Patent Application
20150218893
Not applicable.
Not applicable.
In downhole drilling operations, downhole measuring tools are used to gather information about geological formations, status of downhole tools, and other downhole conditions. Such data is useful to drilling operators, geologists, engineers, and other personnel located at the surface. This data may be used to adjust drilling parameters, such as drilling direction, penetration speed, and the like, to effectively tap into an oil or gas bearing reservoir. Data may be gathered at various points along the drill string, such as from a bottom-hole assembly or from sensors distributed along the drill string. Once gathered, apparatus and methods are needed to rapidly and reliably transmit the data to the surface. Traditionally, mud pulse telemetry has been used to transmit data to the surface. However, mud pulse telemetry is characterized by a very slow data transmission rate (typically in a range of 1-6 bits/second) and is therefore inadequate for transmitting large quantities of data in real time. Other telemetry systems, such as wired pipe telemetry system and wireless telemetry system, have been or are being developed to achieve a much higher transmission rate than possible with the mud pulse telemetry system.
In wired pipe telemetry systems, inductive transducers are provided at the ends of wired pipes. The inductive transducers at the opposing ends of each wired pipe are electrically connected by an electrical conductor running along the length of the wired pipe. Data transmission involves transmitting an electrical signal through an electrical conductor in a first wired pipe, converting the electrical signal to a magnetic field upon leaving the first wired pipe using an inductive transducer at an end of the first wired pipe, and converting the magnetic field back into an electrical signal using an inductive transducer at an end of the second wired pipe. Several wired pipes are typically needed for data transmission between the downhole location and the surface. As is known, the signal coupler or junction between ends of the wired pipe can include other types of electrical couplers beyond inductive transducers, such as direct conductive-type couplers and others. However, the use of a unitary double-shouldered connection typically only allows for an electronics assembly that greatly restricts the inner diameter of the tool. The wired pipes may be subjected to temperatures up to 200° C. and 25,000 psi pressure.
In one embodiment, a downhole sub includes a first tubular housing with a first internal shoulder, a second tubular housing with a second internal shoulder, and a stabilizer assembly to be disposed between the first and second internal shoulders. In addition, the first and second tubular housings are configured to be threaded together. Moreover, the stabilizer assembly is configured to engage the first and second internal shoulders. In some embodiments, the stabilizer assembly includes an outer sleeve and an inner spacer. The outer sleeve may include a first end opposite a second end, wherein the first end is disposed proximate the second internal shoulder of the second housing. The second end of the outer sleeve may form a third internal shoulder. The first internal shoulder may be configured to engage the third internal shoulder such that the engagement of the first internal shoulder and the third internal shoulder provides a torquing interface between the first and second tubular housings.
In another aspect, a downhole sub includes a first tubular housing with a first internal shoulder, a second tubular housing with a second internal shoulder, and a sleeve to be disposed between the first and second internal shoulders. In addition, the first and second tubular housings are configured to be threaded together. Moreover, the sleeve is configured to engage the first and second internal shoulders.
In a further aspect, a downhole sub includes a first tubular housing with a first internal shoulder, a second tubular housing with a second internal shoulder, and a spacer having a first end that is biased and a second end configured to engage the second internal shoulder. Moreover, the first and second tubular housings are configured to be threaded together.
In one embodiment, a method for stabilizing an assembly for use with a downhole sub assembly includes an outer sleeve having a plurality of interlocking interfaces, an inner spacer having a first annular end opposite a second annular end, a cutout and a coupler element disposed in a channel on a the first annular end, and a biasing assembly comprising a biasing element and disposed about and retained by a first end of a spring cap. Moreover, the inner spacer is configured to engage and retain the biasing element at a second annular end of the spring cap.
In one embodiment of a method for coupling tubular housings in a downhole sub, the method includes threadably coupling a first tubular housing and a second tubular housing, wherein the first tubular housing includes a first shoulder and the second tubular housing includes a second shoulder. In addition, the method comprises interlocking a sleeve with and inside the second tubular housing, the sleeve disposed between the first and second shoulders and including a third shoulder. Moreover, the method comprises torquing the first shoulder against the third shoulder.
Embodiments described herein comprise a combination of features and advantages intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical advantages of the disclosure such that the detailed description of the disclosure that follows may be better understood. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims.
For a detailed description of the preferred embodiments, reference will now be made to the accompanying drawings in which:
The following discussion is directed to various exemplary embodiments. However, one skilled in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosures, including the claims, is limited to that embodiment.
Certain terms are used throughout the following description and claim to refer to particular system components. This document does not intend to distinguish between components that differ in name but not function. Moreover, the drawing figures are not necessarily to scale. Certain features of the disclosure may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis. Still further, reference to “up” or “down” may be made for purposes of description with “up,” “upper,” “upward,” or “above” meaning generally toward or closer to the surface of the earth, and with “down,” “lower,” “downward,” or “below” meaning generally away or further from the surface of the earth.
The drill string 13 preferably includes a plurality of network nodes 30. The nodes 30 are provided at desired intervals along the drill string. Network nodes essentially function as signal repeaters to regenerate data signals and mitigate signal attenuation as data is transmitted up and down the drill string. The nodes 30 may be integrated into an existing section of drill pipe or a downhole tool along the drill string. A repeater for this purpose is disclosed in U.S. Pat. No. 7,224,288 (the “'288 Patent”), which is incorporated herein by reference. Sensor package 38 in the BHA 15 may also include a network node (not shown separately). For purposes of this disclosure, the term “sensors” is understood to comprise sources (to emit/transmit energy/signals), receivers (to receive/detect energy/signals), and transducers (to operate as either source/receiver). Connectors 34 represent drill pipe joint connectors, while the connectors 32 connect a node 30 to an upper and lower drill pipe joint.
The nodes 30 comprise a portion of a downhole electromagnetic network 46 that provides an electromagnetic signal path that is used to transmit information along the drill string 13. The downhole network 46 may thus include multiple nodes 30 based along the drill string 13. Communication links 48 may be used to connect the nodes 30 to one another, and may comprise cables or other transmission media integrated directly into sections of the drill string 13. The cable may be routed through the central borehole of the drill string 13, or routed externally to the drill string 13, or mounted within a groove, slot or passageway in the drill string 13. Preferably signals from the plurality of sensors in the sensor package 38 and elsewhere along the drill string 13 are transmitted to the surface 26 through a wire conductor 48 along the drill string 13. Communication links between the nodes 30 may also use wireless connections.
A plurality of packets may be used to transmit information along the nodes 30. Packets may be used to carry data from tools or sensors located downhole to an uphole node 30, or may carry information or data necessary to operate the network 46. Other packets may be used to send control signals from the top node 30 to tools or sensors located at various downhole positions.
Referring to
Referring now to
Referring still to
Referring now to
The first housing pin end 115 is configured to threadingly engage the second housing box end 145, such that first housing external shoulder 117 engages and is torqued against second housing external shoulder 147. Cylindrical portion 149a comprises a plurality of grooves 160 disposed proximate second housing threaded box end 145, wherein each groove 160 comprises an individual curved channel 160a separated by a peak 160b—grooves 160 are not threaded and do not comprise a continuous helical path. Each successive groove 160 from the second housing box end 145 toward the pin end 146 is disposed radially closer to central axis 101, forming a taper angle A160 (see
Referring still to
The electronics housing 170 is configured to be disposed in the second housing 140 such that electronics housing first annular end 170a engages second housing internal shoulder 150 and the tubular passages 171, 151 of the electronics housing 170 and second housing 140, respectively, are aligned. Further, when electronics housing 170 is disposed in the second housing 140, electronics housing outer cylindrical surface 178 is coaxial with and may contact cylindrical portion 149a of second housing inner surface 149 while electronics housing inner cylindrical surface 179 forms a continuous inner surface with angled portion 149b of second housing inner surface 149 (see
Referring now to
Referring now to
Referring now to
Referring now to
Referring now to
Referring now to
Referring still to
The first housing 110 pin end 115 with spring cap 125, biasing member 130, and spacer 250 are inserted into second housing 140 box end 145 with electronics housing 170 and sleeve 250 and then rotated about axis 101 to mate the threaded pin end 115 and threaded box end 145. However, inserting the spacer 275 (with first housing 110, spring cap 125, and biasing element 130) into the sleeve 250 (with second housing 140 and electronics housing 170) is a blind process. The tapered chamfer 276 in spacer 275 reduces potential interference with and allows for proper alignment during insertion of the spacer 275 into the sleeve 250. In addition, tube 282 in tubular passage 281 of the spacer 275 is anchored at both ends 282a, 282b to reduce potential damage to the tubing 282. First annular end 275a is also roughened to reduce the possibility of galling by allowing thread dope to accumulate on first annular end 275a.
The sleeve 250 allows for the maintenance of load sharing and torquing capability in the threaded connection and sub assembly 100 by using the sleeve 250 and its shoulder 250b to functionally replace the secondary shoulder (i.e., internal shoulder 170b of electronics housing 170) of a double shouldered drill pipe threaded connection (i.e., the mating of first housing 110 and second housing 140). More specifically, the sleeve 250, 250b acts as the secondary shoulder and the features of the sleeve 250—the tapered groove profile of grooves 160, 260 combined with the inner frustoconical surface 259 of sleeve 250, the channel 270 in second annular end 250b of sleeve 250, and the stress relief groove 156 in second housing 140—help make load sharing more uniform across the entire length of the grooves 160, 260, which reduces the stress riser typically seen at the first three threads of a threaded connection. In this manner, the sleeve 250 and its shoulder 250b provide the robust surface for the torquing capability that the internal shoulder 170b of the electronics housing 170 may not be able to provide.
The spacer 275 allows for the constant contact of a coupler element (i.e., coupler element 199 disposed in channel 180 of the electronics housing shoulder 170b and coupler element 199 disposed in channel 280 of the spacer first annular end 275a) to ensure continuity of electrical signal under pressure up to 25,000 psi and dynamic loads. Under a 25,000 psi pressure load, the electronics housing 170 tends to compress axially an amount greater than the coupler element 199 would allow if the coupler were not moveable. Thus, maintaining connectivity of the coupler elements 199 in the spacer 275 and electronics housing 170 under high pressure is achieved by the biasing force of the biasing element 130 under load in combination with the cutout 290 of spacer 275, which lowers the inertia of the spacer 275 by reducing its mass. When manufacturing the cutout 290 in spacer 275, the maximum amount of material is removed while maintaining mechanical integrity.
In some embodiments, when the sub assembly 100 is deployed downhole, pressure and temperature conditions can cause the electronics housing 170 to shrink or pull back axially, thus causing the shoulder 170b and the corresponding coupler element 199 to pull away from the mating coupler element 199 in the annular end 275a. The spacer 275 is biased by the biasing element 130 such that the annular end 275a is forced axially toward the shoulder 170b, thereby maintain contact of the coupler elements 199 despite the moveability of the shoulder 170b. Because of the moveability or variable position of the shoulder 170b, shoulder 170b also does not provide a good torquing surface for a robust torquing interface. Thus, the sleeve 250 and its shoulder 250b are provided as described above to functionally replace the shoulder 170b with a shoulder that provides good torquing capability, in an axially displaced location from the shoulder 170b.
While preferred embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order, and disclosed features and components can be arranged in any suitable combination to achieve desired results.
