Attitude measurement method

Abstract

The invention provides an attitude measurement method, relates to the technical field of directional drilling measurement while drilling, and aims to improve the observability of an inertial instrument error, inhibit the repeatability error of a gyroscope and improve the attitude measurement precision. According to the method, initial alignment is performed by adopting a method of respectively performing fine alignment at multiple positions. The method comprises the following steps of S1, taking the current attitude and speed data of the gyroscope as a first initial value, and performing finealignment at a first position; S2, enabling a strapdown inertial navigation system to be trans-positioned to the n position, and performing attitude and speed updating according to the last fine alignment result in the trans-positioning process; and S3, taking attitude updating and speed updating results as the n initial value, and performing n fine alignment at the n position to complete initial alignment of the strapdown inertial navigation system so as to realize attitude measurement. The scheme provided by the invention is suitable for horizontal attitude and azimuth measurement of a whole well inclined section of the horizontal well, and is especially suitable for attitude measurement application of directional drilling gyro measurement while drilling in large well inclined shafts and horizontal wells.

Description

【Technical field】 [0001] The invention relates to the technical field of attitude measurement for directional drilling, in particular to an attitude measurement method for large deviated wells and horizontal wells and a gyro-while-drilling measurement method for directional drilling. 【Background technique】 [0002] At present, as the world's exploration field gradually extends to complex areas and special environments, development difficulty and development cost will increase greatly. Wells with complex structures account for an increasing proportion in the exploration and development of oil and gas fields. With the development of directional drilling technology represented by rotary steerable technology, especially in the application of deep and ultra-deep directional drilling, the requirements for the control accuracy of wellbore trajectory are constantly increasing. [0003] The demand for high-end gyroscopes in petroleum exploration and development: Gyroscopes that can ...

AI Technical Summary

Problems solved by technology

[0004] The existing calibration methods only start from the differences in the ability to suppress external environmental interference and the amount of calculation, and do not consider the specific use environment of GMD, that is, harsh environments such as high temperature and strong vibration, which will cause greater damage to inertial instruments. drift error

However, the actual drift error of the inertial instrument will affect the calibration accuracy of the existing calibration method. Under the working conditions of high temperature, strong vibration and harsh environment, the zero bias repeatability error is the main bottleneck restricting the accuracy of the gyroscope.

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