CN201232544Y - Electric current field receiving antenna apparatus for measurement while drilling - Google Patents

Abstract

The utility model relates to a current field receiving antenna device for measurement while drilling, which is connected between a drilling platform and a control center. The device comprises a primary coil, a secondary coil, a high-sensitivity magnetic core and a high-strength protection jacket. The primary coil and the secondary coil are winded on the high-sensitivity magnetic coil. One end of the primary coil serves as an input end and is connected with the drilling platform. The other end of the primary coil is grounded. One end of the secondary coil serves as an output end and is connected with the input end of the control center while the other end is grounded. The high-strength protection jacket is arranged at the outer side of the primary coil, the secondary coil and the high-strength magnetic coil. The utility model has good signal transmission real time, improving the safety and the speed of drilling.

Description

The current field receiving antenna device that is used for measurement while drilling

Technical field

The utility model relates to measurement while drillings such as being used for oil, mine and geological prospecting or with probing well device, particularly is used for the current field receiving antenna device of measurement while drilling.

Background technology

A lot of downhole testings, survey tool all need the transmission and the reception of signal.For example: various geologic parameter measureing equipments, oil drilling down-hole condition monitoring device etc. will send to control centre from sensing point with signal.And the electronics that may use in the future, electric fixtures need be transferred to the ground control centre from underground or down-hole etc. with signal in order to finish the related work content.

Present domestic drilling measuring technology, as " a kind of wireless communication apparatus of situ of drilling well " of the patent No. 200720069519.0 and " the well site drilling parameter wireless system for transmitting data " of the patent No. 200520089143.0, the problem of the transmission and the reception of wireless signal has all been proposed, in " the electromagnetic wave channel-type wireless drilling measurement mechanism " of the patent No. 200620031576.5, proposed the basic connected mode of current field formula reception antenna, but all do not had deep research for the concrete structure and the implementation method of reception antenna.

Existing measurement while drilling method comprises: take pictures in the down-hole, wire transmission and reception, the transmission of mud-pulse compression wave and reception etc.

But the mode that above-mentioned signal receives all exists a lot of shortcomings or restriction: for example the sensing point real-time of taking pictures is bad; Wire signal transmission signal is reliable, and speed is fast, can cause greatly increasing working strength but make a trip repeatedly, reduces drilling efficiency; The mud-pulse compression wave is realized measurement while drilling, but speed is slow, and real-time is poor, and can not be used for gas drilling etc.

Summary of the invention

The purpose of this utility model just provides a kind of electromagnet signal receiving antenna that transmits signal based on current field.

The purpose of this utility model is achieved through the following technical solutions, a kind of device that is used for measurement while drilling is connected between offshore boring island and the control centre, and this current field receiving antenna device comprises a primary coil at least, a level coil, a high sensitivity magnetic core and high strength protection overcoat; Described primary coil and described secondary coil are wrapped on the described high sensitivity magnetic core; One end of described primary coil is connected to offshore boring island as input, other end ground connection; One end of described secondary coil is connected to the input of control centre, other end ground connection as output; Described high strength protection overcoat is with described primary coil, and secondary coil and high sensitivity magnetic core are surrounded setting.

Wherein, the output of described secondary coil connects the input of the preamplifier of control centre, and the other end connects the ground wire of preamplifier.

Wherein, described high sensitivity magnetic core is made by soft magnetic materials.

Wherein, the selection of material of described high sensitivity magnetic core comprises cobalt base amorphous alloy, the low nanocrystalline iron core of remanent magnetism or Ni-based amorphous iron core of iron or permalloy.

Wherein, described high sensitivity magnetic core is made by cobalt base amorphous CF84.

Wherein, described high sensitivity magnetic core is annular.

Wherein, described high strength protection overcoat is made by the chemical material cast with favorable elasticity.

The beneficial effects of the utility model are: overcome the deficiencies in the prior art, as: the shortcoming that has overcome the real-time difference of shooting style; Overcome the shortcoming that wired mode frequently makes a trip, improved safety and rate of penetration; Overcome the shortcoming that mud-pulse can not be used for aspects such as gas drilling.Can be simultaneously for the wireless measurement of measurement while drilling and down-hole exploration provides ground to receive, this current field reception antenna is easy to processing, and is simple in structure, the receiving signal sensitivity height.

Description of drawings

Fig. 1 is the fundamental diagram that is used for the current field reception antenna of measurement while drilling according to of the present utility model.

Fig. 2 is the structure chart that is used for the current field reception antenna of measurement while drilling according to of the present utility model.

Fig. 3 is the circuit model that is used for the current field reception antenna of measurement while drilling according to of the present utility model.

Fig. 4 is cobalt base amorphous CF84 longitudinal magnetic field annealing curve.

The specific embodiment

For making the purpose of this utility model, technical scheme and advantage clear more understandable,, the utility model is described in further details below in conjunction with accompanying drawing.At this, illustrative examples of the present utility model and explanation thereof are used to explain the present invention, but not as to qualification of the present utility model.

Please refer to Fig. 1 and Fig. 2, Fig. 1 is the fundamental diagram that is used for the current field reception antenna of measurement while drilling according to of the present utility model, and Fig. 2 is the structure chart that is used for the current field reception antenna of measurement while drilling according to of the present utility model.According to the current field reception antenna that is used for measurement while drilling of the present utility model mainly by primary coil 207, secondary coil 208, high sensitivity magnetic core 202, high strength protection overcoat 201 is formed.

When the one part of current signal when drill string 105 upwards conducts, this part electric current is imported the signal receiving end 203 of current field reception antenna, the structure of this antenna is to coil (this magnetic core also can be bar-shaped other shapes that waits as required) on a toroidal core with high initial magnetoconductivity, coil has two groups, one group is primary coil, one group is secondary coil, the signal receiving end 203 of primary coil is connected on the offshore boring island 104 (because drill string is that metal is connected with platform, so have good electrical conductivity), the other end is connected on the earthing electrode 102, and earthing electrode is the earth apart from tens of meters of offshore boring island.As current signal when drill string 105 enters the primary coil 203 of current field reception antenna by platform 104, lead, under the excitation of current signal, producing frequency in magnet ring 202 is the alternating magnetic field of f, and this alternating magnetic fields induces the alternating voltage that frequency is f in the secondary coil of magnet ring 202, send into the preposition amplification input of control centre, catch the low current signal that transmits from the down-hole with the method.

Please refer to Fig. 3 and Fig. 4, Fig. 3 is the circuit model that is used for the current field reception antenna of measurement while drilling according to of the present utility model.Fig. 4 is cobalt base amorphous CF84 longitudinal magnetic field annealing curve.The design and the calculating that are used for the current field reception antenna of measurement while drilling according to of the present utility model will be described below.

The design of current field reception antenna and calculating

1) calculating of equivalent circuit

If being added in the electric current of elementary winding is I ₁, then elementary induced potential is

E1＝I ₁×(R _m+jX _m)

In the secondary windings termination pre-amplification circuit is arranged, it is infinitely great that this circuit input impedance can be thought, then current field formula reception antenna can be estimated each parameter according to no-load running.Then the voltage of secondary windings end input pre-amplification circuit is

$E2=\frac{N_2}{{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">N</figure-callout>}}_1}\&times;\mathrm{<figure-callout\; id="1"\; label="E"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">E</figure-callout>}1=\frac{N_2}{{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">N</figure-callout>}}_1}\&times;{\mathrm{<figure-callout\; id="1"\; label="I"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">I</figure-callout>}}_1\&times;(R_m+j{X}_m)$

Wherein

E1-current field formula reception antenna primary coil induced voltage;

E2-current field formula reception antenna secondary coil induced voltage;

N ₁-current field formula reception antenna number of primary turns;

N ₂-current field formula reception antenna secondary coil the number of turn.

Wherein

U-input voltage;

R _D1～R _Dn-formation resistivity;

R ₁The internal resistance of-winding primary coil;

X ₁-winding primary coil leakage inductance;

R _m-current field formula reception antenna magnetic core iron loss equivalent resistance;

X _m-current field formula reception antenna magnetic core excitation reactance.

2) calculating of equivalent magnetic circuit

If the elementary input current of reception antenna is I ₁, then the primary side induced potential at the current field reception antenna is

${\mathrm{<figure-callout\; id="1"\; label="E"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">E</figure-callout>}}_1={\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">N</figure-callout>}}_1\frac{{\mathrm{d\&phi;}}_m}{\mathrm{dt}}=N_1{B}_{m}S={\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">N</figure-callout>}}_1\mathrm{S\&mu;H}=\frac{\mathrm{<figure-callout\; id="1"\; label="S\; l\; N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">S</figure-callout>}}{l}{N_{}}^{}{{}_1}^2\mathrm{\&mu;}{I}_1$ ①

Wherein

S-high sensitivity magnetic core net sectional area;

L-equivalent magnetic circuit length;

N ₁Be the first siding ring number of turn;

The magnetic conductivity of μ-magnetic core.

From formula as can be seen: under the certain condition of core shapes, the induced voltage in the current field formula reception antenna primary coil is only relevant with exciting current I1 with magnetic conductivity, the number of primary turns of magnetic material.And input current I1 is determined jointly by transmitting power, specific geologic structure and the input impedance of current field formula reception antenna.The wherein input impedance of current field formula reception antenna and ground resistance R _dIt is in parallel the relation as shown in Figure 3.

At emission voltage U and ground resistance R _dUnder certain situation, the elementary winding input current I of current field formula reception antenna ₁Be decided by the impedance of elementary winding.Because R ₁" R _m, X ₁" X _mSo, influence current field formula reception antenna input current I ₁Principal element be R _m, R _dAnd X _mR wherein _mBe magnetic core equivalence iron loss resistance.

The equivalent iron loss of magnetic core $P_{\mathrm{fe}}=k\&times;{\left(\frac{f}{50}\right)}^{\mathrm{\&beta;}}\&times;B_m^2={I_1}^2\&times;R_m,$ Can determine the value of constant k and β according to different core materials, thereby determine iron loss resistance

R _m＝P _fe/I ₁ ² ②

Excitation reactance X _mFor:

$X_m=\mathrm{\&omega;}\&times;L_m=\mathrm{\&omega;}\&times;{{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">N</figure-callout>}}_1}^2\&times;\mathrm{\&Lambda;}=\mathrm{\&omega;}\&times;{{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">N</figure-callout>}}_1}^2\&times;\mathrm{\&mu;}\frac{A}{l}$ ③

Wherein

Λ-magnetic core equivalence magnetic conductance;

L _mThe elementary magnetizing inductance of-current field formula reception antenna;

A-magnetic core net sectional area;

L-effective magnetic circuit length.

Try to achieve the input current of the elementary winding of current field reception antenna according to Fig. 3, for

$I_1=\frac{U}{({\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">R</figure-callout>}}_1+R_m+R_d)+j({\mathrm{<figure-callout\; id="1"\; label="X"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">X</figure-callout>}}_1+X_m)}\&ap;\frac{U}{R_d+R_m+j{X}_m}$ ④

With I ₁1. the substitution formula can try to achieve

${\mathrm{<figure-callout\; id="1"\; label="E"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">E</figure-callout>}}_1=I_1(R_m+j{X}_m)=\frac{U\&times;(R_m+j{X}_m)}{R_d+R_m+j{X}_m}=\frac{U}{\frac{R_d}{R_m+j{X}_m}+1}$ ⑤

From formula 5. as can be seen, improve E ₁Induced voltage, then

The smaller the better.

But R _mBe iron loss resistance, be not used for transmitting energy, so target increases X exactly _m, but excessive X _mCan cause exciting curent too small, can not meet the requirements of magnetic field intensity, magnetic core can not effectively transmit signal, so want the careful selection number of turn.

By formula 3. $X_m=\mathrm{\&omega;}\&times;L_m=\mathrm{\&omega;}\&times;{{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">N</figure-callout>}}_1}^2\&times;\mathrm{\&Lambda;}=\mathrm{\&omega;}\&times;{{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">N</figure-callout>}}_1}^2\&times;\mathrm{\&mu;}\frac{A}{l}$ As can be seen, increase X _mMethod have three:

Increase umber of turn, but can increase the internal resistance R of elementary winding simultaneously ₁With leakage inductance X ₁

Choose the magnetic material of high initial magnetoconductivity μ;

Increase the ratio of core material net sectional area and effective magnetic circuit length.

3) selection of core material: because it is very faint to flow through the electric current of current field reception antenna, so the alternating magnetic field that produces in magnetic core is also very faint, so core material must be selected for use the highstrung soft magnetic materials of weak current.If select for use magnetic material can effectively improve induced voltage with high initial permeability (μ).Optional cobalt base amorphous alloy, the low nanocrystalline iron core of remanent magnetism or the Ni-based amorphous iron core of iron etc., permalloy etc.

These magnetic materials all have high initial magnetoconductivity, low-coercivity, highly sensitive advantage.

4) be annealed into example with cobalt base amorphous CF84 longitudinal magnetic field.Its magnetization curve as shown in Figure 4

Coercivity H _c＜2A/m, as can be seen, when magnetic field intensity surpassed 2A/m, magnetic induction density rose rapidly, near saturated magnetic induction intensity from magnetization curve.

Get magnetic core net sectional area A=1.68cm ², 3. magnetic circuit effective length L=21.77cm is then got by formula

$X_m=\mathrm{\&omega;}\&times;{{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">N</figure-callout>}}_1}^2\&times;\mathrm{\&mu;}\frac{A}{l}=2\&times;3.14\&times;50\&times;{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">N</figure-callout>}}_1^2\&times;8\&times;\frac{1.68\&times;{10}^{-4}}{21.77\&times;{10}^{-2}}=1.94{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">N</figure-callout>}}_1^2$

Get N ₁=50 circles, then X _m=4850 Europe.

The formation resistivity of connecting with current field formula reception antenna is estimated as 30 Europe, and emission voltage U=70V ignores iron loss internal resistance R _m, 4. the substitution formula is tried to achieve exciting curent and is

$I_1=\frac{U}{R_d+j{X}_m}=\frac{70}{30+j4850}=14.4\mathrm{mA}$

Corresponding magnetic field intensity is

$H=\frac{\mathrm{NI}}{l}=\frac{100\&times;0.0144}{21.77\&times;{10}^{-2}}=6.6A/m$

Then actual current is littler than this initial value certainly.According to the iron loss parameter of core material can extrapolate iron loss resistance resistance must less than $\frac{\mathrm{Pfe}}{I_1^2}=\frac{K\&times;{\left(\frac{f}{50}\right)}^{\mathrm{\&beta;}}\&times;B_m^2}{I_1^2}=\frac{1.05\&times;1\&times;0.6}{{(14.4\&times;{10}^{-3})}^2}=3038\mathrm{\&Omega;}.$ 4. the substitution formula recomputates exciting curent

$I_1=\frac{U}{R_d+R_m+j{X}_m}=\frac{70}{30+3038+j4850}=12.1\mathrm{mA}$

So actual exciting curent is between 12.1mA-14.4mA.

Calculate corresponding magnetic field intensity according to minimum current 12.1mA $H=\frac{\mathrm{NI}}{l}=2.77A/m>2A/m\left(\mathrm{Hc}\right),$ Can operate as normal.

This moment, the excitation voltage on the elementary winding of current field formula reception antenna was

${\mathrm{<figure-callout\; id="1"\; label="E"\; filenames="Y200820108506E00122.png,Y200820108506E00131.png"\; state="\{\{state\}\}">E</figure-callout>}}_1=I_1\&times;{\mathrm{jX}}_m=\frac{U\&times;\left|{\mathrm{jX}}_m\right|}{|R_d+R_m+{\mathrm{jX}}_m|}=\frac{70\&times;4850}{|30+3038+j4850|}=59.1V$

The current field reception antenna of Xing Chenging mainly contains following characteristics in this way:

1) can set up real-time receive path with offshore boring island and the earth under with the brill condition, synchronism is good;

2) of many uses, can be used for the receiving system of multiple media such as mud, air, nitrogen, natural gas;

3) receiving efficiency height, power consumption is little.

Above-described specific descriptions; purpose, technical scheme and beneficial effect to invention further describe; institute is understood that; the above only is a specific embodiment of the utility model; and be not used in and limit protection domain of the present utility model; within the spirit and principles in the present invention all, any modification of being made, be equal to replacement, improvement etc., all should be included within the protection domain of the present utility model.

Claims (7)

1, a kind of current field receiving antenna device that is used for measurement while drilling is connected between offshore boring island and the control centre, it is characterized in that:

This current field receiving antenna device comprises a primary coil at least, a level coil, a high sensitivity magnetic core and high strength protection overcoat;

Described primary coil and described secondary coil are wrapped on the described high sensitivity magnetic core;

One end of described primary coil is connected to offshore boring island as input, other end ground connection;

One end of described secondary coil is connected to the input of control centre, another termination signal ground as output;

Described high strength protection overcoat is with described primary coil, and secondary coil and high sensitivity magnetic core wrap up the formation topping.

2, the current field receiving antenna device that is used for measurement while drilling according to claim 1 is characterized in that: the output of described secondary coil connects the input of the preamplifier of control centre, and the other end connects the ground wire of preamplifier.

3, the current field receiving antenna device that is used for measurement while drilling according to claim 1, it is characterized in that: described high sensitivity magnetic core is made by soft magnetic materials.

4, the current field receiving antenna device that is used for measurement while drilling according to claim 3 is characterized in that: the selection of material of described high sensitivity magnetic core comprises cobalt base amorphous alloy, the low nanocrystalline iron core of remanent magnetism or Ni-based amorphous iron core of iron or permalloy.

5, the current field receiving antenna device that is used for measurement while drilling according to claim 1, it is characterized in that: described high sensitivity magnetic core is made by cobalt base amorphous CF84.

6, the current field receiving antenna device that is used for measurement while drilling according to claim 1, it is characterized in that: described high sensitivity magnetic core is annular.

7, the current field receiving antenna device that is used for measurement while drilling according to claim 1 is characterized in that: described high strength protection overcoat is made by the chemical material cast with favorable elasticity.

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