Present embodiments relate generally to the field of drilling and processing of wells. More particularly, present embodiments relate to continuous circulation systems and methods.
In conventional oil and gas operations, a drilling rig is used to drill a wellbore to a desired depth using a drill string, which includes drillpipe, drill collars and a bottom hole drilling assembly. During drilling, the drill string may be turned by a rotary table and kelly assembly or by a top drive to facilitate the act of drilling. As the drill string progresses down hole, additional drillpipe is added to the drill string.
During drilling of the well, the drilling rig may be used to insert joints or stands (e.g., multiple coupled joints) of drillpipe into the wellbore. Similarly, the drilling rig may be used to remove drillpipe from the wellbore. As an example, during insertion of drillpipe into the wellbore by a traditional operation, each drillpipe element (e.g., each joint or stand) is coupled to an attachment feature that is in turn lifted by a traveling block of the drilling rig such that the drillpipe element is positioned over the wellbore. An initial drillpipe element may be positioned in the wellbore and held in place by gripping devices near the rig floor, such as slips. Subsequent drillpipe elements may then be coupled to the existing drillpipe elements in the wellbore to continue formation of the drill string. Once attached, the drillpipe element and remaining drill string may be held in place by an elevator and released from the gripping devices (e.g., slips) such that the drill string can be lowered into the wellbore. Once the drill string is in place, the gripping devices can be reengaged to hold the drill string such that the elevator can be released and the process of attaching drillpipe elements can be started again. Similar procedures may be utilized for removing drillpipe from the wellbore.
Various fluids (e.g., drilling fluid or mud) may be utilized in well-related operations. For example, drilling fluid is typically circulated through the wellbore during rotary drilling operations. This circulation functions to bring cuttings to the surface, cool and lubricate aspects of the drill string (e.g., the drill bit), hold back subsurface pressure, and so forth. It is desirable to provide improved fluid circulation systems and methods for drilling-related applications.
These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Present embodiments are directed to systems and methods for circulating fluids through well strings (e.g., a drilling string) such that interruptions in circulation through the respective well strings are limited during certain transition periods. More particularly, present embodiments relate to continuous circulation systems and methods that employ a coupler that facilitates rapid coupling of the continuous circulation system to a stump of a joint string through which it is desirable to circulate fluids.
In accordance with one embodiment, a continuous circulation management system includes a quick coupler that facilitates sealed engagement of a fluid circulation feature with a pipe stump (e.g., the stump of a drill string). Further, such a system may include features that facilitate directing the fluid to the circulation management system and circulation of the fluid through the pipe string associated with the pipe stump via the sealed engagement. For example, present embodiments include a fluid circulation management system with a coupling feature that enables rapid engagement of the fluid circulation management system with a stump of a drill string for maintaining circulation through the drill string during a process step in which a pipe drive system is decoupled from the stump, such as when the pipe drive system is decoupled for adding drillpipe stands or tripping drillpipe stands out of the hole.
A pipe drive system (e.g., a top drive), which may be broadly referred to as being incorporated with pipe handling equipment, may be used to facilitate assembly and disassembly of drill strings. Indeed, a pipe drive system may be employed to engage and lift a drillpipe element (e.g., a drillpipe joint), align the drillpipe element with a drill string, stab a pin end of the drillpipe element into a box end of the drill string, engage the drill string, and apply torque to make-up a coupling between the drillpipe element and the drill string. Thus, a pipe drive system may be employed to extend the drill string. Similarly, the pipe drive system may be used to disassemble drillpipe elements from a drill string by applying reverse torque and lifting the drillpipe elements out of the engagement with the remaining drill string. It should be noted that torque may be applied using a top drive system coupled to the pipe drive system or integral with the pipe drive system. Further, pipe handling equipment associated with or including the pipe drive system may provide fluid circulation through associated drillpipe while connected with the drillpipe.
Each drillpipe element typically includes a pin end and a box end to facilitate coupling of multiple joints of drillpipe. When positioning and assembling drillpipe elements in the wellbore, a drillpipe element is typically inserted into the wellbore until only an upper end is exposed above the wellbore. This exposed portion, which generally includes the box end, may be referred to as a stump. At this point, slips are typically positioned about the stump near the rig floor to hold the drillpipe element in place. The box end is typically positioned facing upward (“box up”) such that the pin end of subsequently inserted drillpipe with the pin facing downward (“pin down”) can be coupled with the box end of the previously inserted drillpipe or stump to continue formation of the downhole string. Drillpipe being added may be gripped at a distal end by a pipe drive system and the opposite distal end may be stabbed into the box end of the stump. Next, the pipe drive system may be employed to make-up a coupling between the drillpipe being added and the stump. Once the newly added drillpipe is appropriately attached, the gripping member may be removed and the drill string lowered further into the wellbore using an elevator. This process continues until a desired length of the drill string is achieved. Similarly, a reverse process may be used during removal of a drill string from a wellbore.
During a process of installing or removing drillpipe elements, it may be desirable to circulate fluids (e.g., drilling fluid or mud) through the associated drill string substantially continuously. However, during certain phases of a drilling process, the pipe drive system or pipe handling equipment, which may be a source of the fluid flow (e.g., drilling mud flow), must be decoupled from the drill string. For example, in order to engage with a drillpipe stand to be added or to complete extraction of a drillpipe stand from the hole, the pipe drive system is decoupled from communicative engagement with the drill string, which leaves the stump of the string open. This generally results in an inability to flow fluids from the pipe drive system or pipe handling equipment through the drill string during connection, disconnection, removal, or insertion phases of the process. Thus, present embodiments include systems and methods that facilitate rapid engagement of the open stump and circulation of fluids through the associated string during certain phases of the process. Indeed, present embodiments are directed to a circulation system that rapidly engages the stump, directs fluid (e.g., redirects fluid from the pipe handling equipment) through the circulation system into the string, and maintains circulation during phases of operation wherein the pipe handling equipment is decoupled from the stump.
Turning now to the drawings,
In the illustrated embodiment, the drilling rig 10 features an elevated rig floor 12 and a derrick 14 extending above the rig floor 12. A supply reel 16 supplies drilling line 18 to a crown block 20 and traveling block 22 configured to hoist various types of equipment and drillpipe above the rig floor 12. The drilling line 18 is secured to a deadline tiedown anchor 24. Further, a drawworks 26 regulates the amount of drilling line 18 in use and, consequently, the height of the traveling block 22 at a given moment. Below the rig floor 12, a drill string 28 extends downward into a wellbore 30 and is held stationary with respect to the rig floor 12 by a rotary table 32 and slips 34. A portion of the drill string 28 extends above the rig floor 12, forming a stump 36 to which another drillpipe element or length of drillpipe 38 is in the process of being added.
The length of drillpipe 38 is held in place by a pipe drive system 40 that is hanging from the traveling block 22. In the illustrated embodiment, the pipe drive system 40 is holding the drillpipe 38 in alignment with the stump 36 for eventual coupling of the drillpipe 38 with the stump 36. Indeed, in the illustrated embodiment the pipe drive system 40 includes a top drive 46 (in some embodiments, the top drive 46 is separate from the pipe drive system 40) configured to supply torque for making-up and unmaking a coupling between the drillpipe 38 and the stump 36. However, in the illustrated instant of this phase of operation, the pipe drive system 40 remains out of communicative coupling with the stump 36 and thus out of communicative coupling with the drill string 28. Further, for various reasons, the process may be delayed such that the status of the operation is fixed in this decoupled orientation for an amount of time. Thus, present embodiments are directed to a system and method for facilitating maintenance of substantially continuous fluid circulation through the drill string 28 by facilitating rapid coupling of the stump 36 with a coupling device 42 of a circulation management system 44 in accordance with present embodiments. It may be beneficial to maintain circulation in this and similar situations (e.g., while changing drillpipe) to avoid issues that may result from a lack of circulation, such as cutting settling, downhole temperature excursions, stuck pipe incidents, and formation damage.
The coupling device 42 may facilitate communicative coupling (e.g., substantially sealed engagement that enables fluid flow through the engagement) between the circulation management system 44 and the drill string 28. Establishing this sealed passage facilitates circulation of fluid (e.g., drilling mud) through the circulation management system 44 into the drill string 28 via the stump 36 and maintenance of substantially continuous circulation while the pipe drive system 40 is decoupled from the drill string 28. Different embodiments of the coupling device 42 and circulation management system 44 may achieve such communicative coupling in different ways in accordance with present techniques. For example, in order to provide a reaction force with sufficient magnitude to counter pressure of the flowing fluid, the circulation management system 44 may hold the stump 36 (e.g., via a shoulder of the associated upset) with a set of fixed or moveable engagement or gripping features (e.g., elevator like protrusions) and pull the circulation management system 44 together with the stump 36. In other embodiments, the reaction force may be provided via a connection between the circulation management system 44 and the rig 10 or a semi-stationary base lifter (e.g., a cart with adjustable supports). For example, a sufficiently rigid mechanism attached to or integral with the circulation management system 44 may be coupled to the rig floor 12 and utilized to force the coupling device 42 against the stump 36 with sufficient force to establish a sealed engagement.
As generally indicated above, the coupling device 42 may include a seal that can be engaged with the stump 36 with sufficient force to establish a sealed engagement. The force utilized for such an engagement can be provided via various retention devices or techniques in accordance with present embodiments. For example, the stump 36 includes a box end with a shoulder and the coupling device 42 may include gripping features that engage the shoulder and pull the circulation management system 44 together with the stump 36 with sufficient axial force to establish sealed engagement (e.g., a face seal) between the two features, which facilitates fluid flow from the circulation management system 44 into the drill string 28 without substantial spillage. In such embodiments, the coupling device 42 may include gripping features, such as moveable dies, a fixed cradle, an articulated elevator, a pivoting clamp, a chain, or the like. In such embodiments, the coupling device 42 may attach to the stump 36 and apply an axial pulling force (e.g., via a hydraulic piston and cylinder) that pulls the circulation management system 44 over the stump 36 such that a seal within the circulation management system 44, or more specifically within the coupling device 42 of the circulation management system 44, engages with the stump 36 with sufficient force to establish a seal. In such embodiments, the circulation management system 44 may be suspended from the derrick 14 or otherwise non-rigidly attached to the rig 10. For example, the circulation management system 44 may be suspended from an arm 45, which may also include a port to be utilized as an access point to the string 28 via the circulation managing system 44 for a wireline or the like during circulation.
In other embodiments, the reaction force for establishing such sealed engagement may be provided via a rigid attachment of the circulation management system 44 to the rig 10. For example, in the illustrated embodiment, the circulation management system 44 is coupled to the rig floor 12 via a mechanical arm 46 and a base 48. In such an embodiment, the coupling device 42 may not include any features for gripping the stump 36, at least not via circumferential compression. Rather, the attachment (e.g., the attachment via the arm 46 and the base 48) of the circulation management system 44 to the rig 10 may be utilized to provide sufficient force between the coupling device 42 (e.g., a housing including a seal) and the stump 36 to establish a communicative engagement of the circulation management system 44 with the drill string 28.
The rig 10 also includes a general circulation system 52, which includes the circulation management system 44 and at least a fluid coupling point with the pipe drive system 40. During appropriate phases of operation, the general circulation system 52 directs fluid flow to the pipe drive system 40 or the circulation management system 44 via a valve 54 (e.g., a three-way valve) or the like. For example, when the pipe drive system 40 is communicatively coupled with the string 28, the valve 54 may direct fluid flow through the pipe drive system 40 and block flow to the circulation management system 44. However, when the pipe drive system 40 is decoupled from the string 28 to add pipe or the like, the valve 54 may direct flow to the circulation management system 44 to maintain circulation through the string 28 while the pipe drive system 40 is decoupled. In some embodiments, the general circulation system 52 may direct some fluid flow to both the pipe drive system 40 and the circulation management system 44, such as during transition periods. Further, the valve 54 (which may represent a system of valves) may be positioned to block all flow there through. The valve 54 and other aspects of the general circulation system 52, pipe drive system 40, circulation management system 44, and/or other aspects of the rig 10 may be automatically or manually controlled using an automation controller (e.g., programmable logic controller) and related control components generally represented by control system 56, which may include sensors, actuators, memory (non-transitory, computer-readable media), processors, and so forth.
In the illustrated embodiment, the general circulation system 52 includes fluid flow supply features such as a mud pump 60, a discharge line 62, a stand pipe 64, rotary hose 66 for the pipe drive system 40, a rotary hose 68 for the circulation management system 44, a return line 70, a retention tank 72, and other aspects of the rig 10. In operation, the mud pump 60 provides the motivating force for circulation of the drilling fluid. Specifically, the mud pump 60 pumps drilling fluid through the discharge line 62, the stand pipe 64, the rotary hoses 66, 68, the pipe drive system 40 and/or the circulation management system 44 based on an orientation of the valve 54. During circulation via the pipe drive system 40 or circulation management system 44, the drilling fluid flows through the drill string 28 and an associated bottom hole assembly (BHA) 74 to exit into the wellbore 30 via a drill bit 76. As indicated by arrows 78, the drilling fluid is then pushed up toward the surface through the annulus formed between the wellbore 30 and the drill string 28. As the drilling fluid proceeds up the annulus, it generally carries the rock cuttings and so forth with it to the surface. Once the drilling fluid reaches the surface, the return line 70 conveys the drilling fluid to the retention tank 72 (e.g., a series of multiple retention vessels), which feeds the mud pump 60. In some embodiments, a series of tanks and other components may be utilized to separate the cuttings from the drilling fluid before the drilling fluid is returned to the mud pump 60 to continue circulation.
Specifically, with reference to
In one embodiment, the shoulder-coupling features 92 are configured to facilitate both lateral engagement with the stump 36 and to maintain sufficient axial force to provide the desired seal. For example, in one embodiment the shoulder-coupling features 92 include a ball and detent mechanism that includes a plurality of balls (or otherwise rounded features, such as rollers or round-ended cylinders) that are biased out of recesses disposed along an interior of a housing of the coupling feature 42. When the coupling feature 42 is pressed down over the box end 90 of the stump 36, the balls may be pressed into their respective recesses while passing over the outer walls of the box end 90 and then biased outward into engagement with the shoulder 94 when properly aligned therewith. Simply pulling the coupling feature 42 off of the stump 36 could break this engagement. However, the axial force applied while the balls are engaged with the shoulder 94 may be sufficient to maintain a seal during fluid flowing operations.
In other embodiments, as illustrated in
In the embodiment illustrated by
Present embodiments are directed to establishing an engagement between the fluid circulation management system 44 and the stump 36 that can support a fluid seal that allows fluid circulation (e.g., drilling mud circulation) without substantial leakage. In particular, this involves applying sufficient force to establish such a sealed engagement between the seal 87 and aspects of the box end 90, such as the face 88 and threads 205. An initial aspect of establishing such an engagement, in the illustrated embodiment, includes engaging the shoulder 94 with the elevators 200 to support application of the desired axial force. In some embodiments, this includes positioning the box end 90 within the housing 204. For example, this may include maneuvering the circulation management system 44 into position over the stump 36 and lowering it such that the elevators 200 are aligned with the shoulder 94. This maneuvering may be achieved via various mechanisms attached to or integral with the circulation management system 44. For example, the circulation management system 44 may be suspended from a maneuverable arm (e.g., crane or robotic arm) coupled to the rig 10 (e.g., coupled via the arm 45) or positioned on a cart that can be rolled or otherwise maneuvered over the rig floor 12. In
In the illustrated embodiments of
As noted above, when initially coupling the stump 36 and the coupling feature 42, the coupling feature 42 is first positioned over the stump 36 such that the elevator blocks 224 are generally aligned for engagement with the shoulder 94. Once this positioning is achieved, the elevator actuators 210 may actuate the elevators 200 to engage the elevator blocks 224 with the shoulder 94. To establish this alignment, the coupling feature 42 may include specified dimensions that achieve the proper orientation when the seal 87 engages the face 88. For example, to establish proper alignment of the elevator blocks 224 with the shoulder 94, the seal 87 may be arranged within the housing 204 based on standard tool joint sizes such that engagement of the face 88 of the box end 90 with the lowermost face of the seal 87 ensures that the shoulder 94 is properly positioned with respect to the elevator blocks 224 before actuation of the elevators 200. Once a desired positioning is achieved, the elevators 200 may be actuated to engage the stump 36 via the shoulder 94 and thus establish engagement for the application of the sealing force. As will be discussed below, the embodiments illustrated in
In the illustrated embodiment of
The seal piston 202 may be actuated by pressure. For example, an actuator may provide hydraulic pressure via an upper port 258 into the piston housing 232 such that pressure is increased on an upper side of a lip 262 of the seal piston 202 within the piston housing 232. This may force the seal piston 202 downward and correspondingly flush fluid out of a second, lower port 264 accessing the piston housing 232 that is below the lip 262. In turn, this actuation of the seal piston 202 may cause the lower seal 87 to move relative to the housing 204 and to engage the box end 90 (e.g., the face 88 and the threads 205) when the stump 36 is at least partially positioned within the coupling feature 42. Actuation of the seal piston 202 is observable by viewing the transition shown between
Pressure may also be applied to the seal piston 202 by fluid (e.g., drilling mud) passing through the main flow path 208 from the general circulation system 52. Specifically, for example, fluid coming from the general circulation system 52 may press on the upper seal 242 and force the piston assembly 230 in the flow direction. Pressure on the upper seal 242 may not be sufficient pressure to fully actuate the seal piston 202 in some embodiments. However, it may serve to preload the seal piston 202 for actuation by a separate actuator (e.g., a hydraulic actuator). Further, because the surface of the upper seal 242 exposed to pressure from fluid is larger than the surface of the lower seal 87 exposed to pressure from fluid, the seal piston 202 will generally be energized downward under fluid pressure (e.g., mud pressure). This may force the lower seal 87 against the box end 90 to prevent leakage in the event that an actuator for the seal piston 203, such as a hydraulic actuator, loses energy (e.g., pressure).
The upper seal 242 and the lower seal 87 may be integral with or attachable with the seal piston 202. Further, the upper seal 242 and the lower seal 87 may include numerous different seal features and combinations of seal features in accordance with present embodiments. The upper seal 242 illustrated in
In some embodiments, the sealing mechanism 228 may be simplified to not include the seal assembly 230 and yet be capable of accommodating box ends with varying dimensions. For example, as illustrated in
While only certain features of present embodiments have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
This application is a continuation-in-part of U.S. application Ser. No. 13/655,798 entitled “PIPE DRIVE SEALING SYSTEM AND METHOD,” and also a continuation-in-part of U.S. application Ser. No. 13/339,161 entitled “PIPE DRIVE SEALING SYSTEM AND METHOD”, filed Dec. 28, 2011, each of which is hereby incorporated by reference.
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Number | Date | Country | |
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20140224509 A1 | Aug 2014 | US |
Number | Date | Country | |
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Parent | 13655798 | Oct 2012 | US |
Child | 14255814 | US | |
Parent | 13339161 | Dec 2011 | US |
Child | 13655798 | US |