Real-Time Drilling Optimization and Rig Activity-Based Models Deliver Best-In-Class Drilling Performance: Case History

Abstract

This paper presents a case study for improving drilling performance by maximizing penetration rate while ensuring that hole conditions are not compromised. The overall aim was to identify and prevent invisible lost time (ILT) and nonproductive time (NPT) by means of pre-drill engineering studies and real-time drilling optimization. This process was conducted to deliver continuous improvement in a three-well drilling campaign in the East Texas Basin.

Prior to drilling the series of three wells in the East Texas Basin, a pre-drill study of information from offset wells was used to calibrate engineering models and identify opportunities for improvement. These were primarily identified by the analysis of mechanical specific energy (MSE) and rate of penetration (ROP) to create a driller's road map (DRM) to optimize parameters that can be controlled on the rig floor (rpm, WOB, flow rate). Calibrated torque and drag (T&D) and hydraulics models were developed to compare and monitor model versus actual (MvA) in real time.

During the actual drilling of the wells, potential areas of improvement were determined by analyzing MSE and evaluating ILT/NPT. Real-time MSE analysis was conducted during drilling operations to adjust parameters to increase ROP performance. ILT and NPT were reduced by focusing on connection times, optimizing hole cleaning to reduce trip times, increasing flow rate, and improving bit hydraulics. These analyses were used to generate a focused optimization plan to monitor hole conditions at high drilling rates. This plan was incorporated into a recommended real-time process for the wellsite team.

This case history is presented for a three-well development pad in the East Texas Basin. The first well of the campaign was drilled one day faster than the previous well had been drilled, and each subsequent well was delivered in a shorter time with an overall improvement of 30.9%. The Driller's Road Map was refined after each well as part of the continuous improvement process. As a result of improved hole cleaning, major sources of ILT were reduced by 47%. The improved hole cleaning was verified by real-time MvA correlation. The methodology described is being used successfully on other multi-well projects in unconventional reservoirs and other drilling market segments.