Well temperature and pressure monitoring sensor

Abstract

FIELD: oil and gas industry.SUBSTANCE: invention relates to pressure and temperature monitoring devices for intelligent gas and gas condensate wells. The downhole temperature and pressure monitoring sensor includes a housing with an electrical cable installed inside, connected to an electronic board, which is coupled with a temperature and pressure sensor that senses the physical impact of the external environment. The housing is made in the form of a series-connected: tip housing, crimping housing, sealed gland housing, electronics housing and sensor housing. The electrical cable is placed inside the fittings and secured using a collet and compression nut. The electrical cable is connected via a flexible multi-core wire to a cable gland installed in an insulating cable joint and connected to the electronic board. The electronic board is housed inside an insulated, sealed cavity within the electronics housing. The temperature and pressure sensor is installed inside the cavity of the sensor housing and is connected to the electronic board through the sensor connection unit using a plug and socket.EFFECT: increase in the reliability of the downhole temperature and pressure monitoring sensor.3 cl, 1 dwg

Description

[0001] The invention relates to pressure and temperature monitoring devices for intelligent gas and gas condensate wells.

[0002] The prior art contains technical solutions related to borehole sensors that are analogous to the proposed technical solution:

[0003] 1) From patent RU 2648390 C2, published on March 26, 2018, a design of a borehole quartz sensor is known, in which the signal transmission from devices used to measure the pressure and temperature of underground wells to surface equipment is carried out via a power cable or a tubular insulated conductive cable, while a DC source provides power to the control device, and also provides a small measurable current to the borehole passive temperature sensor and the impedance matching load of the system for measuring the resistive value.

[0004] The main drawback of the known design is the insufficient sealing of the cable connection to the sensor, which leads to rapid failure of the system, lack of correct operation throughout the entire service life, transmission of inappropriate temperature and pressure data, as well as complete loss of communication with the submersible equipment.

[0005] 2) The closest technical solution to the proposed design and chosen as a prototype is the design of a borehole sensor described in patent RU 2847787 C1, published 15.10.2025.

[0006] A known borehole pressure sensor using acoustically coupled quartz resonators comprises a two-chamber housing with a baffle. One chamber, the low-pressure chamber, is isolated from the downhole environment. The second, high-pressure chamber, is connected to the downhole environment. The low-pressure chamber contains a broadband piezoelectric element mounted on the surface of the baffle, a quartz temperature resonator, and a signal amplification device. These devices are electrically connected to each other and to a surface command and measurement unit via an electrical cable. A quartz pressure resonator is mounted on the surface of the baffle in the high-pressure chamber. The quartz temperature resonator in the low-pressure chamber, the broadband piezoelectric element, the baffle, and the quartz pressure resonator in the high-pressure chamber form an acoustically coupled system.Quartz temperature and pressure resonators have an identical crystal design, ensuring a discrepancy between their resonant frequencies of no more than 0.1%.

[0007] A disadvantage of the prototype is the lack of sufficient sealing of the chamber with the temperature and pressure sensor located in it from the chamber with electronics, which can lead to flooding of the latter.

[0008] The claimed design solves the technical problem of insufficiently reliable sealing of the housing intended for placing electronics, as well as the place where the cable is connected to the sensor.

[0009] The technical result of the proposed technical solution is to increase the reliability of the downhole temperature and pressure monitoring sensor.

[0010] The specified technical result is achieved by allocating a sealed cavity inside the electronics housing, designed to accommodate the electronic board, as well as a separate cavity designed to accommodate the temperature and pressure sensor inside it.

[0011] In order to ensure better sealing of the temperature and pressure sensor connection unit, instead of soldering the cable and then sealing it, this unit uses a metal-to-metal seal, and the connection of the temperature and pressure sensor to the electronic board is made using a plug and socket.

[0012] Additionally, to improve the reliability of the sensor sealing, laser welding of all sensor housings is used.

[0013] The claimed design of a downhole temperature and pressure monitoring sensor includes a tip housing, a crimping housing, a sealed gland housing, an electronics housing and a sensor housing, connected in series with each other, inside which an electric cable is installed, secured with two fittings and fixed with a collet and a compression nut, wherein the electric cable is connected with the help of a flexible multi-core wire to a plug installed in an insulating cable joint connected to an electronic board, which, in turn, is connected with the help of a plug and socket to a temperature and pressure sensor installed inside the sensor housing, wherein the electronic board is located inside a separate isolated sealed cavity made in the electronics housing, and the temperature and pressure sensor is connected to the electronic board with the help of a sensor connection unit, hermetically installed inside the electronics housing with a metal-to-metal seal.

[0014] In addition, the tip body, crimping body, cable gland body, electronics body and sensor body are connected to each other using laser welding, ensuring additional tightness of the sensor.

[0015] The claimed design of the downhole sensor is explained by the drawing presented in the Figure, which shows the following positions:

[0016] 1 - pressure nut;

[0017] 2 - tip body;

[0018] 3 - crimping body;

[0019] 4 - cable gland housing;

[0020] 5 - electronics housing;

[0021] 6 - sensor housing;

[0022] 7 - collet;

[0023] 8 - cable sealing fittings;

[0024] 9 - electric cable;

[0025] 10 - stranded wire;

[0026] 11 - cable gland;

[0027] 12 - electronic board;

[0028] 13 - sealing elements;

[0029] 14 - sensor connection unit;

[0030] 15 - temperature and pressure sensor;

[0031] 16 - plug;

[0032] 17 - insulating cable joint.

[0033] The downhole temperature and pressure sensor comprises a tip body 2, to which a compression nut 1 is attached. This nut is used to tighten a collet 7, which crimps a submersible encapsulated electrical cable 9, which transmits a signal to the wellhead and the data acquisition unit included in the telemetry system. The crimping of the cable 9 ensures its protection during the application of axial load to the downhole sensor.

[0034] A crimping body 3 is attached to the body of the tip 2, in which a plug 16 is installed, designed for crimping the cable sealing area before lowering the sensor into the well, as well as the first cable sealing fitting 8.

[0035] The gland body 4 is attached to the crimping body 3, in the cavity of which a second cable sealing fitting 8 is installed. Cable 9 is connected to the gland 11 via a multi-core wire 10, which ensures signal transmission from cable 9 to electronic board 12 and back. Furthermore, the cavity inside the gland body 4 is filled with an anaerobic dielectric sealant (compound).

[0036] The housing of the sealed entry 4 is connected to the housing of the electronics 5 by means of an insulating cable joint 17, designed to accommodate the sealed entry 11, while inside the housing of the electronics 5 there is a sealed cavity designed to accommodate the electronic board 12, and also in the housing of the electronics 5 with a metal-to-metal seal, a sensor connection unit 14 is installed.

[0037] The electronics housing 5 is connected to the sensor housing 6, inside which the temperature and pressure sensor 15 is located.

[0038] In addition, at the junctions of housings 3, 4 and 5, duplicate sealing elements 13 with protective rings are installed, providing additional reliability of the connections.

[0039] In addition, the tip body, crimping body, gland body, electronics body and sensor body are connected to each other by laser welding.

[0040] The downhole temperature and pressure monitoring sensor is assembled in the following sequence.

[0041] An electric cable 9 is installed inside the body of the tip 2, connected to the crimping body 3, which in turn is connected to the body of the pressure seal 4, which is fixed with the help of a collet 7 and pressed with the help of a nut 1, which prevents its axial movement during the application of an axial load on the downhole sensor, and, in addition, the cable 9 is passed through fittings 8, ensuring its axial location inside the bodies 3 and 4.

[0042] An electric cable 9 is placed inside the cavity of the housing of the cable gland 4, connected by means of a flexible multi-core wire 10 to the cable gland 11 installed in the insulating cable joint 17, after which the cavity in the housing 4 is filled with an anaerobic dielectric sealant (compound).

[0043] The sealed entry 11, together with the electronic board 12 connected to it, is installed inside the sealed cavity of the electronics housing 5, while the sensor connection unit 14 is installed inside the cavity of the electronics housing 5.

[0044] Then, the sensor housing 6 with the temperature and pressure sensor 15 pre-installed inside it is attached to the electronics housing 5, which is connected using a plug to the socket of the sensor connection unit 14.

[0045] The well temperature and pressure monitoring sensor works as follows:

[0046] Temperature and pressure sensor 15, sensing the physical impact of the external environment, generates signals of a specific frequency. These signals are fed to the signal converter on the electronic board 12, where they are processed and transmitted via the board's integrated modem to the ground-based channel controller module of the data acquisition unit. The channel control module receives signals containing service parameters, as well as temperature and pressure readings, decodes them, and transmits the values ​​to the computing core of the ground-based control and communication module.

[0047] At the same time, by placing the electronic board inside the sealed cavity of the electronics housing, the reliability of the downhole temperature and pressure monitoring sensor is increased.

[0048] To verify the operability of the proposed downhole sensor design, which is part of the underground downhole equipment, pilot tests were conducted on a test rig at the Izmeron Research and Production Company Plant LLC, which creates a gas environment while maintaining downhole temperature and pressure conditions. These tests also included tests at wells in the Urengoy oil and gas condensate field. These tests, using well-known technologies widely used in the oil and gas production industry, demonstrated the operability and reliability of the proposed downhole sensor design for operations such as perforation, hydraulic fracturing, and well completion.

Claims

1. A downhole temperature and pressure monitoring sensor, comprising a housing with an electrical cable installed inside it, connected to an electronic board, coupled with a temperature and pressure sensor that senses the physical impact of the external environment, characterized in that the housing is made in the form of a tip housing, a crimping housing, a sealed gland housing, an electronics housing and a sensor housing connected in series; the electrical cable is placed inside the fittings and secured with a collet and a compression nut; the electric cable is connected by means of a flexible multi-core wire to a cable gland installed in an insulating cable joint and connected to the electronic board; the electronic board is placed inside an isolated, sealed cavity inside the electronics housing; The temperature and pressure sensor is installed inside the cavity of the sensor housing and is connected to the electronic board through the sensor connection unit using a plug and socket.

2. A well sensor according to paragraph 1, characterized in that the sensor connection unit is installed inside the electronics housing with a metal-to-metal seal.

3. A well sensor according to paragraph 1, characterized in that the tip body, the crimping body, the sealed gland body, the electronics body, and the sensor body are connected to each other using laser welding.

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