The ExxonMobil Drilling Advisory System (DAS) is a rig-based drilling-surveillance and -optimization platform that encourages regular drilloff tests, carefully monitors drilling performance, and provides recommendations for controllable drilling parameters to help improve the overall drilling process. Key technical components of the DAS include high-quality adaptive filtering algorithms for computing various drilling-system-performance measures, data-encapsulation/dimensionality-reduction techniques, and reduced-order-modeling techniques that are ultimately used to generate recommendations for improved performance.
Introduction
Approximately a decade ago, the company initiated an internal program to pursue real-time rigsite mechanical-specific-energy (MSE) surveillance. MSE, a quantity initially developed and applied in the mining industry and subsequently applied to oilwell drilling, provides a measure of the energy required for a drilling assembly to drill through an interval of subterranean formation; and underefficient drilling conditions correlate with the compressive strength of the rock being drilled. It was quickly demonstrated that frequent drilloff tests using MSE trends to maximize drilling performance were an effective means of optimizing the drilling process.
