Successful Implementations of Drilling Microchips for Distributed Measurement while Drilling

Abstract Access to downhole properties is essential to ensure the safety and efficiency of drilling operations. This study describes successful implementations of drilling microchips to acquire circulating pressure and temperature while drilling. It also elaborates on our developed scheme for depth conversion of the measured data. In this study, 100 drilling microchips were dropped in three different sections of a wellbore. The microchips were deployed in a single batch in each trial. Although no recovery was achieved in the first trial, the learning lessons were utilized to revise the procedure. In particular, the flow rate was increased to ensure the recovery of microchips. Overall, 35 pieces of microchips were recovered, which shows a success rate of 35%. A data processing method is employed to convert the raw measured data in the time domain into depth scale. The method minimizes the difference between the predicted transit time and the actual transit time, which also takes into account the slip velocity of tracers. The measured circulating pressure data enables obtaining separate velocity profile parameters for pipe and annuli. The results of measured pressure and temperature data show consistent measurements in pipe and annuli regardless of microchip type. The results further show that the measured pressure data can be used for the calculation of the ECD profile. It is also recognized that the accuracy of ECD calculations is better in lower sections of the wellbore. It is realized that a higher recovery rate is expected with increasing the flow rate. Novel results of successful data acquisition of downhole temperature and pressure are presented. In critical zones where the application of logging tools becomes risky, the presented method for acquiring downhole data is advantageous.