A new type of downhole submersible electric pump unit monitoring device suitable for offshore oil fields

Abstract

This utility model belongs to the field of oil well completion technology, and particularly relates to a novel monitoring device for downhole submersible pump units suitable for offshore oil fields. The device comprises a hollow mandrel, a copper slip ring, copper solder joints and wires, a housing, copper conductive contacts, and measuring solder joints. In actual operation, pump operators can use a multimeter to connect to the measuring solder joints to measure the three-phase DC resistance and cable insulation performance of the submersible pump. This operation can be performed simultaneously with the cable release.

Description

Technical Field

[0001] This utility model belongs to, but is not limited to, the field of oil well completion technology, and particularly relates to a new type of monitoring device for downhole submersible electric pump units suitable for offshore oil fields. Background Technology

[0002] During drilling and completion operations in oilfield engineering, for ESP wells, monitoring unit parameters typically requires pausing tubing installation. ESP operators use a multimeter to connect the positive and negative terminals to the exposed copper core of the power cable or the outer steel armor layer to measure insulation and DC resistance. Tubing installation can only continue after the measurements are completed. Because multiple pauses are needed to monitor unit parameters during production string installation, operational efficiency is affected. Furthermore, the high cost of renting large lifting equipment such as offshore drilling vessels hinders cost control. Utility Model Content

[0003] To address the problems existing in the prior art, this utility model provides a novel monitoring device for downhole submersible electric pump units suitable for offshore oil fields.

[0004] This utility model is implemented as follows: a novel monitoring device for downhole submersible electric pump units suitable for offshore oil fields, the device comprising:

[0005] It consists of a hollow mandrel, a copper slip ring, copper solder joints and wires, a housing, copper conductive contacts, and measuring solder joints.

[0006] Furthermore, the hollow mandrel is linked to the cable drum shaft and rotates together with the drum during the lower production column;

[0007] In the copper slip ring, four copper slip rings are fixed on the hollow spindle, and the slip rings can rotate with the shaft;

[0008] In the copper solder joints and wires, one solder joint is fixed on each of the four copper slip rings, and one wire is led out from each of them and passed into the inside of the mandrel. Finally, the wire passes out from the mandrel and is connected to the three copper cores and the armor of the power cable respectively.

[0009] The production column under the housing does not rotate with the hollow shaft and copper slip ring during production;

[0010] There are four copper conductive contacts, which are fixed on the device housing. The contacts are made into contact by spring plates pressing against four copper slip rings to achieve conduction.

[0011] The measured solder points A, B, C, and D are connected to four copper conductive contacts, respectively. The measured solder points A, B, and C correspond to the three copper cores inside the cable, and the measured solder point D corresponds to the steel armor protective layer on the outside of the cable, which is the armor sheath.

[0012] Furthermore, while ensuring the normal release of the electric submersible pump cable, the slip ring rotates with the hollow mandrel and cable drum. The three-phase DC resistance can be measured by simply connecting a multimeter to measure any two of the solder joints A, B, and C.

[0013] Furthermore, the device includes:

[0014] Hollow mandrel, extending axially;

[0015] Multiple copper slip rings are fixedly disposed on the outer periphery of the hollow mandrel;

[0016] Copper solder joints and wires: Each copper slip ring is provided with a copper solder joint and connected to a wire, which is sequentially inserted into the hollow mandrel and led out from the outside of the mandrel;

[0017] A housing is fitted over the outside of the hollow mandrel;

[0018] Multiple copper conductive contacts are disposed on the inner wall of the housing and contact the corresponding copper slip rings;

[0019] The solder joints are measured, located on the outer surface of the housing, and electrically connected to the copper conductive contacts respectively.

[0020] Furthermore, the hollow mandrel is fixedly connected to the cable drum shaft and rotates synchronously with the cable drum during the lower production column process.

[0021] Furthermore, the number of copper slip rings is four, which are equidistantly arranged on the outer periphery of the hollow mandrel.

[0022] Furthermore, there are four wires, which are respectively connected to the three copper cores and the steel armor layer of the submersible pump power cable.

[0023] Furthermore, the housing remains stationary during the lower production column process and does not rotate with the hollow mandrel and copper slip ring.

[0024] Furthermore, there are four copper conductive contacts, which are pressed onto the corresponding copper slip rings by elastic components. The measuring solder points A, B, and C correspond to the three-phase copper core of the submersible pump power cable, and the measuring solder point D corresponds to the steel armor layer of the power cable.

[0025] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this utility model are as follows:

[0026] In actual operation, the electric pump operator can use a multimeter to measure the three-phase DC resistance and cable insulation performance of the electric submersible pump by connecting and measuring the solder joints. This operation can be performed simultaneously with the cable release. Attached Figure Description

[0027] Figure 1 This is a structural diagram of a novel downhole submersible electric pump unit monitoring device for offshore oil fields, provided by an embodiment of this utility model.

[0028] In the diagram: 1. Hollow mandrel; 2. Copper slip ring; 3. Copper solder joint and wire; 4. Housing; 5. Copper conductive contact; 6. Measuring solder joint. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0030] like Figure 1 As shown in the figure, this utility model embodiment provides a novel monitoring device for downhole submersible electric pump units suitable for offshore oil fields. The device includes:

[0031] It consists of a hollow mandrel 1, a copper slip ring 2, copper solder joints and wires 3, a housing 4, copper conductive contacts 5, and measuring solder joints 6.

[0032] The hollow mandrel 1 is linked to the cable drum shaft and rotates together with the drum during the lower production column;

[0033] In the copper slip ring 2, four copper slip rings 2 are fixed on the hollow spindle 1, and the slip rings 2 can rotate with the shaft;

[0034] In the copper solder joints and wires 3, one solder joint is fixed on each of the four copper slip rings 2, and one wire is led out from each of them and passed into the inside of the mandrel. Finally, the wires pass out from the mandrel and are connected to the three copper cores and the armor of the power cable respectively.

[0035] The lower part of the housing 4 does not rotate with the hollow shaft and copper slip ring during the production of the tubular column;

[0036] There are four copper conductive contacts 5, which are fixed on the device housing 4. The contacts are made to make contact by spring plates pressing on the four copper slip rings to achieve conduction.

[0037] The measured solder points 6 A, B, C, and D are respectively connected to four copper conductive contacts 5. The measured solder points A, B, and C correspond to the three copper cores inside the cable, and the measured solder point D corresponds to the steel armor protective layer on the outside of the cable, which is the armor sheath.

[0038] This device allows the slip ring to rotate with the hollow mandrel and cable drum while ensuring the normal release of the electric submersible pump cable. The three-phase DC resistance can be measured by simply connecting a multimeter to measure any two of the solder joints A, B, and C.

[0039] The working principle of this utility model is as follows: During the running of the production tubing, the slip ring rotates with the hollow mandrel 1 and the cable drum. When measuring insulation and DC resistance, the housing 4 and the copper conductive contact 5 remain stationary. Only two of the welding points 6A, B, and C need to be connected with a multimeter to measure the three-phase DC resistance. Connecting any one of the welding points 6A, B, and C and welding point D can measure the insulation to ground. This allows for simultaneous measurement while running the tubing, which can improve the efficiency of well completion operations and reduce operating costs.

[0040] Offshore well completion operations require the continuous lowering of submersible pump cables, some hundreds of meters long, into the narrow wellhead deck. Traditionally, this involves pausing the drum during the lowering of the tubing string, disconnecting the circuit, and then conducting insulation and DC resistance tests. Frequent stop-and-test-and-restart operations not only slow down drilling time but also increase the probability of cable damage due to repeated tension cycles, becoming a "hidden consumable" in the platform's daily production costs.

[0041] This design rigidly connects the hollow mandrel 1 directly to the drive shaft of the cable drum, making the mandrel and cable coaxial rotating bodies. The axially penetrating through hole not only provides a path for the conductor but also significantly reduces the weight of the mandrel, thereby suppressing vibrations caused by off-center loading. Four annular grooves are machined on the outer diameter of the mandrel, and copper slip rings 2 are press-fitted in. The outer surface of each slip ring is precision machined and silver-plated to ensure stable contact resistance even at high speeds.

[0042] The inner side of the slip ring is electrically connected to the three phase wires and armor layer of the cable via copper solder joints and conductor 3. The conductor uses oil-resistant, highly flexible FEP insulation, passes through the inner hole of the mandrel, and is terminated one-to-one with the power cable to reduce the number of additional joints and avoid introducing additional impedance. The entire conductor is wound in a spiral manner within the mandrel to allow for expansion and contraction, which can resist axial movement during the pipe laying process.

[0043] The housing 4 is milled from a single piece of stainless steel and fixed to the derrick beam with a locating key, ensuring that the housing remains stationary relative to the platform. Inside the housing, four spring-loaded copper conductive contacts 5 are arranged radially, using phosphor bronze substrate with beryllium copper gold-plated contact surfaces, which maintain a stable contact force of 2–4 N and resist electrochemical corrosion in long-term oil mist environments.

[0044] After completing the aforementioned mechanical-electrical closed loop, only four shielded test terminals need to be led out from the outside of the weld points 6A, 6B, 6C, and 6D. The well completion technician can use a multimeter to bridging any two points of 6A, 6B, and 6C to obtain the three-phase DC resistance, and bridging 6A / 6B / 6C with 6D to read the insulation resistance to ground in real time. The entire test loop is always in a rotating-stationary hybrid topology, achieving "testing as you go."

[0045] Real-world applications show that when there are micro-cracks or conductor oxidation inside the cable, the three-phase DC resistance curve drifts, and the system issues an early warning just meters from the wellhead. If water enters the armor layer, the AD insulation resistance value drops simultaneously, allowing the problem to be located and corrected within minutes. This avoids the high-cost troubleshooting after the electric pump falls into the well and shortens the average well completion cycle by 4–6 hours, resulting in significant economic benefits and safety redundancy.

[0046] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In addition, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any modifications, equivalent substitutions and improvements made by those skilled in the art within the technical scope disclosed in this utility model, and within the spirit and principles of this utility model, should be included within the protection scope of this utility model.

Claims

1. A novel monitoring device for downhole submersible electric pump units suitable for offshore oil fields, characterized in that, The device includes: Hollow mandrel, extending axially; Multiple copper slip rings are fixedly disposed on the outer periphery of the hollow mandrel; Copper solder joints and wires: Each copper slip ring is provided with a copper solder joint and connected to a wire, which is sequentially inserted into the hollow mandrel and led out from the outside of the mandrel; A housing is fitted over the outside of the hollow mandrel; Multiple copper conductive contacts are disposed on the inner wall of the housing and in contact with corresponding copper slip rings; The solder joints are measured, located on the outer surface of the housing, and electrically connected to the copper conductive contacts respectively.

2. The monitoring device according to claim 1, characterized in that, The hollow mandrel is fixedly connected to the cable drum shaft and rotates synchronously with the cable drum during the lower production column process.

3. The monitoring device according to claim 1, characterized in that, The number of copper slip rings is four, which are equidistantly arranged on the outer periphery of the hollow mandrel.

4. The monitoring device according to claim 1, characterized in that, The number of conductors is four, which are respectively connected to the three copper cores and the steel armor layer of the submersible pump power cable.

5. The monitoring device according to claim 1, characterized in that, The housing remains stationary during the lower production column process and does not rotate with the hollow mandrel and copper slip ring.

6. The monitoring device according to claim 1, characterized in that, The number of copper conductive contacts is four, which are pressed onto the corresponding copper slip rings by elastic components. The measuring solder points A, B, and C correspond to the three-phase copper core of the submersible electric pump power cable, and the measuring solder point D corresponds to the steel armor layer of the power cable.

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