Patent Application
20200149357
None
The disclosure is related to systems and methods for connecting downhole tools. In particular, these systems and methods may facilitate the orientation of the downhole tools relative to a reference line, such as the high side of the bent housing of a mud motor tool.
Measurement-While-Drilling (“MWD”) tool strings are used in the oil and gas industry to provide various measurements to the driller. These measurements can be transmitted in real-time to the earth surface using a telemetry system, such as including a mud pulser, to provide real-time data. These measurements can help the driller to place the well, that is, to direct the drill bit as it cuts into the earth.
MWD tool strings typically include sensors encapsulated inside metal housings that are centralized in drill collars, as well as a telemetry system. In contrast with downhole tools that make an MWD tool string, the sensors of a collar based tool (e.g., a resistivity tool) are not encapsulated inside metal housings that can be introduced into the collars, but these sensors are built on a collar. Thus, the connection between an MWD tool string and a collar based tool involves a collar connection that is made on the drill rig, typically while the collar based tool is held in slips and the MWD tool string is suspended above the collar based tool.
Accordingly, the connection between an MWD tool string and a collar based tool is sometimes made in hazardous conditions, such as in the presence of drilling fluids (e.g., conductive fluids) around the connectors. Connectors suitable for connections in these environments are sometimes referred to as “wet connectors.” For example, US Pub. No. 2005/0070141 describes two connector halves matingly engageable in a co-axial arrangement, where the electrical contacts on each of the connectors are physically covered for protecting electrical contacts on each of said connectors from environmental damage. Electrical switching circuits are connected to the electrical contacts situated on one or both of said connectors. Such electrical switching circuits serve to prevent the flow of electrical power to respective electrical contacts in any, or both, said connectors until the connectors are fully mated. Through the electrical switches, the multiple electrical contacts of the connectors are electrically isolated (i.e. “switched off”) as they slide past one another, and are only electrically powered after mating engagement is complete. A spring may further be provided to exert a force and ensure that the connectors remain fully mated while allowing for some variation in the length of the collars.
Further, when the connection between the MWD tool string and the collar based tool is keyed, it may be necessary to mechanically ensure that electrical contacts on two downhole tools are correctly aligned before the connection. For example, US Pub. No. 2016/0359262 describes first and second electrical couplers each having a plurality of electrical contacts oriented for linear engagement. The electrical contacts of the second electrical coupler are mounted on a first portion of the second electrical coupler which is rotatably received by a second portion to enable linear engagement of the electrical contacts while rotating the components relative to each other to form the mechanical connection.
MWD tool strings include directional sensors (e.g., magnetometers, inclinometers, gyroscopes). Directional or other sensors are typically oriented relative to the high side of the bent housing of a mud motor tool. Therefore, centralizers for MWD tool strings may allow for the rotation of the tool string relative to the drill collars. For example, US Pub. No. 2013/0008669 describes a centralizer having an outer housing with stabilizing fins. An inner housing has a first electrical connector at its first end and a second electrical connector at its second end. The outer housing has threaded rings for threadedly attaching with sleeves of downhole tools. The threaded rings can rotate independently from the outer housing and the inner housing, and the inner housing can be independently rotated within the outer housing.
Despite these advances in the art, there is still a need for systems and methods for connecting downhole tools that facilitate the orientation of the downhole tools relative to a reference line, such as the high side of the bent housing of a mud motor tool. Preferably, connections can be made in the presence of conductive fluids around the connectors, and electrical contacts on two sides of the connection are correctly aligned before the connection without requiring an operator for manually aligning the electrical contacts.
The disclosure describes systems for connecting downhole tools.
The systems may comprise a first tubular body comprised, for example, in a centralizer. A first wet connector may be disposed inside an end of the first tubular body. A first switch connector may be disposed inside the first tubular body. The first switch connector may be translatably fixed relative to the first wet connector. A second switch connector may be disposed inside the first tubular body. The first switch connector may be movable between a first position wherein the first switch connector is electrically insulated from the second switch connector and a second position wherein the first switch connector is electrically connected to the second switch connector. A first biasing means may be capable of biasing the first switch connector in the first position. The first switch connector and the second switch connector may be sealed within the first tubular body by seals, which may be provided on the first wet connector and on a bulkhead. A plurality of centralizer fins may be coupled around the first tubular body by a cylindrical joint, or preferably a revolute joint. In some embodiments, a key may protrude from a surface of the end of the first tubular body. In other embodiments, a keyway may be recessed from a surface of the end of the first tubular body. Preferably, the keyway may comprise a funnel surface, which may include two helical surfaces having opposite handedness and two straight surfaces each adjacent to one of the two helical surfaces. The helical surfaces may be adjacent to an apex surface essentially diametrically opposed to the two straight surfaces.
The systems may comprise a second tubular body comprised, for example, in an adapter. A first portion and a second portion of the second tubular body may be coupled by a cylindrical joint, or preferably a revolute joint. A second wet connector may be disposed inside an end of the second portion. The second wet connector may be configured to electrically connect with the first wet connector. A second biasing means may be coupled to the second wet connector. The second biasing means may preferably be stiffer than the first biasing means that biases the first switch connector in the first position. A first rotatable connector may be coupled to the first portion. A second rotatable connector may be coupled to the second portion. The first rotatable connector may be electrically connected to the second rotatable connector. The second wet connector may be electrically connected to the second rotatable connector. The first rotatable connector and the second rotatable connector may be sealed within the second tubular body by seals, which may be provided on the second wet connector and on a bulkhead. A centralizer ring may be disposed around the second portion and be rotatably fixed relative to the second portion. In embodiments where a key protrudes from a surface of the end of the first tubular body, a keyway may be recessed from a surface of the end of the second tubular body, and the keyway may be rotatably fixed relative to the second portion and the centralizer ring. Preferably, the keyway may comprise a funnel surface, which may include two helical surfaces having opposite handedness and two straight surfaces each adjacent to one of the two helical surfaces. The helical surfaces may be adjacent to an apex surface essentially diametrically opposed to the two straight surfaces. Conversely, in other embodiments where a keyway is recessed from the surface of the end of the first tubular body, a key may protrude from a surface of the end of the second tubular body, and the key may be rotatably fixed relative to the second portion and the centralizer ring. The key and the keyway may be configured to align the first wet connector with the second wet connector and simultaneously orient the first tubular body in a predetermined direction after the key has engaged the keyway.
The systems may comprise a drill collar, which may have a bore sized to receive the centralizer ring. A setting means may be coupled to a wall of the drill collar. In use, the setting means may be engaged with the centralizer ring to hinder a rotation of the centralizer ring relative to the drill collar.
The disclosure describes methods for connecting downhole tools.
The methods may comprise the steps of receiving the centralizer ring, which may be disposed around, and rotatably fixed relative to, the second portion of the second tubular body in the bore of the drill collar.
The methods may comprise the steps of rotating the second portion of the second tubular relative to the first portion of the second tubular to orient either the key or the keyway in a predetermined direction, and selectively engaging the centralizer ring with the setting means coupled to the wall of the drill collar to hinder further rotation of the centralizer ring and the second portion relative to the drill collar. While the second portion is rotated relative to the first portion, the optional second rotatable connector may simultaneously rotate relative to the optional first rotatable connector.
The methods may comprise the steps of engaging the key with the keyway, aligning the first wet connector with the second wet connector while simultaneously orienting the first tubular body in the predetermined direction after the key has engaged the keyway; and electrically connecting the first wet connector with the second wet connector after the first connector is aligned with the second wet connector. While the first tubular body is oriented in the predetermined direction, the first tubular body may simultaneously rotate relative to the optional plurality of centralizer fins. After the first wet connector is electrically connected with the second wet connector, the optional first switch connector may move from the first position wherein the first switch connector is electrically insulated from the optional second switch connector, to the second position wherein the first switch connector is electrically connected to the second switch connector after the first wet connector is electrically connected with the second wet connector. After the first switch connector has moved to the second position, the second biasing means may optionally be compressed.
For a more detailed description of the embodiments of the disclosure, reference will now be made to the accompanying drawings, wherein:
It is to be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and configurations are described below to simplify the disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the disclosure may repeat reference numerals and/or letters in the various exemplary embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various exemplary embodiments and/or configurations discussed in the various Figures. Finally, the exemplary embodiments presented below may be combined in any combination of ways, i.e., any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.
All numerical values in this disclosure may be approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, and ranges disclosed herein without departing from the intended scope. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact.
For transmitting signals from the second downhole tool 78 to the first downhole tool 86, the first downhole tool 86 may be electrically connected to the second downhole tool 78 using a connector system as described herein. Thus, measurements performed by the resistivity module or the Logging-While-Drilling module may be broadcasted to a surface operator using a telemetry module included in the MWD toll string. Further, during the connection between the first downhole tool 86 and the second downhole tool 78, the MWD tool string, including the first downhole tool 86, may preferably orient itself in a predetermined orientation, for example, a direction related to the high side of the bent housing of a mud motor tool. Thus, the directional sensors of a survey module, which may be included in the MWD tool string, may automatically be oriented relative to the high side of the bent housing.
For example, the connector system used for connecting the first downhole tool 86 to the second downhole tool 78 may include a centralizer 82 having a first tubular body mechanically connected to the first downhole tool 86, and an adapter 84 having a second tubular body mechanically connected to the second downhole tool 78. In use, a pin end 70 of the centralizer 82 may stab into a box end 72 of the adapter 84, as indicated by arrow 92, whereby the first downhole tool 86 may be connected to the second downhole tool 78.
Further, the adapter 84 may include a revolute joint that may permit orienting one of a key or a keyway in the predetermined orientation, as indicated by arrow 90. A setting means, such as set screw 74, may be coupled to the drill collar 76. In use, the setting means may be engaged to hinder further rotation after the key or the keyway is oriented in the predetermined orientation. The centralizer 82 may include the other of the key or a keyway. The key sliding along the keyway may cause the centralizer 82 to rotate, as indicated by arrow 94, thus aligning a connector of the centralizer 82 with a connector of the adapter 84, while simultaneously orienting the centralizer 82 and the first downhole tool 86 connected thereto in the predetermined direction.
A first shaft 52 may be disposed in the second centralizer housing 42. A first switch connector 58 (e.g., a male concentric connector) may be affixed to one end of the first shaft 52, and a first wet connector 50 (e.g., a multi-socket connector) may be affixed to the other, opposite end of the first shaft 52. As used herein, a wet connector is a connector suitable for connections in the presence of fluids around the connectors. A first wire harness 56 may electrically connect the first switch connector 58 to the first wet connector 50. The first shaft 52 may slide but not rotate relative to the second centralizer housing 42. As such, the first switch connector 58 and the first wet connector 50 may translate in unison within the second centralizer housing 42, or in other words, the first switch connector 58 may be translatably fixed relative to the first wet connector 50. For example, the first shaft 52 may be held at one end inside a first bushing 44 affixed to the second centralizer housing 42, and may be affixed at the other end to the first wet connector 50, which in turn may be disposed inside the pin end 70 of the first tubular body such that it may slide but not rotate relative to the pin end 70. A first biasing means, for example, a spring 54 or other known compressible, resilient device and/or material, may be capable of biasing the first shaft 52 away from the first centralizer housing 40, for example until the first wet connector 50 abut a shoulder inside the second centralizer housing 42. The shoulder 116 may preferably be configured such that the first wet connector 50 is sufficiently recessed within the second centralizer housing 42. Thus, contact of pin end 70 of the first tubular body with the adaptor 84 (e.g., with a second wet connector 20 shown in
A second switch connector 60 (e.g., a female concentric connector) may be affixed to one end of the first centralizer housing 40. An electrical connector 100 (e.g., a spring-loaded, bulkhead connector) may be disposed in the other, opposite end of the first centralizer housing 40. Conductors 104 may electrically connect the second switch connector 60 to the electrical connector 100.
For selectively preventing the flow of electrical power between the electrical connector 100 and the first wet connector 50 before the first wet connector 50 is fully engaged, the first switch connector 58 may be movable between a first position wherein the first switch connector 58 is electrically insulated from the second switch connector 60, and a second position wherein the first switch connector 58 is electrically connected to the second switch connector 60, as indicated by arrow 96. The spring 54 may be capable of biasing the first switch connector 58 in the first position. Further, the first switch connector 58 and the second switch connector 60 may be sealed within the first tubular body by seals, which may be provided on an outer diameter of the first wet connector 50 and an outer diameter of the bulkhead of the electrical connector 100. As such, the first switch connector 58 and the second switch connector 60 are not required to be wet connectors.
A keyway may be recessed from an outer surface of the pin end 70 of the first tubular body. For example, as illustrated in
A second wet connector 20 (e.g., a multi-pin connector) that is configured to mate with the first wet connector 50 may be disposed inside the box end 72 of the second portion of the second tubular body such that it may slide but not rotate relative to the box end 72. A second shaft 22 may be disposed in the first adapter housing 12 and may be affixed to the second wet connector 20. The second shaft 22 may slide but not rotate relative to the second centralizer housing 42. For example, the second shaft 22 may be held at one end inside a second bushing 18 affixed to the first adapter housing 12 and may be affixed at the other end to the first wet connector 50, which in turn may be disposed inside the box end 72 of the second tubular body such that it may slide but not rotate relative to the box end 72. A second biasing means, for example, a spring 26 or other known compressible, resilient device and/or material, may be capable of biasing the second connector toward the adapter sleeve 10, for example until the first wet connector 50 abut a shoulder inside the first adapter housing 12. A second wire harness 24, which may be connected to the second wet connector 20, may include a deformable portion 68, such as a coiled portion similar to a telephone cord. As such, upon compression of the spring 26 and contraction of the deformable portion 68 of the second wire harness 24, the second wet connector 20 may be pushed away from the adapter sleeve 10 by a nose of the pin end 70 (shown in
For rotating the second portion relative to the first portion, the first portion and the second portion of the second tubular body may be coupled by a revolute joint. For example, the revolute joint may be formed using a split ring 34 inserted in an outer groove of the third adapter housing 30 and locked between a shoulder of the thread ring 16 and a shoulder of the second adapter housing 14. Further, a first rotatable connector 32 may be coupled to one end of the third adapter housing 30. The first rotatable connector 32 may be electrically connected to an electrical connector 110 (e.g., a bulkhead connector) disposed in the other, opposite end of the third adapter housing 30 via conductor 114. A second rotatable connector 28 may be coupled to an end of the second adapter housing 14. The second wet connector 20 may be electrically connected to the second rotatable connector 28 via a second wire harness 24. The first rotatable connector 32 may be electrically connected to the second rotatable connector 28. Further, the first rotatable connector 32 and the second rotatable connector 28 may be sealed within the second tubular body by seals, which may be provided on an outer diameter of the second wet connector 20 and on an outer diameter of the bulkhead of the electrical connector 110. As such, the first rotatable connector 32 and the second rotatable connector 28 are not required to be wet connectors.
One or more keys 38 may protrude from an inner surface of the box end 72 of the second tubular body, and the one or more keys 38 may be rotatably fixed relative to the adapter sleeve 10, the first adapter housing 12, the second adapter housing 14, the thread ring 16, and the centralizer ring 36. The one or more keys 38 engage the keyway (e.g., the keyway formed by the two helical surfaces 46, the two straight surfaces 48, and the apex surface 106 shown in
While the embodiment of
Further, while the embodiment of
Still further, the male and female portions of the rotatable connector comprised in the adapter 84, and/or the male and female portions of the switch connector comprised in the centralizer 82 may be interchanged.
Still further, while the embodiment of
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While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and description. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the claims to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the claims.
