CN1088143C

CN1088143C - Serial telemetry bus of downhole instruments for petroleum logging and its interface technique

Info

Publication number: CN1088143C
Application number: CN99121217A
Authority: CN
Inventors: 鞠晓东; 李会银
Original assignee: China University of Petroleum East China
Current assignee: China University of Petroleum East China
Priority date: 1999-10-01
Filing date: 1999-10-01
Publication date: 2002-07-24
Anticipated expiration: 2019-10-01
Also published as: CN1249391A

Abstract

The present invention discloses a serial telemetry bus of a downhole instrument for petroleum logging, and interface technique. The present invention is composed of a serial telemetry bus, a complex programmable logical device CPLD and a data acquisition subsystem, wherein the serial telemetry bus is composed of four lines, such as a link control line CHAIN, a differential transmission data line DATA+DATA-, an earth line GND, etc., the data acquisition subsystem is composed of a control logic encoder, a universal asynchronous transceiver UART, a complex programmable logical device CPLD of a data acquisition interface, an electrical level comparator group, a differential transceiver and a digital signal processor DSP; each data acquisition subsystem is controlled by a telemetry controller; half-duplex communication is adopted among the serial telemetry bus, the complex programmable logical device CPLD and the data acquisition subsystems, and an electronic switch on the control line CHAIN is controlled by a control logic circuit in the CPLD.

Description

Be used for the circuit that downhole instruments for petroleum logging carries out transfer of data

The present invention relates to the telemetry bus of logger under the oil well, be used for transfer of data.

With high-performance, big data quantity is that the nonpetroleum logger of feature is continually developed success, how the most effective composition downhole telemetry data link (bus), finish well logging information at a high speed, correct transmitted in both directions become important problems, the main difficulty that faces is:

1. the line resource of down-hole is limited, particularly when adopting armored cable to be flexible coupling (as the crosshole seismic system) between each sensor of down-hole, has only the armored cable circuit of 6～7 hearts available.At this moment, because of the down-hole Alternating Current Power Supply needs 2 hearts, downhole telemetry bus comprises that ground wire can not surpass 4 hearts.

2. on certain-length, (reach the 10m*10 joint) sufficiently high transfer rate (reach 1Mbits/s at least, preferably reach more than the 2Mbits/s) must be arranged as the crosshole seismic system.

3. the remote measurement controller of instrument string the top can be controlled (even also can recover normally to be unlikely to interrupt run because of interference causes subsystem to crash) completely to each independent subsystem.

4. each independent subsystem can send data at a high speed by the link order automatically.

At present, solved above problem fully without any a kind of finished product or design scheme both at home and abroad.

The objective of the invention is to develop a kind of circuit that downhole instruments for petroleum logging carries out transfer of data that is used for, solve above-mentioned all problems fully.

The object of the present invention is achieved like this, forms the serial telemetry bus by link control line (CHAIN), two differential transfer data wires (DATA+DATA-) and four lines of ground wire (GND); Constitute a subsystem by a CPLD (CPLD), level comparator group, difference transceiver and digital signal processor (DSP), the present invention comprises a plurality of such subsystems, each subsystem adopts half duplex communication by the control of remote measurement controller between subsystem and the controller.After the level comparator group, send into control logic circuit in the CPLD (CPLD) from the signal of remote measurement controller, control the electronic switch on the link control line (CHAIN) then; CPLD (CPLD) comprises control logic, encoder and UART Universal Asynchronous Receiver Transmitter (UART) and data acquisition interface, and digital signal processor (DSP) imports data into CPLD (CPLD) coding after the difference transceiver is delivered to the serial telemetry bus.

Accompanying drawing is according to the circuit theory schematic diagram that downhole instruments for petroleum logging carries out transfer of data that is used for proposed by the invention.

Further narrate the present invention below in conjunction with accompanying drawing.

1. serial telemetry bus is made up of 5, two differential transfer data wires of link control line (CHAIN) (DATA+DATA-) 3,4 and 6 four lines of ground wire (GND), adopts half duplex communication between remote measurement controller 1 and each subsystem.

2. link control line (CHAIN) 5 is important control lines, is driven by remote measurement controller 1.When level during at 0～3V ± 5%, be the normal link level, when being used for uplink data sending, each subsystem sends data from top to bottom successively under the control of link switch S.When level during at 5V ± 5%, be system's forced resetting state, level comparator group 7 in each subsystem detects at this state, under CPLD (CPLD) 13 controls, not only making the local digital signal handle (DSP) 12 subsystems is reset, and making this state force to arrive next stage by the link switch S, the next stage subsystem is carried out same operation, all is reset until all subsystems.Same principle when level is system's special command state during at 4V ± 5%, is used for bypass count word signal processor (DSP) and carries out some special operational (as pole plate backup operation).As required, the special command status number can increase.

3. CPLD (CPLD) the 13rd is managed the core devices that the serial telemetry bus is operated in the subsystem 15, is made of control logic 8, encoder 9, UART Universal Asynchronous Receiver Transmitter (UART) 10, data acquisition interface 11.CPLD (CPLD) 13 control difference transceivers 14 were accepting state after subsystem resetted, this locality or ground order that UART Universal Asynchronous Receiver Transmitter (UART) 10 decoding remote measurement controllers 1 are sent, if the address of this command string conforms to this subsystem then is received, otherwise is left in the basket.When system need obtain data in each subsystem, remote measurement controller 1 was changed to accepting state with the difference transceiver of self, and with the open link of normal link level.At this moment, the CPLD (CPLD) of the data acquisition subsystem of top blocks link, successively digital signal processor (DSP) is sent here data are encoded and upload by the difference transceiver, the subsystem 16 of below is in wait state because of link is open.Automatically open link after top subsystem 2 is uploaded and finished, the subsystem of below begins to upload data ..., finish whole upload operation until all subsystems.System only has a difference transceiver at any time and is in the transmission state.

4. adopt between CPLD (CPLD) 13 and the digital signal processor (DSP) 12 and interrupt and the inquiry mode swap data.

The present invention is laboratory inspection, proves the transfer rate that reaches 2Mbits/s on the cable length that can save (subsystem of every joint) at 10m*10, and the link control operation is reliable.System can work under 125 ℃, 80Mpa condition.

The present invention has solved technical barriers such as the restriction of cable heart resource, bidirectional high speed transmission and control flexibility and reliability fully.

CPLD (CPLD) adopts the Modern Digital System designing technique to finish under advanced person's EDA development environment, and design fast, flexibly, reliably.

Claims

1. one kind is used for the circuit that downhole instruments for petroleum logging carries out transfer of data, it is characterized in that: form the serial telemetry bus by link control line CHAIN (5), two differential transfer data wire DATA+DATA-(3,4) and (6) four lines of ground wire GND; Constitute a subsystem (15) by a complex programmable logic device (CPLD) (13), level comparator group (7), difference transceiver (14) and digital signal processor DSP (12), this circuit also comprises a plurality of such subsystems, each subsystem adopts half duplex communication by the control of remote measurement controller between controller and the subsystem.

2. circuit according to claim 1, it is characterized in that said complex programmable logic device (CPLD) (13) comprises control logic (8), encoder (9) and UART Universal Asynchronous Receiver Transmitter UART (10) and data acquisition interface (11), digital signal processor DSP (12) imports data into complex programmable logic device (CPLD) (13) coding after difference transceiver (14) is delivered to the serial telemetry bus.

3. circuit according to claim 1, it is characterized in that said level comparator group (7) accepts the instruction of remote measurement controller (1) and send into control logic circuit in the complex programmable logic device (CPLD) (13), control the electronic switch on the link control line CHAIN (5) then.