Field Measurement and Retrieval Research of Multi-physics Micro-measurement Devices During the Drilling Process in Oil and Gas Wells

While-drilling measurements are the primary means for oil and gas well engineers to obtain real-time downhole engineering parameters. Current single-point, dual-point, and intelligent drill-string multi-point measurement systems can achieve early detection of gas cut, leakage, and other conditions. However, these methods have drawbacks such as high usage costs and limited applicability. Micro-measurement devices based on Micro-Electromechanical Systems (MEMS) have emerged as a hot topic in recent years due to their ability to measure temperature, pressure, magnetic field, and dynamic parameters throughout the entire wellbore during mud circulation. These devices offer advantages such as small size, high measurement accuracy, fast data acquisition, cost-effectiveness, and strong applicability. In this study, bullet-shaped multi-physics micro-measurement device encapsulated with PDMS materials was developed and field retrieval tests were conducted. The functionality of parameter measurement under actual downhole circulation conditions was also tested. Results showed that out of 14 micro-measurement devices deployed over a 30-min circulation and retrieval cycle, 6 were successfully retrieved, achieving a recovery efficiency of 42%. The retrieved micro-measurement devices successfully recorded angular velocity, acceleration, and temperature data during the circulation process. Finally, some issues encountered during field testing were identified and suggestions were proposed, which are of significant importance for the further development of this technology.