Triolocation compensation algorithm for single-shaft fiber-optic gyroscope in oil well survey

Abstract

The invention discloses a triolocation compensation algorithm for a single-shaft fiber-optic gyroscope in the oil well survey. According to the algorithm, an installation structure of the gyroscope and an accelerometer is adopted, a compensation calculation algorithm is conducted on output values, and the values are recorded by the accelerometer in the motor transposition process; the single-shaft fiber-optic gyroscope and the single-shaft accelerometer are adopted for forming a gyro inclinometer, the fiber-optic gyroscope and the single-shaft accelerometer are mechanically connected with a transposition mechanism through slip rings, the direction and the well deviation of each measuring point can be calculated in a triolocation mode without zero returning operation, transposition is conducted in one direction, operation is conducted cyclically by 0 degree, 90 degrees, 180 degrees, 270 degrees and 360 degrees, and the number of position point data needed in calculation is only three. According to a triolocation treatment method for the single-shaft fiber-optic gyroscope in the oil well survey, measurement time can be shortened, instrument cost is saved, and the algorithm is designed for determining the inclination and the direction of the gyro inclinometer in the fields such as oil logging and mine exploration and is worthy of application and popularization.

Description

technical field [0001] The invention relates to a three-position compensation calculation method for a single-axis optical fiber gyro inclinometer in oil well inclination measurement, and belongs to the application field of petroleum well logging technology. Background technique [0002] Gyro inclinometer is a commonly used instrument for track measurement of oil wells, mines, tunnels, etc. In terms of oil logging, with the depletion of easy-to-exploit oil resources, higher precision and more reliable use are required in the exploration and development of small scattered oil layers and extended-reach wells, highly deviated wells, cluster wells and horizontal wells. The well trace test directional instrument. The significance of this type of test is to re-understand the block and provide a reliable basis for the readjustment of the injection-production well pattern; to help the reservoir tap the remaining oil potential, and to provide a reference for the implementation of pr...

AI Technical Summary

Problems solved by technology

The diameter of the dual-axis dual-accelerometer fiber optic gyro inclinometer reaches Φ70 or more, while the diameter of the oil pipe is generally Φ62, so the dual-axis dual-accelerometer fiber optic gyro inclinometer can only be used for cased well testing and cannot be used for tubing trajectory testing. At the same time, the dual-axis gyroscope needs dual light sources, which generate a lot of heat, and the requirements for the thermos are more stringent, and the working time in the high-temperature environment underground will also be limited.

Single-axis dual-accelerometer fiber optic gyro inclinometers in China use four-position counter-rotation methods for measurement, respectively at 0°, 90°, 180°, and 270°. On the contrary, return to 0° for the next test. The single-point test time reaches more than 5 minutes, which is not only inefficient, but also requires heat preservation in high-temperature environments.

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