CN104612672B - A kind of signal processing system for NMR logging instrument - Google Patents
A kind of signal processing system for NMR logging instrument Download PDFInfo
- Publication number
- CN104612672B CN104612672B CN201510009321.2A CN201510009321A CN104612672B CN 104612672 B CN104612672 B CN 104612672B CN 201510009321 A CN201510009321 A CN 201510009321A CN 104612672 B CN104612672 B CN 104612672B
- Authority
- CN
- China
- Prior art keywords
- signal
- circuit
- current
- power
- given threshold
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000012545 processing Methods 0.000 title claims abstract description 11
- 230000003321 amplification Effects 0.000 claims abstract description 34
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 34
- 238000005070 sampling Methods 0.000 claims abstract description 28
- 238000000034 method Methods 0.000 claims abstract description 15
- 230000000052 comparative effect Effects 0.000 claims abstract description 14
- 238000005481 NMR spectroscopy Methods 0.000 description 18
- 239000000523 sample Substances 0.000 description 13
- 230000015572 biosynthetic process Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 238000012937 correction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 210000002445 nipple Anatomy 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Magnetic Resonance Imaging Apparatus (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
A kind of signal processing system for NMR logging instrument, is related to expansion cable signal processing system, including communicating circuit, pulse train generation circuit and the power amplification circuit being sequentially connected, it is characterised in that：Also include：Current sample and process circuit；The current sample and process circuit input receive the current signal of power amplification circuit output end in the NMR logging instrument, are exported the comparative result of current sampling signal and the first given threshold and/or the second given threshold as setting control signal from output end；The control end of the communicating circuit receives the setting control signal, and the setting control signal is processed according to pre-defined rule, forms power signal, and the power signal is exported from output end.Protection instrument and power amplification circuit, extend the scope of instrument institute geodetic layer, it is to avoid because logging operation is interrupted and caused by economic loss.
Description
Technical field
At expansion cable signal processing system, more particularly to a kind of signal for NMR logging instrument
Reason system.
Background technology
Current NMR logging instrument as shown in figure 1, including the communicating circuit that is sequentially connected, pulse train occur circuit and
Power amplification circuit, power amplification circuit loop includes high-power resistance R1 and R2 and antenna, wherein communicating circuit and ground
System communicates.As shown in Figure 1, the NMR logging instrument of prior art is separately designed using probe with circuit pipe nipple, by visiting
The NMR signal that head is received need to can be only achieved process circuit by distance more long.Because NMR signal is very micro-
Weak, the pumping signal of some strength could produce quality preferably to carry the echo-signal of formation information, and nuclear magnetic resonance log
The radiating circuit of instrument is constant pressure transmitting, it is therefore necessary to ensure the certain emitting voltage of instrument.Due to the power limit of device,
In well logging, the reduction of the mud resistivity of ground environment can increase the power amplification circuit electric current of instrument, or even damage
Radiating circuit, so as to interrupt logging operation, cannot get corresponding formation information, cause very big economic loss.
At present, only radiating circuit is protected in existing scheme, the electric current in radiating circuit loop exceeds normal model
The transmitting of instrument is interrupted after enclosing immediately, now can the formation information that obtains of lost part, and intentionally got in practical logging and to the greatest extent may be used
The continuous formation information of can completely.
The content of the invention
The technical problem to be solved in the present invention is to overcome current NMR signal to subtract suddenly due to stratum mud resistivity
Defect small that continuous logging operation carries out.
In order to solve the above-mentioned technical problem, the invention provides a kind of signal transacting system for NMR logging instrument
System, including communicating circuit, pulse train generation circuit and the power amplification circuit being sequentially connected, also include：Current sample and place
Reason circuit；
The current sample and process circuit input receive power amplification circuit output in the NMR logging instrument
The current signal at end, using the comparative result of current sampling signal and the first given threshold and/or the second given threshold as setting
Control signal is exported from output end；
The control end of the communicating circuit receives the setting control signal, according to pre-defined rule to the setting control letter
Number processed, formed power signal, the power signal is exported from output end.
Preferably, the current sample and process circuit include：Current sampling circuit, current levels circuit；
Power amplification circuit output end in the input reception NMR logging instrument of the current sampling circuit
Current signal, output end output current sampled signal；
The input of the current levels circuit receives the current sampling signal, the first given threshold and the second setting threshold
Value, using the comparative result of current sampling signal and the first given threshold and/or the second given threshold as set control signal from
Output end is exported.
Preferably, first given threshold is more than the second given threshold：
When the current sampling signal be less than or equal to second given threshold when, the current levels circuit it is defeated
The comparative result for going out is normal signal, and the communicating circuit keeps current power signal, believes current power signal as power
Number output to the pulse train occur circuit；
When the current sampling signal is more than second given threshold and less than or equal to the described first setting threshold
During value, the comparative result of the output of the current levels circuit is early warning signal, the communicating circuit reduction current power signal,
Current power signal after reduction is exported to pulse train as power signal circuit occurs；
When the current sampling signal is more than first given threshold, the comparing of the output of the current levels circuit
Result is over-current signal, and the communicating circuit stops power output signal to the pulse train and circuit occurs.
Preferably, the system also includes control circuit,
The input of the control circuit receives the power amplifier control signal that the pulse train occurs circuit, from output
End power output amplification outputs signal to the power amplification circuit.
Preferably, the control end of the control circuit receives the over-current signal, and after the over-current signal is received,
Stop power output and amplify output signal.
Preferably, the reset terminal of the control circuit receives the reset signal of the communicating circuit, and described receiving
After reset signal, recover power output and amplify output signal.
Compared with prior art, the signal processing apparatus of the embodiment of the present invention, current well logging is obtained by the measurement of electric current
The mud resistivity scope on stratum, in power amplification circuit current anomaly, protects instrument and power amplification circuit, ground system
Respective handling is carried out, makes instrument can continue to carry out logging operation, extend the scope of instrument institute geodetic layer, it is to avoid because of well logging
Job interruption and the economic loss that causes.
Brief description of the drawings
Fig. 1 is a kind of structural representation for NMR logging instrument of prior art；
Fig. 2 is the connection diagram of the signal processing system for NMR logging instrument of the embodiment of the present invention；
Fig. 3 is the current sample of the embodiment of the present invention and the structural representation of process circuit；
Fig. 4 is the current sample of the embodiment of the present invention and the annexation figure of process circuit；
Fig. 5 is the control circuit operation principle schematic diagram of the embodiment of the present invention.
Specific embodiment
To make the object, technical solutions and advantages of the present invention become more apparent, below in conjunction with accompanying drawing to the present invention
Embodiment be described in detail.It should be noted that in the case where not conflicting, in the embodiment and embodiment in the application
Feature can mutually be combined.
As shown in Fig. 2 a kind of signal processing system for NMR logging instrument, including the communication electricity being sequentially connected
There is circuit and power amplification circuit in road, pulse train, also include：Current sample and process circuit；
The current sample and process circuit input receive power amplification circuit output in the NMR logging instrument
The current signal at end, using the comparative result of current sampling signal and the first given threshold and/or the second given threshold as setting
Control signal is exported from output end；
The control end of the communicating circuit receives the setting control signal, according to pre-defined rule to the setting control letter
Number processed, formed power signal, the power signal is exported from output end.
As shown in figure 3, the current sample and process circuit include：Current sampling circuit, current levels circuit；
Power amplification circuit output end in the input reception NMR logging instrument of the current sampling circuit
Current signal, output end output current sampled signal；
The input of the current levels circuit receives the current sampling signal, the first given threshold and the second setting threshold
Value, using the comparative result of current sampling signal and the first given threshold and/or the second given threshold as set control signal from
Output end is exported.
Wherein, first given threshold is more than the second given threshold：
When the current sampling signal be less than or equal to second given threshold when, the current levels circuit it is defeated
The comparative result for going out is normal signal, and the communicating circuit keeps current power signal, believes current power signal as power
Number output to the pulse train occur circuit；
When the current sampling signal is more than second given threshold and less than or equal to the described first setting threshold
During value, the comparative result of the output of the current levels circuit is early warning signal, the communicating circuit reduction current power signal,
Current power signal after reduction is exported to pulse train as power signal circuit occurs；
When the current sampling signal is more than first given threshold, the comparing of the output of the current levels circuit
Result is over-current signal, and the communicating circuit stops power output signal to the pulse train and circuit occurs.
Electric current is adopted as current sampling resistor using the high-power resistance R1 and R2 in power amplification circuit loop
Sample, three ranks are divided into current levels circuit by current sampling signal：Normally, early warning and excessively stream, and corresponding signal is exported,
Early warning signal and over-current signal are sent to by ground system by instrument communication circuit.When producing early warning signal, power amplification is returned
The size of current on road exceeds normal range (NR), but will not damage power amplification circuit, and ground system suitably reduces emitting voltage (power
The high voltage power supply of amplifying circuit is provided by ground high-voltage DC power supply, under normal circumstances ground high-voltage DC power supply power for
600V, in the case that early warning signal is produced, typically rule of thumb, ground high-voltage DC power supply is powered and is set to 500V, therefore, drop
It is low to it is original 83.3%), instrument proceeds logging operation, although emitting voltage now does not reach standard, echo-signal
Quality is under some influence, but can obtain correct formation information by carrying out inverting correction to raw measurement data；Produced
During stream signal, the size of current in power amplification loop reaches the degree for damaging circuit, and ground system stops power amplification circuit control
Signal input processed, stops the transmitting of antenna, and the letter that other instruments or ground system are provided is combined by ground system operating personnel
Breath carrys out decision-making, judges that excessively stream Producing reason is that instrument failure or stratum mud resistivity are extremely low, stops if instrument failure
Well logging, stratum mud resistivity is extremely low in this way, then after mud resistivity reaches range of safety operation, ground system recovers defeated
Go out, power amplification circuit recovers normal work, instrument proceeds logging operation.
As shown in Fig. 2 a kind of signal processing system for NMR logging instrument also includes control circuit,
The input of the control circuit receives the power amplifier control signal that the pulse train occurs circuit, from output
End power output amplification outputs signal to the power amplification circuit.
The control end of the control circuit receives the over-current signal, and after the over-current signal is received, stops defeated
Go out power amplified output signal.
The reset terminal of the control circuit receives the reset signal of the communicating circuit, and is receiving the reset signal
Afterwards, recover power output and amplify output signal.
It is quickly to stop the input of power amplification circuit control signal when producing over-current signal, is put by controlling circuit power
The input of big circuit is controlled.After Failure elimination, control circuit receives reset command, and power amplification circuit recovers normal work
Make.
Embodiment
As shown in figure 3, current sample and process circuit are mainly realized to the current sample of high pressure radiating circuit and to electricity
Stream size is classified, and current sampling signal is divided into three ranks：Normally, early warning and excessively stream, have corresponded to stratum mud resistance
Three scopes of rate：More than 0.02 ohm meter, less than 0.02 ohm meter and more than 0.01 ohm meter, less than 0.01 ohm meter.Just
In the case of often, early warning signal and over-current signal output are low level, when sampled signal exceedes early warning or excessively stream threshold voltage,
The early warning of corresponding output or over-current signal are the positive pulse signal of fixed pulse width.
As shown in figure 4, voltage U1 is input into one group of symmetrical expression RC divider, voltage U2 is input into another group of parameter identical point
Depressor, divider parameter R3=R5, C1=C3, attenuation ratio is K (K is far smaller than 1), while two Same Name of Ends phases of transformer
Even, the voltage signal magnitude U3=K (U1-U2) of such input signal processing circuit.Because transmitting antenna hub of a spool tap connects
Ground, this differential sample mode of symmetrical expression resistive-capacitive voltage divider causes that in the range of frequency 500kHz to 1MHz attenuation ratio K has very
Good uniformity, maintains the symmetry of former transmitting antenna, while to the resonant frequency of antenna, Q values, the parameter base such as impedance operator
This does not influence.
As shown in figure 5, being control circuit operation principle schematic diagram, control circuit possesses latch and reset function.Instrument is just
Often during work, over-current signal ove_cur and reset signal reset is low level, is exported and power amplifier control signal
1input consistent power amplifier control signal 2output, instrument normal transmission.Radiating circuit (power amplification circuit) electric current mistake
During stream, power output is amplified control signal 2output and remains low level state, so as to stop the transmitting of instrument, reaches protection
The purpose of radiating circuit.After ground system takes related safeguard measure over-current signal is remained low level, ground system hair
Reset command reset is sent, the data that removing is latched export the power amplification control consistent with power amplifier control signal 1input
Signal 2output processed, instrument recovers normal transmission.
The embodiment of the present invention is caused in nuclear magnetic resonance logging instrument well logging, is obtained by the measurement of electric current and currently surveyed
The mud resistivity scope on well stratum, in power amplification circuit current anomaly, protects instrument power amplifying circuit, ground system
Respective handling is carried out, makes instrument can continue to carry out logging operation, extend the scope of instrument institute geodetic layer, it is to avoid because of well logging
Job interruption and the economic loss that causes.
The above embodiments are merely illustrative of the technical solutions of the present invention and it is unrestricted, reference only to preferred embodiment to this hair
It is bright to be described in detail.It will be understood by those within the art that, technical scheme can be modified
Or equivalent, without deviating from the spirit and scope of technical solution of the present invention, all should cover in claim model of the invention
In the middle of enclosing.
Claims (5)
1. a kind of signal processing system for NMR logging instrument, including communicating circuit, the pulse train hair being sequentially connected
Raw circuit and power amplification circuit, it is characterised in that：Also include：Current sample and process circuit；
The input of the current sample and process circuit receives power amplification circuit output end in the NMR logging instrument
Current signal, using the comparative result of current sampling signal and the first given threshold and/or the second given threshold as setting control
Signal processed is exported from the output end of the current sample and process circuit；The current sample and process circuit include current sample
Circuit and current levels circuit, wherein,
The input of the current sampling circuit receives the electric current of power amplification circuit output end in the NMR logging instrument
Signal, the output end output current sampled signal of the current sampling circuit；
The input of the current levels circuit receives the current sampling signal, the first given threshold and the second given threshold,
Using the comparative result of current sampling signal and the first given threshold and/or the second given threshold as setting control signal from described
The output end output of current levels circuit；
The control end of the communicating circuit receives the setting control signal, and the setting control signal is entered according to pre-defined rule
Row treatment, forms power signal, and the power signal is exported from the output end of the communicating circuit.
2. the system as claimed in claim 1, it is characterised in that：
First given threshold is more than the second given threshold：
When the current sampling signal is less than or equal to second given threshold, the output of the current levels circuit
Comparative result is normal signal, and the communicating circuit keeps current power signal, and current power signal is defeated as power signal
Go out to the pulse train and circuit occurs；
When the current sampling signal is more than second given threshold and during less than or equal to first given threshold,
The comparative result of the output of the current levels circuit is early warning signal, the communicating circuit reduction current power signal, will be dropped
Current power signal after low is exported to pulse train as power signal there is circuit；
When the current sampling signal is more than first given threshold, the comparative result of the output of the current levels circuit
It is over-current signal, the communicating circuit stops power output signal to the pulse train and circuit occurs.
3. system as claimed in claim 2, it is characterised in that：Also include control circuit,
The input of the control circuit receives the power amplifier control signal that the pulse train occurs circuit, from the control
The output end power output amplification of circuit outputs signal to the power amplification circuit.
4. system as claimed in claim 3, it is characterised in that：
The control end of the control circuit receives the over-current signal, and after the over-current signal is received, stops output work
Rate amplifies output signal.
5. system as claimed in claim 3, it is characterised in that：
The reset terminal of the control circuit receives the reset signal of the communicating circuit, and after the reset signal is received,
Recover power output and amplify output signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510009321.2A CN104612672B (en) | 2015-01-08 | 2015-01-08 | A kind of signal processing system for NMR logging instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510009321.2A CN104612672B (en) | 2015-01-08 | 2015-01-08 | A kind of signal processing system for NMR logging instrument |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104612672A CN104612672A (en) | 2015-05-13 |
| CN104612672B true CN104612672B (en) | 2017-06-30 |
Family
ID=53147297
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510009321.2A Active CN104612672B (en) | 2015-01-08 | 2015-01-08 | A kind of signal processing system for NMR logging instrument |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104612672B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3459955A (en) * | 1966-08-02 | 1969-08-05 | Schlumberger Technology Corp | Electric power transmission system for well logging |
| CN1077775A (en) * | 1992-04-15 | 1993-10-27 | 胜利石油管理局测井公司 | Full-electrode logging method |
| CN201202473Y (en) * | 2008-05-30 | 2009-03-04 | 北京华能通达能源科技有限公司 | Magnetic nuclear resonance logger |
| CN201221353Y (en) * | 2008-06-11 | 2009-04-15 | 中国石油集团钻井工程技术研究院 | Downhole wireless electromagnetic transmitting apparatus |
| CN201549882U (en) * | 2009-11-12 | 2010-08-11 | 中国北车股份有限公司大连电力牵引研发中心 | Insulated gate dipole transistor protection device |
| CN202856693U (en) * | 2012-09-27 | 2013-04-03 | 中国海洋石油总公司 | Power amplifying circuit of underground nuclear magnetic resonance logging instrument |
| CN103117717A (en) * | 2012-12-11 | 2013-05-22 | 中国电子科技集团公司第二十二研究所 | Power amplifier and implementing method thereof, transmitter and wireless measurement while drilling system |
| CN104009445A (en) * | 2012-09-20 | 2014-08-27 | 英飞凌科技股份有限公司 | Semiconductor device including short-circuit protection |
| CN203951161U (en) * | 2014-06-03 | 2014-11-19 | 成都嘉晨科技有限公司 | A kind of overcurrent monitoring protective circuit |
| CN204068793U (en) * | 2014-08-27 | 2014-12-31 | 西京学院 | A kind of used in oil well logging pushing device digitlization current control circuit |
-
2015
- 2015-01-08 CN CN201510009321.2A patent/CN104612672B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3459955A (en) * | 1966-08-02 | 1969-08-05 | Schlumberger Technology Corp | Electric power transmission system for well logging |
| CN1077775A (en) * | 1992-04-15 | 1993-10-27 | 胜利石油管理局测井公司 | Full-electrode logging method |
| CN201202473Y (en) * | 2008-05-30 | 2009-03-04 | 北京华能通达能源科技有限公司 | Magnetic nuclear resonance logger |
| CN201221353Y (en) * | 2008-06-11 | 2009-04-15 | 中国石油集团钻井工程技术研究院 | Downhole wireless electromagnetic transmitting apparatus |
| CN201549882U (en) * | 2009-11-12 | 2010-08-11 | 中国北车股份有限公司大连电力牵引研发中心 | Insulated gate dipole transistor protection device |
| CN104009445A (en) * | 2012-09-20 | 2014-08-27 | 英飞凌科技股份有限公司 | Semiconductor device including short-circuit protection |
| CN202856693U (en) * | 2012-09-27 | 2013-04-03 | 中国海洋石油总公司 | Power amplifying circuit of underground nuclear magnetic resonance logging instrument |
| CN103117717A (en) * | 2012-12-11 | 2013-05-22 | 中国电子科技集团公司第二十二研究所 | Power amplifier and implementing method thereof, transmitter and wireless measurement while drilling system |
| CN203951161U (en) * | 2014-06-03 | 2014-11-19 | 成都嘉晨科技有限公司 | A kind of overcurrent monitoring protective circuit |
| CN204068793U (en) * | 2014-08-27 | 2014-12-31 | 西京学院 | A kind of used in oil well logging pushing device digitlization current control circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104612672A (en) | 2015-05-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3708455B1 (en) | Btm device for multi-information fusion transmission between host and antenna unit | |
| CN105137226B (en) | The detection and positioning device of line-to-ground state | |
| CN103777159A (en) | A control method of monitoring of a high-frequency transmit device of a magnetic resonance tomography system | |
| CN104237954B (en) | The foreign matter detecting method and device of radio energy transmission system | |
| CN104612672B (en) | A kind of signal processing system for NMR logging instrument | |
| CN110501665B (en) | Comparison device of magnetic field radiation sensitivity test equipment | |
| CN110632547A (en) | Current transformer partial discharge detection system based on optical fiber transmission and detection method thereof | |
| CN103018571A (en) | Dual-coupling type on-line monitoring device of ground impedance of electric transmission line | |
| CN108732478A (en) | Partial discharge of switchgear on-line monitoring system based on superfrequency punching current sensor and method | |
| CN113253071A (en) | Current sensor and cable state monitoring device based on magnetic resistance effect | |
| CN107064673A (en) | Electric arc detecting device and double-fed wind power generator electric brush slip ring protection system | |
| CN103517299B (en) | A kind of base-station intermodulation signal detection method and system | |
| CN106533466A (en) | Impulse noise measurement and cancellation system for wireless through-the-earth communication system | |
| CN113970792B (en) | Radio wave perspective instrument receiving system and receiving method thereof | |
| CN104295320A (en) | Intelligent tunnel construction safety monitoring system | |
| CN206209033U (en) | Leakage Current detection probe and Leakage Current detecting system | |
| CN107422231A (en) | A kind of transformer superfrequency local discharge detection device | |
| CN103198600A (en) | Cable shielding layer anti-theft alarm device used for power distribution network | |
| CN205139235U (en) | Stabilize non -linear transmission line thunder current measurement circuit | |
| CN211180052U (en) | Power cable partial discharge monitoring device using high-frequency current transformer | |
| CN102606142A (en) | Logging coupling detection system | |
| CN202929137U (en) | Antenna state detection circuit applied to ship automatic identification system terminal | |
| CN202502199U (en) | Cable ultrahigh frequency partial discharge detection apparatus | |
| WO2016099912A1 (en) | Antenna transmitter health determination and borehole compensation for electromagnetic measurement tool | |
| CN105588972A (en) | Industrial heavy current detection system and method realizing temperature monitoring |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 100010 Chaoyangmen North Street, Dongcheng District, Dongcheng District, Beijing Co-patentee after: China Oilfield Services Limited Patentee after: China Offshore Oil Group Co., Ltd. Address before: 100010 Chaoyangmen North Street, Dongcheng District, Dongcheng District, Beijing Co-patentee before: China Oilfield Services Limited Patentee before: China National Offshore Oil Corporation |