Patent Application
20230091920
In the oil and gas industry, hydrocarbons are located in porous formations far beneath the Earth's surface. Wells are drilled into these formations to access and produce said hydrocarbons. Oftentimes, during drilling the well or throughout the life of the well, equipment or junk gets lost in the well. The equipment or junk that gets lost in a well is called a fish. A fishing job may ensue to clear the well of the fish.
Fishing jobs may include running fishing tools to latch onto the fish and pull the fish out of the hole. Fishing jobs may also include drilling out the fish. Drilling out the fish includes running a mill into the well and drilling, or “milling,” the fish. A mill is a specially designed drill bit that is meant to drill through metals such as casing and fish, whereas a conventional drill bit is used to drill through formations and plastics. Mills are often designed in different shapes depending on the shape of the fish that is lost in the hole.
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.
The present invention presents, in one or more embodiments, methods and system for using an adjustable mill. The system includes a deployment device and an adjustable mill. The deployment device has a box end with internal threads disposed around an internal circumferential surface. The adjustable mill has a tubular body, a cylinder, and a lock ring. The tubular body has a lateral end and a pin end. The pin end has external threads disposed around an external circumferential surface of the pin end, the lateral end is partially enveloped by a plurality of cutters, and the lateral end comprises an inner wall defining an orifice. The cylinder is movably disposed within the orifice of the lateral end of the tubular body. The cylinder is partially enveloped by the plurality of cutters. The lock ring is disposed circumferentially around the cylinder. The lock ring is configured to interact with a lock ring seat machined into the inner wall of the lateral end to place the adjustable mill in a mode. The internal threads of the adjustable mill and the external threads of the deployment device interact to form a connection between the adjustable mill and the deployment device.
The method is for a well having a fish and the method initially includes providing an adjustable mill. The adjustable mill has a tubular body, a cylinder, and a lock ring. The tubular body has a lateral end and a pin end. The pin end has external threads disposed around an external circumferential surface of the pin end, the lateral end is partially enveloped by a plurality of cutters, and the lateral end comprises an inner wall defining an orifice. The cylinder is movably disposed within the orifice of the lateral end of the tubular body. The cylinder is partially enveloped by the plurality of cutters. The lock ring is disposed circumferentially around the cylinder. The lock ring is configured to interact with a lock ring seat machined into the inner wall of the lateral end. The method further includes connecting the adjustable mill to a deployment device, having a box end with internal threads, by threading together the internal threads and the external threads, lowering the adjustable mill into the well using the deployment device, lowering the adjustable mill onto the fish to adjust a mode of the adjustable mill, and drilling the fish out of the well using the adjustable mill.
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. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn are not necessarily intended to convey any information regarding the actual shape of the particular elements and have been solely selected for ease of recognition in the drawing.
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.
The drill string (108) may include one or more drill pipes (109) connected to form conduit and a bottom hole assembly (BHA) (110) disposed at the distal end of the conduit. The BHA (110) may include a drill bit (112) to cut into the subsurface rock. The BHA (110) may include measurement tools, such as a measurement-while-drilling (MWD) tool (114) and logging-while-drilling (LWD) tool 116. Measurement tools (114, 116) may include sensors and hardware to measure downhole drilling parameters, and these measurements may be transmitted to the surface using any suitable telemetry system known in the art. The BHA (110) and the drill string (108) may include other drilling tools known in the art but not specifically shown.
The drill string (108) may be suspended in wellbore (102) by a derrick (118). A crown block (120) may be mounted at the top of the derrick (118), and a traveling block (122) may hang down from the crown block (120) by means of a cable or drilling line (124). One end of the cable (124) may be connected to a drawworks (126), which is a reeling device that may be used to adjust the length of the cable (124) so that the traveling block (122) may move up or down the derrick (118). The traveling block (122) may include a hook (128) on which a top drive (130) is supported.
The top drive (130) is coupled to the top of the drill string (108) and is operable to rotate the drill string (108). Alternatively, the drill string (108) may be rotated by means of a rotary table (not shown) on the drilling floor (131). Drilling fluid (commonly called mud) may be stored in a mud pit (132), and at least one pump (134) may pump the mud from the mud pit (132) into the drill string (108). The mud may flow into the drill string (108) through appropriate flow paths in the top drive (130) (or a rotary swivel if a rotary table is used instead of a top drive to rotate the drill string (108)).
In one implementation, a system (199) may be disposed at or communicate with the well site (100). System (199) may control at least a portion of a drilling operation at the well site (100) by providing controls to various components of the drilling operation. In one or more embodiments, system (199) may receive data from one or more sensors (160) arranged to measure controllable parameters of the drilling operation. As a non-limiting example, sensors (160) may be arranged to measure WOB (weight on bit), RPM (drill string rotational speed), GPM (flow rate of the mud pumps), and ROP (rate of penetration of the drilling operation).
Sensors (160) may be positioned to measure parameter(s) related to the rotation of the drill string (108), parameter(s) related to travel of the traveling block (122), which may be used to determine ROP of the drilling operation, and parameter(s) related to flow rate of the pump (134). For illustration purposes, sensors (160) are shown on drill string (108) and proximate mud pump (134). The illustrated locations of sensors (160) are not intended to be limiting, and sensors (160) could be disposed wherever drilling parameters need to be measured. Moreover, there may be many more sensors (160) than shown in
During a drilling operation at the well site (100), the drill string (108) is rotated relative to the wellbore (102), and weight is applied to the drill bit (112) to enable the drill bit (112) to break rock as the drill string (108) is rotated. In some cases, the drill bit (112) may be rotated independently with a drilling motor. In further embodiments, the drill bit (112) may be rotated using a combination of the drilling motor and the top drive (130) (or a rotary swivel if a rotary table is used instead of a top drive to rotate the drill string (108)). While cutting rock with the drill bit (112), mud is pumped into the drill string (108).
The mud flows down the drill string (108) and exits into the bottom of the wellbore (102) through nozzles in the drill bit (112). The mud in the wellbore (102) then flows back up to the surface in an annular space between the drill string (108) and the wellbore (102) with entrained cuttings. The mud with the cuttings is returned to the pit (132) to be circulated back again into the drill string (108). Typically, the cuttings are removed from the mud, and the mud is reconditioned as necessary, before pumping the mud again into the drill string (108). In one or more embodiments, the drilling operation may be controlled by the system (199).
While drilling the wellbore (102), as described above, various pieces of equipment such as the drill bit (112) or a portion of the drill string (108) may be disconnected from the surface portion of the well site (100) (surface portion being on or above the surface of the Earth) and be lost to the downhole portion of the well site (100) (downhole portion being anywhere beneath the surface of the Earth). The downhole portion of the well site (100) is called the well herein. Equipment or junk that is lost in the well is called a fish. A fish may come from a drilling operation as described above, or a fish may come from any other operation without departing from the scope of this disclosure herein.
The fish may be fished or drilled out to clear the well for production and/or continuing operations. When a fish is drilled out of the well, a mill is used in place of a conventional drill bit (112). A mill is designed to drill through tougher materials, such as steel, when compared to a conventional drill bit (112). Further, mills are available in a plurality of different mill shapes depending on the shape of the fish. However, mills are confined to being one shape and oftentimes the wrong mill shape is used to drill out the fish, because it is difficult to know what the fish looks like downhole. Therefore, a mill that is able to change shapes while downhole is beneficial. As such, embodiments disclosed herein present systems and methods for an adjustable mill that is able to change shapes downhole depending on the shape of the fish.
Because the lateral end (204) and the pin end (206) are in a tubular shape, the lateral end (204) has an inner wall (208) defining an orifice (210) and the pin end (206) has an inner surface (212) defining a passage (214). As shown in
The lateral end (204) of the tubular body (202) is partially enveloped by a plurality of cutters (220). The portion of the lateral end (204) that is enveloped by cutters (220) may be the portion that faces an external environment of the adjustable mill (200). The cutters (220) may be any type of cutters (220) known in the art, such as tungsten carbide cutters (220). A cylinder (222) is movably disposed within the orifice (210) of the lateral end (204) of the tubular body (202). The cylinder (222) is also partially enveloped by a plurality of cutters (220). The cutters (220) disposed on the cylinder (222) and the cutters (220) disposed on the lateral end (204) are the same. The portion of the cylinder (222) that is enveloped by the cutters (220) is also the portion that faces or could face the external environment of the adjustable mill (200).
The cylinder (222) is moveably disposed within the orifice (210) of the lateral end (204) of the tubular body (202). This means that the cylinder (222) is able to move up and down, in relation to the inner wall (208) of the orifice (210), such that the cylinder (222) may be completely within the orifice (210), or a portion of the cylinder (222) extends out of the orifice (210).
The deployment device is shown in
Initially, an adjustable mill (200) is provided (S500). The adjustable mill (200) is made of a lateral end (204) and a pin end (206). The pin end (206) has external threads. The lateral end (204) has an orifice (210) defined by an inner wall (208). A cylinder (222) is moveably disposed within the orifice (210). The inner wall (208) of the lateral end (204) has at least one lock ring seat (226, 228, 230) machined into the inner wall (208). The lock ring seat (226, 228, 230) corresponds to a lock ring (224) disposed around the cylinder (222). The lateral end (204) may have three lock ring seats (226, 228, 230) machined into the inner wall (208): a first lock ring seat (226), a second lock ring seat (228), and a third lock ring seat (230).
The adjustable mill (200) is connected to a deployment device, having a box end (404) with internal threads, by threading together the internal threads and the external threads (216) (S502). The deployment device may be a drill string (108) as described in
In one or more embodiment, the adjustable mill (200) is lowered into the well (400) on a drill string (108). The adjustable mill (200) is run into the well (400) in the first mode (300). When the adjustable mill (200) is located directly above the fish (402) in the well (400), then a weight, such as 30 k-lbs of slack off weight, may be applied against the fish (402). The adjustable mill (200) will either stay in the first mode (300) or the adjustable mill will change into the second mode (302) or the third mode (304) depending on the shape of the fish (402) and how that shape of the fish (402) distributes the resistance of the weight onto the adjustable mill (200).
The fish (402) is drilled out of the well (400) using the adjustable mill (200) (S508) and whichever mode the adjustable mill (200) has transformed into. The cutters (220) located on the cylinder (222) and the lateral end (204) aid in breaking down the fish (402). While the fish (402) is being drilled out of the well (400), a fluid (410) may be pumped from the drill string (108) to the adjustable mill (200), through at least one nozzle (232), and into the external environment. The external environment may be the well (400). The fluid (410) may carry pieces of the drilled-out fish (402) to the surface of the Earth. In other embodiments, as the pieces of the fish (402) are being carried to the surface of the Earth, the junk basket, located in the milling BHA (406), may catch the larger pieces of the drilled-out fish (402).
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.
