Signal transmission method for downhole measurement and control system

Abstract

The invention relates to the work of oil recovery operations of oilfields, in particular to a signal transmission method for a downhole measurement and control system. The signal transmission is achieved through carrying out close connection and sealing on cable cores, a pressing cap, a wire pipe, a spacing ring, a sealing ring, a cable, an oil tube, a guard plate, a rubber protection block, screws, a coupling, an oil tube short joint, a connecting plate, a pressure plate, a sensor, a guard pipe and a steel belt throat hoop; and according to the signal transmission method, the cable or an outer armor of a capillary tube is adopted to be closely connected with the oil tube and serve as a ground wire for signal transmission, and the single-core signal transmission is achieved; the cable is fixed with the sensor by adopting the connecting plate and the back plate which are provided with unique designs, and the cable is fixed with the oil tube by adopting a guard plate assembly and a steel belt, so that the fixation of the cable is achieved; and the sealing of a wellhead is achieved by adopting a wire pipe sealing method with a unique design.

Description

Technical field [0001] The invention relates to a method for transmitting signals of a downhole measurement and control system in oil production operations, in particular: a method for transmitting signals of the downhole measurement and control system. Background technique [0002] At present, in the work of oilfield extraction operations, four methods are mainly used for the downhole working conditions of screw pumps and pumping units: 1. Directional explosion sound waves return to show the liquid level, but it cannot be accurately reflected due to factors such as downhole gas jacket changes. The downhole liquid level has potential safety hazards, and the downhole temperature cannot be displayed; 2. The downhole liquid level can be displayed by the sonic echo of nitrogen injection, which is the same as the liquid level displayed by the directional explosion acoustic wave. It cannot accurately reflect the well liquid level and cannot display the downhole temperature. 3. Put the ...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a method for transmitting signals of the downhole measurement and control system, which uses a single-core high-temperature cable or threaded capillary for data transmission, and transmits the signal from the downhole temperature and pressure gauge to solve the problem. The problem of downhole signal transmission to uphole is to realize real-time and accurate reading and recording of downhole conditions; in order to adopt this simple method, several difficulties must be solved: single-core transmission signal problem, cable fixing problem, wellhead sealing problem; in order to realize the above Purpose, can overcome above-mentioned three difficult points again, the present invention is achieved like this: the transmission method of downhole measurement and control system signal is to utilize: Rubber protection blocks, screws, collars, oil pipe shorts, connections and pressure plates, sensors, protective pipes and steel hose hoops are tightly connected and sealed to complete signal transmission. Connected, as the ground wire for signal transmission, to complete the single-core signal transmission problem; use the uniquely designed connection and pressure plate to fix the cable and the sensor, and use the guard plate component and steel belt to fix the cable and the oil pipe to complete the cable fixing problem; independent design The sealing method of the line pipe solves the problem of wellhead sealing; among them, the signal transmission method of the single-core cable is: the outer casing of the sensor, the outer armor of the cable and the oil pipe are used as the ground wire for signal transmission, and the sensor is fixed on the protective pipe by 4 screws On the top, the protective pipe is connected to the short connection of the oil pipe through the coupling, and the short connection of the oil pipe is connected to the oil pipe through the coupling until it reaches the well; Ensure that the connection between the sensor and the cable core is not affected by external force, so that it will be broken; the cable is connected to the outside of the short connection of the oil pipe through the short connection of the oil pipe. On the coupling between the oil pipes, the protective plate is semicircular, and it is stuck on the coupling at the same time to ensure that the protective pipe and the cable will not slip off; between every two sections of oil pipes, a protective plate and a rubber protection block assembly are used to secure the The cable is fixed on the outer wall of the oil pipe; the rubber protection block is installed on the guard plate by 2 screws; the method of wellhead sealing is: at the wellhead, the cable passes through the wellhead casing valve, and passes through the secondary sealing body to the wellhead intelligent control Cabinet, do not make any changes to the wellhead, and will not affect the original structure and performance of the wellhead; the specific steps are: design a wire tube at the wellhead, the cable core is passed through the wire tube, and several spacers and sealing rings are alternately stacked, pressed by the pressure cap tight, deform the sealing ring, realize the sealing of the wellhead line pipe, and the downhole signal can be transmitted by the cable core and the line pipe

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