CN101798918B - Method for determining relative spatial position of adjacent well parallel segment - Google Patents

Abstract

The invention discloses a calculation method used in MWD (measurement while drilling) electromagnetic detection of parallel distance of adjacent wells, which mainly comprises a rotary magnetic pup joint surrounding space magnetic field calculating model, adjacent well parallel distance algorithm and the like. The calculation method is characterized in that the calculation formula of the magnetic induction intensity of a distant field of the surrounding space of the rotary magnetic pup joint is worked out by taking a rotary magnetic pup joint as a rotary magnetic dipole, and according to a rotary magnetic dipole algorithm model, the invention provides an MWD electromagnetic detection system applied to the distance measurement instruction oriented algorithm of the parallel sections of the adjacent wells. When the adjacent well parallel distance MWD electromagnetic detection system applies the algorithm to calculate the relative spatial positions of the parallel sections of the adjacent wells, the drill is unnecessary to have certain drilling footage, so the measurement calculation can be finished within a short time. Meanwhile, the algorithm can be solidified to a downhole probe tube with double magnetic sensors of the adjacent well parallel distance MWD electromagnetic detection system and the operator only needs to send the calculation result to the ground, thus saving the time for transmitting the data.

Description

A kind of method of relative tertiary location of definite offset well parallel-segment

Technical field

The present invention is a kind of computational methods of while drilling of adjacent-well parallel intervals electromagnetic surveying, belongs to subterranean resource drilling field of engineering technology.

Background technology

In oil, natural gas and coal-bed gas exploitation, the complex structural wells such as two horizontal wells, directional 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.In addition, though abroad developed can substantially satisfy above require with brill electromagnetic guide system, its core technology is still maintained secrecy and is monopolized.Therefore, the special research and design of present inventor " a kind of electromagnetic surveying system while drilling of adjacent-well parallel intervals " (doing in addition patent application), this invention namely is the core algorithm of this system, but the relative tertiary location of accurate Calculation offset well parallel-segment.

Electromagnetic surveying system while drilling of adjacent-well parallel intervals comprises that mainly magnetic short section, the two Magnetic Sensor measuring instruments in down-hole, adjacent-well parallel intervals computing system and ground display system form.The two ends that magnetic short section is comprised of non magnetic drill collar and some permanent magnets etc. are the signal sources of this electromagnetic survey system with the hollow circular cylinder of the API standard shape of the mouth as one speaks, directly follow in the drill bit back.The two Magnetic Sensor measuring instruments in down-hole mainly are comprised of the two Magnetic Sensor inserting tubes in down-hole and terrestrial interface case.The two Magnetic Sensor inserting tubes in down-hole mainly comprise two alternating magnetic field sensors, fluxgate sensor, acceleration transducer, a temperature pick up and are solidified with the single-chip microcomputer of adjacent-well parallel intervals computing system, its Main Function is the magnetic vector signal that detects magnetic short section, and two groups of magnetic signal data are passed in the single-chip microcomputer, through the adjacent-well parallel intervals computing system, obtain the relative tertiary location data of offset well parallel-segment.Then, calculated data is sent to ground display system.

When utilizing electromagnetic surveying system while drilling of adjacent-well parallel intervals to carry out steerable drilling, magnetic short section is closelyed follow in the drill bit back, the two Magnetic Sensor measuring instruments in down-hole are lowered into correct position in the drilling well by drilling rod or the front cable that is connected to crawl device, then power-on is surveyed the magnetic signal that is produced by the rotary magnetic pipe nipple.According to this systematic survey with calculate adjacent-well parallel intervals and the relative bearing data obtain, and in conjunction with conventional MWD survey data, engineers and technicians can control the drill bit movement track effectively, so that accurately adjacent the and parallel-segment of control is crept into a determining deviation.

Summary of the invention

The object of the invention is to the magnetic signal that receives according to the two Magnetic Sensor exploring tube sensors in down-hole, calculate the relative position of magnetic short section and down-hole pair Magnetic Sensor inserting tubes, and then the relative tertiary location of definite offset well parallel-segment.

The operating principle of electromagnetic surveying system while drilling of adjacent-well parallel intervals as shown in Figure 1, the present invention is the core algorithm of this system, and a kind of computational methods of definite offset well parallel-segment relative tertiary location are provided, and comprises the following steps:

Step 1 is extracted the hole condition information of drilling well and positive drilling well.Drilling well and just the well track metrical information of drilling well; Drilling well and the just mouth coordinate of drilling well; Brill dish level (KB) and the EGL (GL) of drilling well and positive drilling well; The casing programme of drilling well.

Step 2, the hole condition information of the drilling well that processing is extracted and positive drilling well.

Step 3 is set up rotary magnetic pipe nipple surrounding space magnetic induction intensity and is calculated model.

Step 4 is measured the equivalent magnetic moment of magnetic short section and is provided the possible excursion of down-hole magnetic short section equivalence magnetic moment on the earth's surface.

Step 5 according to the adjacent-well parallel intervals of estimating, is lowered to drilling well to correct position with drilling rod or crawl device with the two Magnetic Sensor inserting tubes in down-hole.Magnetic short section is lowered between two Magnetic Sensor inserting tube both ends, the magnetic short section of the mid point that preferably makes two Magnetic Sensor inserting tubes in the upper upright drilling well.

Step 6, the relative tertiary location data of the offset well parallel-segment that the two Magnetic Sensor inserting tubes in extraction down-hole calculate.

Step 7, utilize the two Magnetic Sensor inserting tube calculated datas in hole condition information, down-hole, magnetic short section equivalence magnetic moment after the described processing, calculate the two Magnetic Sensor inserting tubes in down-hole and the locus of magnetic short section in positive drilling well-head coordinate system, and then the relative tertiary location of definite offset well parallel-segment in positive drilling well-head coordinate system.

Step 8 according to result of calculation, is adjusted tool-face and is continued to creep into the next position.

Step 9 according to the adjacent-well parallel intervals that calculates, is lowered into the next position with drilling rod or crawl device with the two Magnetic Sensor inserting tubes in down-hole, the magnetic short section of the mid point that equally as far as possible makes two Magnetic Sensor inserting tubes in the upper upright drilling well.

Step 10 forwards step 6 to, so is circulated to and has bored.

Described step 2 comprises:

Step 21, according to positive drilling well and brill dish level (KB) and the EGL (GL) of drilling well, calculated level well brill dish level than straight well brill dish level high what or how much hang down.

Step 22 determines that hole trajectory data is with respect to brill dish level or EGL.

Step 23 aligns the side-play amount of drilling well-head mutually according to positive drilling well and drilling well-head coordinate Calculation drilling well-head.

Step 24 adds or deducts described side-play amount in the true vertical depth (TVD) of two Magnetic Sensor inserting tubes and connectivity points, northern coordinate (N), eastern coordinate (E) data.

Described step 3 comprises:

As shown in Figure 2, when calculating rotary magnetic pipe nipple surrounding space far field magnetic induction intensity, can regard the rotary magnetic pipe nipple as rotating magnetic dipole, its surrounding space far field magnetic induction density B is calculated as follows:

$B=\frac{1}{4\mathrm{\π}}(\frac{3(m\·r)r}{r^5}-\frac{m}{r^3})$

In rectangular coordinate system, $m={\hat{e}}_{x}m\cos \mathrm{\θ}+{\hat{e}}_{y}m\sin \mathrm{\θ},$ $r={\hat{e}}_{x}x+{\hat{e}}_{y}y+{\hat{e}}_{z}z,$ Three axle component B of magnetic induction intensity _x, B _y, B _zBe calculated as follows:

$\left\{\begin{array}{c}{B}_x=\frac{1}{4\mathrm{\π}}(\frac{3(\mathrm{mx}\sin \mathrm{\θ}+\mathrm{mz}\cos \mathrm{\θ})x}{{(x^2+y^2+z^2)}^{5/2}}-\frac{m\cos \mathrm{\θ}}{{(x^2+y^2+z^2)}^{3/2}})\\ B_y=\frac{1}{4\mathrm{\π}}(\frac{3(\mathrm{mx}\sin \mathrm{\θ}+\mathrm{mz}\cos \mathrm{\θ})y}{{(x^2+y^2+z^2)}^{5/2}}-\frac{m\sin \mathrm{\θ}}{{(x^2+y^2+z^2)}^{3/2}})\\ B_z=\frac{1}{4\mathrm{\π}}\frac{3(\mathrm{mx}\sin \mathrm{\θ}+\mathrm{mz}\cos \mathrm{\θ})z}{{(x^2+y^2+z^2)}^{5/2}}\end{array}\right.$

In the formula: m is the equivalent magnetic moment of magnetic short section.

Described step 6 comprises:

According to described computation model, set up as shown in Figure 3 coordinate system.As shown in Figure 3, magnetic short section is R to the radial spacing of two Magnetic Sensor inserting tubes; Magnetic short section is r to the distance of the magnetic field sensor on two Magnetic Sensor inserting tube tops ₁, be r to the distance of the magnetic field sensor of two Magnetic Sensor inserting tube ends ₂Magnetic short section is z to the axial spacing of the magnetic field sensor on two Magnetic Sensor inserting tube tops ₁, be z to the axial spacing of the magnetic field sensor of two Magnetic Sensor inserting tube ends ₂The spacing of two magnetic field sensors is d (known).

As shown in Figure 4, unit vector

Represent X, the Y-axis of three axle alternating magnetic field sensors; Unit vector

Represent the direction of constantly magnetic short section equivalence of t magnetic moment; Unit vector

Represent magnetic short section to two Magnetic Sensor inserting tubes radially; Unit vector

Be orthogonal to the axial of two Magnetic Sensor inserting tubes, be orthogonal to simultaneously unit vector

Represent the high edge direction of well-drilling borehole; AmR represents unit vector

To unit vector

Angle; AhR represents the angle that radially is wired to of magnetic short section and two Magnetic Sensor inserting tubes; Ahx represents well flash Hs to unit vector

Angle; AxR represents unit vector

To unit vector

Angle.

As shown in Figure 3, Figure 4, requiring the relative tertiary location of offset well parallel-segment, mainly is to determine that magnetic short section is to radial spacing R and the included angle A hR of two Magnetic Sensor inserting tubes.

In coordinate system shown in Figure 3:

$B_R=\frac{m}{4\mathrm{\π}}\frac{(3R^2-r^2)\cos \left(\mathrm{AmR}\right)}{r^5}$

$B_q=\frac{m}{4\mathrm{\π}}\frac{\sin \left(\mathrm{AmR}\right)}{r^3}$

$B_z=\frac{m}{4\mathrm{\π}}\frac{3\mathrm{Rz}\cos \left(\mathrm{AmR}\right)}{r^5}$

$\left|B_R\right|=\sqrt{{\left|B_x\right|}^2+{\left|B_y\right|}^2}=\frac{m(2{(R/z)}^2-1)}{4\mathrm{\π}{z}^3{(1+{(R/z)}^2)}^{5/2}}$

$\left|B_z\right|=\frac{3\mathrm{mRz}}{4\mathrm{\π}{(R^2+z^2)}^{5/2}}=\frac{3m(R/z)}{4\mathrm{\π}{z}^3{(1+{(R/z)}^2)}^{5/2}}$

In the formula: | B _z| represent the amplitude of the magnetic induction intensity waveform that alternating magnetic field sensor Z axis detects, | B _R| represent the amplitude of radial magnetic field induction waveform.

As shown in Figure 4, the magnetic induction intensity component that detects of two Magnetic Sensor inserting tube three axle alternating magnetic field sensors X, Y-axis is:

$B_x=\frac{m}{4\mathrm{\π}{r}^3}\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\cos }^2\left(\mathrm{AxR}\right)+{\sin }^2\left(\mathrm{AxR}\right)}\cos (\mathrm{AmR}-P_x)$

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

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

$B_y=\frac{m}{4\mathrm{\π}{r}^3}\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\sin }^2\left(\mathrm{AxR}\right)+{\cos }^2\left(\mathrm{AxR}\right)}\cos (\mathrm{AmR}-P_y)$

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

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

Several formulas below the amplitude substitution of the three-axle magnetic field induction waveform that two alternating magnetic field sensors are detected:

$\left|B_R\right|=\sqrt{{\left|B_x\right|}^2+{\left|B_y\right|}^2}$

$\mathrm{\α}\≡\frac{\left|B_{1R}\right|}{\left|B_{1z}\right|}$

$\mathrm{\β}\≡\frac{\left|B_{2R}\right|}{\left|B_{2z}\right|}$

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

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

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

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

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

Can try to achieve adjacent-well parallel intervals R and z ₁, z ₂With R and z ₁, z ₂The substitution following formula

$\cos \left(2\mathrm{AxR}\right)=\frac{{({2R}^2-z^2)}^2+{(R^2+z^2)}^2}{{({2R}^2-z^2)}^2-{(R^2+z^2)}^2}\frac{{\left|B_x\right|}^2-{\left|B_y\right|}^2}{{\left|B_x\right|}^2+{\left|B_y\right|}^2}$

In the formula: | B _x|, | B _y| represent the amplitude of the magnetic induction intensity waveform that alternating magnetic field sensors X, Y-axis detect.

Can be in two alternating magnetic field sensor place unit vectors

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

$\mathrm{AxR}=\frac{1}{2}({\mathrm{AxR}}_1+{\mathrm{AxR}}_2).$

Obviously, the AxR that more than obtains can not determine it in [0, π] scope, is being in [π, 0] scope also.This is not a problem in actual applications, because its scope can be determined by included angle A hx.Included angle A hx can be recorded by 3-axis acceleration sensor, therefore, the relative bearing of offset well parallel-segment, namely magnetic short section arrives the angle of well-drilling borehole flash

AhR＝π-Ahx-AxR。

Thereby, determined that magnetic short section puts to the space of two Magnetic Sensor inserting tubes, and then also just determined the relative tertiary location of offset well parallel-segment.

Description of drawings

Fig. 1 is electromagnetic surveying system while drilling of adjacent-well parallel intervals work schematic diagram.

Fig. 2 is that rotary magnetic pipe nipple surrounding space magnetic induction intensity calculates model.

Fig. 3 is electromagnetic surveying system while drilling of adjacent-well parallel intervals range finding computation model.

Fig. 4 analyzes offset well parallel-segment relative bearing schematic diagram.

Fig. 5 is positive drilling well and drilling well-head information diagram.

Among the figure:

1 positive drilling well 2 is drilling well 3 boring towers 4 cables 5 drill bits

Two Magnetic Sensor inserting tube 8 ground installations 61 magnetic lines of force in 6 magnetic short sections, 7 down-holes

71 3 axle high accuracy alternating magnetic field sensors, 72 3 axle high accuracy alternating magnetic field sensors

The specific embodiment

The present invention can receive two groups of magnetic signals that magnetic short section produces based on two Magnetic Sensor inserting tubes, determines the relative tertiary location of offset well parallel-segment, and its computational methods comprise following key step:

Step 1 is extracted the hole condition information of drilling well and positive drilling well.Drilling well and just the well track metrical information of drilling well; Drilling well and the just mouth coordinate of drilling well; Brill dish level (KB) and the EGL (GL) of drilling well and positive drilling well; The casing programme of drilling well.

Step 2, the hole condition information of the drilling well that processing is extracted and positive drilling well.

After extracting the hole condition information of drilling well and positive drilling well, as with reference to setting up global coordinate system, then calculate the mouth coordinate of drilling well take positive drilling well-head position.Correct for what guarantee to calculate, be to draw as shown in Figure 5 schematic diagram at last, mark the mouth coordinate of drilling well and positive drilling well at figure.Specific algorithm is as follows:

According to brill dish level (KB) and the EGL (GL) with positive drilling well of drilling well, calculate positive drilling well brill dish level than drilling well brill dish level high what or how much low.

Determine that hole trajectory data is with respect to brill dish level or EGL.

Align mutually the skew of drilling well-head according to drilling well and positive drilling well-head coordinate Calculation drilling well-head.

Add or deduct described side-play amount in the true vertical depth (TVD) of two Magnetic Sensor inserting tubes, northern coordinate (N), eastern coordinate (E) data.

Step 3 is set up rotary magnetic pipe nipple surrounding space magnetic induction intensity and is calculated model.

Provide permanent magnetic field by permanent magnet in the magnetic short section.The cylindrical permanent magnet of different numbers in some way in magnetic short section storehouse form the permanent magnetic field of varying strength together, this design not only is easy to change the intensity in magnetic short section magnetic field, and economical, the intensity of reduction magnetic short section that again can be as far as possible little.The calculating that distributes for the cylindrical permanent magnet space magnetic field has the methods such as Magnetic dipole method, Method of Equivalent Magnetic Charge, finite element simulation.Wherein Magnetic dipole method is the simplest, and the magnetic field range that will survey in electromagnetic surveying system while drilling of adjacent-well parallel intervals satisfies the requirement that Magnetic dipole method is adapted to calculate the far field beyond distance magnetic short section 4m.

As shown in Figure 2, magnetic short section surrounding space far field magnetic induction density B is calculated as follows:

$B=\frac{1}{4\mathrm{\π}}(\frac{3(m\·r)r}{r^5}-\frac{m}{r^3})---\left(1\right)$

In rectangular coordinate system, three axle component B of magnetic induction intensity _x, B _y, B _zBe calculated as follows:

$\left\{\begin{array}{c}{B}_x=\frac{1}{4\mathrm{\π}}(\frac{3(\mathrm{mx}\sin \mathrm{\θ}+\mathrm{mz}\cos \mathrm{\θ})x}{{(x^2+y^2+z^2)}^{5/2}}-\frac{m\cos \mathrm{\θ}}{{(x^2+y^2+z^2)}^{3/2}})\\ B_y=\frac{1}{4\mathrm{\π}}(\frac{3(\mathrm{mx}\sin \mathrm{\θ}+\mathrm{mz}\cos \mathrm{\θ})y}{{(x^2+y^2+z^2)}^{5/2}}-\frac{m\sin \mathrm{\θ}}{{(x^2+y^2+z^2)}^{3/2}})\\ B_z=\frac{1}{4\mathrm{\π}}\frac{3(\mathrm{mx}\sin \mathrm{\θ}+\mathrm{mz}\cos \mathrm{\θ})z}{{(x^2+y^2+z^2)}^{5/2}}\end{array}\right.---\left(2\right)$

M in the formula: be the equivalent magnetic moment of magnetic short section.

Step 4 is measured the equivalent magnetic moment of magnetic short section and is provided the possible excursion of down-hole magnetic short section equivalence magnetic moment on the earth's surface.

Utilize the method for the mensuration magnetic short section equivalence magnetic moment that the present inventor invents in the patent 200910210079X of application, can try to achieve magnetic short section at the equivalent magnetic moment on ground.Generally speaking, the equivalent magnetic moment of down-hole magnetic short section is in 100%～90% scope that ground is measured; At special formation, the equivalent magnetic moment of down-hole magnetic short section is in 100%～80% scope that ground is measured.

Step 5 according to the adjacent-well parallel intervals of estimating, is lowered to drilling well to correct position with drilling rod or crawl device with the two Magnetic Sensor inserting tubes in down-hole.Magnetic short section is lowered between two Magnetic Sensor inserting tube both ends, the magnetic short section of the mid point that preferably makes two Magnetic Sensor inserting tubes in the upper upright drilling well.

Step 6, the relative tertiary location data of the offset well parallel-segment that the two Magnetic Sensor inserting tubes in extraction down-hole calculate.

According to described computation model, set up as shown in Figure 3 coordinate system.As shown in Figure 3, magnetic short section is R to the radial spacing of two Magnetic Sensor inserting tubes; Magnetic short section is r to the distance of the magnetic field sensor on two Magnetic Sensor inserting tube tops ₁, be r to the distance of the magnetic field sensor of two Magnetic Sensor inserting tube ends ₂Magnetic short section is z to the axial spacing of the magnetic field sensor on two Magnetic Sensor inserting tube tops ₁, be z to the axial spacing of the magnetic field sensor of two Magnetic Sensor inserting tube ends ₂The spacing of two magnetic field sensors is d (known).

As shown in Figure 4, unit vector

Represent X, the Y-axis of three axle alternating magnetic field sensors; Unit vector

Represent the direction of constantly magnetic short section equivalence of t magnetic moment; Unit vector

Represent magnetic short section to two Magnetic Sensor inserting tubes radially; Unit vector

Be orthogonal to the axial of two Magnetic Sensor inserting tubes, be orthogonal to simultaneously unit vector Represent the high edge direction of well-drilling borehole; AmR represents unit vector

To unit vector

Angle; AhR represents the angle that radially is wired to of magnetic short section and two Magnetic Sensor inserting tubes; Ahx represents well flash Hs to unit vector

Angle; AxR represents unit vector

To unit vector

Angle.

As shown in Figure 3, Figure 4, requiring the relative tertiary location of offset well parallel-segment, mainly is to determine that magnetic short section is to radial spacing R and the included angle A hR of two Magnetic Sensor inserting tubes.

In coordinate system shown in Figure 3, $m=\hat{R}m\cos \left(\mathrm{AmR}\right)+\hat{q}m\sin \left(\mathrm{AmR}\right),$ $r=R\hat{R}+z\hat{z},$ Therefore can get:

$B_R=\frac{m}{4\mathrm{\π}}\frac{(3R^2-r^2)\cos \left(\mathrm{AmR}\right)}{r^5}---\left(3\right)$

$B_q=\frac{m}{4\mathrm{\π}}\frac{\sin \left(\mathrm{AmR}\right)}{r^3}---\left(4\right)$

$B_z=\frac{m}{4\mathrm{\π}}\frac{3\mathrm{Rz}\cos \left(\mathrm{AmR}\right)}{r^5}---\left(5\right)$

As shown in Figure 4, the magnetic induction intensity component that detects of two Magnetic Sensor inserting tube three axle alternating magnetic field sensors X, Y-axis is:

B _x＝B _Rcos(AxR)-B _qsin(AxR) (6)

B _y＝B _Rsin(AxR)+B _qcos(AxR) (7)

With (3)～(5) formula substitutions (6)～(7) Shi Kede:

$B_x=\frac{m}{4\mathrm{\π}{r}^3}\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\cos }^2\left(\mathrm{AxR}\right)+{\sin }^2\left(\mathrm{AxR}\right)}\cos (\mathrm{AmR}-P_x)---\left(8\right)$

$\cos \left(P_x\right)=\frac{\left(\frac{{3R}^2-r^2}{r^2}\right)\cos \left(\mathrm{AxR}\right)}{\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\cos }^2\left(\mathrm{AxR}\right)+{\sin }^2\left(\mathrm{AxR}\right)}}---\left(9\right)$

$\sin \left(P_x\right)=\frac{-\sin \left(\mathrm{AxR}\right)}{\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\cos }^2\left(\mathrm{AxR}\right)+{\sin }^2\left(\mathrm{AxR}\right)}}---\left(10\right)$

$B_y=\frac{m}{4\mathrm{\π}{r}^3}\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\sin }^2\left(\mathrm{AxR}\right)+{\cos }^2\left(\mathrm{AxR}\right)}\cos (\mathrm{AmR}-P_y)---\left(11\right)$

$\cos \left(P_y\right)=\frac{\left(\frac{{3R}^2-r^2}{r^2}\right)\sin \left(\mathrm{AxR}\right)}{\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\sin }^2\left(\mathrm{AxR}\right)+{\cos }^2\left(\mathrm{AxR}\right)}}---\left(12\right)$

$\sin \left(P_y\right)=\frac{\cos \left(\mathrm{AxR}\right)}{\sqrt{{\left(\frac{{3R}^2-r^2}{r^2}\right)}^2{\sin }^2\left(\mathrm{AxR}\right)+{\cos }^2\left(\mathrm{AxR}\right)}}---\left(13\right)$

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

$\cos \left(2\mathrm{AxR}\right)=\frac{{({2R}^2-z^2)}^2+{(R^2+z^2)}^2}{{({2R}^2-z^2)}^2-{(R^2+z^2)}^2}\frac{{\left|B_x\right|}^2-{\left|B_y\right|}^2}{{\left|B_x\right|}^2+{\left|B_y\right|}^2}---\left(14\right)$

In the formula: | Bx|, | By| represents the amplitude of the magnetic induction intensity waveform that alternating magnetic field sensors X, Y-axis detect.

By (3) formula and (5) Shi Kede:

$\left|B_R\right|=\sqrt{{\left|B_x\right|}^2+{\left|B_y\right|}^2}=\frac{m(2{(R/z)}^2-1)}{4\mathrm{\π}{z}^3{(1+{(R/z)}^2)}^{5/2}}---\left(15\right)$

$\left|B_z\right|=\frac{3\mathrm{mRz}}{4\mathrm{\π}{(R^2+z^2)}^{5/2}}=\frac{3m(R/z)}{4\mathrm{\π}{z}^3{(1+{(R/z)}^2)}^{5/2}}---\left(16\right)$

In the formula: | B _z| represent the amplitude of the magnetic induction intensity waveform that alternating magnetic field sensor Z axis detects, | B _R| represent the amplitude of radial magnetic field induction waveform.

Define at alternating magnetic field sensor place, two Magnetic Sensor inserting tubes top:

$u\≡\frac{R}{z_1}---\left(17\right)$

$\mathrm{\α}\≡\frac{\left|B_{1R}\right|}{\left|B_{1z}\right|}=\frac{{2u}^2-1}{3u}---\left(18\right)$

Again because z ₁＜0, can be solved by (18) formula:

$u=\frac{3\mathrm{\α}-\sqrt{{9\mathrm{\α}}^2+8}}{4}---\left(19\right)$

Define at two Magnetic Sensor inserting tube lower sensors place:

$v=\frac{R}{z_2}=\frac{R}{z_1+d}---\left(20\right)$

$\mathrm{\β}\≡\frac{\left|B_{2R}\right|}{\left|B_{2z}\right|}=\frac{{2v}^2-1}{3v}---\left(21\right)$

Again because z ₁＜d can be solved by (21) formula:

$v=\frac{3\mathrm{\β}-\sqrt{{9\mathrm{\β}}^2+8}}{4}---\left(22\right)$

Can be got by (17) formula and (20) formula simultaneous:

$R=\frac{\mathrm{uvd}}{u-v}---\left(23\right)$

$z_1=\frac{\mathrm{vd}}{u-v}---\left(24\right)$

$z_2=\frac{\mathrm{ud}}{u-v}---\left(25\right)$

With (23)～(25) formula substitutions (14) Shi Kede in two alternating magnetic field sensor place unit vectors

To unit vector

The value AxR of angle ₁, AxR ₂, therefore

$\mathrm{AxR}=\frac{1}{2}({\mathrm{AxR}}_1+{\mathrm{AxR}}_2)---\left(26\right)$

Obviously, the AxR that is obtained by (14) formula can not determine it in [0, π] scope, is being in [π, 0] scope also.This is not a problem in actual applications, because its scope can be determined by included angle A hx.Included angle A hx can be recorded by 3-axis acceleration sensor, therefore, the relative bearing of offset well parallel-segment, namely magnetic short section arrives the angle of well-drilling borehole flash

AhR＝π-Ahx-AxR (27)

By radial spacing R and the included angle A hR of magnetic short section to two Magnetic Sensor inserting tubes, can determine that magnetic short section arrives the relative tertiary location of two Magnetic Sensor inserting tubes.The position of magnetic short section represents positive drilling well position, and the position of two Magnetic Sensor inserting tubes represents drilling well position, has therefore also just been determined the relative tertiary location of offset well parallel-segment to the relative tertiary location of two Magnetic Sensor inserting tubes by magnetic short section.

Step 7, utilize the two Magnetic Sensor inserting tube calculated datas in hole condition information, down-hole, magnetic short section equivalence magnetic moment after the described processing, calculate the two Magnetic Sensor inserting tubes in down-hole and the locus of magnetic short section in positive drilling well-head coordinate system, and then the relative tertiary location of definite offset well parallel-segment in positive drilling well-head coordinate system.

Step 8 according to result of calculation, is adjusted tool-face and is continued to creep into the next position.

Step 9 according to the adjacent-well parallel intervals that calculates, is lowered into the next position with drilling rod or crawl device with the two Magnetic Sensor inserting tubes in down-hole, the magnetic short section of the mid point that equally as far as possible makes two Magnetic Sensor inserting tubes in the upper upright drilling well.

Step 10 forwards step 6 to, so is circulated to and has bored.

Claims (2)

1. a method of utilizing down-hole pair two groups of magnetic signals that Magnetic Sensor inserting tubes reception magnetic short section produces to determine the relative tertiary location of offset well parallel-segment is characterized in that, comprises the following steps:

Step 1 is extracted the hole condition information of drilling well and positive drilling well: drilling well and just the well track metrical information of drilling well; Drilling well and the just mouth coordinate of drilling well; Brill dish level (KB) and the EGL (GL) of drilling well and positive drilling well; The casing programme of drilling well;

Step 2, the hole condition information of the drilling well that processing is extracted and positive drilling well;

Step 3 is set up rotary magnetic pipe nipple surrounding space magnetic induction intensity and is calculated model;

Step 4 is measured the equivalent magnetic moment of magnetic short section and is provided the possible excursion of down-hole magnetic short section equivalence magnetic moment on the earth's surface;

Step 5 according to the adjacent-well parallel intervals of estimating, is lowered to drilling well to correct position with drilling rod or crawl device with the two Magnetic Sensor inserting tubes in down-hole; Magnetic short section is lowered between two Magnetic Sensor inserting tube both ends, the magnetic short section of the mid point that makes two Magnetic Sensor inserting tubes in the upper upright drilling well;

Step 6, the relative tertiary location data of the offset well parallel-segment that the two Magnetic Sensor inserting tubes in extraction down-hole calculate;

Step 7, utilize the two Magnetic Sensor inserting tube calculated datas in hole condition information, down-hole, magnetic short section equivalence magnetic moment after the described processing, calculate the two Magnetic Sensor inserting tubes in down-hole and the locus of magnetic short section in positive drilling well-head coordinate system, and then the relative tertiary location of definite offset well parallel-segment in positive drilling well-head coordinate system;

Step 8 according to result of calculation, is adjusted tool-face and is continued to creep into the next position;

Step 9 according to the adjacent-well parallel intervals that calculates, is lowered into the next position with drilling rod or crawl device with the two Magnetic Sensor inserting tubes in down-hole, the magnetic short section of the mid point that makes equally two Magnetic Sensor inserting tubes in the upper upright drilling well;

Step 10 forwards step 6 to, so is circulated to and has bored.

2. two groups of magnetic signals that utilize the two Magnetic Sensor inserting tubes in down-hole to receive the magnetic short section generation according to claim 1 are determined the method for the relative tertiary location of offset well parallel-segment, and it is characterized in that: step 2 comprises:

Step 21, according to positive drilling well and brill dish level (KB) and the EGL (GL) of drilling well, calculated level well brill dish level than straight well brill dish level high what or how much hang down;

Step 22 determines that hole trajectory data is with respect to brill dish level or EGL;

Step 23 aligns the side-play amount of drilling well-head mutually according to positive drilling well and drilling well-head coordinate Calculation drilling well-head;

Step 24 adds or deducts described side-play amount in the true vertical depth (TVD) of two Magnetic Sensor inserting tubes and connectivity points, northern coordinate (N), eastern coordinate (E) data.

Images