Electronic Data Captured at Bit is Utilized to Improve Drilling Practices and Performance in Laterals

Abstract

Abstract When drilling laterals, the horizontal portions of an unconventional well, one of the primary unknowns has been how much weight and torque is effectively being transferred from surface to bit, and how that affects performance. The introduction of high-frequency vibration, motion, and strain sensors integrated into the drill bit has yielded new insights into drill bit behavior. This paper presents a recent field study, in which these downhole measurements were utilized to develop a solution for improving drilling performance in the lateral section. Operators often use computer-controlled "auto-driller" settings, either weight on bit (WOB) or rate of penetration (ROP) mode, to drill through lateral sections. While higher instantaneous ROP can be achieved by using WOB mode, it can create inconsistent performance, thus, leading to dysfunctions. In this case, a high resolution, at-bit vibration, motion, and strain sensor was introduced to characterize dysfunctions and drill bit behavior in the interval of interest. Data was captured during multiple drilling modes across multiple wells to conduct an engineering analysis and determine appropriate drilling practices to enhance drilling efficiency. The same drill bit equipped with the at-bit sensor was used to drill two lateral intervals with the same target formation in the same well pad. Both lateral runs made it to total depth (TD) in a single run. During the first run, overall higher dysfunctions (axial and lateral+torsional) were observed when WOB mode was used in contrast to ROP mode. Therefore, for the next run, ROP mode was recommended along with a higher ROP setting. The same consistent vibration levels were observed but at an overall higher ROP, while also improving the drill bit's dull condition. When drilling in WOB mode, spikes in downhole WOB were observed on connections when tool joints would pass through the rotating head. However, this was not shown on surface WOB measurements. When cross-plotting differential pressure and torque-on-bit, a gradual decrease in torque was observed throughout the run with similar differential pressure indicating a loss in drilling efficiency. As a result, when applying the optimized drilling practices learned from these runs using the innovative at-bit sensor, a 20% overall ROP increase and dull conditions improvement were observed. This paper describes how novel features were placed in an at-bit sensor capturing continuous 1,024 Hz data to visualize dysfunction, motion, and strain downhole, and to determine the effect of drilling practices, and how they are related to drilling performance, leading to recommendations that improve performance. Detailed field data from different runs, in which revised drilling practices helped manage dysfunctions and enhance overall drilling performance, will be presented.