Technology Focus: Drilling Technology (February 2013)
Authors: Menand Stephane 
Published: February 2015

Technology Focus
When searching OnePetro (www.onepetro.org) for papers dealing with “real time,” “drilling,” and “optimization,” one notices that 85% of SPE papers dealing with these three terms have been written over the last decade (2002–12). Indeed, there is an accelerated trend strongly supported by drilling companies (especially operators and service companies) of reducing nonproductive time, speeding up the learning curve, and optimizing drilling efficiency to reduce drilling cost and avoid unexpected failures. If drilling optimization is not new and dates back mainly to the 1960s, drilling-optimization departments and engineers today have an increasing number of tools (software and hardware) to facilitate their optimization tasks. Moreover, this can be achieved with a limited amount of investment compared with the huge cost reduction that can be gained. Depending on each application and purpose, many levels of drilling optimization in real time or almost real time can be achieved. From surface drilling data alone, mechanical-specific-energy surveillance can already be monitored to optimize rate of penetration, better detect the moment to pull the bit, and detect bit balling or vibration. Many companies have set up this process and have obtained very good results in drilling efficiency. Simultaneously having surface and downhole data (measured close to the bit or distributed along the drillstring) enables better assessment of the amount of energy transferred downhole (from friction loss along the drillstring) and enables better detection of downhole conditions (e.g., vibrations and hole cleaning). Predictive physical models coupled with surface and downhole data enable the addition of even more value because one can better detect ongoing or future abnormal conditions. For example, visualizing predictive critical rotation speeds (taken from dynamic modal analysis software), current rotation speed, and downhole vibration indicators on the same plot helps drillers adjust the rotation speed accordingly to avoid harmonic vibrations. Torque-and-drag and hydraulics calculation software is also very useful to detect deteriorating hole-cleaning conditions.
However, if the tools exist to acquire, process, and visualize the drilling data, the most difficult part consists of understanding and interpreting the data to make a decision and provide the driller with a solution to mitigate the problem or optimize the drilling efficiency. This part is a real challenge because managing and analyzing downhole drilling data require highly skilled experts and analysts, to take full advantage of this information. Some of the papers selected for this month’s feature are good illustrations of the latest developments and applications in real-time drilling optimization.
Recommended additional reading at OnePetro: www.onepetro.org.
SPE 151176 The Effect of Equivalent-Diameter Definitions on Frictional-Pressure-Loss Estimation in an Annulus With Pipe Rotation by Olatunbosun Anifowoshe, University of Oklahoma, et al.
SPE/IADC 151389 Drilling Performance Is a Function of Power at the Bit and Drilling Efficiency by Rolf Pessier, Baker Hughes, et al.
SPE/IADC 151248 Directional-Drilling Tests in Concrete Blocks Yield Precise Measurements of Borehole Position and Quality by Ed Stockhausen, Chevron, et al.
SPE/IADC 156445 BHA Modeling Coupled With High-Frequency Downhole Vibration Data Provides Unique Solution to Inconsistent Drilling Performance in South Iraq Oil Field by Paul Teasdale, Alwaha Petroleum, et al.