CN109826618A - A kind of NMR RF coil that can be used under high-salinity mud Drilling Fluid Conditions - Google Patents
A kind of NMR RF coil that can be used under high-salinity mud Drilling Fluid Conditions Download PDFInfo
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- CN109826618A CN109826618A CN201910023691.XA CN201910023691A CN109826618A CN 109826618 A CN109826618 A CN 109826618A CN 201910023691 A CN201910023691 A CN 201910023691A CN 109826618 A CN109826618 A CN 109826618A
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- flexible board
- conducting wire
- pedestal
- lower flexible
- drilling fluid
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
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- Y02A90/30—Assessment of water resources
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Abstract
The invention discloses a kind of NMR RF coils that can be used under high-salinity mud Drilling Fluid Conditions, coil is made of two panels flexible PCB, two panels flexible board is tightly attached on the pedestal that one side is arc, it is integrally formed solenoid structure, this kind of coil fitting skeleton is preferable, it is high compared to traditional copper band antenna signal-to-noise ratio, it is easier to assemble, generate the RF magnetic field distribution for more meeting theoretical calculation.
Description
Technical field
The present invention relates to oil well logging instrument fields, and in particular to one kind can be used under high-salinity mud Drilling Fluid Conditions
NMR RF coil.
Background technique
In nuclear magnetic resonance image tool device, nuclear magnetic resonance technique is widely used in as a kind of nondestructiving detecting means
The fields such as life medical treatment, geophysics, food analysis, material science.Radio-frequency coil is to emit and receive the dedicated of radiofrequency signal
Device, or perhaps the source device of nmr frequency is provided, it is most important to image quality, and relative to other component,
Have the characteristics that be easy to develop and optimize, therefore the hot issue of always MRI research field.In nuclear magnetic resonance log, penetrate
Frequency coil mainly generates and the mutually perpendicular static RF magnetic field in main magnet magnetic field.Underground type nuclear magnetic resonance log placed in the middle at present
It is a kind of saddle-shaped coils structure used in instrument, the RF magnetic field and magnetostatic field matching with higher generated, detection
It is formation rock sample information of one week away from fixed range a certain outside coil, therefore higher signal-to-noise ratio can be obtained.Correspondingly,
The invalid noise of mud filtrate can be detected in the case where wellbore expands biggish situation due to using circumferential detection mode
Information causes the limitation of application.
On the other hand, saddle-shaped coils are in measurement since RF magnetic field needs to can be only achieved stratum, well by wellbore mud
Eye fluid plays load effect, loss is generated to RF energy, to reduce signal-to-noise ratio.There is an urgent need to a kind of small-sized, resolutions at present
Rate is high, is influenced lesser patch borehole wall type nuclear-magnetism antenna body by borehole environment.
Summary of the invention
The purpose of the present invention is to provide a kind of magnetic nuclear resonance radio frequencies that can be used under high-salinity mud Drilling Fluid Conditions
Coil, to solve the problems, such as that instrument nuclear-magnetism antenna placed in the middle is non-serviceable under high salinity pit shaft solution condition, the present invention can be used for
NMR system is built, the detection of stratum NMR signal is carried out, measurement data can be directly used for Rock physical analysis and survey
Well is explained, to determine oil-containing (or aqueous) saturation degree, total porosity, have aperture porosity, constraint content, T2 Spectral structure, permeability
Etc. parameters.
In order to achieve the above objectives, the present invention adopts the following technical scheme:
A kind of NMR RF coil that can be used under high-salinity mud Drilling Fluid Conditions, including upper flexible board, under
Flexible board and pedestal, the upper flexible board and lower flexible board are pcb board, and the upper surface of the pedestal is arcwall face, upper flexibility
Plate is arranged on the upper surface of pedestal, and lower flexible board is arranged on the lower surface of pedestal, and divides on upper flexible board and lower flexible board
It is not disposed with three conducting wires, it is in solenoid that three conducting wires head and the tail on three conducting wires and lower flexible board on upper flexible board, which weld,
Structure is wound on the base, forms two circle coils, and a conducting wire on the head end and lower flexible board of a conducting wire on upper flexible board
The end end of motivating on input points or upper flexible board a conducting wire as two and lower flexible board on a conducting wire head end
As two excitation input points.
Further, the upper flexible board is integrally in rectangle, and the middle part of lower flexible board is in rectangle, and both ends are fan-shaped.
Further, several fixation holes for facilitating by the installation of upper flexible board on the base are provided on upper flexible board,
Several fixation holes for facilitating by the installation of lower flexible board on the base, lower flexible board are provided in the rectangular configuration of lower flexible board
Sector structure on be provided with it is several for making lower flexible board be close to the location holes of pedestal.
Further, the substrate of the upper flexible board and lower flexible board uses polyimides, and conductor material uses cathode copper,
Base material is polytetrafluoroethylene (PTFE).
Further, three conducting wires on upper flexible board are equidistantly evenly distributed, between three conducting wires on lower flexible board etc.
Away from evenly distributed.
Further, lower flexible board is stretched out in conducting wire one end on lower flexible board positioned at pedestal side, on lower flexible board remaining
Lower flexible board is stretched out at the both ends of two conducting wires.
Further, the end of three conducting wires on upper flexible board and three conducting wires on lower flexible board is provided with weldering
Disk, three conducting wires on three conducting wires and lower flexible board on upper flexible board pass through pad head and the tail and weld.
Further, one end of flexible board and upper flexible board are upper under the conducting wire on lower flexible board positioned at pedestal side stretches out
It welds, is located on the conducting wire other end and lower flexible board of pedestal side on upper flexible board in being located in conducting wire one end of pedestal side
Between the welding of conducting wire one end, be located in the middle on lower flexible board on the conducting wire other end and upper flexible board and be located in the middle conducting wire one end
It welds, the conducting wire one end welding for being located at the pedestal other side on the conducting wire other end and lower flexible board is located in the middle on upper flexible board,
The conducting wire one end for being located at pedestal neck prediction on the conducting wire other end and upper flexible board of the pedestal other side on lower flexible board is welded,
It is located at the conducting wire other end conduct of the pedestal other side on lower flexible board on the conducting wire other end and upper flexible board of pedestal side
Two excitation input points.
Compared with prior art, the invention has the following beneficial technical effects:
Antenna of the invention uses winding electric wire structure, has higher inductance and emission effciency compared to flat plane antenna,
To can be obtained higher detectivity under conditions of not using magnetic core.This structure design not only makes nuclear-magnetism antenna
Structure greatly simplifies, and avoids the additional unfavorable factor brought using core material to magnetostatic field.Since the antenna emits
With directionality, as long as therefore guarantee that antenna is tightly attached to the borehole wall in use, can be used under any borehole size, together
When, being close to the borehole wall, another advantage is using bring, and the electromagnetic wave of transmitting is directly entered stratum without mud, therefore keeps away
Decaying of the mud to electromagnetic wave is exempted from, i.e. antenna can use under the conditions of any mud drilling liquid conductivity, due to using
Flexible structure design, thus with antenna frame --- pedestal be bonded more preferable, and assembly precision is higher, therefore with higher noise
Than the present invention can overcome wellbore mud influence, reduce the load effect of high-salinity mud, do not depend on wellbore size and expand well
The application limitation of section；In addition, since antenna and search coverage distance are shorter, in this way, it is sensitive to have stronger radiofrequency signal arrival
Area, therefore, relatively narrow radio-frequency pulse can cause broader frequency band to be activated, and can be used for building NMR system, carry out stratum
NMR signal detection, measurement data can be directly used for Rock physical analysis and well log interpretation, to determine oil-containing (or aqueous)
Saturation degree, total porosity have the parameters such as aperture porosity, constraint content, T2 Spectral structure, permeability.
Further, by the way that fixation hole is arranged, it can be first fixed using screw when installation, be torn open again after completing installation
It removes, installation can be facilitated, by the way that location hole is arranged, so that lower flexible board is bonded with pedestal.
Detailed description of the invention
Fig. 1 is radio-frequency coil structure schematic diagram provided in an embodiment of the present invention；
Fig. 2 is radio-frequency coil wire connection diagram provided in an embodiment of the present invention；
Fig. 3 is flexible board schematic diagram on radio-frequency coil provided in an embodiment of the present invention；
Fig. 4 is flexible board schematic diagram under radio-frequency coil provided in an embodiment of the present invention；
Fig. 5 is the Distribution of Magnetic Field figure that radio-frequency coil provided in an embodiment of the present invention generates.
In figure, A1-A6 is the pad on upper flexible board；B1-B6 is the pad on lower flexible board；21-24 is upper flexible board
On fixation hole；16-19 is the fixation hole on lower flexible board；1-15 is the location hole on lower flexible board；25 be wellbore；26 be spy
Survey sensitizing range.
Specific embodiment
Present invention is further described in detail with reference to the accompanying drawing:
Referring to Fig. 1 to Fig. 5, a kind of NMR RF coil that can be used under high-salinity mud Drilling Fluid Conditions, line
The pedestal that the pcb board (upper flexible board and lower flexible board) and one side that coil structures draw connecting terminal by two are arc forms.On
Flexible board and lower flexible board are close to antenna base, carry out bonding wire connection in two sides of base, overall structure solenoid structure is wrapped in
On pedestal, two panels pcb board is respectively distributed three conducting wires, is welded in pedestal cambered surface, constitutes two circle coils, and there are two tools
Input point is motivated, provides big AC signal for entire coil from input point, two panels pcb board is flexible board, is distributed on plate
Three parallel conducting wires, and flexible board ends have the solder joint that can be welded, flexible board substrate uses polyimides, conductor material
Using cathode copper, flexible board is doubling plate, and each conducting wire use is equidistant evenly distributed, and two panels flexibility board ends draw wiring respectively
Terminal is welded in skeleton end face, and the connecting terminal that two panels flexible board is drawn is welded using pad, and there are seep tin for pad
Hole, so that conducting wire is bonded, two panels flexible board is a piece of to be tightly attached in pedestal cambered surface, a piece of to be tightly attached in base bottom surface, two panels
It is welded by pad in cambered surface, respectively reserves an excitation input terminal up and down in pedestal one end, the flexibility on pedestal fan-shaped surface
The connecting terminal that plate is drawn need to be seamlessly transitted to be welded with the flexible board of bottom surface, and connecting terminal turning radian requires to be 35 °, soft
Property plate there is location hole and fold line so that flexible board is preferably bonded antenna base in order to install, in use, radio-frequency coil
It is fixed in the main magnet with scalloped recess by fixed device, excitation forms RF magnetic field required for resonance condition, into
Row Well Logging by Nuclear Magnetic Resonance Imaging.
Operating process of the invention is described in detail below:
The present invention uses two panels flexible PCB and polytetrafluoroethylene material pedestal, and two panels flexible PCB is logical in base end face
It crosses and current path is formed by welding.The coil turn that the structure is constituted is 2 circles half, every approximate rectangular structure of circle coil, every circle coil
Turn-to-turn away from equal, each side of coil is parallel to each other, and excitation input point and motivates output point that the upper layer and lower layer of pedestal are arranged in.Excitation
Source enters from one layer of excitation input point, flows out from another layer of excitation output point, in order to fix the coil, it is also necessary to 3M adhesive tape
It is fitted closely on the base.
As shown in Figure 1, patch borehole wall formula nuclear-magnetism antenna structure is made of two panels flexible board and antenna base two parts, pacifying
To guarantee two o'clock when dress: 1, flexible board and pedestal good fit；2, upper and lower flexible board is by pad in endface firm welding.
Specific implementation: two panels flexible board is for double-sided PCB board, and PCB substrate is polyimide material resistant to high temperature, conducting wire material
Matter is cathode copper.Wherein, upper flexible board is rectangular configuration, and a length of 65cm, width 9.5cm are placed on pedestal in cambered surface, such as Fig. 3
It is shown；It is rectangular configuration among lower flexible board, a length of 80cm, width 13cm, both ends are sector structure, and the terminal for wiring is prominent
Outside for sector structure, it is placed on pedestal bottom surface, as shown in Figure 4.There are pad A1, A2, A3, A4, A5 on upper flexible board,
A6, fixation hole 21,22,23,24 are to facilitate installation, being first fixed during installation with M3 screw, and completion is removed after installing.
There are pad B2, B3, B4, B5, B6 on lower flexible board, welded respectively with pad A2, A3, A4, A5, A6, welding uses nothing
Lead high temperature scolding tin；In addition there are also location holes 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 for being preferably bonded base
Seat, fixation hole 16,17,18,19 are equally first fixed during installation, rear to remove.
It is illustrated in figure 5 the alternating magnetic field distribution of antenna generation.Antenna module needs to guarantee in use to cling to
The borehole wall of wellbore 25, the pumping signal that underground electronics generate certain bandwidth is emitted to stratum by antenna, to generate alternation
Magnetic field.According to nuclear magnetic resonance principle, the radio-frequency pulse of fixed frequency (can only detect sensitive in the magnetic field strength region to match
Area 26) excitation nuclear magnetic resonance scene, therefore by changing the working frequency being loaded on antenna, i.e., the detection of changeable antenna is deep
Degree.Investigation depth is deeper, and the signal that can receive is weaker.Investigation depth and signal strength in order to balance recommend the antenna to use
Frequency range in 500K-1MHz range.
Claims (8)
1. a kind of NMR RF coil that can be used under high-salinity mud Drilling Fluid Conditions, which is characterized in that including upper
Flexible board, lower flexible board and pedestal, the upper flexible board and lower flexible board are pcb board, and the upper surface of the pedestal is arc
Face, upper flexible board are arranged on the upper surface of pedestal, and lower flexible board is arranged on the lower surface of pedestal, and upper flexible board is soft under
Property plate on be respectively disposed with three conducting wires, three conducting wires on three conducting wires and lower flexible board on upper flexible board head and the tail weld,
On the base in solenoid structure winding, two circle coils are formed, and on upper flexible board on the head end and lower flexible board of a conducting wire
It is led for one on end that a conducting wire is motivated on input points or upper flexible board as two in the end of a piece conducting wire and lower flexible board
The head end of line is as two excitation input points.
2. a kind of magnetic nuclear resonance radio frequency line that can be used under high-salinity mud Drilling Fluid Conditions according to claim 1
Circle, which is characterized in that the upper flexible board is integrally in rectangle, and the middle part of lower flexible board is in rectangle, and both ends are fan-shaped.
3. a kind of magnetic nuclear resonance radio frequency line that can be used under high-salinity mud Drilling Fluid Conditions according to claim 2
Circle, which is characterized in that several fixation holes for facilitating by the installation of upper flexible board on the base are provided on upper flexible board, under it is soft
Property plate rectangular configuration on be provided with it is several for facilitating lower flexible board installation fixation holes on the base, the fan of lower flexible board
It is provided in shape structure several for making lower flexible board be close to the location hole of pedestal.
4. a kind of magnetic nuclear resonance radio frequency line that can be used under high-salinity mud Drilling Fluid Conditions according to claim 1
Circle, which is characterized in that the substrate of the upper flexible board and lower flexible board uses polyimides, and conductor material uses cathode copper, base
Seat material is polytetrafluoroethylene (PTFE).
5. a kind of magnetic nuclear resonance radio frequency line that can be used under high-salinity mud Drilling Fluid Conditions according to claim 1
Circle, which is characterized in that three conducting wires on upper flexible board are equidistantly evenly distributed, and three conducting wires on lower flexible board are equidistantly equal
Even arrangement.
6. a kind of magnetic nuclear resonance radio frequency line that can be used under high-salinity mud Drilling Fluid Conditions according to claim 1
Circle, which is characterized in that on lower flexible board remaining two on the lower flexible board of conducting wire one end stretching of pedestal side, lower flexible board
Lower flexible board is stretched out at the both ends of conducting wire.
7. a kind of magnetic nuclear resonance radio frequency line that can be used under high-salinity mud Drilling Fluid Conditions according to claim 6
Circle, which is characterized in that the end of three conducting wires on upper flexible board and three conducting wires on lower flexible board is provided with pad, on
Three conducting wires on three conducting wires and lower flexible board on flexible board are welded by pad head and the tail.
8. a kind of magnetic nuclear resonance radio frequency line that can be used under high-salinity mud Drilling Fluid Conditions according to claim 7
Circle, which is characterized in that be located on one end of flexible board and upper flexible board under the conducting wire on lower flexible board positioned at pedestal side stretches out
Conducting wire one end of pedestal side is welded, and is located on the conducting wire other end and lower flexible board of pedestal side on upper flexible board and is located at centre
The welding of conducting wire one end, be located in the middle on lower flexible board on the conducting wire other end and upper flexible board and be located in the middle the weldering of conducting wire one end
It connects, the conducting wire one end welding for being located at the pedestal other side on the conducting wire other end and lower flexible board is located in the middle on upper flexible board, under
The conducting wire one end for being located at pedestal neck prediction on the conducting wire other end and upper flexible board of the pedestal other side on flexible board is welded, under
It is located at the conducting wire other end of the pedestal other side on flexible board on the conducting wire other end and upper flexible board of pedestal side as two
A excitation input point.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910023691.XA CN109826618B (en) | 2019-01-10 | 2019-01-10 | Nuclear magnetic resonance radio frequency coil capable of being used under high-salinity mud drilling fluid condition |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910023691.XA CN109826618B (en) | 2019-01-10 | 2019-01-10 | Nuclear magnetic resonance radio frequency coil capable of being used under high-salinity mud drilling fluid condition |
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| CN109826618A true CN109826618A (en) | 2019-05-31 |
| CN109826618B CN109826618B (en) | 2022-06-03 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113266342A (en) * | 2021-06-22 | 2021-08-17 | 华中科技大学 | Signal wireless transmitting device |
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| CN113266342B (en) * | 2021-06-22 | 2022-05-17 | 华中科技大学 | Signal wireless transmitting device |
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| Publication number | Publication date |
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| CN109826618B (en) | 2022-06-03 |
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