CN-122014180-A - Water injection well control system and method for calibrating downhole water distributor through same

CN122014180ACN 122014180 ACN122014180 ACN 122014180ACN-122014180-A

Abstract

The invention relates to a water injection well control system and a method for calibrating an underground water distributor by the system, wherein the method comprises the following steps of S1 assembling the water injection well control system, namely connecting a ground controller with a water injection well oil pipe column, then arranging a plurality of intelligent water distributors in the water injection well oil pipe column, arranging a packer between the intelligent water distributors, finally connecting a double-acting valve and a plug at the lowest end of the water injection well oil pipe column, and completing assembly, S2 sending an instruction to the underground intelligent water distributors by a wave code sending device in the ground controller, so as to calibrate sensors in the underground intelligent water distributors, and performing quick test allocation of full well flow and automatic test allocation of layered flow after calibration. The method provided by the invention effectively realizes the calibration and control of the underground intelligent water distributor, and can solve the technical problems of inaccurate sensor measurement and insufficient control precision of the intelligent water distributor after the intelligent dispensing underground intelligent water distributor works for a long time.

Inventors

JU YAFENG
LI ZHENGTIAN
WANG ERZHEN
SHEN XIAOLI
LIU YANQING
YANG LINGZHI
BI FUWEI
WANG SHOUHU
RONG GUANGHUI
HE RUXIAN

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260512
Application Date: 20241112

Claims (10)

1. A method of calibrating a downhole water distributor by a water injection well control system, comprising the steps of: S1, assembling a water injection well control system The water injection well control system comprises a ground controller positioned at a wellhead, a plurality of intelligent water distributors positioned underground and matched packers, when the water injection well control system is installed, the ground controller is connected to a wellhead production tree, then the intelligent water distributors are arranged in a water injection well oil pipe column, the packers are positioned among the intelligent water distributors, finally the upper end of the water injection well oil pipe column is connected to the wellhead production tree, and the lowest end of the water injection well oil pipe column is connected with a double-acting valve and a plug, so that the assembly of the water injection well control system is completed; S2, sending an instruction to an underground intelligent water distributor through a wave code sending device in a ground controller, calibrating a sensor in the underground intelligent water distributor, and performing quick test allocation of the full well flow and automatic test allocation of the layered flow after calibration; The instructions sent by the wave code sending device comprise an underground pressure correction instruction, a flow correction instruction, a full well flow rapid test allocation instruction and/or a layered flow automatic test allocation instruction.
2. The method for calibrating a downhole water distributor by a water injection well control system according to claim 1, wherein S2 sends a command to a downhole intelligent water distributor by a wave code sending device in a surface controller, realizes the calibration of sensors in the downhole intelligent water distributor, and performs rapid test deployment of full well flow and automatic test deployment of stratified flow after the calibration, at least comprising one of steps A, B, C, D, Step A, after an underground intelligent water distributor receives an underground pressure correction instruction sent by a wave code sending device in a ground controller, performing pressure sensor calibration; step B, after the underground intelligent water distributor receives an underground flow correction instruction sent by a wave code sending device in a ground controller, performing layered flow sensor calibration; step C, after receiving a full well flow rapid test allocation instruction sent by a wave code sending device in a ground controller, the underground intelligent water distributor performs full well flow rapid test allocation; and D, after the underground intelligent water distributor receives the automatic layered flow test allocation instruction sent by the wave code sending device in the ground controller, performing automatic layered flow test allocation.
3. The method for calibrating a downhole water distributor by a water injection well control system according to claim 2, wherein after the step a of the downhole intelligent water distributor receiving the downhole pressure correction command sent by the wave code sending device in the ground controller, the step a of calibrating the pressure sensor comprises the following steps: A1. all intelligent water distributors receive the underground pressure correction instruction sent by the wave code sending device; A2. Firstly, performing pressure sensor calibration on an intelligent water distributor at the uppermost layer; A3. and then performing pressure sensor calibration operation on all intelligent water distributors sequentially from top to bottom to finish the calibration of the pressure sensors of all layers of intelligent water distributors.
4. The method for calibrating a downhole water distributor by a water injection well control system according to claim 3, wherein the calibrating process of the pressure sensor is that the flow control device of the intelligent water distributor which is calibrated is controlled to a maximum opening position, and the flow control devices of other layers of intelligent water distributors are controlled to be closed positions; The pressure in the oil pipe column of the water injection well is controlled to rise by a certain pressure value respectively, the pressure value is kept continuously stable in the set time under 3 different pressure values, and the intelligent water distributor calibrated during the pressure stability calibrates the pressure sensor by utilizing an interpolation method.
5. The method for calibrating a downhole water distributor by a water injection well control system according to claim 2, wherein the step B of calibrating the layered flow sensor after the downhole intelligent water distributor receives the downhole flow correction command sent by the wave code sending device in the ground controller comprises the following steps: B1. All intelligent water distributors receive the underground flow correction instruction sent by the wave code sending device; B2. firstly, the intelligent water distributor at the uppermost layer carries out flow sensor calibration, B3. and then carrying out flow sensor calibration operation on all intelligent water distributors sequentially from top to bottom to finish the calibration of the flow sensors of all layers of intelligent water distributors.
6. The method for calibrating a downhole water distributor by a water injection well control system according to claim 5, wherein the flow sensor calibration process comprises the steps of controlling the self-flow control device of the intelligent water distributor to a maximum opening position, controlling the self-flow control device of other intelligent water distributors to a closing position by the intelligent water distributor to make the intelligent water distributor to be calibrated enter a flow calibration mode; And then controlling the flow injected into the water injection well to be stabilized at three different proportions of the preset calibration value through a flow control device of the ground controller according to the preset flow calibration value of the ground controller, continuously stabilizing for a specified time, collecting 3 flow values from the intelligent water distributor for calibration during the flow stabilization period, and comparing the flow values with the preset flow calibration value of the ground controller to finish three-point flow calibration of a standard meter method.
7. The method for calibrating an underground water distributor through a water injection well control system according to claim 2, wherein after the underground intelligent water distributor receives the rapid test deployment instruction of the total well flow sent by the wave code sending device in the ground controller, the method for rapidly testing and deploying the total well flow comprises the following steps: C1. all intelligent water distributors receive the rapid full well flow test allocation instruction sent by the wave code sending device and enter a rapid full well flow test allocation state; C2. The position of the uppermost intelligent water distributor firstly carries out a binary optimization method to quickly reach the target position of flow control, namely the preset injection quantity in the intelligent water distributor, and carries out the binary optimization method to quickly reach the target position of flow control by the next intelligent water distributor at intervals of a certain preset time, and carries out the binary optimization method to quickly reach the target position of flow control by the next intelligent water distributor at intervals of the same preset time, and so on until all intelligent water distributors complete one round of operation; C3. The operation method described in C2 is repeatedly performed for three times, and the preset injection allocation amount in the intelligent water distributor can be achieved under the condition of eliminating interlayer interference, so that quick allocation of the full well flow is realized.
8. The method for calibrating an underground water distributor by a water injection well control system according to claim 2, wherein after the underground intelligent water distributor receives the automatic test and deployment instruction of the layered flow sent by the wave code sending device in the ground controller, the method for automatically testing and deployment of the layered flow comprises the following steps: D1. all intelligent water distributors receive the layered flow automatic test allocation instruction sent by the wave code sending device and enter a flow automatic test allocation state; D2. The intelligent water distributors are subjected to flow control allocation one by one according to the sequence from top to bottom, and enter the flow automatic test allocation state from top to bottom at intervals of a certain preset time, so that the intelligent water distributors are not subjected to flow control at the same time, and interlayer interference is eliminated.
9. The method for calibrating the underground water distributors by the water injection well control system according to claim 8, wherein the specific method for controlling the flow rate of each intelligent water distributor is that the injection flow rate of the layer is continuously measured by a flow sensor of the intelligent water distributor according to a preset test allocation period in the intelligent water distributor, when the flow rate error is larger than a preset flow rate error value in the intelligent water distributor, the intelligent water distributor enters a flow rate control mode, namely, a binary optimization method is adopted to quickly obtain target flow rate control, and the injection flow rate reaches a control target under the condition of low energy consumption.
10. A water injection well control system for implementing the method for calibrating the underground water distributor through the water injection well control system according to any one of claims 1-9 is characterized in that the water injection well control system comprises a ground controller positioned at a wellhead, a plurality of intelligent water distributors positioned underground and matched packers, the ground controller is connected to a wellhead production tree, the plurality of intelligent water distributors are arranged in a water injection well oil pipe column, the packers are positioned among the plurality of intelligent water distributors, the upper end of the water injection well oil pipe column is connected to the wellhead production tree, and the lower end of the water injection well oil pipe column is connected with a double-acting valve and a plug.

Description

Water injection well control system and method for calibrating downhole water distributor through same Technical Field The invention belongs to the technical field of oilfield separated layer water injection, and particularly relates to a water injection well control system and a method for calibrating a downhole water distributor through the system. Background Water injection is an important means for improving the recovery ratio of the oil field, refined separated layer water injection is a guarantee of continuous high yield of the low permeability oil field, and the wave code communication separated layer water injection technology is widely applied to the oil fields at home and abroad at present. The intelligent water distributor can measure the pressure value and the flow value of the layer where the intelligent water distributor is located in real time through the pressure sensor and the flow sensor. Because the intelligent water distributor works underground for a long time, the pressure sensor and the flow sensor in the intelligent water distributor are easy to drift in an underground high-temperature high-corrosion environment, influence the measurement accuracy and need to be calibrated regularly. At present, no method for calibrating a pressure sensor in an underground intelligent water distributor exists, and pressure sensor drift can influence pressure measurement precision and pressure wave detection in wave code communication. The calibration rule of the flow sensor in the intelligent water distributor is that the flow sensor in the intelligent water distributor cannot be calibrated by certain correction after data are transmitted back to the ground, and the main problem is that the accuracy of constant flow control of the intelligent water distributor on the layer is affected. The ground controller is mainly used for sending instructions to control the control system in place, and an automatic autonomous control method is lacked. The invention discloses (bulletin) No. CN110847868A discloses a remote calibration method for the underground layered flow of intelligent separate injection, which comprises the following steps of 1) installing two pressure sensors on each underground intelligent water distributor, synchronously measuring the front pressure and the back pressure of an adjustable water nozzle of each underground intelligent water distributor, 2) calculating the flow of the adjustable water nozzle of each underground intelligent water distributor according to a throttling formula, 3) descending all underground intelligent water distributors into the well, calculating the flow through the throttling formula of the step 2), establishing an artificial intelligent three-dimensional metering model, 4) periodically returning a large number of opening degree of the adjustable water nozzle, the front pressure and the back pressure differential value of the nozzle to the artificial intelligent three-dimensional metering model in the long-term normal water injection process after the manual metering is completed, comparing the corresponding flow with the standard flow obtained by a ground standard flow, and correcting, thereby completing remote calibration. The method is that the pressure flow data recorded by the underground intelligent water distributor is transmitted back to the ground for revision, and great errors exist. In conclusion, only the surface flowmeter can be calibrated at present, and no method for calibrating and controlling the pressure sensor in the underground intelligent water distributor exists, so that the problems of inaccurate sensor measurement and insufficient control precision of the water distributor after the intelligent dispensing underground water distributor works for a long time are difficult to solve in the prior art. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a water injection well control system and a method for calibrating a downhole water distributor by the system, wherein the method is a method for calibrating a stratified pressure sensor, calibrating a stratified flow sensor, rapidly testing and allocating the flow of a whole well and automatically testing and allocating the flow of the stratified well. In order to achieve the above purpose, the present invention adopts the following technical scheme: A method of calibrating a downhole water distributor by a water injection well control system, comprising the steps of: S1, assembling a water injection well control system The water injection well control system comprises a ground controller positioned at a wellhead of the water injection well, a plurality of intelligent water distributors positioned underground and matched packers, wherein when the water injection well control system is installed, the ground controller is firstly connected to a wellhead production tree, then the intelligent water distributors are arranged in an oil pipe column of the wate