Development of downhole dynamic measuring system and field trial

Downhole engineering parameters such as weight on bit (WOB), torque on bit (TOB) and vibration play a significant role in safe and efficient drilling when operating in severe geological environment. Monitoring downhole parameters in real-time will improve drilling safety and efficiency greatly. Traditionally, engineering parameters obtained in the well site are based on data collection on surface, which is not an accurate way to estimate downhole conditions. In order to explain dynamical state and stress distribution of bottom hole assembly (BHA), a comprehensive suite of downhole dynamic measuring system (DDMS) is developed. The paper provides an overview of the downhole dynamic measuring system which has the ability to measure axial force, torsional force, annular pressure, internal pressure, vibrations in three orthogonal directions and annular temperature with changeable sampling rate as high as 1000 Hz. The measurement of axial force and torsional force with strain sensors is an intricate issue which relates to environmental factors, therefore calibration of strain sensors in laboratory is included in this paper. In the subsequent content, field trail is covered to illustrate the performance of downhole dynamic measuring system. © 2018 Computer Society of the Republic of China. All Rights Reserved.