RU96103393A - METHOD FOR DETERMINING AN AZIMUT AND ANTI-GRAIN ANGLE OF A WELL AND A GYROSCOPIC INCLINOMETER - Google Patents

Claims (5)

1. The method of determining the azimuth and zenith angle of the well by means of a gyroscopic inclinometer, including measuring the acceleration of gravity along two mutually perpendicular axes, measuring the angular velocity relative to one of the above axes using a three-degree gyroscope, determining the initial orientation of the sensitivity axes of acceleration meters in azimuth, calculating the azimuth and zenith angle of the well, characterized in that the sensitivity axis of the acceleration meters and the sensitivity axis of the angular velocity meter the axes stabilize relative to the axis coinciding with the longitudinal axis of the downhole tool, at each step of the calculator when the downhole tool is moving in the well, the azimuth and zenith angle of the well are determined, for example, by the formulas

where i + 1 is the current step of the calculator;
b $\genfrac{}{}{0ex}{}{\text{i + 1}}{\text{lq}}$ , l, q∈ [1,3] - elements of the orientation matrix B ^{i + 1} , which is formed as a product of matrices
B ^{i + 1} = ΔB ^{i + 1} • B ⁱ ,
where B ⁱ , B ^{i + 1} - orientation matrix at the previous and current steps of the calculator;

the increment of the orientation matrix, the elements of which are determined depending on the orientation angles θ _x , θ _y , θ _z according to the formulas

where ω $\genfrac{}{}{0ex}{}{\text{Pack}}{\text{dr}}$ - the angular velocity of the drift axes of sensitivity of the accelerometers and angular velocity relative to the stabilization axis;
Ω $\genfrac{}{}{0ex}{}{\text{i}}{\text{up}}$ - projection of the angular velocity of the Earth's rotation on the axis of stabilization;

elements of the orientation matrix formed by measuring projections a $\genfrac{}{}{0ex}{}{\text{i + 1}}{\text{x}}$ , a $\genfrac{}{}{0ex}{}{\text{i + 1}}{\text{z}}$ acceleration of gravity g;
τ is the sampling period of the calculator, and, the initial value of the orientation matrix is

where α _xв - azimuthal angle of the axes of sensitivity of the acceleration meters at the end of the exhibition. 2. The method for determining the azimuth and zenith angle of a well according to claim 1, characterized in that to determine the azimuthal angle of the sensitivity axes of the acceleration meters at the time of the end of the exhibition, these axes are rotated around the stabilization axis at a constant speed by a predetermined angle, and the rotation angle of these axes relative to the housing, the horizontal component Ω _sr Earth's angular velocity in conjunction with the angular velocity of the gyroscope relative drift, sensitivity axis being the axis of the meter the angular velocity is calculated from measurements of the average angular velocity ω of rotation of the platform _in, systematic component gyro drift ω $\genfrac{}{}{0ex}{}{\text{with}}{\text{dr}}$ and form a reference model of the measured angular velocity
ω _ej = ω $\genfrac{}{}{0ex}{}{\text{with}}{\text{dr}}$ + Ω _zg sin (ω _in • j + φ _x ),
where j is the measurement number; φ _x is the phase shift
and to estimate the phase shift, a residual function is calculated that represents the sum of the squares of the difference of the reference ω _{ej /} and the measured ω _j angular velocities over the entire set of measurements, which is minimized by the phase shift, and the azimuthal angle of the sensitivity axes of the acceleration meters at the time the exhibition ends is determined by the formula
α _xb = ψ _in -ψ ₁ + α _x1 ,
where ψ ₁ , ψ _in - the angle of rotation of the axes of sensitivity of the acceleration meters relative to the body of the downhole tool around the axis of stabilization at the moments of the beginning and end of the exhibition;
α _x1 is the azimuthal angle of the sensitivity axes of the acceleration meters at the beginning of the exhibition, which is equal to the phase shift φ _x minimizing the residual function.  3. A gyroscopic inclinometer containing a downhole tool, equipped with an acceleration meter along two mutually perpendicular axes that are perpendicular to the longitudinal axis of the downhole tool, and an angular velocity meter relative to one of the two indicated axes, consisting of a three-stage gyroscope with angular sensors and sensors mounted on its suspension axes moments, and the first angle sensor on the measuring axis of the gyroscope is connected through an amplifier of the loop for measuring the angular velocity to the second torque sensor, perpendicular bright to the axis angle sensor, a ground computer connected by a logging cable to the downhole tool, characterized in that the downhole tool contains a uniaxial gyrostabilizer, on the platform of which an acceleration meter is rigidly mounted with sensitivity axes oriented perpendicular to the gyro stabilizer stabilization axis and a three-stage gyroscope, the second angle sensor through the amplifier stabilization is connected to the mining engine, kinematically connected with the stabilization axis, on which the output angle sensor is fixed, made, for example, in the form of a sine-cosine transformer, and a digital processing unit, to the corresponding inputs of which are connected the outputs of the gyro stabilizer angle sensor, the outputs of the acceleration meter and the output of the angular velocity meter, the first output of the digital processing unit being connected to the control input of the reference current master, signal the output of which is connected to the first gyroscope moment transducer located on an axis perpendicular to the stabilization axis, and the wireline cable is connected with its second inputs to the second and t etim outputs a digital processing unit.  4. The gyroscopic inclinometer according to claim 3, characterized in that the digital processing unit contains a single-chip microcomputer, a transceiver, three two-channel voltage-frequency converters and three two-channel reversible counters, the ports P0 and P2 of a single-chip microcomputer programmed to the input connected to their inputs with the corresponding outputs of the least significant and highest bytes of the data bus of the reversible counters, port P1, programmed for output, with bits from P1.0 to P1.5, is connected respectively to the sampling resolution inputs and p read permissions of the corresponding reversible counters, bit P1.6 is connected to the polling inputs of all reversible counters, and bit P1.7 is connected to the synchronization inputs of all voltage-frequency converters and reversible counters, port discharge P3.0, programmed to issue a control command, is connected to the first output of the digital processing unit, the inputs of the voltage-frequency converters are respectively the inputs of the digital processing unit, and the bits of the port P3.1 and P3.2 of a single-chip microcomputer, programmed to solid input / output, connected through the transceiver to the logging cable and are the input / output of the downhole tool.  5. The gyroscopic inclinometer according to claims 3 and 4, characterized in that it contains a temperature sensor that signals the temperature in the downhole tool, the output of which is connected to one of the inputs of the digital processing unit.