Adjustable Hydraulic Coupling For Drilling Tools And Related Methods
An adjustable hydraulic coupling device allows simultaneously mounting of different parts of a downhole drilling tool to the drill string near its upper and lower extremities. This top- and bottom-mounting is made to points on the drill string separated by an indeterminate length. The coupling device allows a mechanical and sealed fluid connection between two portions of the tool, and allows assembling of both portions of the drilling tool into one functional unit, and allows both axial translation and rotational motion therebetween. A cylindrical protruding tube is attached to the portion of the drilling tool mounted at its upper extremity while a mating cylindrical tube is attached to the part of the drilling tool mounted near the bottom. During assembly, the smaller tube enters the larger tube and provides a sealed fluid path and also allows for the engagement length of the assembly to vary as required.
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The present application claims priority to U.S. Provisional Patent Application Ser. No. 62/451,538, filed Jan. 27, 2017, and that application is incorporated by reference in its entirety.
BACKGROUND OF THE INVENTIONIn general, the present invention relates to a device or system capable of allowing a downhole drilling tool to be simultaneously mounted at two different axial locations to a drill string while allowing the length of the tool to vary as required to accommodate such mounting locations. Specifically, the present invention discloses a hydraulic coupling device that allows the top portion of the tool and the bottom portion of the tool to be mounted to the drill string at points on the drill string that are separated by an indeterminate length and still allow a mechanical and sealed fluid connection between the two portions. Thus, this invention allows a drilling tool to potentially use both a top mounted telemetry or sensor system and a bottom mounted mud pulse telemetry system simultaneously.
In the drilling of deep bore holes, the rotary drilling technique has become a commonly accepted practice. This technique involves using a drill string which consists of numerous sections of hollow pipe connected together and to the bottom end of which a drill bit is attached. By imparting axial forces onto the drilling bit and by rotating the drill string either from the surface or using a hydraulic motor attached to the drill string, a reasonably smooth and circular bore hole is created. The rotation and compression of the drilling bit causes the formation being drilled to be crushed and pulverized. Drilling fluid is pumped down the hollow center of the drill string through nozzles on the drilling bit and then back to the surface around the annulus of the drill string. This fluid circulation is used to transport the cuttings from the bottom of the bore hole to the surface where they are filtered out and the drilling fluid is re circulated as desired. The flow of the drilling fluid also provides other secondary functions such as cooling and lubricating the drilling bit cutting surfaces and exerts a hydrostatic pressure against the borehole walls to help contain any entrapped gases that are encountered during the drilling process. To enable the drilling fluid to travel through the hollow center of the drill string, the restrictive nozzles in the drilling bit and to have sufficient momentum to carry cutting and debris back to the surface, the fluid circulation system at the surface includes a pump or multiple pumps capable of sustaining sufficiently high pressures and flow rates, piping, valves and swivel joints to connect the piping to the rotating drill string.
The need to measure certain parameters at the bottom of a bore hole and provide this information to the driller has long been recognized. These parameters include, but are not limited to the temperature, pressure, inclination and direction of the bore hole, vibration levels, inclination, azimuth, toolface (rotational orientation of the drill string), but also include various geophysical and lithological measurements and formation geophysical properties such as resistivity, porosity, permeability, and density as well as insitu formation analysis for hydrocarbon content. The challenge of measuring these parameters in the hostile environment at the bottom of a borehole during the drilling process and conveying this information to the surface in a timely fashion has led to the development of many devices and practices.
It is an advantage to be able send data from the bottom of a bore well to the surface, while drilling, and without the use of wires or cables, and without the continuous and/or frequent interruption of drilling activity. Thus, tools commonly referred to as “measurement while drilling” or “MWD” tools have been developed. Several types of MWD tools have been contemplated in the prior art and are discussed in brief below.
MWD tools may transmit data in several ways, including: creating EM (low frequency radio waves or signals, currents in the earth or magnetic fields) waves to propagate signals through the earth; imparting high frequency vibrations to the drill string which can be used to encode and transmit data to the surface; and creating pressure pulses to encode and transmit data to the surface of the earth from the bottom of a borehole.
MWD tools using pressure pulses can operate in a number of ways, such as: closing or opening a valve in the drill string so as to create a substantial pressure pulse that is detectable at the surface when a particular parameter reaches a pre-selected or particular value or threshold, or creating a series or group of pulses depending upon the parameter's value, or by using the time between the pressure pulse signals in addition to the total number of pressure pulse signals to encode information. Opening and closing and sensing may be accomplished mechanically or electronically or electromechanically, or by a combination thereof.
MWD tools of the types described are limited in that they are non-reciprocating in nature. The measurements in such devices are made when the fluid flow is stopped for a short period of time and the data is transmitted only once when the fluid flow resumed. Acquiring downhole measurements while drilling with a device that can measure parameters whenever desired (not just when the fluid flow is interrupted) and can transmit these parameters to the surface continuously or when desired would be an advantage.
Such an MWD drilling tool may include a pulsing mechanism (pulser) coupled to a power source (e.g, a turbine generator capable of extracting energy from the fluid flow), a sensor package capable of measuring information at the bottom of a well bore, and a control mechanism that encodes the data and activates the pulser to transmit this data to the surface as pressure pulses in the drilling fluid. The pressure pulses may be recorded at the surface by means of a pressure sensitive transducer and the data decoded for display and use to the driller.
A pulser may create pressure pulses in a number of fashions. In one embodiment, a servo mechanism opens and closes the main pulsing mechanism indirectly. Here, the fluid flow does most of the work of opening and closing the main valve to generate pulses to transmit data. Other representative examples of servo driven pulser mechanisms have been proposed in U.S. Pat. Nos. 3,958,217, 5,333,686 and 6,016,288. In another embodiment, the pulse is created not by creating a restriction to the flow of drilling fluid in the hollow center of the drill string, but by opening a closing a port on the side of the drill string. This methodology, often referred to as “a negative pulser”, creates pressure decreases (as opposed to pressure increases) as venting fluid through a port in the drill string allows for some portion of the fluid to bypass the nozzles in the drilling bit. In another, hybrid, embodiment, a positive pulser (one capable of creating positive pressure pulses) is coupled with a negative pulser (one capable of creating negative pulses) to provide the ability to create pressure pulses of various shapes and sizes by combining the action of both types of pulsers. And yet another embodiment is the “siren” type pulsing mechanism, which creates positive pulses of reasonable magnitude in rapid succession and in a continuous fashion (as opposed to creating single pulses on demand). This generates a hydraulic carrier wave, over which data may be transmitted to the surface by varying the frequency of the pulses being generated or by creating phase shifts in the carrier wave. Other examples of siren type pulsers are proposed in U.S. Pat. Nos. 3,309,656 and 3,792,429.
Such data delivery systems, whether EM, Acoustic or Mud Pulse, have particular inherent limitations which make use in all applications challenging. For example, EM systems are often limited by the depth they can be used to due to the inherent attenuation of the earth's rock formations. Acoustic telemetry systems are also limited by depth due to the length of the drill string and by the attenuating effects of the friction of the drill string against the borehole, which tend to retard the transmission of the acoustic sound pulses to the surface. Mud pulse telemetry tools are generally more robust and can be used in most applications; however, these tools are bandwidth limited and are generally not able to provide data at a high rate.
Using multiple telemetry methods may allow data to be delivered from deeper wells using one transmission device while using the second transmission device to provide faster data at shallower depths. Or in certain situations, using multiple devices may allow data to be transmitted effectively faster by utilizing both data channels to simultaneously transmit different data. It may also be desirable to have multiple transmission devices and allow one to be used in certain portions of the well while the other is used in a different portion to optimize the frequency and density of the data being sent to the surface.
Thus, a primary goal in the design of such multiple telemetry MWD tools is to provide technologies and methods that can be designed, manufactured and installed is such a way as to allow multiple telemetry methods to be used simultaneously.
Using multiple telemetry methods simultaneously can be challenging due to the nature of the drilling process & how the telemetry methods work. Mud pulse telemetry tools are generally mounted to one extremity or the other of the downhole drilling tool because they require the porting or obstruction of the drilling fluid to create pressure pulses in the fluid flow. In such cases, a different or secondary telemetry device must necessarily be mounted at a different location on the drilling tool. This combined drilling tool is usually many feet in length and needs to be attached to portions of the drill string where the distance between those portions may vary (even between nominally identical equipment. Moreover, such a drilling tool may need to straddle or fully pass through a single piece of non-magnetic drill string, itself of variable length, to enable proper sensor measurements. Thus, in such a case, an MWD tool is mounted on one end of a single non-magnetic drill collar (with, e.g., a mud pulse telemetry device at that end) and also at the opposite end (with, e.g., a second telemetry device, such as EM, at that end). In these case, the length of that non-magnetic drill collar may not be known in advance and/or may vary from the nominal length.
An extensible or variable-length member or module in the drilling tool may allow for easy installation and usage of such multiple telemetry devices.
SUMMARY OF THE INVENTIONA new and improved apparatus, system, and method of use are presented that allow for the assembly of a tool incorporating multiple telemetry devices onto a drill string with the capability to adapt to varying length of the drill string components such as a non-magnetic drill collar.
A method and apparatus are provided to adjust the length of a multiple telemetry-method capable drilling tool and allow a sealed fluid path through the adjustable apparatus for using in actuating a mud pulser or transmitting a signal in the fluid column. A novel hydraulic coupling mechanism of adjustable length is assembled inline to a drilling tool, typically including a mud pulser telemetry device and one or more other telemetry devices. The assembled apparatus or “MWD Tool” can be attached above and below a non-magnetic drill collar (NMDC) in respective hang-off or landing collars, and can span the length of the NMDC while allowing portions of the tool to be mounted and fixed in space to both the top, hang off, collar and the bottom, landing, collar.
A system and method are provided to allow a mud pulse telemetry system to be installed at the bottom part of the MWD Tool and have a secondary telemetry system, either EM, Acoustic or a second mud pulse telemetry system, to be installed at the top portion of the MWD tool. The system and method also provide a hydraulic coupling between components of a mud pulse telemetry system. The bottom portion of the MWD tool is both mounted near the bottom of the NMDC to a landing collar and simultaneously the top portion of the MWD Tool is mounted to a hang-off collar above the NMDC. In addition, the hang-off collar may be used to locate and mount a device other than a secondary telemetry system, and could be used instead to mount any number of sensors or devices that require a fixed mounting location above the NMDC.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in this application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Therefore, it is an object of the present invention to provide an extensible hydraulic coupling and mounting mechanism or apparatus and method of using the same, and a MWD tool system and method of using the same, that are robust and durable and of reliable construction, may be easily and efficiently manufactured and marketed, and at low cost, that are simple to assemble and require minimal training and time to assemble and operate, reduce or eliminate the susceptibility of being obstructed by contaminants and additives in the drilling fluid, are capable of downhole operations off-shore and under water, are usable interchangeably in all types of wells, and with various types of telemetry devices.
Further objects of the present invention are to provide a new hydraulic coupling apparatus and method of using the same with a reasonably small cross section that minimizes the pressure drop associated with use thereof with a servo-assisted main pulser, and that does not significantly impede the flow of drilling fluid on its way to the bit during normal drilling operations and thus will significantly reduce erosion and wear that is caused due to the high flow velocities of the drilling mud.
A further object of the present invention is to provide a new hydraulic coupling apparatus and method of using the same that is short in length. This short length may allow the MWD tool, and specifically the hydraulic coupling apparatus to be built to be stiffer and without the need for special flexible members to allow for the curvature of the bore hole. This added stiffness also permits the MWD tool to have greater resilience in the presence of high vibration and shock levels that are found in the bottom of a bore hole while drilling.
A further object of the present invention is to provide a new hydraulic coupling apparatus and method of using the same which provides a mechanism to adequately shock isolate the internal components of the MWD Tool from the damaging effects of axial vibration imparted through the bottom landing sub, and reduce the occurrence and severity of damage caused by excessively high vibrations in the drilling environment.
A further object of the present invention is to provide an extensible hydraulic coupling and mounting mechanism or apparatus and method of using the same, and a MWD tool system and method of using the same, that provide a mechanism to allow for variations in the length of the drill string components between mounting points for the MWD Tool, such as the length of an NMDC and allow for such variations to be accommodated rapidly, easily and effectively during the assembly of the MWD Tool into the NMDC, the hang-off collar and the landing collar.
A further object of the present invention to provide a hydraulic coupling apparatus and method of using the same that is able to be rapidly installed or uninstalled from the MWD Tool to minimize and eliminate valuable time and cost at the drilling rig.
A further object of the present invention is to provide a hydraulic coupling apparatus and method of using the same that can be manufactured in multiple different lengths to tailor effective to different ranges of lengths of the drill string components between mounting points for the MWD Tools, while still allowing a sufficient and reasonable amount of length adjustment to easily and effectively install the MWD Tool into the drill string.
A further object of the present invention is to provide a new hydraulic coupling apparatus and method of using the same that provides diametrically stabilizing bearings and multiple insertion and extraction features to allow the coupling apparatus to be installed and uninstalled easily and effectively in instances where the upper portion of the MWD Tool and the lower portion of the MWD Tool are not reasonably concentric.
A further object of the present invention is to provide a new hydraulic coupling apparatus and method of using the same that provides a robust sliding seal system that is able to accommodate the translation of the hydraulic apparatus during installation without sacrificing the quality or effectiveness of the pressure sealing between the inner and outer portion of the apparatus.
These, together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages, and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
In an embodiment of the invention, information of use to the driller is measured at the bottom of a bore hole relatively close to the drilling bit and this information is transmitted to the surface using pressure pulses in the fluid circulation loop. This information, or other information, may also be transmitted using a secondary telemetry device which could be a second mud pulser transmitter, an EM telemetry device or an acoustic telemetry device. Some of the data thus gathered to transmit may be acquired from sensors or systems that are mounted to the drill string near the top or bottom of the MWD Tool.
The command to initiate the transmission of data is sent by stopping fluid circulation and allowing the drill string to remain still for a minimum period of time. Upon detection of this command, the downhole tool measures at least one downhole condition, which is usually an analog signal. The signal is processed by the downhole tool and readied for transmission to the surface. When the fluid circulation is restarted, the downhole tool waits a predetermined amount of time to allow the fluid flow to stabilize and then begins transmission of the information by repeatedly closing and then opening the pulser valve to generate pressure pulses in the fluid circulation loop. The sequence of pulses sent is encoded into a format that allows the information to be decoded at the surface and the embedded information extracted and displayed.
It is also possible that a command to initiate transmission is sent by different means, including by transmitting EM signals down to the MWD Tool which may have a receiver to accept such command, or through vibrations in the drill string sent to a vibration sensitive detector included as part of the MWD Tool. Such additional command methods, in combination or independent of the first method, may initiate data transmission using one or both transmission methods, or may initiate any number of other functions that the downhole MWD Tool can perform.
Referring now to the drawings and specifically to
In some drilling operations, a hydraulic turbine of a positive displacement type (not shown) may be inserted below landing sub 38 to enhance the rotation of the drill string desired. In addition, various other drilling tools such as stabilizers, one-way valves and mechanical shock devices (commonly referred to as jars or agitators) may also be inserted in the bottom section of drill string 30 either below or above NMDC 36. Some of these components could be used in the process of directionally drilling the well. As a representation of a hydraulic turbine or any such optional device, tubular component 40 is shown attached below landing collar 38. At the bottom of drill string 30, and below optional tubular component 40, drilling bit 42 is attached.
The drilling fluid or “mud” is usually stored in mud pits or mud tanks 50, and is sucked up by mud pump 52, which then forces the drilling fluid to flow through surge suppressor 54, then through kelly hose 56, and through swivel joint 22 and into the top of drill string 30. The fluid flows through drill string 30, through drill collars 32, through hang-off sub 34, through NMDC 36, through landing collar 38, through tubular component 40 and through drilling bit 42 and its drilling nozzles (not shown). The drilling fluid then returns to the surface by traveling through annular space 60 between outer diameter of drill string 30 and well bore 10. When the drilling fluid reaches the surface, it is diverted through mud return line 62 back to mud tanks 50.
The pressure required to keep the drilling fluid in circulation is measured by pressure sensitive transducer 70 on kelly hose 56. The measured pressure is transmitted as electrical signals through transducer cable 72 to surface computer 74 which decodes and displays the transmitted information to the driller.
In situations where multiple telemetry devices are used downhole as part of an MWD Tool, additional sensors may be placed at or near drilling rig 11 to measure any pertinent information required to receive and decode the data being sent from the downhole tool which resides inside and is substantially part of the drill string. Such sensors may be electrical in nature, as shown by ground current sensing electrode 76 which is attached to the earth some distance from drilling rig 11, and whose data is sent to surface computer 74 through cable 78. Other sensors may also be attached to the drilling rig itself, preferably at a location close to the center of well bore 10 and in good electrical contact with drilling rig 11. Such a sensor 90 is shown attached to surface casing pipe 82 of drilling rig 11 and whose signals are transmitted to surface computer 74 through cable 80. It will be clear to those familiar with the art that multiple other such sensors could be attached at, on or near the drilling rig to measure magnetic fields, electrical currents, vibrations or any number of other parameters which may aid in the detection and decoding of the data being sent from a downhole tool.
The MWD Tool may include a top mounted device 102. Top mounted device 102 could be a secondary telemetry device such as an EM transmitter, an acoustic transmitter or a sensing device. A common feature of top mounted device 102 is that it needs to be mounted to hang-off sub 34. Top mounted device 102 might need to make good electrical contact with hang-off sub 34 to enable the transmission of electrical signals by an EM telemetry device, or need to make good mechanical contact with the hang-off sub 34 to enable transmission of acoustic signals by an acoustic telemetry device, or need to be connected to the hang-off sub 34 to enable taking of measurements, such examples as measuring the pressure of the annular fluid 60. Top mounted device 102 may be mounted to hang-off sub 34 in such ways as bolts, or other fasteners that will withstand the forces imposed by a downhole tool.
MWD Tool 100 also may include one or more tubular modules.
MWD Tool 100 also includes mud pulse telemetry device 108 which is attached to the bottom of tubular modules 104 and 106. The purpose of this mud pulse telemetry device is actuate a valve to impede the flow of the drilling fluid and generate pressure pulses. This mud pulse telemetry device may be a servo pulser, such as one described in U.S. Pat. No. 9,133,950 (issued Sep. 15, 2015) or a direct mud pulser, such as one described as part of a measurement while drilling apparatus in U.S. Pat. No. 7,735,579, or a negative pulser. (Both preceding U.S. Patents are incorporated by reference in their entirety.) Mud pulse telemetry device 108 may contain one or a plurality of fluid inlets 110 through which the part of the drilling fluid pumped by mud pump 52 that is present in annular space 92 may flow into mud pulse telemetry device 108. Ultimately, pressure pulses can be transmitted through the fluid column existing in annular space 60 to the surface, and used to encode and transmit data from the subterranean environment to the surface.
Female hydraulic coupler 112 is attached to the bottom of mud pulse telemetry device 108, and the fluid entering fluid inlet(s) 110 may flow through female hydraulic coupler 112. This fluid flow through mud pulse telemetry device 108 may be intermittent as may be required for the proper operation of the system and this intermittent flow may be achieved by mud pulse telemetry device 108 opening and closing a valve (not shown) that may reside internal to the mud pulse telemetry device. A representative valve of this type is described in detail in U.S. Pat. No. 9,133,950.
Main pulser valve 116 is attached to the bottom of male hydraulic coupler 114. Main valve 116 is used to generate pressure pulses used to encode and transmit data from the bottom of the well bore to the surface, and this generation may be activated by the intermittent flow of fluid from annular cavity 92 going through fluid inlet(s) 110, entering mud pulse telemetry device 108 and then flowing through a valve (not shown) inside said mud pulse telemetry device 108, and then further on through female hydraulic coupler 112, and then through male hydraulic coupler 114 to activate main pulser valve 116.
Placement of male hydraulic coupler 114 and female hydraulic coupler 112 could be reversed (not shown), to have male hydraulic coupler 114 attached to mud pulse telemetry device 108 and inserted into female hydraulic coupler 112 from above.
The bottom of the main pulser valve 116 is attached to main pulser mount 118, which in turn is mechanically connected to landing sub 38. Main pulser valve 116 may be hydraulically coupled to main pulser mount 118, and main pulser mount 118 to landing sub 38. Landing sub 38 may provide a port (not shown) therein to annular space 60 to permit movement of drilling fluid and transmission of pulses thereinto.
Mechanically attaching top mounted device 102 to hang-off sub 34 and simultaneously mechanically attaching main pulser mount 118 to the landing sub 38 without the presence of the hydraulic coupling system 111 consisting of the female hydraulic coupler 112 and the male hydraulic coupler 114 would be extremely challenging. This challenge arises from the fact that the lengths of hang-off sub 34, NMDC 36 and landing sub 38 may vary significantly. Variations may arise from several sources, including different nominal lengths, manufactured variances from nominal lengths, and variances from nominal lengths arising from sources such as recutting threads (which can shorten the drill string components). In addition, the act of attaching hang-off sub 34, NMDC 36 and landing sub 38 together as part of drill string 30 requires that they be rotated relative to each other to tighten threads joints (not shown), and such rotation cannot be accomplished if both ends of MWD Tool 100 are attached to their respective mounting locations. Sliding engagement of male hydraulic coupler 114 with female hydraulic coupler 112 is free, subject to friction between the two, and does not transmit axial loads between the connected devices (e.g. top mounted device 102 and main pulser valve 116).
In other embodiments (not shown), mud pulse telemetry device 108 does not use a second telemetry device to create mud pulses in annular space 60. In such embodiments, mud pulse telemetry device 108 comprises a direct mud pulser or a negative pulser. In either case, mud pulse telemetry device 108 may generate pulses by the intermittent flow of fluid from annular cavity 92 going through fluid inlet(s) 110, entering mud pulse telemetry device 108 and then flowing through a valve (not shown) inside said mud pulse telemetry device 108, and then further on through hydraulic coupling system 111. In the case of a negative pulser, the fluid may flow from the hydraulic coupling to outside the system, without a valve. Hydraulic coupling system 111 is, however, mechanically connected and hydraulically coupled to landing sub 38 via mount 118. Landing sub 38 may provide a port (not shown) therein to annular space 60 to permit movement of drilling fluid and transmission of pulses thereinto.
To further explain the components and for purposes of convenience and clarity, the following will describe individual sections of the adjustable hydraulic coupling device as shown in
Top mounted device 102 can be attached to hang-off sub 34 in different ways, but generally, MWD Tool 100 must be mounted inside hang-off sub 34 so as to prevent rotation between MWD Tool 100 and hang-off sub 34. This need for rotational alignment is due to the need to measure and transmit the rotation position of the downhole components as measured by any inertial sensing system to enable the drilling of directional wellbores. In addition, any such mounting may also need to be thus rotationally aligned to enable access to fluid ports, sensor ports or other devices or means to enable the proper measurement or transmission of data. In addition, such rotational alignment may also be a consequence of the need to axially align top mounted device 102 inside hang-off sub 34 for substantially the same reasons.
A downhole tool also needs to be mechanically coupled to a drill string to reduce the damaging effects of the shock and vibrations that are routinely encountered during the drilling of wellbores. Thus, it is a necessary result that any top mounted device 102 will need to be mounted so as to prevent both axial and radial movement between it and hang-off sub 34.
Main pulser mount 118 will also need to be mounted inside landing sub 38 to prevent rotation between main pulser mount 118 and landing sub 38. This need for rotational alignment shares substantially the same reasons as those described above for top mounted device 102. However, in addition to the foregoing, bottom mounted main pulser valve 116 may also need said mounting to allow for proper operation of the pulser valve system to generate pressure pulses.
Thus a multiple telemetry MWD Tool 100 may require that both its top and bottom extremities be mounted to components of drill string 30, specifically and respectively hang-off sub 34 and landing sub 38, in such a way as to prevent both extremities from translating axially or rotating relative thereto.
However, due to the nature of the components generally used in the rotary drilling of wellbores, such multiple locations of mounting are challenging to accomplish. It is well known by those familiar with the drilling of wellbores that the lengths of hang-off sub 34, NMDC 36 and landing sub 38 vary substantially. These variations are usually caused by the routine inspection and rethreading of the helical threaded connections (not shown) on these tubular components, which necessarily reduces their length. Such length changes result in the need for MWD Tool 100 to be able to vary the length as required between the points at which it mounts to allow for the mounting it to both the upper extremity and the lower extremity.
In addition, the act of mechanically engaging the tubular components and tightening their threaded connections cannot be accomplished without allowing some part of MWD Tool 100 to spin or rotate relative to the rest of MWD Tool 100. A lack of such a rotational capability will result in the twisting of MWD Tool 100 to the point of destruction.
To enable this need to both change the length of MWD Tool 100 and to allow said MWD Tool 100 to have part of it rotate relative to another part of itself, a hydraulic coupling device such as is described below may be used.
As mentioned previously, hydraulic coupling system 111 is placed between the bottom of mud pulse telemetry device 108 and main pulser valve 116. This is to enable the drilling fluid present in annular space 92 in the inner volume of NMDC 36 to enter inlet port(s) 110 of mud pulse telemetry device 108 and to be intermittently allowed to flow through the bottom of mud pulse telemetry device 108 due to the action of servo valve 130. When servo valve 130 is opened, fluid from annular space 92 is allowed to flow through inlet port(s) 110, through servo valve 130, and then further along cavity 134 and then into inner cavity 136 of female hydraulic coupler 112. The drilling fluid then flows through inner cavity 138 of male hydraulic coupler 114 and on to main pulser valve 116, where this fluid flow is used to activate main pulser valve 116 to generate pressure pulses in the drilling fluid in annular space 92.
It will be understood by those familiar with the art that inner cavities 136 and 138, forming part of hydraulic flow path 91, need to be substantially sealed from the fluid column in annular space 92 allow proper activation of main pulser valve 116. In addition, male hydraulic coupler 112 and female hydraulic coupler 114 need to be relatively concentric to allow for easy assembly of MWD Tool 100 when its two sub sections are brought together during assembly of NMDC 36 to landing sub 38. In addition, male hydraulic coupler 112 and female hydraulic coupler 114 being concentric facilitates free rotational motion between the two, such that they are not rotationally coupled. Thus, end fittings 113 and 115 are likewise able to freely rotate relative to one another.
The sealing of inner cavities 136 and 138 is accomplished by a plurality of radial seals 140 that are mounted onto male hydraulic coupler 114. As NMDC 36 is axially aligned to landing sub 38 during the assembly process, male upper end 146 of male hydraulic coupler 114 enters female lower end 144 of female hydraulic coupler 112, and is guided so as to allow both male hydraulic coupler 114 and female hydraulic coupler 112 to be positioned concentrically to each other before male upper end 146 fully engages into cylindrical bore 137 of female hydraulic coupler 112. That engagement causes radial seals 140 to also enter cylindrical bore 137 of female hydraulic coupler 112, to seal with sealing surface 141 and thus create a tight seal impeding the connection of fluid between inner cavities 136 and 138, hydraulic flow path 91, and fluid column 92.
To further enable said engagement, female lower end 144 is proved with a large smooth conical chamfered surface 145, and the male upper end is provided with a large smooth filleted surface 147 to ensure that the engagement is not impeded by the presence of mechanical discontinuities that would retard said engagement or damage radial seals 140.
In addition, the outer diameter of male hydraulic coupler 114 is provided with radial bearing 142 to allow male hydraulic coupler 114 to be held relatively concentric to female hydraulic coupler 112. Radial bearing 142 is preferably made in the plain bearing style and preferably uses a material with a low coefficient of friction which can sustain the chemically abrasive nature of the drilling fluids found in the wellbore. A material such a ToughMet® or PEEK may be used. Radial seals 140 and radial bearing 142 also facilitate male hydraulic coupler 114 and female hydraulic coupler 112 being rotationally decoupled, and that end fittings 113 and 115 are likewise rotationally decoupled.
During assembly of NMDC 36 to landing sub 38, the engagement length of male hydraulic coupler 114 inside female hydraulic coupler 112 may vary as required to allow for the proper shouldering of NMDC 36 to landing sub 38, and to further thread NMDC 36 and landing sub 38 to be threaded together.
To further enable the ability of male hydraulic coupler 114 to engage effectively into cylindrical bore 137 of female hydraulic coupler 112, the upper end of female hydraulic coupler 112 is provided with centralizing fins 120 mounted onto MWD Tool 100 at said location. Centralizing fins 120 may be formed or rubber or other materials, and may be retained using bolts 132. Centralizing fins 120 may be provided at other locations along MWD tool 100. Other types of centralizing devices may also be used, such as bow springs or integrated fins as the application demands.
The foregoing thus describes an adjustable hydraulic coupling that may be used in downhole tools to enable easy assembly of said tools into the drill string components while simultaneously allowing for adjustment of the length of the downhole tools to be mounted on both extremities of the tool, and allow said drilling tool to be assembled inside the drill string components by the act of rotationally threading the drill string components together without damage to the drilling tool.
Another embodiment may be the inversion of the foregoing described invention (not depicted) in which the mud pulse telemetry device and the main valve are mounted to a hang off sub mounted to the upper portion of the non-magnetic drill collar, and a bottom mounted device to be mounted to the landing sub, in which case, the final assembly step would be the threading of the hang-off sub onto the top of the non-magnetic drill collar.
Another possible embodiment may be one in which the fluid being connected between the mud pulse transmitter and the main valve is a hydraulic fluid instead of drilling fluid.
Yet another possible embodiment is one in which such an adjustable coupling is made between sealed compartments between modules of the MWD tool. In this instance, the interval cavity of the adjustable coupling is used to connect wires or radio signals in lieu of connecting a fluid.
In the embodiment of the invention as described above, MWD Tool 100 is described that is capable of measuring desired parameters at the bottom of a bore hole during the process of drilling, at when desired, is able to telemeter this information to the surface from such a subsurface location using a series of pressure pulses in the drilling fluid where the pressure pulses thus telemetered encode data about these desired parameters which are then subsequently measure at the surface location, detected, decoded and the telemetered information is retrieved, stored, displayed or transmitted further as required. MWD Tool 100 is mounted near its bottom extremity to landing sub 38, which resides below NMDC 36.
In addition, MWD Tool 100 also consists of a secondary telemetry device or sensor device, where said telemetry device or sensor device is a top mounted device 102 that is mounted near its top extremity inside hang-off sub 34.
MWD Tool 100 has disposed between its top extremity and bottom extremity hydraulic coupling system 111, which includes male hydraulic coupler 114 mounted to the bottom part of MWD Tool 100 and female hydraulic coupler 112 mounted to the top part of MWD Tool 100. Hydraulic coupling system 111 has an internal cavity of variable and adjustable length and volume to allow for easy assembly and functionality of MWD Tool 100.
In order to further explain the method of using the invention, and for purposes of convenience and clarity, the following will describe the adjustable hydraulic coupling device as shown in
In an embodiment, lower portion 150 is aligned relatively concentric to upper portion 148 and lower portion 150 is inserted gently into upper portion 148, thereby inserting male hydraulic coupler 114 into the relatively circular hole that makes up the inner diameter of NMDC 36. This act of insertion eventually causes the upper extremity of lower portion 150, male upper end 146 of male hydraulic coupler 114, to enter the lower extremity of upper portion 148, female lower end 144 of female hydraulic coupler 112. Then it causes radial seals 140 and radial bearing 142 to engage in cylindrical bore 137 of female hydraulic coupler 112. This causes female hydraulic coupler 112 to be moved concentric with male hydraulic coupler 114 and creates a sealed cavity inside male hydraulic coupler 114 and female hydraulic coupler 112.
Additional movement of landing sub 38 towards NMDC 36 causes male hydraulic coupler 114 to engage further into female hydraulic coupler 112. The sealed internal cavity will be reduced in length and volume as required until such a point that the landing sub 38 may be threaded to NMDC 36 and then torqued as required to tighten said landing sub 38 to NMDC 36. This act of threading will cause male hydraulic coupler 114 to rotate relative to female hydraulic coupler 112 (and end fittings 113 and 115 likewise to rotate relative to one another), but such rotation will not cause any damage to either component or MWD Tool 100 in general, and will continue to retain the sealing integrity of the internal cavity.
Referring to
As the length of hang-off sub 34, NMDC 36 and landing sub 38 may vary due to manufacturing and maintenance reasons, a hydraulic coupling system as described will allow these aforementioned three tubular components to be attached and threaded to each other, while simultaneously allowing MWD Tool 100 substantially retained inside these tubular components to be assembled, and further allow such MWD Tool to be both top mounted at hang-off sub 34 and bottom mounted at landing sub 38. In addition, the invention described in this document and the method for the utilization of said invention as described above, will allow MWD Tool 100 with multiple mounting locations and potentially multiple telemetry devices to be assembled and utilized for intended purpose of telemetering data from the bottom of a wellbore to the surface using mud pulses in the fluid flow and potentially utilizing other telemetry methods in conjunction.
Claims
1. A variable length hydraulic coupling for creating a flowpath for drilling fluid in a downhole tool, comprising:
- two hydraulic fitting ends;
- a male coupling shaft; and
- a female receiving tube;
- said shaft and tube hydraulically coupling said ends creating a drilling fluid flowpath therebetween; and
- said shaft and tube permitting rotation between said fitting ends during assembly of said downhole tool.
2. The hydraulic coupling of claim 1, further comprising:
- said shaft and tube permitting axial translation between said fitting ends.
3. The hydraulic coupling of claim 1, further comprising:
- said coupling having a longitudinal axis;
- said shaft extending along said axis from a first of said hydraulic fitting ends; and
- said tube extending along said axis from a second of said hydraulic fitting ends; and
- said tube defining a receiver void aligned with said axis.
4. The hydraulic coupling of claim 3, further comprising:
- said tube having a receiver end exposing said receiver void;
- said coupling shaft and receiver void hydraulically coupling said fitting ends.
5. The hydraulic coupling of claim 3, further comprising:
- a first portion of said receiver void having a substantially cylindrical shape in the longitudinal axis;
- a second portion of said receiver void being chamfered to be larger away from said second hydraulic fitting.
6. The hydraulic coupling of claim 1, further comprising:
- said shaft comprising an exterior shaft coupler; said exterior shaft coupler comprising one or more hydraulic seals and one or more radial bearings;
- said shaft being slidably engageable with said tube along said exterior shaft coupler.
7. A downhole tool, comprising:
- a variable length hydraulic coupling comprising two hydraulic fitting ends; a male coupling shaft; and a female receiving tube; said shaft and tube hydraulically coupling said ends creating a drilling fluid flowpath therebetween; and said shaft and tube permitting rotation between said fitting ends during assembly of said downhole tool; and
- a first downhole telemetry device; said first telemetry device mechanically coupled to a first of said fitting ends.
8. The downhole tool of claim 7, further comprising:
- said shaft and tube permitting axial translation between said fitting ends.
9. The downhole tool of claim 7, further comprising:
- a second downhole telemetry device;
- said second downhole telemetry device mechanically coupled to a second of said fitting ends.
10. The downhole tool of claim 9, further comprising:
- said variable length hydraulic coupling hydraulically coupling said downhole telemetry devices.
11. The downhole tool of claim 9, further comprising:
- said variable length hydraulic coupling permitting axial translation and rotation between said downhole telemetry devices during assembly of said drilling tool.
12. The downhole tool of claim 7, further comprising:
- said first downhole telemetry device mounted to a first sub;
- a second downhole telemetry device; said second downhole telemetry device mounted to a second sub; and
- said variable length hydraulic coupling forming a hydraulic connection between said first downhole telemetry device and said second downhole telemetry device;
- wherein the length of said variable length hydraulic coupling adjusts while said subs are translate axially relative to one another.
13. The downhole tool of claim 12, further comprising:
- a non-magnetic drill collar;
- wherein each of said subs is connected to an opposite end of said drill collar; and
- said first downhole telemetry device comprises a main pulser valve.
14. The downhole tool of claim 12, further comprising:
- a downhole tubular component connected at opposite ends thereof to said first and second subs.
15. The downhole tool of claim 7, further comprising:
- a first hydraulic flowpath between a second of said fitting ends and said first downhole telemetry device; and
- a downhole component containing said variable length hydraulic coupling; said downhole component and said variable length hydraulic coupling forming an annular space therebetween; and
- said annular space forming a second hydraulic flowpath.
16. The downhole tool of claim 15, further comprising:
- a second downhole telemetry device;
- said second hydraulic flowpath extending between said downhole telemetry devices.
17. The downhole tool of claim 15, further comprising:
- said first hydraulic flowpath comprising said drilling fluid flowpath.
18. A method of assembling a downhole tool having a longitudinal axis, comprising:
- hydraulically coupling a variable length hydraulic coupling to a first telemetry device; said variable length hydraulic coupling comprising two hydraulic fitting ends; a male coupling shaft; and a female receiving tube; said shaft and tube hydraulically coupling said ends creating a drilling fluid flowpath therebetween; and said shaft and tube permitting rotation between said fitting ends during assembly of said downhole tool; and
- said hydraulically coupling step comprising mechanically coupling said first telemetry device to a first of said fitting ends.
19. The method of assembling of claim 18, further comprising:
- coupling said first telemetry device to a first sub in a position axially and rotationally fixed thereto about said longitudinal axis.
20. The method of assembling of claim 18, further comprising:
- coupling a second downhole telemetry device to a second sub in a position axially and rotationally fixed thereto about said longitudinal axis;
- said second telemetry device mechanically coupled to a second of said fitting ends.
21. The method of assembling of claim 18:
- said hydraulically coupling step further comprising engaging said shaft within said tube; creating axial translation between said fitting ends along said longitudinal axis; and creating relative rotation between said fitting ends about said longitudinal axis.
22. The method of assembling of claim 18, further comprising:
- said first telemetry device in a position axially and rotationally fixed to a first sub about said longitudinal axis; and
- a second of said fitting ends in a position axially and rotationally fixed to a second sub about said longitudinal axis.
24. The method of assembling of claim 22:
- said hydraulically coupling step further comprising engaging said shaft within said tube; advancing said second sub along said longitudinal axis toward said first sub; and rotating said second sub about said longitudinal axis.
25. The method of assembling of claim 22, further comprising:
- connecting each of said subs to an opposite end of a downhole tubular component.
26. The method of assembling of claim 25, further comprising:
- connecting each of said subs to an opposite end of a non-magnetic drill collar.
27. The method of assembling of claim 25:
- said downhole tubular component comprising a plurality of downhole tubular elements.
28. The method of assembling of claim 22, wherein:
- one of said first and second subs is a drill collar; and
- comprising connecting the other of said first and second subs to the drill collar.
29. The method of assembling of claim 22, further comprising:
- threadingly connecting the first and second subs to one another.
30. The method of assembling of claim 18, further comprising:
- said hydraulically coupling step further comprising directly mechanically coupling said first telemetry device to a first of said fitting ends.
Type: Application
Filed: Sep 26, 2017
Publication Date: Aug 2, 2018
Applicant: RIME Downhole Technologies, LLC (Fort Worth, TX)
Inventor: Manoj Gopalan (Dalworthington Gardens, TX)
Application Number: 15/716,243