CN103883317A - Measuring method and measuring system for formation resistivity - Google Patents

Abstract

The invention relates to the technical field of formation resistivity measurement and discloses a measuring method and a measuring system for formation resistivity. The measuring method includes: arranging at least two emission electrodes, at least one reference potential electrode and at least four measuring probes on a casing; arranging at least two loop electrodes on the ground; measuring total resistance of partial casing and formation; obtaining the resistance between every two continuous measuring probes; obtaining electric current leaked to the formation; substituting the electric current leaked to the formation from reference potential and different ranges to an apparent resistivity formula to obtain the formation resistivity among the three continuous measuring probes. By the measuring method, the resistivity among multiple neighboring formation sections can be measured simultaneously in one-step measurement, so that measurement efficiency of an instrument is improved on the basis of not increasing the length and the complexity of the measuring instrument, and use efficiency of the instrument is further improved.

Description

A kind of measuring method of formation resistivity and system

Technical field

The present invention relates to formation resistivity field of measuring technique, particularly a kind of measuring method of formation resistivity and system.

Background technology

Formation resistivity is to evaluate the requisite key element of reservoir hydrocarbonaceous amount.Formation resistivity depends primarily on the contained liquid in stratum, more much smaller than the resistivity on stratum that is full of hydrocarbon medium containing the resistivity on the stratum of conduction salt solution, thereby the measurement of resistivity has irreplaceable construction value for location hydro carbons ore bed.The measurement of traditional resistivity is carried out in open hole well, owing to being that atomic little (resistivity on stratum is in 1 ohm/meter between 1000 ohm/meter, and the representative value of the resistivity of metal sleeve is 2 × 10 compared with the resistivity of metal sleeve and formation resistivity ^-7ohm/meter), therefore traditional resistivity logging tool cannot be realized the measurement to formation resistivity, is necessary to develop sleeve pipe formation resistivity logging instrument.This instrument passes through to measure small voltage drop on sleeve pipe, thereby reaches the object of Formation Resistivity Measurement.

Crossing sleeve pipe formation resistivity logging instrument is a kind of instrument at sleeve pipe borehole measurement formation apparent resistivity.Its important feature is that investigation depth is large, is applicable to the stratum of different aperture degree and formation water salinity.Domestic cased hole formation resistivity logging demand is large, especially in grand celebration, the Liaohe River, tell and breathe out the oil field of contour moisture development late stage, joint-stock company of PetroChina Company Limited. utilizes the cased hole formation resistivity logger of Si Lunbeixie company to carry out the well logging of up to a hundred mouthfuls of wells.Therefore, this measuring apparatus is monitored for oil-gas Layer, determines in old well that the position of the dead oil band of gas and the distribution of remaining oil saturation are of great significance to extend old well production life of well tool.But the subject matter that this instrument exists is at present exactly the measurement that can only complete the resistivity on one section of stratum, has reduced the measurement efficiency of formation resistivity at every turn.

Summary of the invention

Technical problem to be solved by this invention is to provide a kind of measuring method and system of formation resistivity, and it can be in one-shot measurement, completes the measurement of multiple resistivity that are adjacent to interval, has improved the measurement efficiency of formation resistivity.

For solving the problems of the technologies described above, the invention provides a kind of measuring method of formation resistivity, comprising:

At least 2 emission electrodes, at least 1 reference potential electrode and at least 4 measuring probes are set on the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument; At least 2 loop electrodes are set on the ground;

By electric current I _oinject a described emission electrode, described electric current I _oflow out from a described loop electrode; Measure the current potential V of described reference potential electrode corresponding to a described loop electrode _o; The all-in resistance Q that obtains measure portion sleeve pipe and stratum based on Ohm's law is:

By electric current I _ninject a described emission electrode, described electric current I _nflow out from another emission electrode; The voltage of measuring between every 2 continuous described measuring probes is respectively V ₁', V ₂' and V ₃'; The resistance obtaining between every 2 continuous measuring probes based on Ohm's law is respectively:

$R_3=\frac{{V_3}^{\′}}{I_n};$

By electric current I _minject a described emission electrode, described electric current I _mflow out from a described loop electrode; The voltage of measuring between every 2 continuous described measuring probes is respectively V ₁, V ₂and V ₃; The electric current obtaining between every 2 continuous measuring probes based on Ohm's law is respectively V ₁/ R ₁, V ₂/ R ₂and V ₃/ R ₃; The electromotive force producing on sleeve pipe and stratum is QI _m, reference potential is now QI _m; The difference of two continuous electric currents is just respectively the electric current that is leaked to stratum in different intervals, is:

$\mathrm{\&Delta;}{I}_a=\frac{V_1}{R_1}-\frac{V_2}{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000382026620000011.png"\; state="\{\{state\}\}">R</figure-callout>}}_2},$ $\mathrm{\&Delta;}{I}_b=\frac{V_2}{R_2}-\frac{V_3}{R_3};$

The apparent resistivity formula on the electric current substitution stratum on stratum will be leaked in described reference potential and described different interval

and by the resistance substitution apparent resistivity formula between described every 2 continuous measuring probes, obtain 3 formation resistivities between described continuous measuring probe

and formation resistivity between other 3 described continuous measuring probes

wherein, V is reference potential; Δ I is the electric current that is leaked to stratum; K=k Δ z, k is calibration factor, Δ z is the half of the maximum spacing of described 3 continuous measuring probes.

Further, the measuring method of described calibration factor k comprises:

Measure the voltage between reference potential, described every 2 continuous measuring probes and measure electric current at non-measurement formation interval; The formation resistivity of the described non-measurement formation interval based on known and Δ z inverse go out calibration factor k; Particularly, formation resistivity formula is converted to $K=\mathrm{\&rho;}/\left(Q\frac{I_m}{I_n}{(\frac{V_2}{V_2^{\text{'}}}-\frac{V_3}{{V_3}^{\&prime;}})}^{-1}\right),$ Inverse obtains $k=\frac{K}{\mathrm{\&Delta;z}}.$

Further, the step that at least 1 reference potential electrode and at least 4 measuring probes are set on the described sleeve pipe crossing sleeve pipe formation resistivity logging instrument is specially: on the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument, 2 reference potential electrodes and 8 measuring probes are set, and described reference potential electrode is that horizontal symmetrical is arranged on described sleeve pipe, described measuring probe be every two be one group from top to bottom horizontal symmetrical be arranged on sleeve pipe.

Further, described in every group, measuring probe is set in qually spaced on described sleeve pipe from top to bottom.

Further, described reference potential electrode is arranged on the top of described measuring probe.

The present invention also provides a kind of measuring system of formation resistivity, comprising:

Installation module, for arranging at least 2 emission electrodes, at least 1 reference potential electrode and at least 4 measuring probes on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument; At least 2 loop electrodes are set on the ground;

The first resistance measuring module, for by electric current I _oinject a described emission electrode, described electric current I _oflow out from a described loop electrode; Measure the current potential V of described reference potential electrode corresponding to a described loop electrode _o; The all-in resistance Q that obtains measure portion sleeve pipe and stratum based on Ohm's law is:

The second resistance measuring module, for by electric current I _ninject a described emission electrode, described electric current I _nflow out from another emission electrode; The voltage of measuring between every 2 continuous described measuring probes is respectively V ₁', V ₂' and V ₃'; The resistance obtaining between every 2 continuous measuring probes based on Ohm's law is respectively: $R_1=\frac{{V_1}^{\&prime;}}{I_n},{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000382026620000011.png"\; state="\{\{state\}\}">R</figure-callout>}}_2=\frac{{{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HDA0000382026620000011.png"\; state="\{\{state\}\}">V</figure-callout>}}_2}^{\&prime;}}{I_n},R_3=\frac{{V_3}^{\&prime;}}{I_n};$

Current measurement module, for by electric current I _minject a described emission electrode, described electric current I _mflow out from a described loop electrode; The voltage of measuring between every 2 continuous described measuring probes is respectively V ₁, V ₂and V ₃; The electric current obtaining between every 2 continuous measuring probes based on Ohm's law is respectively V ₁/ R ₁, V ₂/ R ₂and V ₃/ R ₃; The electromotive force producing on sleeve pipe and stratum is QI _m, reference potential is now QI _m; The difference of two continuous electric currents is just respectively the electric current that is leaked to stratum in different intervals, is:

$\mathrm{\&Delta;}{I}_a=\frac{V_1}{R_1}-\frac{V_2}{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000382026620000011.png"\; state="\{\{state\}\}">R</figure-callout>}}_2},$ $\mathrm{\&Delta;}{I}_b=\frac{V_2}{R_2}-\frac{V_3}{R_3};$

Computing module, for being leaked to the apparent resistivity formula on the electric current substitution stratum on stratum in described reference potential and described different interval

and by the resistance substitution apparent resistivity formula between described every 2 continuous measuring probes, obtain 3 formation resistivities between described continuous measuring probe

and formation resistivity between other 3 described continuous measuring probes

wherein, V is reference potential; Δ I is the electric current that is leaked to stratum; K=k Δ z, k is calibration factor, Δ z is the half of the maximum spacing of described 3 continuous measuring probes.

Further, also comprise: calibration factor measuring unit, for measuring the voltage between reference potential, described every 2 continuous measuring probes at non-measurement formation interval and measuring electric current; The formation resistivity of the described non-measurement formation interval based on known and Δ z inverse go out calibration factor k; Particularly, formation resistivity formula is converted to $K=\mathrm{\&rho;}/\left(Q\frac{I_m}{I_n}{(\frac{V_2}{V_2^{\text{'}}}-\frac{V_3}{{V_3}^{\&prime;}})}^{-1}\right),$ Inverse obtains $k=\frac{K}{\mathrm{\&Delta;z}}.$

Further, described installation module comprises:

The first installation unit, for 2 reference potential electrodes and 8 measuring probes being set on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, and described reference potential electrode is that horizontal symmetrical is arranged on described sleeve pipe, described measuring probe be every two be one group from top to bottom horizontal symmetrical be arranged on sleeve pipe;

The second installation unit, on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, 2 emission electrodes being set, arranges 2 loop electrodes on the ground.

Further, described the first installation unit, comprising:

First installs subelement, on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, 8 measuring probes being set, and measuring probe every two be one group from top to bottom horizontal symmetrical be set in qually spaced on sleeve pipe;

Second installs subelement, and on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, 2 reference potential electrodes being set, and described reference potential electrode is that horizontal symmetrical is arranged on described sleeve pipe, and reference potential electrode is arranged on the top of described measuring probe.

Beneficial effect of the present invention is:

The measuring method of formation resistivity provided by the invention and system, realize in one-shot measurement by multiplexing measuring probe, complete the measurement of multiple resistivity that are adjacent to interval simultaneously, thereby do not increasing on the basis of measuring apparatus length and complexity, improve the measurement efficiency of instrument, and then improved the service efficiency of instrument.

Brief description of the drawings

The flow chart of the measuring method of the formation resistivity that Fig. 1 provides for the embodiment of the present invention;

The distribution map of measuring probe in the measuring method of the formation resistivity that Fig. 2 provides for the embodiment of the present invention;

The schematic diagram that the measuring method of the formation resistivity that Fig. 3 provides for the embodiment of the present invention is carried out formation resistivity measurement under reference potential measurement pattern;

The schematic diagram that the measuring method of the formation resistivity that Fig. 4 provides for the embodiment of the present invention is carried out formation resistivity measurement under sleeve pipe resistance measurement pattern;

The schematic diagram that the measuring method of the formation resistivity that Fig. 5 provides for the embodiment of the present invention is carried out formation resistivity measurement under Leakage Current measurement pattern.

Detailed description of the invention

For further setting forth technological means and effect that the present invention takes for reaching predetermined goal of the invention, below in conjunction with accompanying drawing and preferred embodiment, the measuring method of formation resistivity proposing according to the present invention and the detailed description of the invention of system and operating principle are elaborated.

The measuring method of the formation resistivity that the embodiment of the present invention provides and system are the formula of the apparent resistivity based on stratum

carry out computation and measurement; Wherein, k is calibration factor, and V is reference potential value, and Δ Z is the length of measuring stratum, and Δ I is leaked to the electric current of measuring stratum.

Referring to Fig. 1, the measuring method of the formation resistivity that the embodiment of the present invention provides, comprising:

At least 2 emission electrodes, at least 1 reference potential electrode and at least 4 measuring probes are set on the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument; At least 2 loop electrodes are set on the ground;

In order to ensure that probe contacts with sleeve pipe well, and make probe apply enough large pressure to pierce through wax deposition corrosion layer to casing wall, and in the time that losing efficacy, a probe had probe for subsequent use to use, on the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument, adopt two sonde configurations to arrange, to ensure normally carrying out of formation resistivity measurement operation.Referring to Fig. 2 and Fig. 3, in the present embodiment, 2 loop electrodes are set on the ground, i.e. loop electrode B and loop electrode G; On the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument, 2 emission electrodes are set, are respectively emission electrode A and emission electrode Z; On the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument, 2 reference potential electrodes are set, be respectively reference potential electrode J and reference potential electrode J ', and reference potential electrode is that horizontal symmetrical is arranged on sleeve pipe, for example: reference potential electrode J and reference potential electrode J ' are that horizontal symmetrical is arranged on sleeve pipe; On the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument, 8 measuring probes are set, be respectively measuring probe C, measuring probe C ', measuring probe D, measuring probe D ', measuring probe E, measuring probe E ', measuring probe F and measuring probe F ', and measuring probe be every two be one group from top to bottom horizontal symmetrical be arranged on sleeve pipe, measuring probe C and measuring probe C ' are that one group of horizontal symmetrical is arranged on sleeve pipe; Measuring probe D and measuring probe D ' are that one group of horizontal symmetrical is arranged on sleeve pipe; Measuring probe E and measuring probe E ' are that one group of horizontal symmetrical is arranged on sleeve pipe; Measuring probe F and measuring probe F ' are that one group of horizontal symmetrical is arranged on sleeve pipe.Wherein, measuring probe is set in qually spaced on sleeve pipe from top to bottom, and measuring probe C, measuring probe D, measuring probe E and measuring probe F are set in qually spaced on sleeve pipe from top to bottom, and the spacing of adjacent measuring probe is L1; Measuring probe C ', measuring probe D ', measuring probe E ' and measuring probe F ' are set in qually spaced on sleeve pipe from top to bottom, and the spacing of adjacent measuring probe is L1.Further, in order to improve the signal strength signal intensity of reference potential electrode, to increase the validity of potential measurement of the present invention, reference potential electrode is arranged on the top of measuring probe, be the top that reference potential electrode J is arranged on measuring probe C, the spacing of reference potential electrode J and measuring probe C is L2; Reference potential electrode J ' is arranged on the top of measuring probe C ', and reference potential electrode J ' is L2 with the spacing of measuring probe C '.Loop electrode A is arranged on the top of reference potential electrode J, and loop electrode Z is arranged on the below of measuring probe F.

By electric current I _oinject an emission electrode A, electric current I _oflow out from a loop electrode B; Witness mark potential electrode J is corresponding to the current potential V of a loop electrode G _o; The all-in resistance Q that obtains measure portion sleeve pipe and stratum based on Ohm's law is:

it should be noted that, witness mark potential electrode J is corresponding to the current potential V of a loop electrode G _oconcrete steps comprise: reference potential electrode J carries out signal amplification by the voltage transmission measuring to amplification module, amplification module will be transferred to frequency modulation module through amplifying signal and carry out frequency modulation, frequency modulation module is carried out amplitude modulation by being transferred to amplitude modulation module through the signal of frequency modulation, amplitude modulation module is carried out analog-to-digital conversion by being transferred to analog-to-digital conversion module through the signal of amplitude modulation, analog-to-digital conversion module outputs to single-chip microcomputer by data signal and carries out computing, obtains current potential V _o.Memory module is to the current potential V obtaining _opreserve, communication module is by current potential V _osend to active station.

By electric current I _ninject an emission electrode A, electric current I _nflow out from another emission electrode Z; The voltage of measuring between every 2 continuous measuring probes is respectively V ₁', V ₂' and V ₃'; The resistance obtaining between every 2 continuous measuring probes based on Ohm's law is respectively:

it should be noted that measuring voltage V ₁', voltage V ₂' and voltage V ₃' concrete steps be: measuring probe C, measuring probe D, measuring probe E and measuring probe F carry out signal amplification by the voltage transmission measuring to amplification module respectively separately, amplification module will be transferred to frequency modulation module through amplifying signal and carry out frequency modulation, frequency modulation module is carried out amplitude modulation by being transferred to amplitude modulation module through the signal of frequency modulation, amplitude modulation module is carried out analog-to-digital conversion by being transferred to analog-to-digital conversion module through the signal of amplitude modulation, analog-to-digital conversion module outputs to single-chip microcomputer by data signal and carries out computing, obtains respectively the voltage V between measuring probe C and measuring probe D ₁', the voltage V between measuring probe D and measuring probe E ₂' and measuring probe E and measuring probe F between voltage V ₃'.Memory module is to the voltage V calculating ₁', voltage V ₂' and voltage V ₃' to preserve, communication module is by voltage V ₁', voltage V ₂' and voltage V ₃' send to active station.Wherein, R ₁for the resistance between measuring probe C and measuring probe D, R ₂for the resistance between measuring probe D and measuring probe E, R ₃for the resistance between measuring probe E and measuring probe F.

By electric current I _minject an emission electrode A, electric current I _mflow out from a loop electrode B; The voltage of measuring between every 2 continuous measuring probes is respectively V ₁, V ₂and V ₃; The electric current obtaining between every 2 continuous measuring probes based on Ohm's law is respectively V ₁/ R ₁, V ₂/ R ₂and V ₃/ R ₃; The electromotive force producing on sleeve pipe and stratum is QI _m, reference potential is now QI _m; The difference of two continuous electric currents is just respectively the electric current that is leaked to stratum in different intervals, is:

$\mathrm{\&Delta;}{I}_a=\frac{V_1}{R_1}-\frac{V_2}{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000382026620000011.png"\; state="\{\{state\}\}">R</figure-callout>}}_2},$ $\mathrm{\&Delta;}{I}_b=\frac{V_2}{R_2}-\frac{V_3}{R_3};$

It should be noted that measuring voltage V ₁, voltage V ₂with voltage V ₃concrete steps be: measuring probe C, measuring probe D, measuring probe E and measuring probe F carry out signal amplification by the voltage transmission measuring to amplification module respectively separately, amplification module will be transferred to frequency modulation module through amplifying signal and carry out frequency modulation, frequency modulation module is carried out amplitude modulation by being transferred to amplitude modulation module through the signal of frequency modulation, amplitude modulation module is carried out analog-to-digital conversion by being transferred to analog-to-digital conversion module through the signal of amplitude modulation, analog-to-digital conversion module outputs to single-chip microcomputer by data signal and carries out computing, obtains respectively the voltage V between measuring probe C and measuring probe D ₁, the voltage V between measuring probe D and measuring probe E ₂and voltage V between measuring probe E and measuring probe F ₃.Memory module is to the voltage V calculating ₁, voltage V ₂with voltage V ₃preserve, communication module is by voltage V ₁, voltage V ₂with voltage V ₃send to active station.Wherein, V ₁/ R ₁for the electric current between measuring probe C and measuring probe D, V ₂/ R ₂for the electric current between measuring probe D and measuring probe E, V ₃/ R ₃for the electric current between measuring probe E and measuring probe F.Further,

for be leaked to the electric current on stratum to measuring probe E interval by measuring probe C,

for be leaked to the electric current on stratum to measuring probe F interval by measuring probe D.

With reference to current potential QI _mwith the apparent resistivity formula on electric current substitution stratum that is leaked to stratum in different intervals and by the resistance substitution apparent resistivity formula between every 2 continuous measuring probes, obtain 3 formation resistivities between continuous measuring probe

and formation resistivity between other 3 continuous measuring probes

wherein, V is reference potential, i.e. V=QI _m; Δ I is the electric current that is leaked to stratum; K=k Δ z, k is calibration factor, Δ z is the half of the maximum spacing of 3 continuous measuring probes.Particularly, at formation resistivity formula

in, Δ z is the half of the spacing of measuring probe C and measuring probe E, i.e. Δ z=L1; ρ _a1for measuring probe C is to the formation resistivity between measuring probe E; At formation resistivity formula

in, Δ z is the half of the spacing of measuring probe D and measuring probe F, i.e. Δ z=L1; ρ _a2for measuring probe D is to the formation resistivity between measuring probe F.

Further, the measuring method of calibration factor k is:

Measure the voltage between reference potential, every 2 continuous measuring probes and measure electric current at non-measurement formation interval; The formation resistivity of the non-measurement formation interval based on known and Δ z inverse go out calibration factor k.Wherein, non-measurement stratum is near shale layer or water layer measurement target.

For example: the reference potential measuring at non-measurement formation interval is QI _m, the voltage between measuring probe D and measuring probe E is V ₂, the voltage between measuring probe E and measuring probe F is V ₃, measure electric current and be respectively I _nand I _m; The formation resistivity of known non-measurement formation interval is ρ, and the half of the spacing of measuring probe D and measuring probe F is Δ z, formation resistivity formula can be converted to $K=\mathrm{\&rho;}/\left(Q\frac{I_m}{I_n}{(\frac{V_2}{V_2^{\text{'}}}-\frac{V_3}{{V_3}^{\&prime;}})}^{-1}\right),$ Therefore can obtain $k=\frac{K}{\mathrm{\&Delta;z}}.$

Particularly, the measuring process of measuring electric current comprises: current sensing elements carries out signal amplification by the current delivery measuring to amplification module, amplification module will be transferred to frequency modulation module through amplifying signal and carry out frequency modulation, frequency modulation module is carried out amplitude modulation by being transferred to amplitude modulation module through the signal of frequency modulation, amplitude modulation module is carried out analog-to-digital conversion by being transferred to analog-to-digital conversion module through the signal of amplitude modulation, analog-to-digital conversion module outputs to single-chip microcomputer by data signal and carries out computing, obtains measuring electric current.Memory module is preserved the measurement electric current measuring, and measurement electric current is sent to active station by communication module.

The embodiment of the present invention also provides a kind of measuring system of formation resistivity, comprising:

Installation module, for arranging at least 2 emission electrodes, at least 1 reference potential electrode and at least 4 measuring probes on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument; At least 2 loop electrodes are set on the ground;

In order to ensure that probe contacts with sleeve pipe well, and make probe apply enough large pressure to pierce through wax deposition corrosion layer to casing wall, and in the time that losing efficacy, a probe had probe for subsequent use to use, on the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument, adopt two sonde configurations to arrange, to ensure normally carrying out of formation resistivity measurement operation.Installation module, specifically for 2 loop electrodes are set on the ground, i.e. loop electrode B and loop electrode G; On the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument, 2 emission electrodes are set, are respectively emission electrode A and emission electrode Z; On the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument, 2 reference potential electrodes are set, are respectively reference potential electrode J and reference potential electrode J '; On the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument, 8 measuring probes are set, are respectively measuring probe C, measuring probe C ', measuring probe D, measuring probe D ', measuring probe E, measuring probe E ', measuring probe F and measuring probe F '.

Preferably, installation module, comprising:

The first installation unit, for 2 reference potential electrodes and 8 measuring probes being set on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, and reference potential electrode is that horizontal symmetrical is arranged on sleeve pipe, measuring probe be every two be one group from top to bottom horizontal symmetrical be arranged on sleeve pipe, for example: reference potential electrode J and reference potential electrode J ' are that horizontal symmetrical is arranged on sleeve pipe; Measuring probe C and measuring probe C ' are that one group of horizontal symmetrical is arranged on sleeve pipe; Measuring probe D and measuring probe D ' are that one group of horizontal symmetrical is arranged on sleeve pipe; Measuring probe E and measuring probe E ' are that one group of horizontal symmetrical is arranged on sleeve pipe; Measuring probe F and measuring probe F ' are that one group of horizontal symmetrical is arranged on sleeve pipe.

The second installation unit, on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, 2 emission electrodes being set, is respectively emission electrode A and emission electrode Z; 2 loop electrodes are set on the ground, i.e. loop electrode B and loop electrode G; And loop electrode A is arranged on the top of reference potential electrode J, loop electrode Z is arranged on the below of measuring probe F.

Further, the first installation unit comprises:

First installs subelement, and on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, 8 measuring probes being set, and measuring probe is set in qually spaced on sleeve pipe from top to bottom; That is, measuring probe C, measuring probe D, measuring probe E and measuring probe F are set in qually spaced on sleeve pipe from top to bottom, and the spacing of adjacent measuring probe is L1; Measuring probe C ', measuring probe D ', measuring probe E ' and measuring probe F ' are set in qually spaced on sleeve pipe from top to bottom, and the spacing of adjacent measuring probe is L1.

Second installs subelement, and on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, 2 reference potential electrodes being set, and reference potential electrode is that horizontal symmetrical is arranged on sleeve pipe, and reference potential electrode is arranged on the top of measuring probe.Reference potential electrode J is arranged on the top of measuring probe C, and the spacing of reference potential electrode J and measuring probe C is L2; Reference potential electrode J ' is arranged on the top of measuring probe C ', and reference potential electrode J ' is L2 with the spacing of measuring probe C '.

The first resistance measuring module, for by electric current I _oinject an emission electrode A, electric current I _oflow out from a loop electrode B; Witness mark potential electrode J is corresponding to the current potential V of a loop electrode G _o; The all-in resistance Q that obtains measure portion sleeve pipe and stratum based on Ohm's law is:

It should be noted that, the first resistance measuring module, comprising:

The first electric current generating unit, for by electric current I _oinject an emission electrode A, electric current I _oflow out from a loop electrode B;

The first voltage measurement unit, the current potential V for witness mark potential electrode J corresponding to a loop electrode G _o; Further, the first voltage measurement unit, specifically for reference potential electrode, J carries out signal amplification by the voltage transmission measuring to amplification module, amplification module will be transferred to frequency modulation module through amplifying signal and carry out frequency modulation, frequency modulation module is carried out amplitude modulation by being transferred to amplitude modulation module through the signal of frequency modulation, amplitude modulation module is carried out analog-to-digital conversion by being transferred to analog-to-digital conversion module through the signal of amplitude modulation, and analog-to-digital conversion module outputs to single-chip microcomputer by data signal and carries out computing, obtains current potential V _o;

The first memory module, for the current potential V to obtaining _opreserve;

First communication module, for by current potential V _osend to active station;

The first arithmetic element, for the all-in resistance Q that obtains measure portion sleeve pipe and stratum based on Ohm's law is: $V=\frac{V_o}{I_o}.$

The second resistance measuring module, for by electric current I _ninject an emission electrode A, electric current I _nflow out from another emission electrode Z; The voltage of measuring between every 2 continuous measuring probes is respectively V ₁', V ₂' and V ₃'; The resistance obtaining between every 2 continuous measuring probes based on Ohm's law is respectively: $R_1=\frac{{V_1}^{\&prime;}}{I_n},{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000382026620000011.png"\; state="\{\{state\}\}">R</figure-callout>}}_2=\frac{{{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HDA0000382026620000011.png"\; state="\{\{state\}\}">V</figure-callout>}}_2}^{\&prime;}}{I_n},R_3=\frac{{V_3}^{\&prime;}}{I_n};$

It should be noted that, the second resistance measuring module comprises:

The second electric current generating unit, for by electric current I _ninject an emission electrode A, electric current I _nflow out from another emission electrode Z;

Second voltage measuring unit, is respectively V for the voltage of measuring between every 2 continuous measuring probes ₁', V ₂' and V ₃', further, second voltage measuring unit, specifically for measuring probe C, measuring probe D, measuring probe E and measuring probe F carry out signal amplification by the voltage transmission measuring to amplification module respectively separately, amplification module will be transferred to frequency modulation module through amplifying signal and carry out frequency modulation, frequency modulation module is carried out amplitude modulation by being transferred to amplitude modulation module through the signal of frequency modulation, amplitude modulation module is carried out analog-to-digital conversion by being transferred to analog-to-digital conversion module through the signal of amplitude modulation, analog-to-digital conversion module outputs to single-chip microcomputer by data signal and carries out computing, obtain respectively the voltage V between measuring probe C and measuring probe D ₁', the voltage V between measuring probe D and measuring probe E ₂' and measuring probe E and measuring probe F between voltage V ₃',

The second memory module, for the voltage V to calculating ₁', voltage V ₂' and voltage V ₃' preserve;

Second communication module, for by voltage V ₁', voltage V ₂' and voltage V ₃' send to active station;

The second arithmetic element, is respectively for the resistance obtaining based on Ohm's law between every 2 continuous measuring probes:

and R ₁for the resistance between measuring probe C and measuring probe D, R ₂for the resistance between measuring probe D and measuring probe E, R ₃for the resistance between measuring probe E and measuring probe F.

Current measurement module, for by electric current I _minject an emission electrode A, electric current I _mflow out from a loop electrode B; The voltage of measuring between every 2 continuous measuring probes is respectively V ₁, V ₂and V ₃; The electric current obtaining between every 2 continuous measuring probes based on Ohm's law is respectively V ₁/ R ₁, V ₂/ R ₂and V ₃/ R ₃; The electromotive force producing on sleeve pipe and stratum is QI _m, reference potential is now QI _m; The difference of two continuous electric currents is just respectively the electric current that is leaked to stratum in different intervals, is:

$\mathrm{\&Delta;}{I}_a=\frac{V_1}{R_1}-\frac{V_2}{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000382026620000011.png"\; state="\{\{state\}\}">R</figure-callout>}}_2},$ $\mathrm{\&Delta;}{I}_b=\frac{V_2}{R_2}-\frac{V_3}{R_3};$

It should be noted that current measurement module comprises:

The 3rd electric current generating unit, for by electric current I _minject an emission electrode A, electric current I _mflow out from a loop electrode B;

Tertiary voltage measuring unit, is respectively V for the voltage of measuring between every 2 continuous measuring probes ₁, V ₂and V ₃, further, tertiary voltage measuring unit, specifically for measuring probe C, measuring probe D, measuring probe E and measuring probe F carry out signal amplification by the voltage transmission measuring to amplification module respectively separately, amplification module will be transferred to frequency modulation module through amplifying signal and carry out frequency modulation, frequency modulation module is carried out amplitude modulation by being transferred to amplitude modulation module through the signal of frequency modulation, amplitude modulation module is carried out analog-to-digital conversion by being transferred to analog-to-digital conversion module through the signal of amplitude modulation, analog-to-digital conversion module outputs to single-chip microcomputer by data signal and carries out computing, obtain respectively the voltage V between measuring probe C and measuring probe D ₁, the voltage V between measuring probe D and measuring probe E ₂and voltage V between measuring probe E and measuring probe F ₃,

The 3rd memory module, for the voltage V to calculating ₁, voltage V ₂with voltage V ₃preserve;

Third communication module, for by voltage V ₁, voltage V ₂with voltage V ₃send to active station;

The 3rd arithmetic element, is respectively V for the electric current obtaining based on Ohm's law between every 2 continuous measuring probes ₁/ R ₁, V ₂/ R ₂and V ₃/ R ₃; The electromotive force producing on sleeve pipe and stratum is QI _m, reference potential is now QI _m; The difference of two continuous electric currents is just respectively the electric current that is leaked to stratum in different intervals, is:

and V ₁/ R ₁for the electric current between measuring probe C and measuring probe D, V ₂/ R ₂for the electric current between measuring probe D and measuring probe E, V ₃/ R ₃for the electric current between measuring probe E and measuring probe F.

for be leaked to the electric current on stratum to measuring probe E interval by measuring probe C,

for be leaked to the electric current on stratum to measuring probe F interval by measuring probe D.

Computing module, for reference to current potential QI _mwith the apparent resistivity formula on electric current substitution stratum that is leaked to stratum in different intervals

and by the resistance substitution apparent resistivity formula between every 2 continuous measuring probes, obtain 3 formation resistivities between continuous measuring probe

and formation resistivity between other 3 continuous measuring probes wherein, V is reference potential, i.e. V=QI _m; Δ I is the electric current that is leaked to stratum; K=k Δ z, k is calibration factor, Δ z is the half of the maximum spacing of 3 continuous measuring probes.Wherein, at formation resistivity formula

in, Δ z is the half of the spacing of measuring probe C and measuring probe E, i.e. Δ z=L1; ρ _a1for measuring probe C is to the formation resistivity between measuring probe E; At formation resistivity formula

in, Δ z is the half of the spacing of measuring probe D and measuring probe F, i.e. Δ z=L1; ρ _a2for measuring probe D is to the formation resistivity between measuring probe F.

Particularly, the system that the embodiment of the present invention provides, also comprises: calibration factor measuring unit, for measuring the voltage between reference potential, every 2 continuous measuring probes at non-measurement formation interval and measuring electric current; The formation resistivity of the non-measurement formation interval based on known and Δ z inverse go out calibration factor k.Wherein, non-measurement stratum is near shale layer or water layer measurement target.

For example: the reference potential measuring at non-measurement formation interval is QI _m, the voltage between measuring probe D and measuring probe E is V ₂, the voltage between measuring probe E and measuring probe F is V ₃, measure electric current and be respectively I _nand I _m; The formation resistivity of known non-measurement formation interval is ρ, and the half of the spacing of measuring probe D and measuring probe F is Δ z, formation resistivity formula can be converted to $K=\mathrm{\&rho;}/\left(Q\frac{I_m}{I_n}{(\frac{V_2}{V_2^{\text{'}}}-\frac{V_3}{{V_3}^{\&prime;}})}^{-1}\right),$ Therefore can obtain $k=\frac{K}{\mathrm{\&Delta;z}}.$

In order to measure the measurement electric current in the embodiment of the present invention, the method and system that the embodiment of the present invention provides, also comprise:

Current sensing elements, for surveying measurement electric current;

Data processing module, for the current delivery measuring is carried out to signal amplification to amplification module, amplification module will be transferred to frequency modulation module through amplifying signal and carry out frequency modulation, frequency modulation module is carried out amplitude modulation by being transferred to amplitude modulation module through the signal of frequency modulation, amplitude modulation module is carried out analog-to-digital conversion by being transferred to analog-to-digital conversion module through the signal of amplitude modulation, analog-to-digital conversion module outputs to single-chip microcomputer by data signal and carries out computing, obtains measuring electric current;

The 4th memory module, preserves for the measurement electric current to calculating;

The 4th communication module, for sending to active station by measurement electric current.

In actual applications, the measuring method of the formation resistivity providing by the embodiment of the present invention is measured the resistivity on stratum, and reference potential electrode J-J ' is first set, and is used for the electrical potential difference of the relative ground of measuring apparatus reference point; Measuring probe C-C ' is set, D-D ', E-E ', F-F '; Emission electrode A and emission electrode Z are set, are used for to union body transmitting high-power signal; Loop electrode B and loop electrode G are set, and loop electrode B is for providing loop from probe A to the high-power electric current that sends of probe Z, and loop electrode G provides potential reference zero point for reference potential electrode J.

The measurement of formation resistivity need to be carried out under three kinds of patterns, is respectively: reference potential measurement pattern, sleeve pipe resistance measurement pattern and Leakage Current measurement pattern.Concrete steps comprise:

1. referring to Fig. 3, under reference potential measurement pattern (impedance measurement pattern), by electric current I _oinject emission electrode A, return from the loop electrode B on ground, witness mark potential electrode J is corresponding to the current potential V of a loop electrode G _o.At this moment the all-in resistance on measure portion sleeve pipe and stratum is:

$Q=\frac{V_o}{I_o}---\left(5.1\right)$

2. referring to Fig. 4, under sleeve pipe resistance measurement pattern (scale measurement pattern), the cover tube resistor between measuring probe C and probe D, probe D and probe E, probe E and probe F.Under this measurement pattern, by electric current I _ninject emission electrode A, electric current I _nfrom emission electrode, Z returns.Measure the voltage V ' between C and D ₁, the voltage V ' between D and E ₂, the voltage V ' between E and F ₃, the resistance that calculates interpolar sleeve pipe is respectively:

$R_1=\frac{{V_1}^{\&prime;}}{I_n},---\left(5.2\right)$

${\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000382026620000011.png"\; state="\{\{state\}\}">R</figure-callout>}}_2=\frac{{{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HDA0000382026620000011.png"\; state="\{\{state\}\}">V</figure-callout>}}_2}^{\&prime;}}{I_n},---(5.3)$

$R_3=\frac{{V_3}^{\&prime;}}{I_n}---(5.4)$

3. referring to Fig. 5, under leakage of current measurement pattern, by electric current I _minject electric current I from emission electrode A _mreturn from the loop electrode B on ground.By the voltage V between measuring probe C and probe D ₁, the voltage V between probe D and probe E ₂and the voltage V popping one's head between E and probe F ₃the C that estimates to pop one's head in is leaked to the electric current on stratum in to probe E, probe D to the F interval of popping one's head in.Calculating the electric current of popping one's head between C and probe D on sleeve pipe based on Ohm's law is V ₁/ R ₁, the electric current between probe D and probe E is V ₂/ R ₂, the electric current between probe E and probe F is V ₃/ R ₃.The difference of two continuous electric currents is just respectively the electric current that is leaked to stratum in different intervals, is:

$\mathrm{\&Delta;}{I}_a=\frac{V_1}{R_1}-\frac{V_2}{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HDA0000382026620000011.png"\; state="\{\{state\}\}">R</figure-callout>}}_2},---\left(5.5\right)$

$\mathrm{\&Delta;}{I}_b=\frac{V_2}{R_2}-\frac{V_3}{R_3}---\left(5.6\right)$

According to Ohm's law, under leakage of current measurement pattern, the electromotive force producing on sleeve pipe and stratum is QI _m, reference potential is now QI _m.(5.7)

4. by the apparent resistivity formula on formula (5.2), (5.3), (5.4), (5.5), (5.6) and (5.7) substitution stratum

can obtain respectively:

Cannula C to E section the resistivity on corresponding stratum

wherein, K=k Δ z, k is calibration factor, Δ z is the half of C and E distance.

Sleeve pipe D to F section the resistivity on corresponding stratum

wherein, K=k Δ z, k is calibration factor, Δ z is the half of D and F distance.

Here it is to be noted, the embodiment of the present invention can base area layer resistivity practical measurement requirement, increase voluntarily the quantity of measuring probe on sleeve pipe, thereby realize in one-shot measurement, complete the measurement of multiple resistivity that are adjacent to interval simultaneously, and be not only confined to the use of 4 measuring probes set in the present embodiment.

The measuring method of the formation resistivity that the embodiment of the present invention provides and system, realize in one-shot measurement by multiplexing measuring probe, complete the measurement of multiple resistivity that are adjacent to interval simultaneously, thereby do not increasing on the basis of tool length and complexity, improve the measurement efficiency of instrument, and then improved the service efficiency of instrument.The present invention, by electrode is set in pairs, on the one hand, can ensure that probe applies enough large pressure to pierce through wax deposition corrosion layer to casing wall, realizes the measurement of voltage; On the other hand, in the time that losing efficacy, a probe had probe for subsequent use to use, to ensure normally carrying out of formation resistivity measurement operation.Step of the present invention is clear and definite, effect is remarkable, practical.

It should be noted last that, above detailed description of the invention is only unrestricted in order to technical scheme of the present invention to be described, although the present invention is had been described in detail with reference to example, those of ordinary skill in the art is to be understood that, can modify or be equal to replacement technical scheme of the present invention, and not departing from the spirit and scope of technical solution of the present invention, it all should be encompassed in the middle of claim scope of the present invention.

Claims (9)

1. a measuring method for formation resistivity, is characterized in that, comprising:

At least 2 emission electrodes, at least 1 reference potential electrode and at least 4 measuring probes are set on the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument; At least 2 loop electrodes are set on the ground;

By electric current I _oinject a described emission electrode, described electric current I _oflow out from a described loop electrode; Measure the current potential V of described reference potential electrode corresponding to a described loop electrode _o; The all-in resistance Q that obtains measure portion sleeve pipe and stratum based on Ohm's law is:

By electric current I _ninject a described emission electrode, described electric current I _nflow out from another emission electrode; The voltage of measuring between every 2 continuous described measuring probes is respectively V ₁', V ₂' and V ₃'; The resistance obtaining between every 2 continuous measuring probes based on Ohm's law is respectively:

$R_3=\frac{{V_3}^{\&prime;}}{I_n};$

By electric current I _minject a described emission electrode, described electric current I _mflow out from a described loop electrode; The voltage of measuring between every 2 continuous described measuring probes is respectively V ₁, V ₂and V ₃; The electric current obtaining between every 2 continuous measuring probes based on Ohm's law is respectively V ₁/ R ₁, V ₂/ R ₂and V ₃/ R ₃; The electromotive force producing on sleeve pipe and stratum is QI _m, reference potential is now QI _m; The difference of two continuous electric currents is just respectively the electric current that is leaked to stratum in different intervals, is:

$\mathrm{\&Delta;}{I}_a=\frac{V_1}{R_1}-\frac{V_2}{R_2},$ $\mathrm{\&Delta;}{I}_b=\frac{V_2}{R_2}-\frac{V_3}{R_3};$

The apparent resistivity formula on the electric current substitution stratum on stratum will be leaked in described reference potential and described different interval

and by the resistance substitution apparent resistivity formula between described every 2 continuous measuring probes, obtain 3 formation resistivities between described continuous measuring probe

and formation resistivity between other 3 described continuous measuring probes

wherein, V is reference potential; Δ I is the electric current that is leaked to stratum; K=k Δ z, k is calibration factor, Δ z is the half of the maximum spacing of described 3 continuous measuring probes.

2. the measuring method of formation resistivity as claimed in claim 1, is characterized in that, the measuring method of described calibration factor k comprises:

Measure the voltage between reference potential, described every 2 continuous measuring probes and measure electric current at non-measurement formation interval; The formation resistivity of the described non-measurement formation interval based on known and Δ z inverse go out calibration factor k; Particularly, formation resistivity formula is converted to $K=\mathrm{\&rho;}/\left(Q\frac{I_m}{I_n}{(\frac{V_2}{V_2^{\text{'}}}-\frac{V_3}{{V_3}^{\&prime;}})}^{-1}\right),$ Inverse obtains $k=\frac{K}{\mathrm{\&Delta;z}}.$

3. the measuring method of formation resistivity as claimed in claim 2, it is characterized in that, the step that at least 1 reference potential electrode and at least 4 measuring probes are set on the described sleeve pipe crossing sleeve pipe formation resistivity logging instrument is specially: on the sleeve pipe of crossing sleeve pipe formation resistivity logging instrument, 2 reference potential electrodes and 8 measuring probes are set, and described reference potential electrode is that horizontal symmetrical is arranged on described sleeve pipe, described measuring probe be every two be one group from top to bottom horizontal symmetrical be arranged on sleeve pipe.

4. the measuring method of formation resistivity as claimed in claim 3, is characterized in that, described in every group, measuring probe is set in qually spaced on described sleeve pipe from top to bottom.

5. the measuring method of formation resistivity as claimed in claim 4, is characterized in that, described reference potential electrode is arranged on the top of described measuring probe.

6. a measuring system for formation resistivity, is characterized in that, comprising:

Installation module, for arranging at least 2 emission electrodes, at least 1 reference potential electrode and at least 4 measuring probes on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument; At least 2 loop electrodes are set on the ground;

The first resistance measuring module, for by electric current I _oinject a described emission electrode, described electric current I _oflow out from a described loop electrode; Measure the current potential V of described reference potential electrode corresponding to a described loop electrode _o; The all-in resistance Q that obtains measure portion sleeve pipe and stratum based on Ohm's law is:

The second resistance measuring module, for by electric current I _ninject a described emission electrode, described electric current I _nflow out from another emission electrode; The voltage of measuring between every 2 continuous described measuring probes is respectively V ₁', V ₂' and V ₃'; The resistance obtaining between every 2 continuous measuring probes based on Ohm's law is respectively: $R_1=\frac{{V_1}^{\&prime;}}{I_n},R_2=\frac{{V_2}^{\&prime;}}{I_n},R_3=\frac{{V_3}^{\&prime;}}{I_n};$

Current measurement module, for by electric current I _minject a described emission electrode, described electric current I _mflow out from a described loop electrode; The voltage of measuring between every 2 continuous described measuring probes is respectively V ₁, V ₂and V ₃; The electric current obtaining between every 2 continuous measuring probes based on Ohm's law is respectively V ₁/ R ₁, V ₂/ R ₂and V ₃/ R ₃; The electromotive force producing on sleeve pipe and stratum is QI _m, reference potential is now QI _m; The difference of two continuous electric currents is just respectively the electric current that is leaked to stratum in different intervals, is:

$\mathrm{\&Delta;}{I}_a=\frac{V_1}{R_1}-\frac{V_2}{R_2},$ $\mathrm{\&Delta;}{I}_b=\frac{V_2}{R_2}-\frac{V_3}{R_3};$

Computing module, for being leaked to the apparent resistivity formula on the electric current substitution stratum on stratum in described reference potential and described different interval

and by the resistance substitution apparent resistivity formula between described every 2 continuous measuring probes, obtain 3 formation resistivities between described continuous measuring probe

and formation resistivity between other 3 described continuous measuring probes wherein, V is reference potential; Δ I is the electric current that is leaked to stratum; K=k Δ z, k is calibration factor, Δ z is the half of the maximum spacing of described 3 continuous measuring probes.

7. the measuring system of formation resistivity as claimed in claim 6, is characterized in that, also comprises: calibration factor measuring unit, for measuring the voltage between reference potential, described every 2 continuous measuring probes at non-measurement formation interval and measuring electric current; The formation resistivity of the described non-measurement formation interval based on known and Δ z inverse go out calibration factor k; Particularly, formation resistivity formula is converted to $K=\mathrm{\&rho;}/\left(Q\frac{I_m}{I_n}{(\frac{V_2}{V_2^{\text{'}}}-\frac{V_3}{{V_3}^{\&prime;}})}^{-1}\right),$ Inverse obtains $k=\frac{K}{\mathrm{\&Delta;z}}.$

8. the measuring system of formation resistivity as claimed in claim 7, is characterized in that, described installation module comprises:

The first installation unit, for 2 reference potential electrodes and 8 measuring probes being set on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, and described reference potential electrode is that horizontal symmetrical is arranged on described sleeve pipe, described measuring probe be every two be one group from top to bottom horizontal symmetrical be arranged on sleeve pipe;

The second installation unit, on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, 2 emission electrodes being set, arranges 2 loop electrodes on the ground.

9. the measuring system of formation resistivity as claimed in claim 8, is characterized in that, described the first installation unit, comprising:

First installs subelement, on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, 8 measuring probes being set, and measuring probe every two be one group from top to bottom horizontal symmetrical be set in qually spaced on sleeve pipe;

Second installs subelement, and on the sleeve pipe crossing sleeve pipe formation resistivity logging instrument, 2 reference potential electrodes being set, and described reference potential electrode is that horizontal symmetrical is arranged on described sleeve pipe, and reference potential electrode is arranged on the top of described measuring probe.

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