RU2541990C1 - Control system of mutual orientation process of shafts during cluster drilling of oil and gas wells - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: control system of mutual orientation process of shafts during cluster drilling of oil and gas wells is suggested; the system comprises the core body including power supply source, electromagnetic oscillator made as dipole installed over bit of the drilling well (DW) thus ensuring electromagnetic coupling between DW string and at least one production string (PS) of drilled holes (DH) and the surface part including converter of the parameter being function of electrical performance for a section of the circuit formed by DW string and rock in the vicinity of dipole area to voltage and m converters of the parameter being function of electrical performance for a section of the circuit formed by PS DH and a section of the rock lying between DW bit and PS DH to voltage, where m is a number of PS. At that the above converters are made as toroidal inductance coils placed axially at the wellhead (DW), and m of the same coils is placed at the wellhead, where m≥1; value of current induced in pipe strings is selected as electrical performance for rock sections and is defined as per the mathematical expression specified above.

EFFECT: improved accuracy for determination of a drilling well position in regard to unlimited quantity of production strings of wells drilled earlier with number identification for these wells.

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Description

The invention relates to the field of drilling directional wells, mainly by a cluster method on land and at sea using a telemetry system, and is intended to control the relative position of the wells in order to prevent the meeting of their trunks.

A well-known system for preventing the occurrence of trunks during cluster drilling of oil and gas wells, consisting of a vibration sensor or vibration sensors, a signal-conversion amplifier, a process controller, a recording device in the form of a personal computer with software, a warning device in the form of means (light and / or sound) alarm.

A vibration sensor or vibration sensors are installed at the wellhead of the production well and connected to a signal conversion amplifier. The signal converter amplifier is connected to a technological controller, the outputs of which are respectively connected to a personal computer with software and a warning device.

The communication between the devices of the warning system for meeting boreholes during cluster drilling of oil and gas wells is carried out via a wire (cable) or combined (wire and radio) line (US Pat. No. 2235844, prior. February 25, 2003, publ. September 10, 2004).

When using elastic waves propagating from the bit of a well being drilled along a production well, it is possible to completely attenuate it due to the quenching of the rock located between the well being drilled and the production string. In addition, the application of the known solution is limited by the ability to determine the proximity or removal of the well being drilled relative to only one column of a previously drilled well.

The closest in technical essence and the achieved result to the proposed one is a control system for the process of mutual orientation of the shafts during cluster drilling of oil and gas wells, containing a deep part, including an electromagnetic oscillation generator, made in the form of a dipole mounted above the bit, providing electromagnetic coupling between the well being drilled and at least one production casing of a previously drilled well, and the surface part, including a complex transducer the apparent electrical resistance of the section of the circuit formed by the drill string and rock near the dipole region to voltage and n converters of the complex electrical resistance of the section of the circuit formed by the production string and the rock section enclosed between the bit of the well being drilled and the production string of the previously drilled well, where n is the number of previously drilled wells, the outputs of these n converters of complex electrical resistance to voltage are connected to the information inputs of the switch, the output of which is the converter of the complex electrical resistance of the circuit section formed by the drill string and rock near the dipole region, the voltage is connected to the input of the adder connected to the filter, connected through a reference amplifier to a comparison circuit with a reference voltage, the output of which connected to the input of the technological controller, the information output of which is connected to the input of the memory unit, and the control outputs are connected to the control input of the comm Tatorey and signaling and control inputs mud pump units (US Pat. RF №2405106, prior. 06/18/2009, publ. 11/27/2010).

A disadvantage of the known system is the use as an informative parameter of the voltage amplitude proportional to the complex resistance of the circuit (rock) section between the bit of the well being drilled and the production string, the value of which under the conditions of anisotropy of different layers, will be a function of not so much the distance between them (as it would be in isotropic medium), and depend on the properties of the formation currently being drilled by a bit in the well being drilled, and therefore, have an unpredictable case Ayny character. When using such a communication channel, there is a high probability of false positives of the system about the critical approximation of the boreholes of the well being drilled and the production casing of the previously drilled well, and vice versa, the erroneous determination of the sufficiency of removal at its actual critical values.

In addition, in conditions of common grounding of the production casing and the ground equipment of the drilled well through the piping, it is extremely difficult to isolate individual complex resistances of the sections of the “production casing-bit of the drilled well” circuit.

The objective of the invention is to increase the accuracy of determining the relative position of the bottom of the wells being drilled and to ensure the reliability of the system in the process of controlling the proximity or removal of the wells being drilled with respect to an unlimited number of production cores of previously drilled wells with identification numbers of these wells.

The problem is solved in that in the control system for the process of mutual orientation of the trunks during cluster drilling of oil and gas wells, containing a deep part, including a power source and an electromagnetic oscillation generator, made in the form of a dipole installed in the well being drilled, providing electromagnetic coupling between the well being drilled wells and at least one production string of a previously drilled well, and the surface part, including a parameter converter, which is a function of the electrical characteristic of a section of a circuit formed by a drill string and rock near a dipole region into voltage and m converters of a parameter that is a function of the electrical characteristic of a section of a circuit formed by a production string of a previously drilled well and a piece of rock enclosed between the bit of the drilled well and production a string of previously drilled wells, in tension, where m is the number of previously drilled wells, in contrast to the known technical solution Iya (US Pat. 2405106) these transducers are made in the form of a toroidal inductor (coil) located coaxially in the upper part of the column at the mouth of the well being drilled, and m coils located in the upper part of the production string at the mouth of previously drilled wells, where m is the number of previously drilled wells (at m≥1). At the same time, the value of the current parameter induced in the pipe columns by the electromagnetic oscillation generator was selected as the electrical characteristic of the rock sections.

In addition, the outputs of these m coils are equipped with strip amplifiers of a signal supplied to a voltage recorder connected to the information inputs of a switch, the output of which is connected to the input of an adder connected to a filter connected through a reference amplifier to a comparison circuit with a voltage reference, which serves as the output of the toroidal coils of a well being drilled. The latter is a guarantee of a correct comparison of currents even with strong changes (surges) in the current supplied to the column by an AC source with a modulation and current supply unit (power source).

The output of the comparison circuit is connected to the input of the technological controller, the information output of which is connected to the input of the memory unit, and the control outputs are connected to the control input of the switch and the inputs of the alarm and control units of the mud pump.

The solution of the problem in the present invention is achieved through the use of the magnitude of the induced current in the pipe columns and the use of an electromagnetic communication channel, which increases the reliability of determining the relative position of the wellbores.

The invention is illustrated by figure 1, which shows a General diagram of a control system for the process of mutual orientation of the shafts during cluster drilling of oil and gas wells, figure 2, where a block electronic circuit of the system is given, and figure 3, which shows a diagram of a device for converting induced current in columns into voltage (converter).

The control system for the process of relative orientation of the trunks during cluster drilling of oil and gas wells (Fig. 1) contains an alternating current source 2 with a modulation and supply unit for the column (power source) installed in the column of the drilling well 1 (deep part), an electromagnetic oscillation generator 3 made in the form of a dipole 5 mounted above the bit 4 with a dielectric insert 6 dividing the column into the upper part 7 and the lower part 8, and providing electromagnetic coupling between the column of the well being drilled 1 and at least with at least one production casing of a previously drilled well 9, and the ground part, including one parameter transformer 10, which is a function of the electrical characteristic of the circuit section formed by the drill string 1 and rock near the dipole region, into voltage and m parameter transformers 11, which is a function electrical characteristics of the section of the circuit formed by the production string of the previously drilled well 9 and the rock section, concluded between the bit 4 of the drilled well 1 and production string previously drilled wells 9, in voltage, where m is the number of previously drilled wells (with m≥1).

These transducers 10 and 11 are made in the form of a toroidal inductor (coil) 12 located coaxially in the upper part of the column at the mouth 13 of the drilled well 1, and m of the same coils 12 ₁ , 12 ₂ , ..., 12 _m located in the upper part of the operational columns at the mouth of previously drilled wells 9, where m is the number of previously drilled wells (with m≥1) (figure 3).

Moreover, as the electrical characteristics of the rock sections, the value of the current parameter induced in the pipe columns by an alternating current source 2 (Fig. 3) was selected.

In the electronic circuit of the system (Fig. 2), the outputs of the indicated m coils (12 ₁ , 12 ₂ , ..., 12 _m ) are connected to the information inputs of the switch 14, the output of which is connected to the input of the adder 15 connected to the filter 16 connected through the model amplifier 17 to the comparison circuit 18 with the reference voltage value, which is the output of the coil 12 of the well being drilled 1. The latter is a guarantee of the correct comparison of currents even with strong changes (jumps) in the current of the electromagnetic oscillation generator.

The output of the comparison circuit 18 is connected to the input of the technological controller 19, the information output of which is connected to the input of the memory unit 20, and the control outputs are connected to the control input of the switch 14 and the inputs of the alarm and control units of the mud pump 21.

In the upper part of the column of a previously drilled well 9, one or more ground coils 12 can be located one above the other (three coils are shown in Fig. 3) with strip amplifiers of a signal 22 supplied to a voltage recorder 23 connected to a switch 14. A magnetic circuit 24 of coils made in the form of a cylinder, the height of which H significantly exceeds its thickness d, and is installed coaxially to the column at the wellhead 13. The coil 12 with the magnetic circuit 24, the signal converter 22 and the voltage recorder 23 form a converter 10 (11).

The technology controller 19 controls the operation of the switch 14 in accordance with a pre-programmed algorithm for interrogating production wells 9. In addition, the technology controller allows you to identify the number of the production well to which the well is being drilled, due to the fact that the corresponding signal from the switch 14 is identified with the number of the well, to the casing of which bit 4 is approaching at a minimum close distance.

The device operates as follows.

The column of the well being drilled 1 is divided by a dielectric insert 6, the electromagnetic oscillation generator is made in the form of a dipole 5 mounted above the bit 4, providing electromagnetic coupling between the column of the well being drilled 1 and at least one production casing of a previously drilled well 9 (Fig. 1).

At the bottom of the borehole 1 using an alternating current source 2 with a modulation and current supply unit into the pipe string 1, separated by a dielectric insert 6, a modulated informative (useful) signal is supplied to the pipe bore through the pipe 1, which generates a coaxial current passing through the pipe 1 the column 1 is an electromagnetic field that creates an alternating magnetic flux of electromagnetic induction, penetrating the turns of coils 12 ₁ , 12 ₂ , ..., 12 _m at the mouth of a previously drilled well 9 and, accordingly, the EMF variable at the terminals of this coil (Fig. 3).

The shape of the emf taken from the coil is determined by the encryption module of the downhole measurement unit (not shown due to the well-known). Thus, a useful signal is the change in voltage at the terminals of the coil, which is a function of the alternating current flowing in the drill pipe string, determined by the variable EMF of the alternating current source.

Next, the signal is processed by the electronic circuit (figure 2) and enters the comparison circuit 18, where it is compared with the reference voltage value, which is the output of the coil 12 of the borehole 1 being drilled.

The output of the comparison circuit 18 is connected to the input of the technological controller 19, the information output of which is connected to the input of the memory unit 20, and the control outputs are connected to the control input of the switch 14 and the inputs of the alarm and control units of the mud pump 21.

Thus, during the drilling of well 1 in the space between the bit 3 of the well being drilled 1 (bottom part 7 of dipole 5) and the column of the previously drilled well 9, the volume of the rock changes and, as a result, the currents induced in the production casing of the previously drilled well 9 change. Tracking the change in the effective values of currents I _rms :

Where

I _rms is the effective value of currents, A;

I (t) is the magnitude of the induced current, A;

(T ₂ -T ₁ ) is the time period of integration, not less than 100 periods of electromagnetic waves of the generator of electromagnetic waves, s;

t is the time, s;

and comparing them with the current in the pipe string of the drilling well 1, it becomes possible to obtain information about the distance between the bit of the drilling well 1 and the string of the previously drilled well 9. The distance between the wells is inversely proportional to the current, which is measured using EMF (voltage) at the clamps of the coil.

Based on the information received, in real time, the value of the monitored distance is compared with the a priori set maximum value of the distance and when it is reached, the mud pump is turned off and / or prompt by sound and light alarms.

Claims (2)

1. A control system for the process of relative orientation of the shafts during cluster drilling of oil and gas wells, comprising a deep part, including a power source, an electromagnetic oscillation generator, made in the form of a dipole installed in the borehole above the bit of the dipole, providing electromagnetic coupling between the column of the borehole and at least one production string of a previously drilled well, and the ground part, including a parameter converter, which is a function of the electrical characteristic ki of the chain section formed by the drill string and rock near the dipole region into voltage, and m converters of the parameter, which is a function of the electrical characteristics of the circuit section formed by the production string of the previously drilled well and the rock section enclosed between the drill bit and the production string earlier drilled wells, in voltage, where m is the number of previously drilled wells, characterized in that the said transducers are made in the form of a toroidal cable carcasses of inductance (coil) located coaxially at the mouth of the well being drilled, and m of the same coils located at the mouth of previously drilled wells, where m is the number of previously drilled wells (at m≥1), while as an electrical characteristic of the rock sections the magnitude of the induced current in the pipe columns, determined by the formula:
$$I_{rms}=\sqrt{\frac{\mathrm{one}}{T_2-T_{\mathrm{one}}}{\displaystyle \underset{T_{\mathrm{one}}}{\overset{T_2}{\int }}{(I(t))}^2\cdot dt}}\text{(one)}$$

,
Where
I _rms is the effective value of currents, A;
I (t) is the magnitude of the induced current, A;
(T ₂ -T ₁ ) is the time period of integration, not less than 100 periods of electromagnetic waves of the generator of electromagnetic waves, s;
t is the time, s. 2. The control system for the process of relative orientation of the shafts during cluster drilling of oil and gas wells according to claim 1, characterized in that the outputs of these m coils are equipped with strip amplifiers of the signal fed to the voltage recorder connected to the information inputs of the switch, the output of which is connected to the input of the adder connected to a filter connected through a reference amplifier to a comparison circuit with a reference voltage value, which is the output of the coil located at the mouth of the well being drilled, at The output of the comparison circuit is connected to the input of the technological controller, the information output of which is connected to the input of the memory unit, and the control outputs are connected to the control input of the switch and the inputs of the alarm and control units of the mud pump.

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