Dynamic solution approach to inclination and azimuth of strap-down rotary steerable system

Key words:  drillings  rotary steerable  dynamic resolution  stick-slip  accelerometers  flux gate  strap-down

Abstract:

According to strap-down vertical drilling field test, the playback analysis on underground storage of the measurement system was curried out. A dynamic resolution approach to inclination and azimuth of strap-down rotary steerable system was proposed, that is, with non rotating stringt filtered real time signals on three-axis was ali used for calculation, at the same time, filtered signals on x-axis, j-axis were stored. On the condition of rotation string, real time filtered signals on z~ axis and stored signals of %-axis, y-axis with non-rotating string were adopted. In addition, stick-slip state of the downhole drilling tools was seen as a non-rotating M stationary" state. Real-time judgement method of string rotation state based on downhole survey data was proposed, and solution equation and dynamic solution process of deviation azimuth were given.And simulation in Matlab was done. The results show that the drill string vibration caused by rotation is the main reason for measurement error of deviation azimuth. The recommended dynamic survey approach could effectively enhance measurement precision, and deduce the effect of vibration on resolving results.