A method and system for low-power encoding and decoding data transmission in wells

Abstract

This invention discloses a low-power downhole encoding and decoding data transmission method and system. The drilling homing equipment determines whether it has entered the working state based on the drilling pump start-up time. Once in the working state, it performs well inclination and temperature measurements when the pump is stopped. After a certain period of pump operation, it sends coded pulses to the surface equipment. The transmission time interval T between the first and second coded pulses is calculated according to a set rule based on the measured well inclination data. The surface equipment continuously monitors the pump pressure after a certain period of pump operation. Timing begins when the first pressure change waveform is detected and ends when the second pressure change waveform is detected, obtaining the time difference T between the two waveforms. Well inclination data is then decoded based on the obtained time difference T and the aforementioned rule. This ultra-low-power encoding and transmission method for well inclination data transmission allows for downhole working time exceeding 30 days, effectively improving drilling homing efficiency.

Description

Technical Field

[0001] This invention relates to the field of drilling technology, specifically to a downhole low-power encoding and decoding data transmission method and system. Background Technology

[0002] With increasing demands for drilling depth and speed, especially for improving drilling efficiency in vertical well sections, the current domestic practice of using MWD (Micro-Range Drilling) and self-floating single-point MWD for vertical well deviation monitoring suffers from problems such as long measurement times, complex and expensive tool assembly, and downhole safety hazards, failing to improve work efficiency. This invention, based on a low-power vertical well MWD system, simplifies drilling tools, extends downhole working time to over 30 days, and utilizes an ultra-low-power encoding transmission method for well deviation data transmission, effectively improving drilling efficiency. Summary of the Invention

[0003] To address this issue, the present invention provides a low-power downhole encoding and decoding data transmission method and system to solve the problems of long measurement time and low drilling efficiency in existing well deviation monitoring systems.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] According to a first aspect of the present invention, a downhole low-power encoding and decoding data transmission method is proposed, the method comprising:

[0006] Determine whether the well has entered the working state based on the drilling pump start-up time;

[0007] Once the pump is in operation, well inclination and temperature measurements are performed when the pump is stopped.

[0008] After the pump has been running for a certain period of time, an coded pulse is sent to the ground equipment. The time interval T between the first and second coded pulses is calculated according to the measured well inclination data and the set rules.

[0009] The ground equipment continuously monitors the pump pressure after the pump has been running for a certain period of time. Timing begins when the first pressure change waveform is detected and ends when the second pressure change waveform is detected, obtaining the time difference T between the two waveforms. Based on the obtained time difference T and the rules, well inclination decoding is performed to obtain the measured well inclination data.

[0010] Furthermore, determining whether the drilling pump has entered the working state based on the drilling pump start-up time specifically includes:

[0011] The drilling surveying equipment is in a low-power standby state during normal drilling.

[0012] Furthermore, determining whether the drilling pump has entered the working state based on the drilling pump start-up time specifically includes:

[0013] When the pump is stopped for a certain period of time, it is restarted. The pump must be restarted for more than the first preset time and stopped within the second preset time. After the pump is stopped, it is restarted for the third preset time and the flow rate is stabilized to the preset flow rate threshold and kept stable within the fourth preset time. The inclinometer is then activated.

[0014] Furthermore, the transmission time interval T between the first and second encoded pulses is T = INC * a + b, where a is a constant coefficient, b is a set time value in seconds, and INC is the measured well inclination data.

[0015] Furthermore, the measured well inclination data is obtained by decoding the obtained time difference T, specifically including:

[0016] Based on the well inclination INC=1+(Tb) / a, the well inclination data is calculated.

[0017] Furthermore, timing begins when the first pressure change waveform is detected and ends when the second pressure change waveform is detected, obtaining the time difference T between the two waveforms, specifically:

[0018] The time difference between the first pump pressure drop and the second pump pressure drop is denoted as T.

[0019] According to a second aspect of the present invention, a downhole low-power data encoding and decoding transmission system is provided, the system comprising a drilling surveying and mapping device and a surface device communicating with the drilling surveying and mapping device;

[0020] The drilling surveying equipment includes:

[0021] The activation module is used to determine whether to enter the working state based on the drilling pump start-up time.

[0022] The inclination measurement module is used to measure well inclination and temperature when the pump is stopped after the pump has entered the working state.

[0023] The encoding transmission module is used to send encoded pulses to the ground equipment after the pump has been running for a certain period of time. The time interval T between the first and second encoded pulses is calculated according to the measured well inclination data and a set rule.

[0024] The ground equipment includes a well inclination decoding module, which is used to continuously monitor the pump pressure after the pump has been running for a certain period of time. Timing starts when the first pressure change waveform is detected and ends when the second pressure change waveform is detected, obtaining the time difference T between the two waveforms. Well inclination data is obtained by well inclination decoding based on the obtained time difference T and the rules.

[0025] Furthermore, the encoding and transmission module is specifically used for:

[0026] The transmission time interval between the first and second encoded pulses is T = INC * a + b, where a is a constant coefficient, b is a set time value in seconds, and INC is the measured well inclination data.

[0027] Furthermore, the well inclination decoding module is specifically used for:

[0028] Based on the well inclination INC=1+(Tb) / a, the well inclination data is calculated.

[0029] Furthermore, the activation module is specifically used for:

[0030] When the pump is stopped for a certain period of time, it is restarted. The pump must be restarted for more than the first preset time and stopped within the second preset time. After the pump is stopped, it is restarted for the third preset time and the flow rate is stabilized to the preset flow rate threshold and kept stable within the fourth preset time. The inclinometer is then activated.

[0031] The present invention has the following advantages:

[0032] This invention proposes a low-power downhole encoding and decoding data transmission method and system. The drilling homing equipment determines whether it has entered the working state based on the drilling pump start-up time. Once in the working state, it performs well inclination and temperature measurements when the pump is stopped. After a certain period of pump operation, it sends coded pulses to the surface equipment. The transmission time interval T between the first and second coded pulses is calculated according to a set rule based on the measured well inclination data. The surface equipment continuously monitors the pump pressure after a certain period of pump operation. Timing begins when the first pressure change waveform is detected and ends when the second pressure change waveform is detected, obtaining the time difference T between the two waveforms. Well inclination data is then decoded based on the obtained time difference T and the aforementioned rule. This ultra-low-power encoding and transmission method for well inclination data transmission allows for downhole working time exceeding 30 days, effectively improving drilling homing efficiency. Attached Figure Description

[0033] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0034] Figure 1 This is a flowchart illustrating a low-power downhole encoding and decoding data transmission method provided in Embodiment 1 of the present invention.

[0035] Figure 2This is a schematic diagram illustrating the specific implementation process of a downhole low-power encoding and decoding data transmission method provided in Embodiment 1 of the present invention. Detailed Implementation

[0036] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] like Figure 1 and Figure 2 As shown, this embodiment proposes a downhole low-power encoding and decoding data transmission method. The method is executed by a drilling surveying and mapping (MS / CR) device and used in vertical well drilling. The method includes:

[0039] S100. Determine whether the system has entered the working state based on the drilling pump start-up time.

[0040] During normal drilling, the measurement-while-drilling (MWD) equipment is in a low-power standby state. The activation of the instrument for MWD is determined by the time the drilling pump is turned on. The pump should be turned on 1 minute after being turned off, and the pump should be turned on for more than 2 minutes and then turned off within 5 minutes. After the pump is turned off, it should be turned on within 2 to 3 minutes. The flow rate should be turned on stably to about 30 L / min within 20 seconds and kept stable.

[0041] S200: When the pump stops, well inclination and temperature measurements are performed and stored.

[0042] S300: After a certain period of pump operation, an coded pulse is sent to the ground equipment. The time interval T between the first and second coded pulses is calculated according to the measured well inclination data and the set rules.

[0043] Thirty seconds after the pump is started, the first coded pulse is sent. The interval for sending the second coded pulse is: T = INC * 1.2 + 11S, where INC is the measured well inclination data.

[0044] S400. The ground equipment continuously monitors the pump pressure after the pump has been running for a certain period of time. When the first pressure change waveform is detected, the timing starts and ends when the second pressure change waveform is detected. The time difference T between the two waveforms is obtained, and the well inclination data is obtained by well inclination decoding based on the obtained time difference T and the rules.

[0045] The ground equipment then follows up on the pump pressure changes and begins decoding. Pump pressure monitoring begins 30 seconds after the pump is started. The time from the first pump pressure drop to the second pump pressure drop is recorded as T. The well inclination INC is then calculated as 1 + (T-11) / 1.2.

[0046] This embodiment is based on a low-power vertical well inclination measurement and drilling (MWD) system used in vertical well drilling. With an inclination measurement range of 20°, the standby current is only 1.5mA after insertion into the well, allowing for continuous drilling operations. A single well insertion can last up to 30 days. The use of an ultra-low-power encoded transmission method for inclination data transmission effectively improves drilling efficiency.

[0047] Example 2

[0048] Corresponding to Embodiment 1 above, this embodiment proposes a downhole low-power data encoding and decoding transmission system, the system including a drilling surveying and mapping device and a surface device communicating with the drilling surveying and mapping device;

[0049] The drilling surveying equipment includes:

[0050] The activation module is used to determine whether to enter the working state based on the drilling pump start-up time.

[0051] The inclination measurement module is used to measure well inclination and temperature when the pump is stopped after the pump has entered the working state.

[0052] The encoding transmission module is used to send encoded pulses to the ground equipment after the pump has been running for a certain period of time. The time interval T between the first and second encoded pulses is calculated according to the measured well inclination data and a set rule.

[0053] The ground equipment includes a well inclination decoding module, which is used to continuously monitor the pump pressure after the pump has been running for a certain period of time. Timing starts when the first pressure change waveform is detected and ends when the second pressure change waveform is detected, obtaining the time difference T between the two waveforms. Well inclination data is obtained by well inclination decoding based on the obtained time difference T and the rules.

[0054] Furthermore, the encoding and transmission module is specifically used for:

[0055] The transmission time interval between the first and second encoded pulses is T = INC * a + b, where a is a constant coefficient, b is a set time value in seconds, and INC is the measured well inclination data.

[0056] Furthermore, the well inclination decoding module is specifically used for:

[0057] Based on the well inclination INC=1+(Tb) / a, the well inclination data is calculated.

[0058] Furthermore, the activation module is specifically used for:

[0059] When the pump is stopped for a certain period of time, it is restarted. The pump must be restarted for more than the first preset time and stopped within the second preset time. After the pump is stopped, it is restarted for the third preset time and the flow rate is stabilized to the preset flow rate threshold and kept stable within the fourth preset time. The inclinometer is then activated.

[0060] The functions performed by each component in the downhole low-power data encoding and decoding transmission system provided in this embodiment of the invention have been described in detail in the above embodiment 1, so they will not be repeated here.

[0061] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A low-power encoding and decoding data transmission method for downhole applications, characterized in that, The method includes: Determine whether the well has entered the working state based on the drilling pump start-up time; Once the pump is in operation, well inclination and temperature measurements are performed when the pump is stopped. After the pump has been running for a certain period of time, an coded pulse is sent to the ground equipment. The time interval T between the first and second coded pulses is calculated according to the measured well inclination data and the set rules. The ground equipment continuously monitors the pump pressure after the pump has been running for a certain period of time. When the first pressure change waveform is detected, the timing starts and ends when the second pressure change waveform is detected. The time difference T between the two waveforms is obtained, and the well inclination data is obtained by decoding the well inclination based on the obtained time difference T and the rules. The transmission time interval between the first and second encoded pulses is T = INC * a + b, where a is a constant coefficient, b is a set time value in seconds, and INC is the measured well inclination data. The measured well inclination data is obtained by decoding the obtained time difference T, specifically including: Based on the well inclination INC=1+(Tb) / a, the well inclination data is calculated.

2. The downhole low-power encoding and decoding data transmission method according to claim 1, characterized in that, Determining whether the well has entered the working state based on the drilling pump start-up time includes: The drilling surveying equipment is in a low-power standby state during normal drilling.

3. The downhole low-power encoding and decoding data transmission method according to claim 1, characterized in that, Determining whether the well has entered the working state based on the drilling pump start-up time includes: When the pump is stopped for a certain period of time, it is restarted. The pump must be restarted for more than the first preset time and stopped within the second preset time. After the pump is stopped, it is restarted for the third preset time and the flow rate is stabilized to the preset flow rate threshold and kept stable within the fourth preset time. The inclinometer is then activated.

4. The downhole low-power encoding and decoding data transmission method according to claim 1, characterized in that, Timing begins when the first pressure change waveform is detected and ends when the second pressure change waveform is detected. The time difference T between the two waveforms is obtained, specifically: The time difference between the first pump pressure drop and the second pump pressure drop is denoted as T.

5. A low-power downhole data encoding and decoding transmission system, characterized in that, The system includes a drilling surveying and mapping (MSD) device and ground equipment that communicates with the MSD device. The drilling surveying equipment includes: The activation module is used to determine whether to enter the working state based on the drilling pump start-up time. The inclination measurement module is used to measure well inclination and temperature when the pump is stopped after the pump has entered the working state. The encoding transmission module is used to send encoded pulses to the ground equipment after a certain period of pump operation. The transmission time interval T between the first and second encoded pulses is calculated according to a set rule based on the measured well inclination data. Specifically, the encoding transmission module is used for: The transmission time interval between the first and second encoded pulses is T = INC * a + b, where a is a constant coefficient, b is a set time value in seconds, and INC is the measured well inclination data. The ground equipment includes a well inclination decoding module, which is used to continuously monitor the pump pressure after the pump has been running for a certain period of time. Timing starts when the first pressure change waveform is detected and ends when the second pressure change waveform is detected, obtaining the time difference T between the two waveforms. Well inclination data is obtained by well inclination decoding based on the obtained time difference T and the rules. Specifically, the well inclination decoding module is used to calculate the well inclination data based on the well inclination INC = 1 + (Tb) / a.

6. The downhole low-power data encoding and decoding transmission system according to claim 5, characterized in that, The activation module is specifically used to: start the pump after a certain period of pump stoppage, the pump start-up must exceed the first preset time, and the pump must stop within the second preset time, the pump stoppage is followed by the start-up of the pump in the third preset time, and the flow rate is stably increased to the preset flow rate threshold and kept stable within the fourth preset time, thereby activating the inclination measurement device.

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