Apparatus and method for coupling conduit segments

A method of coupling segments of a borehole conduit is disclosed. The method includes: positioning a first conduit segment at a location selected from a surface location and a downhole location, the first conduit segment having a first end and a second end, the first conduit segment including a pin connector at the first end; orienting the first conduit segment so that the first end is located uphole relative to the second end; and coupling a second conduit segment in operable communication with the first conduit segment, the second conduit segment having a box connector at an end of the second conduit segment that is configured to engage the pin connector of the first segment.

BACKGROUND

During subterranean drilling and completion operations, a pipe or other conduit is lowered into a borehole in an earth formation during or after drilling operations. Such pipes are generally configured as multiple pipe segments to form a “string”, such as a drill string or production string. As the string is lowered into the borehole, additional pipe segments are coupled to the string by various coupling mechanisms, such as threaded couplings.

Various power and/or communication signals may be transmitted through the pipe segments via a “wired pipe” configuration. Such configurations include electrical, optical or other conductors extending along the length of selected pipe segments. The conductors are operably connected between pipe segments by a variety of coupling configurations.

One such coupling configuration includes a threaded male-female configuration often referred to as a pin box connection. The pin box connection includes a male member, i.e., a “pin” that includes an exterior threaded portion, and a female member, i.e., a “box”, that includes an interior threaded portion and is configured to receive the pin in a threaded connection.

Some wired pipe configurations include a transmission device mounted on the tip of the pin. However, such transmission devices can be easily damaged because of the exposed mounting location, such as when the pipe segment is racked back onto a derrick. Devices such as thread protectors may help to some degree, but are time consuming to use and add additional complexity and expense.

BRIEF DESCRIPTION

Disclosed herein is a method of coupling segments of a borehole conduit. The method includes: positioning a first conduit segment at a location selected from a surface location and a downhole location, the first conduit segment having a first end and a second end, the first conduit segment including a pin connector at the first end; orienting the first conduit segment so that the first end is located uphole relative to the second end; and coupling a second conduit segment in operable communication with the first conduit segment, the second conduit segment having a box connector at an end of the second conduit segment that is configured to engage the pin connector of the first segment.

Also disclosed herein is a borehole conduit including: a first conduit segment configured to be disposed in a borehole, the first conduit segment having a first end and a second end, the first conduit segment including a pin connector at the first end and configured to be oriented so that the first end is located uphole relative to the second end; and a second conduit segment configured to be coupled in operable communication with the first conduit segment, the second conduit segment having a box connector at an end of the second conduit segment that is configured to engage the pin connector of the first segment.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed system, apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

Referring toFIG. 1, an exemplary embodiment of a portion of a well drilling, logging and/or production system10includes a conduit or string12, such as a drillstring or production string, that is configured to be disposed in a borehole for performing operations such as drilling the borehole, making measurements of properties of the borehole and/or the surrounding formation downhole, and facilitating hydrocarbon production.

For example, during drilling operations, drilling fluid or drilling “mud” is introduced into the string12from a source such as a mud tank or “pit” and is circulated under pressure through the string12, for example via one or more mud pumps. The drilling fluid passes into the string12and is discharged at the bottom of the borehole through an opening in a drill bit located at the downhole end of the string12. The drilling fluid circulates uphole between the string12and the borehole and is discharged into the mud tank or other location.

The string12includes at least one string or pipe segment14having an uphole end16and a downhole end18. As described herein, “uphole” refers to a location near the surface relative to a reference location when the segment14is disposed in a borehole, and “downhole” refers to a location away from the surface relative to the reference location.

An inner bore or other conduit20extends along the length of each segment14to allow drilling mud or other fluids to flow therethrough. A communication conduit22is located within the segment14to provide protection for electrical, optical or other conductors to be disposed along the segment14.

The segment14includes an uphole coupling24and a downhole coupling26. The segment14is configured so that the uphole coupling24is positioned at an uphole location relative to the downhole coupling26. The uphole coupling24includes a male coupling portion28having an exterior threaded section, and is referred to herein as a “pin”24. The downhole coupling26includes a female coupling portion30having an interior threaded section, and is referred to herein as a “box”26.

The pin24and the box26are configured so that the pin24can be disposed within the box26to effect a fixed connection therebetween to connect the segment14with an adjacent segment14or other downhole component. In one embodiment, the exterior of the male coupling portion28and the interior of the female coupling portion30are tapered along the length of the segment14to facilitate coupling. Although the pin24and the box26are described has having threaded portions, the pin24and the box26may be configured to be coupled using any suitable mechanism, such as bolts or screws or an interference fit.

Referring toFIGS. 2 and 3, adjacent segments14are shown in a coupled position, where the pin24is disposed in and engaged with the box26. When the pin24is fully engaged with the box26, at least one seal32is formed between surfaces on the pin24and the box26. In one embodiment, the pin24includes multiple sealing surfaces that contact corresponding surfaces on the box26to form one or more seals32. The sealing configurations described herein are exemplary. Other sealing configurations such as o-rings, gaskets and packings may be utilized in addition to or in place of the sealing surfaces described herein.

Referring toFIGS. 4 and 5, the segment14includes at least one transmission device34disposed therein and located at the pin24and/or the box26. The transmission device34is configured to provide communication between conductors disposed in adjacent segments14when the pin24and the box26are engaged. The transmission device34may be of any suitable type, such as an inductive coil, direct electrical contacts and an optical connection ring. In the configuration described herein, the transmission device34is protected from mechanical damage due to the uphole position of the pin24and/or due to the position of the transmission device34in the box26.

The position of the transmission device34is exemplary. The transmission device34may be disposed at any suitable location. In one example, the transmission device34is recessed within or mounted on a surface of the pin24and/or the box26. In another example, the transmission device34is located at the uphole end of the pin24and/or the uphole end of the box26. In one embodiment, shown inFIGS. 4 and 5, the transmission device34is recessed in an interior uphole surface of the box26and a corresponding transmission device34is mounted on an exterior uphole surface of the pin24.

In one embodiment, the pin24and the box26include corresponding sealing surfaces configured to create a seal32when the pin24and the box26are engaged. In one embodiment, each sealing surface is configured to contact a corresponding sealing surface to create a watertight and/or airtight seal therebetween.

In one embodiment, the box26includes a first interior sealing surface or bore36located at a downhole portion of the pin box interior. The pin24includes, in one embodiment, a first exterior sealing surface or counterbore38located at a downhole portion of the pin exterior. Upon engagement between the threads of the male portion28and the female portion30, the first bore36and the first counterbore38come into contact with one another to form a seal32.

In one embodiment, the box26includes an additional interior sealing surface or bore40located at an uphole portion of the box interior. The pin24includes an additional exterior sealing surface or counterbore42located at an uphole portion of the pin exterior. Upon engagement between the threads of the male portion28and the female portion30, the additional bore40and the additional counterbore42come into contact with one another to form a seal32.

In one embodiment, one or more of the sealing surfaces36,38,40,42are smooth bore surfaces that are generally parallel to the interior surface of the inner conduit20. The sealing surfaces may take any suitable shape or configuration, such as a smooth or grooved shape, a curved shape, tapered shape or cylindrical shape.

In one embodiment, the first bore36is an outer bore having a diameter greater than the diameter of the additional bore40, referred to as an inner bore. The threaded portion of the box26is tapered along the length of the segment14. The threaded portion has a diameter that is substantially equal to the diameter of the first bore36at the downhole end of the threaded portion, and the diameter gradually decreases along the length of the segment14to a diameter that is substantially equal to the diameter of the additional bore40at the uphole end of the threaded portion.

Correspondingly, the first counterbore38is an inner counterbore having a diameter greater than the additional counterbore42. The threaded portion of the pin24is tapered similarly to the tapered portion of the box26. The threaded portion of the pin24has a diameter that is substantially equal to the first counterbore38at the uphole end of the threaded portion, and the diameter gradually decreases along the length of the segment14to a diameter that is substantially equal to the diameter of the additional counterbore42.

The sealing configurations described herein are exemplary. The position and number of sealing surfaces are not limited, and the sealing surfaces may be located at any desired position to affect an airtight and/or watertight seal between the pin24and the box26.

The segment14, the pin24and/or the box26are made from any material, including a metal such as steel and aluminum. In addition, the sealing surfaces36,38,40,42are made of any suitable material, such as a metal, and may also be made of a combination of materials such as metallic materials and deformable and/or resilient materials, such as plastic and rubber materials.

In one embodiment, the system10is operably connected to a downhole or surface processing unit which may act to control various components of the system10, such as drilling, logging and production components or subs. Other components include machinery to raise or lower segments14and operably couple segments14, and transmission devices. The downhole or surface processing unit may also collect and process data generated by the system10during drilling, production or other operations.

As described herein, “drillstring” or “string” refers to any structure or carrier suitable for lowering a tool through a borehole or connecting a drill bit to the surface, and is not limited to the structure and configuration described herein. For example, the string12is configured as a drillstring, hydrocarbon production string or formation evaluation string. The term “carrier” as used herein means any device, device component, combination of devices, media and/or member that may be used to convey, house, support or otherwise facilitate the use of another device, device component, combination of devices, media and/or member. Exemplary non-limiting carriers include drill strings of the coiled tube type, of the jointed pipe type and any combination or portion thereof. Other carrier examples include casing pipes, wirelines, wireline sondes, slickline sondes, drop shots, downhole subs, BHA's and drill strings.

FIG. 6illustrates a method60for coupling segments of a borehole conduit or string such as a wired pipe. The method60includes one or more stages61-64. The method60is described herein in conjunction with the system10, although the method60may be performed in conjunction with any number and configuration of rigs, processors or other machinery. In one embodiment, the method60includes the execution of all of stages61-64in the order described. However, certain stages may be omitted, stages may be added, or the order of the stages changed.

In the first stage61, a first segment14is lowered or otherwise positioned or suspended at a surface location or within a borehole. The first segment includes the uphole end16and the downhole end18. The first segment14is generally oriented so that the pin24is positioned at the uphole end16of the first segment14. In one embodiment, the first segment14includes drilling components such as a drill bit and/or additional components such as various measurement devices. In one embodiment, the first segment14includes the box26at the downhole end18that is configured to be connected to another segment14by engagement with a corresponding pin24located at an uphole end16of the other segment14.

In the second stage62, a second segment14is lowered onto or otherwise positioned into engagement with the first segment14. The second segment includes at least the box26located at the downhole end18of the second segment. In one embodiment, the second segment is positioned so that the threaded portions of the pin24and the box26are engaged, and the second segment14is rotated relative to the first segment14to fully engage the segments14in a sealing connection. In one embodiment, fully engaging the segments14includes positioning the transmission device34in one of the first and second segments14in operable communication with a corresponding transmission device34and/or a conductor in the other of the first and second segments14. In one embodiment, the second segment14includes a pin24at its uphole end16to facilitate connection with additional segments14.

In the third stage63, the first and second segments14are lowered into the borehole. The segments14may be lowered into the borehole during or after a drilling operation.

In the fourth stage64, additional segments14are connected together via respective pins24and boxes26to further lengthen the string and lower the string12into the borehole.

In one embodiment, the segments14are lowered or otherwise positioned by use of a drilling rig supported by a derrick or other structure. In one embodiment, the segments14are placed on fingerboards or other support structures prior to lowering the segments14into the borehole or after racking the segments14back from the borehole.

FIG. 7illustrates a method70for positioning a segment of a borehole conduit at a location such as on a derrick or other support structure. The method70includes one or more stages71-72. The method70is described herein in conjunction with the system10, although the method70may be performed in conjunction with any number and configuration of rigs, processors or other machinery. In one embodiment, the method70includes the execution of all of stages71-72in the order described. However, certain stages may be omitted, stages may be added, or the order of the stages changed.

In the first stage71, a segment14is oriented so that the pin24is located at the uphole end16and/or the box26is located at the downhole end18. Although the segment14is described herein as having both a pin24and a box26, the segment14may include only one of the pin24or the box26.

In the second stage72, the segment14is positioned at a surface location such as a derrick of a drilling rig. In one embodiment, the segment14is placed on a fingerboard or other storage structure supported by the derrick or located at another surface location.

In one embodiment, the method70is performed as the segment14is racked back from a borehole. In another embodiment, the method70is performed prior to lowering the segment14into a borehole during a drilling, logging, production or other operation.

The apparatuses and methods described herein provide various advantages over existing methods and devices, in that the configuration of the pin and box prevents damage to the transmission device, for example, when the pipe segments are racked to a derrick. For example, the transmission device on the bottom of the pipe segment is no longer exposed to mechanical damage when the pipe segment is stored at the surface, because it is mounted deep inside the box. In addition, the transmission device is no longer exposed to damage from the weight of the pipe segment when the pipe segment is stored at the surface. The configuration described herein ensures that transmission devices located in the box and/or on the pin are protected from being mechanically damaged by the weight of the segment or by other external forces. In addition, sealing surfaces such as a shoulder surface in the box and nose surface on the pin are protected from damage.