CN101852078B - 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 electromagnetic distance measurement guide system for double solenoid set during drilling

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 the subterranean resource such as oil, natural gas and coal bed gas, the complex structural wells such as two horizontal wells, connected well, U-shaped 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 substantially satisfy above require with brill electromagnetic guide system (such 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 ", although this system has larger finding range, but measurement and data transmission period are longer, have wasted overall drilling time.For saving measurement and the data transmission period of detection system, improve drilling efficiency, the special research and design of present inventor " a kind of electromagnetic distance measurement guide system for double solenoid set during drilling ", 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 larger 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 in the short period of time measurement.Simultaneously, data analysis and adjacent well spacing calculation program can be put into the down-hole, and a small amount of necessary data sends to ground after only will calculating, and has saved the data transmitting time.

Summary of the invention

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

In order to survey spacing and the relative bearing of offset well with probing, the invention provides a kind of electromagnetic distance measurement guide system for double solenoid set during drilling, 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, its Main Function are the rotating excitation fields that produces two different frequencies at sensing point, are the signal sources of this electromagnetic survey system, determine 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 axle alternating magnetic field sensors be solidified with data analysis and the microprocessor of adjacent well spacing calculation program forms, 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 geomagnetic fieldvector and the gravitational field vector at place, MWD position.Data analysis and adjacent well spacing calculation program, its effect is signal and the MWD that calculates repacking and spacing and the relative bearing of double solenoid group pipe nipple that analyte sensors detects, calculate simultaneously hole angle and the azimuth at the well depth place, MWD place of repacking, 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 that with forms such as numeral, literal and figures drill bit is to the relative tertiary location of offset well.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 in order to 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 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 electromagnetic distance measurement guide system for double solenoid set during drilling also can have following characteristics: described double solenoid group pipe nipple mainly comprises two sections solenoid group, every section solenoid group is comprised 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 to without on the 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 one without the 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 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 axis 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 signal that the processes sensor module detects, and sends signal to ground installation.

Further, the MWD of above-mentioned repacking also can have following characteristics: sensor assembly is comprised of three axle alternating magnetic field sensors, three axis fluxgate sensors, a 3-axis acceleration sensor and a temperature pick up.Three axle alternating magnetic field sensors are identical with the mounting means of other three-axis sensor.The alternating magnetic field sensor is used for detecting place, MWD position by the magnetic signal of 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.The signal that detects 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 MWD after the repacking receives, calculate MWD to spacing and the relative bearing of double solenoid group pipe nipple.Drill bit is known to the distance of MWD, and then can calculate drill bit to the relative position of 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 as shown in Figure 6 rectangular coordinate system, 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, take the bearing of trend of straight well well as the w axle, the high edge direction of straight well well is the u axle, and 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 the three-axle magnetic field induction of two groups of different frequencies detecting 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))

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

$C_1\≡\frac{\left|B_{1R}\right|}{\left|B_{1Z}\right|}$

${\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">C</figure-callout>}}_2\&equiv;\frac{\left|B_{2R}\right|}{\left|B_{2Z}\right|}$

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

$v=\frac{{3C}_2-\sqrt{{{9\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">C</figure-callout>}}_2}^2+8}}{4}$

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

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

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

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 axis detect.Can try to achieve adjacent-well parallel intervals R and Z ₁, Z ₂With R and Z ₁, Z ₂The substitution following formula:

$\cos \left(2\mathrm{\&alpha;}\right)=\frac{{({2R}^2-Z^2)}^2+{({\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">R</figure-callout>}}^2+Z^2)}^2{\left|B_w\right|}^2-{\left|B_v\right|}^2}{{({2R}^2-Z^2)}^2-{({\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">R</figure-callout>}}^2+Z^2)}^2{\left|B_w\right|}^2{+\left|B_v\right|}^2}$

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 drill bit to the relative position of 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 the electric circuit constitute of polarity by 12 volts of small-size lead-acid accumulators.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 easily finding range; 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 in the short period of time measurement, simultaneously data analysis and adjacent well spacing calculation program are put into the down-hole, a small amount of necessary data sends to ground after only will calculating, 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 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 electromagnetic distance measurement guide system for double solenoid set during drilling of the present invention 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 electromagnetic distance measurement guide system for double solenoid set during drilling 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 electromagnetic distance measurement guide system for double solenoid set during drilling of the present invention 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

71 3 axle alternating magnetic field sensors, 72 3 axle high-precision fluxgate sensors

73 3 axle Gravity accelerometers, 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 electromagnetic distance measurement guide system for double solenoid set during drilling mainly is comprised 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, the magnetic vector signal that detects calculates double solenoid group pipe nipple to the relative position of the MWD of repacking by the 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 relationship of MWD and drill bit, can calculate drill bit to the relative position of solenoid group pipe nipple.At last, ground display system is shown to the drilling engineer with the position relationship 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 comprised 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 to without on the 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 one without the magnetic shell in order to protect better solenoid group.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 comprised of three axis fluxgate sensors and 3-axis acceleration sensor, be used for surveying 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 signal that the processes sensor module detects, and sends signal to ground installation.

Mwd system and traditional MWD of repacking different are to have installed in the downhole sensor module three axle 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 respectively detecting earth's magnetic field, gravitational field and the downhole temperature that MWD is in the position.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 axis 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 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 relationship calculating drill bit of MWD and drill bit.

In addition, the MWD of repacking compares with traditional MWD and has added a microprocessor, and the above has been solidified adjacent well spacing calculation program, 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:

Every section solenoid group at double solenoid group pipe nipple is set up RQZ rectangular coordinate system, unit vector Point to the bearing of trend of straight well, take double solenoid group pipe nipple to the MWD that reequips radially as unit vector

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:

$B_R=\frac{m}{4\mathrm{\&pi;}}\frac{({3R}^2-r^2)\cos \left(A_{\mathrm{mR}}\right)}{r^5}---\left(1\right)$

$B_Q=\frac{m}{4\mathrm{\&pi;}}\frac{\sin \left(A_{\mathrm{mR}}\right)}{r^3}---\left(2\right)$

$B_Z=\frac{m}{4\mathrm{\&pi;}}\frac{3\mathrm{RZ}\cos \left(A_{\mathrm{mR}}\right)}{r^5}---\left(3\right)$

As shown in Figure 7, take the bearing of trend of straight well well as the w axle, the high edge direction of straight well well is the u axle, and 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:

$B_w=\frac{m}{{4\mathrm{\&pi;r}}^3}\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\cos }^2\left(\mathrm{\&alpha;}\right)+{\sin }^2\left(\mathrm{\&alpha;}\right)}\cos (A_{\mathrm{mR}}-P_x)---\left(6\right)$

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

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

$B_v=\frac{m}{{4\mathrm{\&pi;r}}^3}\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\sin }^2\left(\mathrm{\&alpha;}\right)+{\cos }^2\left(\mathrm{\&alpha;}\right)}\cos (A_{\mathrm{mR}}-P_y)---\left(9\right)$

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

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

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

$\cos \left(2\mathrm{\&alpha;}\right)=\frac{{({2R}^2-Z^2)}^2+{({\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">R</figure-callout>}}^2+Z^2)}^2}{{({2R}^2-Z^2)}^2-{({\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">R</figure-callout>}}^2+Z^2)}^2}\frac{{\left|B_w\right|}^2-{\left|B_v\right|}^2}{{\left|B_w\right|}^2+{\left|B_v\right|}^2}---\left(12\right)$

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 respectively the amplitude of magnetic induction intensity component on Z, R axle.

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:

$v\&equiv;\frac{R}{Z_1}=\frac{R}{Z_2-D}---\left(18\right)$

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

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

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

Can be got by (15) formula and (18) formula simultaneous:

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

$Z_1=\frac{\mathrm{uD}}{v-u}---\left(22\right)$

${\mathrm{<figure-callout\; id="2"\; label="Z"\; filenames="HSA00000134034700011.png"\; state="\{\{state\}\}">Z</figure-callout>}}_2=\frac{\mathrm{vD}}{v-u}---\left(23\right)$

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 that the MWD that reequips is to the relative tertiary location of 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 that to the relative tertiary location of double solenoid group pipe nipple drill bit is to the relative tertiary location of connectivity points by the MWD of repacking.

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 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 the normal square wave alternating-current that adopts is electric in real world applications.Then, the magnetic signal data that detect 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 MWD of repacking to the relative tertiary location of 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 respectively rotating excitation field, earth's magnetic field and the gravitational field that the solenoid group pipe nipple produces.These signals that detect 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 the adjacent well spacing calculation program analytical calculation repacking relative position to the double solenoid group, result of calculation is transferred to ground display system by cable or mud-pulse behind the coding of down-hole, 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, the angular velocity of two equivalent magnetic moment rotations is different, therefore 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.Electromagnetic distance measurement guide system for double solenoid set during drilling of the present invention has the certainty of measurement suitable with RMRS, and is easy to change the intensity of signal source, controls easily finding range, can finish in the short period of time measurement simultaneously, has improved whole drilling efficiency.The present invention provides the measurement while drilling instrument that a kind of guiding accuracy is high, finding range is wide, Measuring Time is short, simple in structure for adjacent well spacing control.

Claims (8)

1. electromagnetic distance measurement guide system for double solenoid set during drilling, it is characterized in that: this system mainly is comprised of MWD, ground display system and the ground installation of double solenoid group pipe nipple, repacking; The MWD of described repacking mainly by traditional MWD, three axle alternating magnetic field sensors be solidified with data analysis and the microprocessor of adjacent well spacing calculation program forms, is installed in the residing position of traditional MWD.

2. electromagnetic distance measurement guide system for double solenoid set during drilling as claimed in claim 1, it is characterized in that: double solenoid group pipe nipple mainly is comprised of two sections solenoid group and sensor assembly, 5～6 meters of total lengths, diameter are 60 millimeters, are lowered in the drilling well by drilling rod or crawl device.

3. electromagnetic distance measurement guide system for double solenoid set during drilling as claimed in claim 2, it is characterized in that: every section solenoid group in described two sections solenoid group is comprised of the mutually orthogonal solenoid of two row again, long 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, in solenoid and the slit without the magnetic skeleton, pour into epoxy resin, put into one without the magnetic shell.

4. electromagnetic distance measurement guide system for double solenoid set during drilling as claimed in claim 2, it is characterized in that: described sensor assembly mainly is comprised of three axis fluxgate sensors and 3-axis acceleration sensor, be used for surveying 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. electromagnetic distance measurement guide system for double solenoid set during drilling as claimed in claim 1, it is characterized in that: be solidified with data analysis and adjacent well spacing calculation program above the described microprocessor, adjacent well spacing calculation program comprises that adjacent-well parallel intervals computational methods and offset well are communicated with computational methods, the magnetic signal of two groups of different frequencies that detect by analyte sensors calculates the MWD of repacking to the relative position of double solenoid group pipe nipple.

6. electromagnetic distance measurement guide system for double solenoid set during drilling as claimed in claim 1, it is characterized in that: described ground display system is by suitable calculating, with numeral, literal and graphic form the relative position of offset well parallel-segment or drill bit is shown to the drilling engineer to the relative position of connectivity points.

7. electromagnetic distance measurement guide system for double solenoid set during drilling as claimed in claim 1, it is characterized in that: described ground installation mainly comprises surface power supply equipment and signal receiver; Surface power supply equipment is to provide two groups of synchronous square wave alternating-current electricity 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.

8. electromagnetic distance measurement guide system for double solenoid set during drilling as claimed in claim 7, it is characterized in that: the period of change of described two groups of synchronous square wave alternating-current electricity was respectively 0.4 second and 0.6 second, every prescription alternating current wave all is comprised of two synchronous square wave alternating-current electricity, the waveform of these two synchronous square wave 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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