aspect, embodiments disclosed herein relate to a method including deploying a bottom hole assembly downhole into a wellbore lined with a casing. While the bottom hole assembly is deployed downhole, the bottom hole assembly is used to: place a guiding profile within the wellbore casing, wherein the guiding profile is structured to physically guide a downhole drill in a direction different from that of a longitudinal axis of the casing; cut a window in the casing with a laser cutter; and withdraw at least one cut portion of the casing away from the window.
In one aspect, embodiments disclosed herein relate to a bottom hole assembly including: a laser cutter for cutting a window in a wellbore casing; a withdrawal mechanism for withdrawing at least one cut portion of the casing away from the cut window; and a releasable guiding profile structured to physically guide a downhole drill in a direction away from the wellbore casing.
In one aspect, embodiments disclosed herein relate to a method including: appending a guiding profile to a bottom hole assembly; and thereafter deploying the bottom hole assembly downhole into a wellbore lined with a casing. While the bottom hole assembly is deployed downhole, the bottom hole assembly is used to: attach the guiding profile to the wellbore casing, wherein the guiding profile is structured to physically guide a downhole drill in a direction different from that of a longitudinal axis of the casing; withdraw the bottom hole assembly away from the guiding profile; thereafter cut a window in the casing with a laser tool; and withdraw at least one cut portion of the casing away from the window.
Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.
Specific embodiments of the disclosed technology will now be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency.
In the following detailed description of embodiments of the disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the disclosure. However, it will be apparent to one of ordinary skill in the art that the disclosure may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.
Throughout the application, ordinal numbers (e.g., first, second, third, etc.) may be used as an adjective for an element (i.e., any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as using the terms “before”, “after”, “single”, and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element is distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements.
Broadly contemplated herein, in accordance with one or more embodiments, are methods and systems for optimizing and enhancing sidetracking operations via the use of a laser cutter instead of mechanical cutting tools (such as mills) to create a casing window for facilitating subsequent lateral (or non-vertical) drilling. More particularly, such methods and systems permit running in hole, and setting an enhanced guiding profile—analogous to a whipstock—in the same downhole run as cutting a window and retrieving its physical remnants.
Additionally, by way of general background in accordance with one or more embodiments, the drill string 112 may be suspended in wellbore 102 by a derrick structure 101. A crown block 106 may be mounted at the top of the derrick structure 101. A traveling block 108 may hang down from the crown block 106 by means of a cable or drill line 103. One end of the drill line 103 may be connected to a drawworks 104, which is a reeling device that can be used to adjust the length of the drill line 103 so that the traveling block 108 may move up or down the derrick structure 101. The traveling block 108 may include a hook 109 on which a top drive 110 is supported. The top drive 110 is coupled to the top of the drill string 112 and is operable to rotate the drill string 112. Alternatively, the drill string 112 may be rotated by means of a rotary table (not shown) on the surface 114. Drilling fluid (commonly called mud) may be pumped from a mud system 130 into the drill string 112. The mud may flow into the drill string 112 through appropriate flow paths in the top drive 110 or through a rotary swivel if a rotary table is used (not shown).
Further, by way of general background in accordance with one or more embodiments, and during a drilling operation at the well site 100, the drill string 112 is rotated relative to the wellbore 102 and weight is applied to the drill bit 128 to enable the drill bit 128 to break rock as the drill string 112 is rotated. In some cases, the drill bit 128 may be rotated independently with a drilling motor (not shown). In other embodiments, the drill bit 128 may be rotated using a combination of a drilling motor (not shown) and the top drive 110 (or a rotary swivel if a rotary table is used instead of a top drive) to rotate the drill string 112. While cutting rock with the drill bit 128, mud (not shown) is pumped into the drill string 112. The mud flows down the drill string 112 and exits into the bottom of the wellbore 102 through nozzles in the drill bit 128. The mud in the wellbore 102 then flows back up to the surface 114 in an annular space between the drill string 112 and the wellbore 102 carrying entrained cuttings to the surface 114. The mud with the cuttings is returned to the mud system 130 to be circulated back again into the drill string 112. Typically, the cuttings are removed from the mud, and the mud is reconditioned as necessary, before pumping the mud again into the drill string 112.
Moreover, by way of general background in accordance with one or more embodiments, drilling operations are completed upon the retrieval of the drill string 112, the BHA 124, and the drill bit 128 from the wellbore 102. In some embodiments of wellbore 102 construction, production casing operations may commence. A casing string 116, which is made up of one or more larger diameter tubulars that have a larger inner diameter than the drill string 112 but a smaller outer diameter than the wellbore 102, is lowered into the wellbore 102 on the drill string 112. Generally, the casing string 116 is designed to isolate the internal diameter of the wellbore 102 from the adjacent formation 126. Once the casing string 116 is in position, it is set and cement is typically pumped down through the internal space of the casing string 116, out of the bottom of the casing shoe 120, and into the annular space between the wellbore 102 and the outer diameter of the casing string 116. This secures the casing string 116 in place and creates the desired isolation between the wellbore 102 and the formation 126. At this point, drilling of the next section of the wellbore 102 may commence.
Conventionally, a whipstock may be deployed when there is a need to alter the trajectory of the wellbore, such as for a sidetracking operation (e.g., to drill a lateral or non-vertical wellbore). Upon reaching a predetermined setting depth, an anchoring mechanism is typically activated and attaches the whipstock to the inside surface of the wellbore casing. Then, in a subsequent operation to mill out a casing window, the deflection surface of the whipstock is used as a ramp to deflect the drill bit away from the existing (e.g., vertical) wellbore so as to commence drilling of a new wellbore with a new (e.g., lateral or non-vertical) trajectory.
As such,
Additionally, by way of general background and in accordance with one or more embodiments, the whipstock 200 includes a deflection surface 202, and a connection to an anchor 206 via an anchor connection 208. The mill bit 216 of drilling assembly 210 may be a fixed-style bit that is designed for milling through metal or steel, especially as configured for milling a window in the casing string 116 when there is a need to “sidetrack” or change the trajectory of a wellbore 102. Thus,
The disclosure now turns to working examples of a mechanical coupling in accordance with one or more embodiments, as described and illustrated with respect to
As such, in accordance with one or more embodiments, the BHA 324 is deployed to a predetermined depth within the casing 316 (and associated wellbore). The laser cutter 352 begins an operation for cutting a window in the casing 316, guided by decoded mud pulse data sent from the surface to telemetry system 360. (The cutting of a window may occur before or after a guiding profile is set in place, as discussed further below.) A window is thus cut in the casing 316 to predetermined dimensions. Thus, by way of example, an outline of the window may generally be rectilinear, circular or elliptical in shape when viewed in a two-dimensional projection of its shape. The power source 358 can be pre-programmed (e.g., via suitable internal logic) to circulate power to the laser cutter 352 in a manner to prevent overheating.
In accordance with one or more embodiments, as can generally be appreciated, the laser cutter 352 is capable of performing its cutting operation even with fluid intervening in its path. Once the window cutting operation is complete, the latching hooks 354 are appended to the cut window (in casing 316) in preparation for retrieving the cut window piece. The sidewise jar 362 is then activated to create an impact force at or near the position of the cut window in order to break the cement behind the casing 316, such that the cut window piece is sufficiently loosened to be withdrawn away from the window opening.
As such, in accordance with one or more embodiments, a guiding profile—which functions analogously to a whipstock—may also be appended or attached to a lowermost portion of BHA 324 (e.g., just below the laser cutter 352). Accordingly,
As shown in
In accordance with one or more embodiments, to attach the guiding profile 460 to the casing, releasable latching hooks 466 are provided at an underside of horizontal frame portion 462b; here, two are shown. Hooks 466 can be released (e.g., via pressure pulses) when the BHA 424 (to which the guiding profile 460 is attached) reaches a predetermined depth within the wellbore, to then attach to the casing to help hold the guiding profile 460 in place. After the hooks 466 are latched into the casing, the BHA 424 can deploy upwardly and thus be withdrawn away from the guiding profile 460, and packers 468 can be set to secure the position of the guiding profile 460 within the casing even more firmly, bridging between the guiding profile 460 and the casing. The packers 468, for their part, may be pull-to-release inflatable packers which are set by being inflated.
In accordance with one or more embodiments, in order to retrieve the guiding profile 460 to return the same to the surface, the guiding profile 460 may be equipped with one or more retrieval portions. As such, guiding profile 460 may include a primary retrieval portion 470 and two backup mechanisms in the form of additional retrieval portions (472, 474) to ensure that the profile 460 can reliably be retrieved after lateral drilling (or sidetracking) is completed. These first, second and third retrieval portions (470, 472, 474), which may also be termed “latching profiles”, are separately disposed on different portions of the support frame 462a/b, spaced apart from one another. As such, once lateral drilling operations are completed, an incoming retrieval element (or tool), deployed downhole into the wellbore from the surface, may be latched to the primary retrieval portion 470. Thus primary retrieval portion 470 receives the retrieval element to permit withdrawal of the guiding profile 460 from the wellbore and to assist in deflation of the packers 468. In other words, as the guiding profile 460 is withdrawn from the wellbore by being pulled upwardly, this causes the pull-to-release packers 468 to deflate.
In accordance with one or more embodiments, if there is any difficulty with the retrieval element latching onto the primary retrieval portion 470, the secondary retrieval portion 472—provided on the vertical frame portion 462a as shown—will also permit the retrieval element to latch to permit withdrawal of the guiding profile 460 from the wellbore and to assist in deflation of the packers 468. In other words, as the guiding profile 460 is withdrawn from the wellbore by being pulled upwardly via secondary retrieval portion 472, the pull-to-release packers 468 will be caused to deflate.
Moreover, in accordance with one or more embodiments, if there is any difficulty in latching onto the secondary retrieval portion 472, the tertiary retrieval portion 474—provided on the horizontal frame portion 462b as shown—will permit the retrieval element to latch to permit withdrawal of the guiding profile 460 from the wellbore and to assist in deflation of the packers 468. In one possible arrangement, the retrieval element can be deployed downhole to latch onto both of the secondary 472 and tertiary 474 retrieval portions, pulls the guiding profile 460 upwardly, and thereby creates an equal force at different ends of the frame 462a/b to promote deflation of the packers 468.
In accordance with one or more embodiments,
As shown in
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As shown in
In accordance with one or more embodiments, as discussed previously in connection with
As such, in accordance with one or more embodiments, a BHA may be deployed downhole into a wellbore lined with a casing (580). By way of illustrative example, the casing may correspond to that indicated at 316 in
It can be appreciated from the foregoing that, in accordance with one or more embodiments, a retrievable guiding profile for a sidetracking operation may be set in the same downhole operation, using the same BHA, as cutting a corresponding window in the wellbore casing and retrieving its remnants. Generally, this helps resolve many problems encountered in conventional sidetracking, such as milling inefficiency (e.g., as may arise from extended milling duration), difficulties in establishing a desired window size and smoothness, and difficulties with whipstock retrieval. As broadly contemplated herein, a pre-programmed laser cutter can cut a casing window precisely even through ambient fluid. This process can be undertaken in a shorter time than in conventional operations while mitigating any potential impact of human error. Further, the need for an additional smoothing operation is eliminated along with any need for collecting excess metal cuttings or chips.
Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function.
