Connector for downhole instrument

Abstract

A connector for connecting a downhole instrument includes a male joint assembly and a female joint assembly. The male connector assembly comprises a first shell and a rotatable male connector which are connected together. The female joint assembly has a second housing and a rotatable female joint. The second housing is adapted to receive a rotatable female connector. The rotatable male connector has a first end including a plurality of cylinders concentrically connected in sequence and a second end adapted to receive a first set of a plurality of electrical wires on which a first set of a plurality of electrical contacts is arranged. The rotatable female connector has a first end having a cavity having a plurality of steps adapted to receive the plurality of cylinders in the rotatable male connector and a second end adapted to receive the second plurality of wires.

Description

Technical Field

[0001] The present disclosure provides a connector for connecting downhole instruments, particularly suitable for oil and gas exploration. Background Art

[0002] Modern oil and gas exploration technology relies heavily on the ability to measure operating conditions and formation environment while drilling. For example, directional drilling requires real-time monitoring of the wellbore's inclination and azimuth at a location near the drill bit, which can be achieved by using accelerometers and magnetometers. In addition, the data collected by the sensors can also be transmitted to the surface through a mud pulse telemetry system (including a mud pulse generator) or an electromagnetic telemetry system with a wider bandwidth. Instruments that measure and transmit such directional information are generally referred to as measurement while drilling (MWD) instruments / tools. Directional drilling also requires formation properties to guide the drill bit to the effective layer. Formation properties include density, porosity, resistivity, sonic borehole curves, magnetic resonance, and formation pressure, each of which is measured by a specific instrument. Instruments that measure formation properties are generally called logging while drilling (LWD) instruments. In this article, MWD instruments and LWD instruments can be used interchangeably or collectively referred to as downhole instruments. The numerous downhole instruments required for drilling require connectors for mechanical and / or electrical connections. A connector with high mechanical strength, corrosion resistance, and easy installation is required. Summary of the invention

[0003] In one embodiment of the present disclosure, a connector for connecting downhole instruments includes a male connector assembly and a female connector assembly. The male connector assembly includes a first housing and a rotatable male connector that can be connected together. The female connector assembly has a second housing and a rotatable female connector. The second housing is suitable for receiving the rotatable female connector. In addition, the rotatable male connector has a first end and a second end, the first end includes a plurality of cylinders connected concentrically in sequence, the second end is suitable for receiving a first group of multiple wires, and a first group of multiple electrical conduits are arranged on the plurality of cylinders. The rotatable female connector has a first end and a second end, the first end has a cavity, the cavity has a plurality of steps, suitable for receiving the plurality of cylinders in the rotatable male connector, and the second end is suitable for receiving a second group of multiple wires.

[0004] In some embodiments, the connector further comprises one or more centralizers fixed to the outer surface of the second housing. In some examples, each of the one or more centralizers has one or more holes each receiving a screw, a metal disk covering the top of the screw, and a filler sealing the one or more holes.

[0005] In some other embodiments, the male connector assembly and the female connector assembly are configured to be connected together by a tubular fastener.

[0006] In some other embodiments, the male connector assembly further comprises a first machine key fixed at the second end of the rotatable male connector, a second machine key fixed at the first end of the first housing, and a split coupling configured to receive the first and second machine keys to form a connection between the rotatable male connector and the first housing. The first machine key is made of epoxy resin.

[0007] The present disclosure also provides a downhole instrument module, which includes a downhole instrument connected to the connector as described above. The downhole instrument may be a directional sensor, a pulse generator, an unfocused and focused gamma probe, a battery, an alternator, a gyroscope, a vibration monitor, a pressure sensor, an electromagnetic telemeter, a resistivity sensor, a nuclear logging tool, and a sonic / acoustic sensor.

[0008] Two or more downhole instrument modules as described above may be connected together via the male connector assembly and the female connector assembly as described above to form a tool string. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings.

[0010] Figure 1 is an isometric view of a connector having rotatable male and female connector assemblies.

[0011] Figure 2 yes Figure 1 A cross-sectional view of the connector shown.

[0012] Figure 3 Shows Figure 2 Detail of the medium AA area.

[0013] Figure 4 An assembly drawing of the male connector assembly is shown.

[0014] Figure 5 A male connector assembly and a female connector assembly connected to a downhole tool are shown.

[0015] Figure 6 Details of the centralizers provided on the rotatable box joint housing are shown.

[0016] The following table lists the reference numerals used in the drawings.

[0017]

[0018] DETAILED DESCRIPTION

[0019] Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. It should be noted that, where applicable, the same or similar reference numerals are used in the drawings to represent the same or similar elements.

[0020] The accompanying drawings describe embodiments of the present disclosure, but are for illustrative purposes only. It will be readily apparent to those skilled in the art from the following description that other alternative embodiments exist without departing from the general principles of the present disclosure.

[0021] Figure 1 and Figure 2 A connector 100 is shown, which has a male connector assembly and a female connector assembly integrated together by a pressure housing 2. The female connector assembly has a housing 1, which has an upstream end 101 (i.e., a proximal end) and a downstream end 102 (i.e., a distal end). A rotatable female connector 4 is inserted into the downstream end 102 of the housing 1. The male connector assembly has a housing 3, which has an upstream end 301 and a downstream end 302, and a rotatable male connector 5. One end of the rotatable male connector 5 is received by the rotatable female connector 4, and the other end is located near the downstream end 302 of the housing 3.

[0022] Figure 3 Shows Figure 2 The AA area in Figure 4 is an isometric view of the male connector assembly. Figure 3 and 4 More details about the connection between the male connector assembly and the female connector assembly are provided together. First, the rotatable female connector 4 and the rotatable male connector 5 have pads 401 and 505 for electrical connection, respectively. In addition, the rotatable female connector 4 and the rotatable male connector 5 both have electrical contacts, which can form a conduit for power and signals when assembled. In this article, the electrical contacts can be any suitable device that can form a current path when in contact with each other.

[0023] like Figure 3 and Figure 4As shown, one embodiment of the rotatable male connector 5 has four cylinders of different diameters arranged concentrically in sequence. The outer surfaces of the four concentric cylinders form four steps. One or more electrical contacts are arranged on each step. In some embodiments, the conductor strip 501 arranged on the first step is used for electrical grounding; the conductor strip 502 arranged on the second step is used to power the Hall sensor switch of the DC brushless motor (not shown) electrically and signal-connected to the connector; the conductor strip 503 arranged on the third step is used to power the DC brushless motor (not shown); and the conductor strip 504 arranged on the fourth step is used to transmit signals to the Hall effect sensor (not shown). In other embodiments, all conductor strips have the same rated voltage and current, so each conductor strip can transmit power or data signals. In other embodiments, the conductor strips may have different ratings, so some of the conductor strips are used to transmit power, while other conductor strips are used to transmit data signals.

[0024] Accordingly, the distal end portion of the rotatable female connector 4 forms a cavity having four steps, which correspond to the four steps in the rotatable male connector 5. Each of the four steps of the rotatable female connector 4 also has a contact point, which is configured to form an electrical connection with the conductor strip on the rotatable male connector 5 after assembly, such as the one commercially available from RAMPART PRODUCTS.

[0025] The rotatable male connector 5 also has a machine key 506, and the housing 3 also has a machine key 303. During assembly, the machine keys 506 and 303 are locked in place by the split coupling 8, so that the rotatable male connector 5 and the housing 3 are integrated and can rotate together. The machine key 506 can be made of metal or epoxy resin. For example, the epoxy resin machine key 506 is bonded to the pad end of the rotatable male connector using a mold. Liquid epoxy resin is injected into the mold and allowed to fully cure. The mold is then removed to obtain the machine key 506 fixed to the end of the rotatable male connector 5, as shown in FIG. Figure 5 shown.

[0026] In addition, if Figure 3 As shown, the rotatable female connector 4 is fixed by a cap 6, which is threadedly connected to the upstream end 101 of the housing 1. Similarly, the rotatable male connector is fixed by a cap 7, which is threadedly connected to the downstream end 302 of the housing 3. Therefore, the female connector assembly and the male connector assembly are independent parts that can be connected together by tightening the pressure housing 2 to form an integrated connector.

[0027] During installation, the upstream end 101 of the female connector assembly is connected to the first downhole tool, and the wires / cables from the first downhole tool are welded to the pad 401. Similarly, the downstream end 302 is mechanically connected to the second downhole tool, and the wires / cables from the second downhole tool are welded to the pad 505. The pressure housing is connected to the female connector assembly or the male connector assembly by threading. Subsequently, the rotatable male connector 5 can be slid into the rotatable female connector 4 and firmly connected by tightening the pressure housing 2.

[0028] Figure 5 A module is shown having a male connector assembly (including components 3 and 5) connected to the proximal end of a downhole instrument 200 and a female connector assembly (including components 1 and 4) connected to the distal end of the downhole instrument 200, which can be a direction sensor or other instrument, such as a pulse generator, a gamma probe (unfocused and focused), a battery, an AC generator, a gyroscope, a vibration monitor, a pressure sensor, an electromagnetic (EM) telemeter, a resistivity sensor, a nuclear logging tool, or a sonic / acoustic sensor.

[0029] like Figure 5 The multiple modules shown can be interconnected by connecting the male connector assembly in one module to the female connector assembly in an adjacent module to form a tool string having a plurality of downhole tools connected in series.

[0030] Figure 6 A centralizer 11 is shown on the housing 1 of the female joint assembly, which is used to stabilize the female joint assembly in the downhole short joint. The centralizer 11 can be made of rubber, silicone or other suitable materials. In this embodiment, it is fixed to the outer surface of the housing 1 by two screws. The top of each screw is covered with a metal disk 12 (such as brass), and the screw hole is filled with a filler, such as room temperature vulcanized silicone (such as RTV). The filler 14 and the metal disk 12 can prevent or delay corrosion.

[0031] Although the embodiments of the present disclosure have been shown and described, modifications may be made by those skilled in the art without departing from the spirit or teachings of the present invention. The embodiments described herein are exemplary only and are not restrictive. Various changes and modifications may be made to these methods, systems and devices within the scope of the present invention. Therefore, the scope of protection of the present invention is not limited to the embodiments described herein. The scope of protection is limited only by the claims. The scope of the claims shall include all equivalents of the subject matter of the claims.

Claims

1. Connectors for connecting downhole instruments, including: Male connector assembly and female connector assembly, in: The male connector assembly comprises a first housing and a rotatable male connector connected together, The female connector assembly comprises a second housing and a rotatable female connector, wherein the second housing is adapted to receive the rotatable female connector. The rotatable male connector has a first end and a second end, the first end comprising a plurality of cylinders connected concentrically in sequence, the second end being adapted to receive a first plurality of wires, a first plurality of electrical contacts being arranged on the plurality of cylinders, and The rotatable female connector has a first end and a second end, the first end having a cavity with a plurality of steps adapted to receive the plurality of cylinders in the rotatable male connector, and the second end adapted to receive a second plurality of wires.

2. The connector according to claim 1, characterized in that: The connector also includes one or more centralizers secured to an outer surface of the second housing.

3. The connector according to claim 2, characterized in that: Each of the one or more centralizers has one or more holes each receiving a screw, a metal disk covering the top of the screw, and a filler sealing the one or more holes.

4. The connector according to claim 1, characterized in that: The male connector assembly and the female connector assembly are configured to be connected together by a tubular fastener.

5. The connector according to claim 1, characterized in that: The rotatable female connector is fixed to the second housing via a cover.

6. The connector according to claim 1, characterized in that: The male connector assembly also includes a first machine key fixed at the second end of the rotatable male connector, a second machine key fixed at the first end of the first housing, and a split coupling configured to receive the first and second machine keys to form a connection between the rotatable male connector and the first housing.

7. The connector according to claim 6, characterized in that: The first machine key is made of epoxy resin.

8. A downhole instrument module, comprising a downhole instrument connected to the connector according to claim 1.

9. The downhole instrument module according to claim 8, characterized in that: The downhole tools are selected from directional sensors, pulse generators, unfocused and focused gamma probes, batteries, alternators, gyroscopes, vibration monitors, pressure sensors, electromagnetic telemeters, resistivity sensors, nuclear logging tools, and sonic / acoustic sensors.

10. A downhole instrument tool string, comprising two or more downhole instrument modules according to claim 8 connected together.

Images