RU2490448C1 - Device for positional control of horizontal borehole - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device is composed of the following components: main and directional units of gamma-ray logging sensors installed in MWD casing. The directional unit of gamma-ray logging sensors is placed into a lead case with a window to register directional gamma-ray emission which is interrelated physically with a deflector position. The units of gamma-ray logging sensors are placed into a measuring gamma-module with a wire communication channel and MWD unit and are equipped with an electronic circuit for MWD signals matching with pulses of gamma-ray logging sensors.

EFFECT: improving accuracy of gamma quantum registration, simplifying the design and optimisation of control efficiency during horizontal and directional sidetracking.

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Description

The invention relates to drilling equipment and is intended to control the position of the horizontal wellbore between the roof and the bottom of the reservoir - collector, as well as for lithological dissection of the section during drilling.

A device for monitoring the position of the horizontal wellbore between the roof and the bottom of the reservoir - collector. The device comprises gamma-ray sensors installed in the immediate vicinity of the bit, oriented at an angle of 180 ° to each other, and a flux probe located at an angle of 90 ° to the diametrical axis of the gamma-ray sensors. Gamma-ray and flux-gage sensors are located in a separate measuring bitmap module with a wireless electromagnetic communication channel and are equipped with an electronic circuit for matching flux-gate signals with pulses of gamma-ray sensors. The electronic signal matching circuit includes a control unit, a gamma-ray sensor pulse switching switch, gamma-ray pulse counters, and a total gamma-ray pulse counter. The output of the measuring winding of the flux gate is connected to the input of the control unit, which determines the polarity of the output signal of the flux gate and connected to the switch. The switch provides switching channels of the passage of pulses of gamma-ray log meters, depending on the polarity of the output of the flux-gate, to the corresponding gamma-ray pulse counters, designated as GK - “top” or GK - “bottom”, the outputs of which are connected to the total gamma-ray pulse counter - “sum” connected to the measuring circuit of the over-bit module. (Patent RU 2362012, class Е21В 47/02, G01V 3/30, priority 01/21/2008).

A disadvantage of the known device is the absence in the design of elastic elements that significantly dampen mechanical vibration and shock, which reduces the reliability of the device as a whole, as well as the rigid installation of the sensors in the housing, which leads to the collision of the sensors when exposed to vibration and shock. In addition, the design is subject to the influence of large loads and vibrations, which affects the registration characteristics.

Known equipment for determining the direction of the well during drilling in the form of a structure with a directional gamma-ray sensor, containing a series of Geiger-Muller counters located in a pipe segment above the drill bit and several magnetic and gravity sensors that provide directional characteristics during the rotation of gamma-ray sensors . These orientation sensors include accelerometers and magnetometers suitable for detecting changes in the orientation and position of the instrument sub. Accelerometers are able to detect in real time a rotational displacement from the standard as it occurs during drilling. Magnetic flux sensors, or magnetometers, facilitate the detection of the azimuthal orientation of the device based on the Earth's magnetic field. (Patent WO 02082124, class Е21В 47/022, G01V 3/38, priority 04/06/2001, prototype).

According to accelerometers, the apsidal angle of the gravimeter and the orientation of a number of gamma - counters can be calculated. The magnetometer output is a sine wave, the period of which is the speed of rotation, and the amplitude of which represents the position of the device in the Earth's magnetic field. During rotation, the magnetometer output is measured and its amplitude is determined from peak to peak. Possessing this information and applying well-known mathematical formulas, they establish the angular position of the magnetometer at any given moment.

A disadvantage of the known equipment is the complexity of the design, which contains a number of Geiger-Muller counters and a special mechanism with a step motor for positioning windows for transmitting radiation. In addition, up to 8 magnetometers and several accelerometers are used here, which also complicates the signal processing scheme and their coordination with the readings of gamma counters.

The objective of the invention is to simplify the design and increase the efficiency of controlling the wiring process during horizontal drilling, in particular in low-power formations.

This problem is solved in that the device for monitoring the position of the horizontal wellbore contains the main and directional blocks of gamma-ray sensors installed in the housing of the television system. The directed block of gamma-ray sensors is placed in a lead case with a window for detecting directional gamma radiation, which is physically related to the position of the diverter. The gamma-ray sensor blocks are located in the gamma-ray measuring module with a wired communication channel with the telesystem unit and are equipped with an electronic circuit for matching the telesystem signals with gamma-ray sensor pulses, containing a control unit, a switch for switching the power supply to the gamma-ray sensor blocks, and a direct current source , high-voltage power supplies, gamma-ray pulse counters, microprocessor. In this case, the output of the telesystem signals is connected to the input of the control unit, which determines the type of the telesystem output signal and is connected to the switch, which switches the power supply to one of the gamma-ray sensor blocks depending on the type of the telesystem output signal.

Figure 1 shows the housing of the measuring gamma module with blocks of gamma-ray sensors.

Figure 2 shows a diagram of the matching signals of the telesystem with the pulses of the gamma-ray sensors.

The measuring gamma module 1 comprises a main block of gamma-ray sensors 2 and a directional block of gamma-ray sensors 3, which is placed in a lead case 4 with a window for detecting directional gamma radiation 5, which is physically related to the position of the diverter. These sensors are placed in the recesses of the housing of the measuring gamma module 1 with a wired communication channel that transmits information to the receiving module of the main television system that provides the well wiring.

Figure 2 shows the matching scheme of the signals of the telesystem with the pulses of the main and directional block of gamma-ray sensors. It contains a control unit 6, to which the signal output of the telesystem 7 is connected, a direct current source 8 is connected to the input of the switch 9. The switch 9 is connected to the input of the high-voltage power supply 10 of the main block of gamma ray sensors 2 and the input of the high-voltage power supply 11 of the directional block of gamma sensors logging 3. The outputs of the pulse counter 12 of the main block of gamma-ray sensors 2 and the outputs of the pulse counter 13 of the directed block of gamma-ray sensors 3 are connected to the input of the microprocessor 14.

The device operates as follows.

In the process of drilling a well through a reservoir, gamma radiation is measured by the main unit of gamma-ray sensors 2, which measures the gamma radiation of all the rocks surrounding it and the readings are transmitted to microprocessor 14 and then to the receiving module of the main telesystem providing well wiring. The reservoir (sandstone) is characterized by significantly underestimated values of gamma radiation, in contrast to the overlapping rocks (clay). The average value of natural radioactivity for sandstone is 10-15 Bq / kg, for clay - 50-80 Bq / kg. An increase in gamma radiation values in the direction of drilling indicates that the drilling arrangement is approaching the boundary of the reservoir. In order to determine in which direction the values of gamma radiation increase, the signal from the television system 7 enters the control unit 6, which determines the type of signal and controls the operation of the switch 9, and he, in turn, switches the power supply from the DC source 8 to the directional block of gamma-ray sensors 3 through a high-voltage power supply 11. After switching to the directional block of sensors of gamma-ray logs 3, the drilling assembly is rotated 360 ° with simultaneous measurement of gamma radiation in each Turning sector unit directed gamma ray sensors 3. Analysis operator received gamma values allows to locate bed boundaries relative to the drill tool arrangement and control the drilling process.

Claims (1)

A device for monitoring the position of the horizontal wellbore, comprising the main and directional gamma-ray sensor blocks installed in the television system casing, the directional gamma-ray sensor block placed in a lead case with a window for detecting directional gamma radiation, which is physically related to the position of the diverter, sensor blocks gamma-ray logs are located in the measuring gamma-module with a wired communication channel with the telesystem unit and are equipped with an electronic circuit for matching the telesystem signals with pulses the gamma-ray sensors themselves, containing the control unit, a switch for switching the power supply to the gamma-ray sensor blocks, a direct current source, high-voltage power sources, gamma-ray pulse counters, a microprocessor, while the signal output of the tele-system is connected to the input of the control unit that determines the type the output signal of the telesystem and connected to the switch, providing switching the power supply to one of the gamma-ray sensor blocks depending on the type of the telesystem output signal.

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