RU2351960C1 - Method of generating data burst of wireless telemetric system measurements in process of well boring - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: Method includes coding of each four information bits with noise-like signal (NLS) of 16 bit length and transmitting coded information by means of phase-manipulated signal. Carrier frequency of 10.17, 5.09, 2.54, or 0.64 Hz modulated by phase can be used for information transmitting In the beginning each transmitted data burst contains a synchronous packet consisting of four NLS which are not met among NLS by which given data are coded. Bits of zenith, azimuth and standoff are spread in different groups coded in NLS independently. Transmission of information is performed in the following succession: synchronous packet, standoff, zenith, standoff, azimuth, standoff and additional parameter, standoff. Each value of standoff is transmitted with two successions of four bits. Values of zenith angle and azimuth are transmitted with three successions of four bits. Value of additional parameter is transmitted with two successions of four bits. Rotations of a generator, temperature, amount of cadres of statistic measurement, indication of apparatus battery discharge or one of survey parameters can be transmitted in the additional channel.

EFFECT: increased bandwidth through standoff channel, increased self-descriptiveness and noise immunity of data transmitting channel.

11 cl

Description

The invention relates to information-measuring equipment, in particular to downhole telemetry systems with a cableless communication channel, and can be used to form measurement data packets of a telemetric system for transmitting information from the bottom of a borehole to the surface.

There is a known method of generating data packets implemented in the ZIS-4 telemetric system (“Downhole inclinometric system ZIS-4”. Technical description and operating instructions. AXA 2.788.003 TO, VNIIGIS, 1988).

The method includes encoding every four bits of information with a noise-like signal (BSS) of 16 bits in length and transmitting the information encoded in this way using a phase-shifted signal. To transmit information, a carrier frequency of 10.2 Hz, phase modulated, is used. The carrier phase changes by 180 ° with each change of values between adjacent transmitted bits (phase shift keying). The most significant bits of the zenith, azimuth, and divergence are combined into one group of four bits, encoded by SHPS. Each data packet contains a synchronization sequence (sync sending) of four BSCs with constant codes, the least significant zenith bits encoded by two BSCs, the lower azimuth bits encoded by two BSCs, the least significant bits of the rejecter encoded by two BSCs, and the revolutions encoded by two BSCs. Each of the four SHPS synchro-parcels does not occur among the SHPS, which encoded measurement data.

The known method has an insufficient number of information channels (transmits only four parameters) and low throughput on the diverter channel. The use of only one frequency of 10.2 Hz reduces the likelihood of reliable information transfer in adverse conditions (in the presence of layers with high conductivity, adverse interference conditions, etc.).

The task that the proposed method of forming data packets solves is to increase the throughput on the diverter channel, increase the information content and noise immunity of the data transmission channel of the telemetry system from the bottom to the surface.

The solution to this problem was achieved by the fact that the zenith, azimuth, and divergence bits are separated into different groups encoded in the ShPS independently, while the transmission of information occurs in the following sequence: synchronization, diverter, zenith, divergent, azimuth, diverter, additional parameter, diverter. The first value of the diverter is transmitted in two sequences of four bits, each of which is encoded by SHPS. The value of the zenith angle is transmitted in three sequences of four bits, each of which is encoded by SHPS. The second value of the diverter is transmitted in two sequences of four bits, each of which is encoded by SHPS. The azimuth value is transmitted in three sequences of four bits, each of which is coded with NLS. The third diverter value is transmitted in two sequences of four bits, each of which is encoded with SHPS. The value of the additional parameter is transmitted in two sequences of four bits, each of which is encoded by SHPS. The fourth value of the diverter is transmitted in two sequences of four bits, each of which is encoded SHPS. In an additional channel, the generator speed, temperature, frame number of the static measurement, a sign of the battery’s discharge or one of the logging parameters (vibration level, apparent formation resistance, gamma-ray level, etc.) can be transmitted. A data packet containing a speed parameter and a data packet containing a temperature parameter are maximally spaced in time. For information transmission, frequencies of 10.17 can be used; 5.09; 2.54; 1.27 and 0.64 Hz.

The method is as follows.

To transmit information using one of the carrier frequencies (10.17; 5.09; 2.54; 1.27 or 0.64 Hz), modulated by the phase of the NPS. After sync (S) is transmitted:

- the first value of the diverter (O ₁ ) with a step of 2 ° by two sequences of four bits, each of which is encoded by ШПС;

- the value of the zenith angle (Z) in increments of 0.1 ° by three sequences of four bits, each of which is encoded by SHPS;

- the second value of the diverter (O ₂ ) with a step of 2 ° by two sequences of four bits, each of which is encoded by ШПС;

- azimuth value (A) with a step of 1 ° by three sequences of four bits, each of which is encoded by ШПС;

- the third value of the diverter (O ₃ ) with a step of 2 ° by two sequences of four bits, each of which is encoded by SHPS;

- the value of the additional parameter (D) by two sequences of four bits, each of which is encoded by ШПС;

- the fourth value of the deflector (O ₄ ) in increments of 2 ° by two sequences of four bits, each of which is encoded by SHPS.

After that, the next data packet is transmitted, starting with the synchronization sequence.

Thus, the transmission of information occurs in the following sequence: SO ₁ -ZO ₂ -A-O ₃ -D-O ₄ . The alternation of data on the diverter channel with the data of other channels ensures the uniformity of its transmission.

In an additional channel, the following may be transmitted:

- one of the logging parameters (K);

- generator speed (V);

- temperature (T);

- a sign of data measured in statics.

Turnovers are transmitted in an additional channel of every fourth data packet. In this case, the data transfer occurs in the sequence P _K -P _K -P _K -P _O , where P _K is the data packet containing the log parameter K in the additional channel, P _Ob is the data packet containing the generator speed parameter in the additional channel.

In case of exceeding the permissible temperature (80 ° C) in every fourth data packet, the temperature parameter is transmitted via an additional channel. In this case, the data packet containing the revolutions parameter in the additional channel and the data packet containing the temperature excess parameter in the additional channel are maximally separated in time. Data transfer in case of temperature rise occurs in the sequence P _K -P _Ob -P _K -P _T , where P _T is a data packet containing an over-temperature parameter in an additional channel.

The parameters of the “statics” signs are transmitted at the place of the additional channel in the first three packets after resuming circulation of the drilling fluid and turning on the device. At the same time, in addition to the “static” data indicator, the indicator of the battery’s discharge and the number of one of the three static frames transmitted in a row are transmitted. The package contains the parameters of zenith and azimuth, as well as the parameter of the fourth diverter, measured in "static". The first three diverter parameters in the packet transmit the current measured values of the diverter.

The method of generating data packets of a cableless telemetry system during drilling is successfully used to transmit information from the bottom to the surface when drilling horizontal and directional wells.

Using the proposed technical solution allows the following.

1. Increase the throughput on the diverter channel, as in each packet, four of its values are transmitted. The “diverter” parameter is the most important for directional drilling.

2. To increase noise immunity:

a) due to the separation of the zenith, azimuth, and divergence bits into different groups, independently encoded in the NPS. In this case, a short-term effect of interference will lead to the loss of data of only one of the measuring channels (zenith, azimuth, or divergence), but not all at once.

b) by providing the ability to work at different frequencies: 10.17; 5.09; 2.54; 1.27 and 0.64 Hz. Signals transmitted at lower frequencies are less attenuated as they pass through the rock.

3. To increase the information content of the signal. In addition to the zenith, azimuth, diverter and generator speed, the results of measurements in statics, information about the temperature and battery charge of the device, and logging parameters are additionally transmitted.

4. To increase the reliability of the measurement results by transmitting information about the parameters obtained in the "statics".

Claims (11)

1. A method of generating data packets of measurements of a cableless telemetry system during well drilling, including encoding every four bits of information with a noise-like signal (SPS) 16 bits in length, transmitting information using a phase-shifted signal, and each transmitted packet contains at the beginning a clock package consisting of four ShPS which are not found among the NPS, which encodes the measurement data, characterized in that the zenith, azimuth and divergence bits are separated into different groups, encoded by the NPS independently Apparently, in this case, the transmission of information occurs in the following sequence: clock transmission, diverter, zenith, diverter, azimuth, diverter, additional parameter, diverter. 2. The method according to claim 1, characterized in that the first value of the diverter is transmitted in two sequences of four bits, each of which is coded with BSC. 3. The method according to claim 1, characterized in that the value of the zenith angle is transmitted in three sequences of four bits, each of which is coded with BSC. 4. The method according to claim 1, characterized in that the second value of the diverter is transmitted in two sequences of four bits, each of which is coded with BSC. 5. The method according to claim 1, characterized in that the azimuth value is transmitted in three sequences of four bits, each of which is coded with BSC. 6. The method according to claim 1, characterized in that the third value of the deflector is transmitted in two sequences of four bits, each of which is encoded by SHPS. 7. The method according to claim 1, characterized in that the value of the additional parameter is transmitted in two sequences of four bits, each of which is coded with BSC. 8. The method according to claim 1, characterized in that the fourth value of the diverter is transmitted in two sequences of four bits, each of which is coded with BSC. 9. The method according to claim 7, characterized in that the alternator speed, temperature, frame number of the static metering, a sign of battery discharge of the device, or one of the logging parameters (vibration level, apparent formation resistance, gamma background level, and other). 10. The method according to claim 9, characterized in that the data packet containing the revolutions parameter and the data packet containing the temperature parameter are maximally spaced in time. 11. The method according to any one of claims 1 to 10, characterized in that frequencies of 10.17 can be used to transmit information; 5.09; 2.54; 1.27 and 0.64 Hz.