Research and Application of Continuous Monitoring Technology of Annulus Liquid Level Based on Electromagnetic Acoustic Emission
After drilling encounters total lost circulation,the fluid column pressure in the wellbore is lower than the formation pressure for a long time,which easy to cause lost circulation turn to blowout.Currently,the air gun rangefinder is mainly used to monitor the liquid level height of the drilling fluid in the annulus,however,due to the limitation of nitrogen gas cylinder storage,continuous monitoring of annulus liquid level height is not possi-ble,so that it is difficult for on-site operators to timely discover the well control risk.Starting from the study of the attenuation characteristics of the annulus acoustic wave,the structure design of the transmitter is optimized to improve its low-frequency response characteristics.A set of automatic recognition and monitoring system for the annulus liquid level height based on the electromagnetic acoustic transmitter is developed.The system has the characteristics of automatic continuous monitoring,small measurement error(measurement error less than 2%),small volume,and easy operation,which facilitates on-site operators to timely monitor the annular liquid level height,analyze the lost circulation of lost-circulation zone,predict whether there is a risk of lost circulation to o-verflow in well control,and provide technical support for for quickly handling the complexity of well leakage and reducing well control risks.
total lost circulationelectromagnetic typeannular acousticssound wave emissionannular liq-uid levelcontinuous monitoring