CN101852078A - Electromagnetic distance measurement guide system for double solenoid set during drilling - Google Patents

Abstract

The invention discloses an electromagnetic distance measurement guide system for a double solenoid set during drilling. The system can provide accurate guide measurement and calculation for well track control of double horizontal wells, communicated wells, U-shaped wells, infill wells, and other complex-structure wells. The system mainly comprises a double solenoid set pup joint, a converted MWD, a ground display system, ground equipment, and the like. The double solenoid set pup joint serving as a magnetic signal emission source is put into a drilled well, two rotating magnetic fields with different frequencies are generated, and the system has the measurement accuracy equivalent to the RMRS. During measurement and calculation, the spacing between adjacent wells and relative azimuth can be accurately detected and calculated without dragging the double solenoid set pup joint. Therefore, the measurement can be finished in short time. The data analysis and adjacent well spacing calculation program of the system can be put underground, only a little of calculated necessary data is transmitted to the ground, and the data transmission time is saved. Meanwhile, by improving the current intensity of a solenoid coil, and the like, the intensity of the magnetic signal emission source is improved, and the distance measurement range of the system is easily increased. The system has the advantages of high guide accuracy, wide distance measurement range, short measurement time, and simple structure, and is an effective high-tech means for the detection and control of the distance between the adjacent wells during drilling.

Description

A kind of double solenoid set during drilling electromagnetic guiding distance measurement system

Technical field

The present invention relates to a kind of electromagnetic guide system of measurement while drilling offset well distance, belong to subterranean resource drilling field of engineering technology.

Background technology

In the exploitation of subterranean resource such as oil, natural gas and coal bed gas, complex structural wells such as two horizontal wells, connected well, U type well and infill well require the offset well distance is carried out surveying with boring accurately.At present, the domestic measurement while drilling instrument that generally uses can not directly be measured the offset well distance, thereby is difficult to satisfy the specific (special) requirements that complex structural well offset well distance is surveyed with probing.Though abroad developed can satisfy substantially above require with boring electromagnetic guide system (as MGT, RMRS etc.), its core technology is still maintained secrecy and is monopolized.The present inventor is on the basis of MGT and RMRS, in the patent 201010145020X of former application and the patent 2010101450233 research and design " a kind of system using solenoid groups to achieve electromagnetic guiding distance measurement while drilling ", though this system has bigger finding range, but measurement and data transmission period are longer, have wasted overall drilling time.For saving the measurement and the data transmission period of detection system, improve drilling efficiency, the special research and design of present inventor " a kind of double solenoid set during drilling electromagnetic guiding distance measurement system ", the present invention adopts double solenoid group pipe nipple as the magnetic signal emission source, be put in the drilling well, can produce the rotating excitation field of two different frequencies, have suitable certainty of measurement with RMRS; This system not only has bigger finding range, and measures when calculating, and need not to drag double solenoid group pipe nipple and just can accurately survey calculating adjacent well spacing and relative bearing, therefore can finish measurement in the short period of time.Simultaneously, data analysis and adjacent well spacing calculation program can be put into the down-hole, only will calculate a spot of necessary data in back and send to ground, have saved the data transmitting time.

Summary of the invention

Technical problem underlying of the present invention provides a kind of double solenoid set during drilling electromagnetic guiding distance measurement system, it can accurately measure the relative distance and the orientation of offset well within the specific limits, for complex structural wells such as two horizontal wells, connected well, U type well and infill well provide a kind of effective detection and control device.

In order to survey the spacing and the relative bearing of offset well with probing, the invention provides a kind of double solenoid set during drilling electromagnetic guiding distance measurement system, it is characterized in that: mainly comprise a double solenoid group pipe nipple, MWD (Measurement While Drilling), ground display system and the ground installation of a cover through reequiping, wherein:

Described double solenoid group pipe nipple, it mainly acts on is the rotating excitation field that produces two different frequencies at sensing point, is the signal source of this electromagnetic survey system, determines the position of drill bit in positive drilling well with this.In use, drill string or crawl device with under the solenoid group pipe nipple in drilling well.

The MWD of described repacking mainly by traditional MWD, three alternating magnetic field sensors be solidified with data analysis and the microprocessor of adjacent well spacing calculation program is formed, is installed in the residing position of traditional MWD.The mounting means of alternating magnetic field sensor in MWD is identical with other three-axis sensor mounting means among the MWD, and its effect is to survey the rotating excitation field that is produced by solenoid group.Three axis fluxgate sensors among the MWD and 3-axis acceleration sensor are mainly used to detect the geomagnetic fieldvector and the gravitational field vector at place, MWD position.Data analysis and adjacent well spacing calculation program, its effect is the detected signal of analyte sensors and calculates the MWD of repacking and the spacing and the relative bearing of double solenoid group pipe nipple, calculate the hole angle and the azimuth at the well depth place, MWD place of repacking simultaneously, and result of calculation is transferred to ground installation by MWD.

Described ground display system mainly is that the down-hole that will receive sends data, through further calculating, shows the relative tertiary location of drill bit to offset well with forms such as numeral, literal and figures.The drilling engineer can in conjunction with traditional MWD deviational survey data, control the drill bit movement track effectively according to these information, creeps into or make adjacent two mouthfuls of wells to be communicated with by design pitch so that accurately control adjacent two mouthfuls of well parallel-segment.

Described ground installation mainly is two groups of synchronous ACs to be provided and to receive the signal that double solenoid group pipe nipple inner sensor is surveyed for double solenoid group pipe nipple.Wherein every group of alternating current comprises two synchronous ACs, the waveform of two synchronizing currents differs four/one-period in time, but the waveform sine and the cosine waveform of alternating current can all be square waves also, and this is because the Fourier harmonic wave of two square waves also is sine and cosine waveform.Usually, it is more much easier than producing pure sine and cosine waveform alternating current to produce the square waveform alternating current, therefore the normal square waveform alternating current that adopts in real world applications.

Further, above-mentioned double solenoid set during drilling electromagnetic guiding distance measurement system also can have following characteristics: described double solenoid group pipe nipple mainly comprises two sections solenoid group, every section solenoid group is made up of the mutually orthogonal solenoid of two row, it is characterized in that: two sections solenoid group lay respectively at double solenoid group pipe nipple two ends, at a distance of 4 meters, about 1 meter of every section solenoid group leader, diameter is 60 millimeters.Wherein each solenoidal coil is on stacked soft magnet core.Solenoid group can tie up on the no magnetic skeleton with nylon rope, also can pour into epoxy resin in the slit of solenoid and skeleton and fix solenoid.Also the solenoid and the skeleton that fix can be put into a no magnetic shell in order to protect solenoid group.

Further, described double solenoid group pipe nipple also comprises sensor assembly and treatment circuit, it is characterized in that: sensor assembly is mainly by three axis fluxgate sensor and 3-axis acceleration sensors, be used for surveying the geomagnetic fieldvector and the gravitational field vector of well depth position, double solenoid group pipe nipple place, to calculate the placing attitude of double solenoid group pipe nipple self.The Z axle of two three-axis sensors is axial along double solenoid group pipe nipple; The X-axis of two sensors is positioned on the same plane, and is parallel to each other; The situation of Y-axis is identical therewith.Treatment circuit is mainly used to the detected signal of processes sensor module, and sends signal to ground installation.

Further, the MWD of above-mentioned repacking also can have following characteristics: sensor assembly is made up of three alternating magnetic field sensors, three axis fluxgate sensors, a 3-axis acceleration sensor and a temperature pick up.Three alternating magnetic field sensors are identical with the mounting means of other three-axis sensor.The alternating magnetic field sensor is used for detecting the magnetic signal of place, MWD position by two different frequencies of double solenoid group pipe nipple generation; Fluxgate sensor, acceleration sensing and temperature pick up are used for detecting place, MWD position geomagnetic fieldvector, gravitational field vector and downhole temperature.Detected signal also is transferred to ground installation by MWD, for adjacent well spacing calculation program provides data.

Further, the adjacent well spacing calculation program of solidifying in little processing in the MWD of described repacking comprises that adjacent-well parallel intervals computational methods and offset well are communicated with computational methods, it is characterized in that: two groups of magnetic signals that can produce according to the double solenoid group pipe nipple that repacking back MWD receives, calculate spacing and the relative bearing of MWD to double solenoid group pipe nipple.Drill bit is known to the distance of MWD, and then can calculate the relative position of drill bit to double solenoid group pipe nipple according to the relative position relation of drill bit and MWD, can determine that in conjunction with the deviational survey data drill bit arrives the relative tertiary location of drilling well or connectivity points at last.

Further, it is similar that described adjacent-well parallel intervals computational methods and present inventor apply for a patent the computational methods of introducing among the 201010127554X, do not repeat them here.

Further, described offset well is communicated with computational methods, it is characterized in that:

Set up rectangular coordinate system as shown in Figure 6, the MWD of repacking is R to the radial spacing of double solenoid group pipe nipple; The MWD of repacking is r to the distance of double solenoid group pipe nipple top solenoid group ₁, be r to the distance of double solenoid group pipe nipple bottom solenoid group ₂The MWD of repacking is Z to the axial spacing of double solenoid group pipe nipple top solenoid group ₂, the axial spacing to the MWD that reequips to double solenoid group pipe nipple bottom solenoid group is Z ₁Two sections solenoidal spacings are D (known).As shown in Figure 7, be the w axle with the bearing of trend of straight well well, the high edge direction of straight well well is the u axle, the v axle is orthogonal to w axle and u axle, sets up the UVW rectangular coordinate system.

With several formulas below the amplitude substitution of three-axle magnetic field induction of the detected two groups of different frequencies of MWD of repacking:

|B _v|＝|B _x|sin(A _hx)+|B _y|cos(A _hx)

|B _w|＝B _z|

|B _Z|＝-(|B _x|cos(A _hx)+|B _y|sin(A _hx))

$\left|B_R\right|=\sqrt{{\left|B_w\right|}^2+{\left|B_v\right|}^2}$

${\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HSA00000134034700051.png"\; state="\{\{state\}\}">C</figure-callout>}}_1\&equiv;\frac{\left|B_{1R}\right|}{\left|B_{1Z}\right|}$

$C_2\&equiv;\frac{\left|B_{2R}\right|}{\left|B_{2Z}\right|}$

$u=\frac{{3C}_1-\sqrt{{{9\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HSA00000134034700051.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}^2+8}}{4}$

$v=\frac{{3C}_2-\sqrt{{{9C}_2}^2+8}}{4}$

$R=\frac{\mathrm{uvd}}{u-v}$

$z_1=\frac{\mathrm{vd}}{u-v}$

$z_2=\frac{\mathrm{ud}}{u-v}$

Wherein: | B _x|, | B _y|, | B _z| represent the amplitude of the magnetic induction intensity waveform that alternating magnetic field sensors X, Y and Z repacking measures.Can try to achieve adjacent-well parallel intervals R and Z ₁, Z ₂With R and Z ₁, Z ₂The substitution following formula:

$\cos \left(2\mathrm{\&alpha;}\right)=\frac{{({2R}^2-Z^2)}^2+{(R^2+Z^2)}^2{\left|B_w\right|}^2-{\left|B_v\right|}^2}{{({2R}^2-Z^2)}^2-{(R^2+Z^2)}^2{\left|B_w\right|}^2{+\left|B_v\right|}^2}$

Can be two sections solenoid place unit vectors

To unit vector

The value α of angle ₁, α ₂, therefore

$\mathrm{\&alpha;}=\frac{1}{2}({\mathrm{\&alpha;}}_1+{\mathrm{\&alpha;}}_2)$

By the above R that tries to achieve, Z ₁, Z ₂Just can determine the phase position relation of the MWD that reequips and double solenoid group pipe nipple with α.Then, in conjunction with the MWD of repacking and the spatial relation of drill bit and double solenoid group pipe nipple and connectivity points, can calculate the relative position of drill bit to connectivity points.

Further, provide the power supply unit of two groups of synchronous square waveform alternating currents in the described ground installation for double solenoid group pipe nipple, it is characterized in that: can connect a reversible switch with field-effect transistors circuit of polarity by 12 volts of small-sized lead-acid accumulators and form.Sense of current periodically reversed in the solenoid coil is controlled by the square wave reference signal that crystal oscillator produces, and the cycle of two groups of alternating currents was respectively 0.4 second and 0.6 second.

This invention adopts double solenoid group pipe nipple as signal source, produces the rotating excitation field of two groups of different frequencies, has the certainty of measurement suitable with RMRS, and is easy to change the intensity of signal source, controls finding range easily; Measure when calculating, need not to drag double solenoid group pipe nipple and just can accurately survey calculating adjacent well spacing and relative bearing, can finish measurement in the short period of time, data analysis simultaneously and adjacent well spacing calculation program are put into the down-hole, only will calculate a spot of necessary data in back and send to ground, therefore save overall drilling time, improved drilling efficiency.This invention can be used for the control that adjacent-well parallel intervals and offset well are communicated with, for the measurement and the control of offset well distance provides the more high-precision instrument of MWD that generally uses than now.

Description of drawings

Fig. 1 is the double solenoid set during drilling electromagnetic guiding distance measurement of the present invention system schematic diagram of working in connected well.

Fig. 2 is the inner spatial arrangement schematic diagram of double solenoid group pipe nipple.

Fig. 3 is double solenoid group pipe nipple excitation ac power waveform figure.

Fig. 4 is that the MWD internal sensor axis direction of down-hole repacking is arranged schematic diagram.

Fig. 5 is the MWD high-level schematic functional block diagram of down-hole repacking.

Fig. 6 is a double solenoid set during drilling electromagnetic guiding distance measurement system range finding computation model.

Fig. 7 (a) and Fig. 7 (b) are the MWD relative bearing schematic diagrames of analyzing double solenoid group pipe nipple and repacking.

Fig. 8 is the double solenoid set during drilling electromagnetic guiding distance measurement of the present invention system schematic diagram of working in two horizontal wells.

Among the figure:

1 positive drilling well 2 is drilling well 3 boring towers 4 cable cars 5 cables

MWD 8 double solenoid group pipe nipples 9 magnetic lines of force of 6 drill bits, 7 repackings

72 3 high accuracy fluxgate sensors of 71 3 alternating magnetic field sensors

73 3 acceleration of gravity sensor 81 solenoid group 82 solenoid group

The specific embodiment

The present invention will be described below in conjunction with drawings and Examples.

As shown in Figure 1, the hardware of double solenoid set during drilling electromagnetic guiding distance measurement system mainly is made up of the MWD of double solenoid group pipe nipple, repacking, ground installation etc.The MWD of repacking is placed in the positive drilling well, is placed on traditional MWD installed position behind the drill bit, surveys the rotating excitation field of two groups of different frequencies that double solenoid group pipe nipple produces in the offset well (drilling well).Then, detected magnetic vector signal calculates the relative position of double solenoid group pipe nipple to the MWD of repacking by data analysis in the MWD down hole processor and adjacent well spacing calculation program, and result of calculation is transferred to ground display system.And then, in conjunction with the position relation of MWD and drill bit, can calculate the relative position of drill bit to the solenoid group pipe nipple.At last, ground display system is shown to the drilling engineer with the position relation of drill bit and double solenoid group pipe nipple with forms such as numeral, literal and figures.The drilling engineer just can accurately control the movement locus of drill bit with reference to the deviational survey data.

As shown in Figure 2, double solenoid group pipe nipple mainly is made up of two sections solenoid group, and the number of every section solenoid group can be adjusted with the distance of detection range, about 1 meter of every section solenoid group leader, diameter is 60 millimeters, and wherein each solenoidal coil is on stacked soft magnet core.Solenoid can tie up on the no magnetic skeleton with nylon rope, also can pour into epoxy resin in the slit of solenoid and skeleton and fix solenoid.Also the solenoid and the skeleton that fix can be put into a no magnetic shell in order to protect solenoid group better.Double solenoid group pipe nipple is lowered in the drilling well by drill string or crawl device, and can move in the drilling well.In two horizontal wells, double solenoid group pipe nipple is approximate be placed on repacking MWD under; In connected well, the approximate connectivity points place that is placed on of the mid point of double solenoid group pipe nipple.

Double solenoid group pipe nipple also comprises sensor assembly and treatment circuit, sensor assembly mainly is made up of three axis fluxgate sensors and 3-axis acceleration sensor, be used for surveying the geomagnetic fieldvector and the gravitational field vector of well depth position, double solenoid group pipe nipple place, to calculate the placing attitude of double solenoid group pipe nipple self.Treatment circuit is mainly used to the detected signal of processes sensor module, and sends signal to ground installation.

Mwd system and traditional MWD of repacking different are to have installed in the downhole sensor module three alternating magnetic field sensors more, are used for detecting the rotating excitation field by the generation of solenoid group pipe nipple.Fluxgate sensor in the sensor assembly, acceleration pass device and temperature pick up is used for detecting earth's magnetic field, gravitational field and the downhole temperature that MWD is in the position respectively.As shown in Figure 4, alternating magnetic field sensor, fluxgate sensor and acceleration transducer are three-axis sensor, and the alternating magnetic field sensor is identical with the mounting means of other three-axis sensor.The Z axle of three sensors and MWD dead in line, X-axis and Y-axis are perpendicular to the MWD axis; The X-axis of three sensors is positioned on the same plane, and is parallel to each other, and the situation and the X-axis of Y-axis are similar.The MWD of repacking is installed in traditional MWD installation site behind the drill bit, try to achieve the position of MWD after, can be by the locus of the position relation calculating drill bit of MWD and drill bit.

In addition, the MWD of repacking compares with traditional MWD and has added a microprocessor, has solidified adjacent well spacing calculation program above, and the magnetic signal that can arrive by analyzing and testing calculates the MWD of repacking and the relative position of double solenoid group pipe nipple.Adjacent well spacing calculation program comprises that adjacent-well parallel intervals computational methods and offset well are communicated with computational methods, it is similar that adjacent-well parallel intervals computational methods and present inventor apply for a patent the computational methods of introducing among the 201010127554X, and offset well is communicated with computational methods and it is characterized in that:

On every section solenoid group of double solenoid group pipe nipple, set up the RQZ rectangular coordinate system, unit vector

Pointing to the bearing of trend of straight well, radially is unit vector with double solenoid group pipe nipple to the MWD that reequips

Direction, unit vector

Be orthogonal to unit vector

With

In the RQZ coordinate system, the magnetic moment of every section solenoid group is

Can get:

$B_R=\frac{\mathrm{<figure-callout\; id="4"\; label="m"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">m</figure-callout>}}{4\mathrm{\&pi;}}\frac{({3R}^2-r^2)\cos \left(A_{\mathrm{mR}}\right)}{r^5}---\left(1\right)$

$B_Q=\frac{\mathrm{<figure-callout\; id="4"\; label="m"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">m</figure-callout>}}{4\mathrm{\&pi;}}\frac{\sin \left(A_{\mathrm{mR}}\right)}{r^3}---\left(2\right)$

$B_Z=\frac{\mathrm{<figure-callout\; id="4"\; label="m"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">m</figure-callout>}}{4\mathrm{\&pi;}}\frac{3\mathrm{RZ}\cos \left(A_{\mathrm{mR}}\right)}{r^5}---\left(3\right)$

As shown in Figure 7, be the w axle with the bearing of trend of straight well well, the high edge direction of straight well well is the u axle, the v axle is orthogonal to w axle and u axle, sets up the UVW rectangular coordinate system.The component of magnetic induction intensity on w axle, v axle is:

B _w＝-B _Rcos(α)-B _Qsin(α) (4)

B _w＝-B _Rsin(α)+B _Qcos(α) (5)

With (1)～(2) formula substitutions (4)～(5) Shi Kede:

$B_w=\frac{\mathrm{<figure-callout\; id="4"\; label="m"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">m</figure-callout>}}{{4\mathrm{\&pi;r}}^3}\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\cos }^2\left(\mathrm{\&alpha;}\right)+{\sin }^2\left(\mathrm{\&alpha;}\right)}\cos (A_{\mathrm{mR}}-P_x)---\left(6\right)$

$\cos \left(P_x\right)=\frac{-\left(\frac{{3R}^2-r^2}{r^2}\right)\cos \left(\mathrm{\&alpha;}\right)}{\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\cos }^2\left(\mathrm{\&alpha;}\right)+{\sin }^2\left(\mathrm{\&alpha;}\right)}}---\left(7\right)$

$\sin \left(P_x\right)=\frac{-\sin \left(\mathrm{\&alpha;}\right)}{\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\cos }^2\left(\mathrm{\&alpha;}\right)+{\sin }^2\left(\mathrm{\&alpha;}\right)}}---\left(8\right)$

$B_v=\frac{\mathrm{<figure-callout\; id="4"\; label="m"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">m</figure-callout>}}{{4\mathrm{\&pi;r}}^3}\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\sin }^2\left(\mathrm{\&alpha;}\right)+{\cos }^2\left(\mathrm{\&alpha;}\right)}\cos (A_{\mathrm{mR}}-P_y)---\left(9\right)$

$\cos \left(P_y\right)=\frac{-\left(\frac{{3R}^2-r^2}{r^2}\right)\sin \left(\mathrm{\&alpha;}\right)}{\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\sin }^2\left(\mathrm{\&alpha;}\right)+{\cos }^2\left(\mathrm{\&alpha;}\right)}}---\left(10\right)$

$\sin \left(P_y\right)=\frac{\cos \left(\mathrm{\&alpha;}\right)}{\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\sin }^2\left(\mathrm{\&alpha;}\right)+{\cos }^2\left(\mathrm{\&alpha;}\right)}}---\left(11\right)$

By (6) formula and (9) Shi Kede:

$\cos \left(2\mathrm{\&alpha;}\right)=\frac{{({2R}^2-Z^2)}^2+{(R^2+Z^2)}^2}{{({2R}^2-Z^2)}^2-{(R^2+Z^2)}^2}\frac{{\left|B_w\right|}^2-{\left|B_v\right|}^2}{{\left|B_w\right|}^2+{\left|B_v\right|}^2}---\left(12\right)$

In the formula: | B _w|, | B _v| represent the amplitude of magnetic induction intensity w, v axle component.

By (1) formula and (3) Shi Kede:

$\left|B_R\right|=\frac{m(2{(R/Z)}^2-1)}{4\mathrm{\&pi;}{Z}^3{(1+{(R/Z)}^2)}^{5/2}}---\left(13\right)$

$\left|B_Z\right|=\frac{3m(R/Z)}{4\mathrm{\&pi;}{Z}^3{(1+{(R/Z)}^2)}^{5/2}}---\left(14\right)$

In the formula: | B _Z|, | B _R| represent the amplitude of magnetic induction intensity component on Z, R axle respectively.

Define at double solenoid group pipe nipple epimere solenoid group place:

$u\&equiv;\frac{R}{Z_2}---\left(15\right)$

$\mathrm{\&alpha;}\&equiv;\frac{\left|B_{1R}\right|}{\left|B_{1Z}\right|}=\frac{{2u}^2-1}{3u}---\left(16\right)$

Again because Z ₂＜D can be solved by (1 6) formula:

$u=\frac{3\mathrm{\&alpha;}-\sqrt{{9\mathrm{\&alpha;}}^2+8}}{4}---\left(17\right)$

Define at double solenoid group pipe nipple hypomere helix tube place:

$v\&equiv;\frac{\mathrm{<figure-callout\; id="1"\; label="R\; Z"\; filenames="HSA00000134034700051.png"\; state="\{\{state\}\}">R</figure-callout>}}{Z_{}}=\frac{R}{Z_2-D}---\left(18\right)$

$\mathrm{\&beta;}\&equiv;\frac{\left|B_{2R}\right|}{{|B}_{2Z}|}=\frac{{2v}^2-1}{3v}---\left(19\right)$

Again because Z ₁＜0, can solve by (19) formula:

$v=\frac{3\mathrm{\&beta;}-\sqrt{{9\mathrm{\&beta;}}^2+8}}{4}---\left(20\right)$

Can get by (15) formula and (18) formula simultaneous:

$R=\frac{\mathrm{uvD}}{v-u}---\left(21\right)$

${\mathrm{<figure-callout\; id="1"\; label="Z"\; filenames="HSA00000134034700051.png"\; state="\{\{state\}\}">Z</figure-callout>}}_1=\frac{\mathrm{uD}}{v-u}---\left(22\right)$

$Z_2=\frac{\mathrm{vD}}{v-u}---\left(23\right)$

With (21)～(23) formula substitutions (14) Shi Kede two sections solenoid group place unit vectors

To unit vector The value α of angle ₁, α ₂, therefore

$\mathrm{\&alpha;}=\frac{1}{2}({\mathrm{\&alpha;}}_1+{\mathrm{\&alpha;}}_2)---\left(24\right)$

By R, Z ₁, Z ₂With angle α, can determine the MWD that reequips relative tertiary location to double solenoid group pipe nipple.Because the relative position relation of the MWD of repacking and the relative position relation of drill bit and connectivity points and double solenoid group pipe nipple is known, therefore can determine the relative tertiary location of drill bit to the relative tertiary location of double solenoid group pipe nipple by the MWD of repacking to connectivity points.

Ground installation mainly is two groups of synchronous ACs to be provided and to receive the signal that double solenoid group pipe nipple inner sensor is surveyed for double solenoid group pipe nipple.As shown in Figure 3, every group of alternating current comprises two synchronous ACs, the waveform of two synchronizing currents differs four/one-period in time, and the solenoid that electric current is installed for same direction provides electric current, and another electric current provides electric current for another row solenoid with this direction quadrature.The waveform of electric current can one be sinusoidal, and another is a cosine, can all be square wave also, and this is because the Fourier component of two square waves also is sine and cosine wave.Usually, it is easy more than producing pure sine and cosine alternating current wave to produce square alternating current, so often adopt square wave alternating-current in real world applications.Then, detected magnetic signal data are carried out Fourier analysis, try to achieve the sine and cosine component of magnetic signal, utilize the sine and cosine component of trying to achieve to calculate the relative tertiary location of the MWD of repacking to solenoid group.The period of change of two groups of alternating currents was respectively 0.4 second and 0.6 second.

Each functional module of the MWD of repacking as shown in Figure 5.Exciting circuit is each sensor power supply of MWD, and alternating magnetic field sensor, fluxgate sensor and the acceleration transducer in the MWD detects rotating excitation field, earth's magnetic field and the gravitational field that the solenoid group pipe nipple produces respectively.These detected signals are after signal amplifier amplifies, become data signal through analog-to-digital conversion circuit, pass to the microprocessor of down-hole, by the MWD of the data analysis in the microprocessor and adjacent well spacing calculation program analytical calculation repacking relative position to the double solenoid group, result of calculation is transferred to ground display system in coding back, down-hole by cable or mud-pulse, ground display system extracts useful data after with signal decoding, in conjunction with related algorithm, calculate the relative position of drill bit and drilling well or connectivity points.Then, be shown to the drilling engineer with forms such as numeral, literal and figures.

Among the present invention, form the equivalent magnetic moment that produces two rotations by two sections solenoids that are positioned at double solenoid group pipe nipple two ends, therefore the angular velocity differences of two equivalent magnetic moment rotations can detect the magnetic field of two groups of different frequencies at sensing point.The rotating excitation field probe is converted by traditional MWD, is easy to realize.Double solenoid set during drilling electromagnetic guiding distance measurement of the present invention system has the certainty of measurement suitable with RMRS, and is easy to change the intensity of signal source, controls finding range easily, can finish measurement in the short period of time simultaneously, has improved whole drilling efficiency.The present invention provides a kind of guiding accuracy height, finding range is wide, Measuring Time is short, simple in structure measurement while drilling instrument for adjacent well spacing control.

Claims (10)

1. a double solenoid set during drilling electromagnetic guiding distance measurement system is characterized in that this system mainly is made up of MWD, ground display system and the ground installation etc. of double solenoid group pipe nipple, repacking.

2. double solenoid group pipe nipple as claimed in claim 1 is characterized in that, mainly forms by two sections solenoid group and sensor assembly, and 5～6 meters of total lengths, diameter is 60 millimeters, is lowered in the drilling well by drilling rod or crawl device.

3. two sections solenoid group as claimed in claim 2 is characterized in that, every section solenoid group is made up of the mutually orthogonal solenoid of two row again, and long about 1 meter, diameter is 60 millimeters, and two sections solenoid group lay respectively at the two ends of double solenoid group pipe nipple.In order to protect solenoid group, can in the slit of solenoid and no magnetic skeleton, pour into epoxy resin, put into a no magnetic shell.

4. sensor assembly as claimed in claim 2, it is characterized in that, mainly form by three axis fluxgate sensors and 3-axis acceleration sensor, be used for surveying the geomagnetic fieldvector and the gravitational field vector of well depth position, double solenoid group pipe nipple place, to calculate the placing attitude of double solenoid group pipe nipple self.

5. the MWD of repacking as claimed in claim 1 is characterized in that, downhole sensor module and traditional MWD many three alternating magnetic field sensor and microprocessor.The MWD of repacking is installed in traditional MWD position behind the drill bit.

6. microprocessor as claimed in claim 5, it is characterized in that, be solidified with data analysis and adjacent well spacing calculation program above the microprocessor, adjacent well spacing calculation program comprises that adjacent-well parallel intervals computational methods and offset well are communicated with computational methods, can calculate the relative position of the MWD of repacking by the magnetic signal of the detected two groups of different frequencies of analyte sensors to double solenoid group pipe nipple.

7. offset well as claimed in claim 6 is communicated with computational methods, it is characterized in that, with several formulas below the amplitude substitution of the three-axle magnetic field induction of the detected two groups of different frequencies of MWD of repacking:

|B _v|＝|B _x|sin(A _hx)+|B _y|cos(A _hx)

|B _w|＝|B _z|

|B _z|＝-(|B _x|cos(A _hx)+|B _y|sin(A _hx))

$\left|B_R\right|=\sqrt{{\left|B_w\right|}^2+{\left|B_v\right|}^2}$

$C_1\&equiv;\frac{\left|B_{1R}\right|}{\left|B_{1Z}\right|}$

$C_2\&equiv;\frac{\left|B_{2R}\right|}{\left|B_{2Z}\right|}$

$u=\frac{{3C}_1-\sqrt{9{C_1}^2+8}}{4}$

$v=\frac{3C_2-\sqrt{{{9C}_2}^2+8}}{4}$

$R=\frac{\mathrm{uvd}}{u-v}$

$z_1=\frac{\mathrm{vd}}{u-v}$

$z_2=\frac{\mathrm{ud}}{u-v}$

Wherein: | B _x|, | B _y|, | B _z| represent the amplitude of the magnetic induction intensity waveform that alternating magnetic field sensors X, Y and Z repacking measures.Can try to achieve adjacent-well parallel intervals R and Z ₁, Z ₂With R and Z ₁, Z ₂The substitution following formula:

$\cos \left(2\mathrm{\&alpha;}\right)=\frac{{({2R}^2-Z^2)}^2+{(R^2+Z^2)}^2{\left|B_w\right|}^2-{\left|B_v\right|}^2}{{({2R}^2-Z^2)}^2-{(R^2+Z^2)}^2{\left|B_w\right|}^2+{\left|B_v\right|}^2}$

Can be two sections solenoid place unit vectors

To unit vector The value α of angle ₁, α ₂, therefore

$\mathrm{\&alpha;}=\frac{1}{2}({\mathrm{\&alpha;}}_1+{\mathrm{\&alpha;}}_2)$

By the above R that tries to achieve, Z ₁, Z ₂Just can determine the phase position relation of the MWD that reequips and double solenoid group pipe nipple with α.Then, in conjunction with the MWD of repacking and the spatial relation of drill bit and double solenoid group pipe nipple and connectivity points, can calculate the relative position of drill bit to connectivity points.

8. ground display system as claimed in claim 1 is characterized in that, by suitable calculating, with forms such as numeral, literal and figures the relative position of offset well parallel-segment or drill bit is shown to the drilling engineer to the relative position of connectivity points.

9. ground installation as claimed in claim 1 is characterized in that, mainly comprises surface power supply equipment and signal receiver.Surface power supply equipment is to provide two groups of synchronous square wave alternating-currents for double solenoid group pipe nipple; Signal receiver is mainly used to receive the signal that double solenoid group pipe nipple inner sensor is surveyed.

10. two groups of synchronous square wave alternating-currents as claimed in claim 9, it is characterized in that, the period of change of two groups of alternating currents was respectively 0.4 second and 0.6 second, every group of alternating current all is made up of two synchronous ACs, the waveform of these two synchronizing currents differs four/one-period in time, the solenoid that electric current is installed for same direction provides electric current, and another electric current provides electric current for another row solenoid with this direction quadrature.

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