Omnibearing continuous measurement method of gyroscopic clinometer

Abstract

The invention discloses an omnibearing continuous measurement method of a gyroscopic clinometer. The method comprises the following steps of: extending the gyroscopic clinometer into a wellbore; establishing an instrument coordinate system OXbOYbOZb and a geographic coordinate system OXiYiZi; and solving a hole deviation angle I, an azimuth angle A and a tool face azimuth T in consideration of earth rotation and instrument movement by using a component formula of angular velocity sensed by a gyroscope on an instrument coordinate system. The method can be used for static single-point measurement and continuous measurement and has high measurement speed; drift correction is not required in a short time; and the method can be used for wellbore track repetition measurement and casing directional window-cutting side tracking, and can be matched with other well logging methods in a cased well under a magnetic interference environment to indicate the azimuth of a measuring instrument. In themethod, an inertial sensor is directly and fixedly connected with the instrument, and the azimuth of an oil well is continuously measured in real time by using a mathematic platform; and compared with a gyroscopic clinometer with a mechanical frame structure, the gyroscopic clinometer provided by the invention has the advantages of wide measurement range, no angular limitation during measurement,high accuracy, low power consumption and the like.

Description

technical field [0001] The invention relates to a method for oil well logging and geological exploration, in particular to a method for omnidirectional continuous measurement by a gyro inclinometer. Background technique [0002] At present, the inclinometers used in oil well logging construction are mainly fluxgate inclinometers. It uses a three-axis orthogonal angular velocity meter to measure the earth's gravitational acceleration, and a three-axis orthogonal fluxgate to measure the geomagnetic field vector. While this inclinometer sensor is reliable, it requires that there be no ferromagnetic material around the fluxgate. However, old wells have casings, which cannot provide a good non-magnetic environment for the inclinometer, so it is impossible to measure the borehole trajectory of old wells by using a fluxgate. [0003] The gyro inclinometer with a mechanical frame structure uses a suspended pendent to provide a vertical reference. When the well axis is inclined, th...

AI Technical Summary

Problems solved by technology

However, since this measurement method is all based on mechanical structure and electromechanical measurement, its accuracy will be greatly limited by the movement accuracy of mechanical components; When the angle is greater than a certain angle (generally > 5°), the accuracy of the azimuth angle can be guaranteed

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