A mud pulse data encoding method and transmission method

Abstract

The invention provides a mud pulse data encoding method and transmission method. The encoding method includes: determining the number of pressure pulse combinations and the number of binary digits according to the range of the data to be transmitted and the required accuracy; converting the binary system to the binary system, dividing the converted binary system into time segments according to the digits, and each minute The segment includes different numbers of time slots; use pressure pulse combinations of different amplitudes to represent the value of each digit, and encode the amplitude, number of pulse pressures, and positions corresponding to the pulses, and use different amplitudes to Numerical values ​​and time slot positions establish a coding protocol to complete mud pulse data coding. The transmission method encodes the data according to the encoding method before transmitting. The invention can prolong the service life of the valve, can transmit more data in the same time period, and can effectively improve the transmission rate.

Description

technical field [0001] The invention relates to the technical field of oil and gas drilling, and more specifically, to a mud pulse data encoding method and transmission method. Background technique [0002] During the drilling process, engineers need to grasp the measurement-while-drilling information such as wellbore trajectory parameters, formations and bottomhole environment in real time, and this information is mainly transmitted to the ground through MWD (measurement while drilling) and LWD (logging) tools. The coding of the downhole data signal is one of the key technologies. The coding methods commonly used in MWD and LWD instruments at home and abroad mainly include pulse position modulation coding, Manchester coding and optimized combination code. [0003] Pulse position modulation encoding uses time intervals as data streams to transmit information, and 1 pulse represents 1 hexadecimal number (0-F), and its specific number depends on its position, that is, depends...

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Problems solved by technology

[0006] The above three encoding methods all have a common characteristic of only detecting the pulse position and number, not the pulse amplitude. The advantage is that it is beneficial to the decoding of ground signals. The disadvantage is that the unit time period contains less information and the transmission rate is slow.

During the drilling process, as the well depth increases, the drilling conditions become more and more complex, and the more downhole data needs to be measured, not only the wellbore trajectory data and geological data, but also the downhole vibration, bit pressure, torque, etc. For data such as borehole magnification ratio and dielectric constant, the transmission rate is difficult to meet the transmission requirements of a large amount of underground data by using the conventional optimized combination coding method

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