Application of Descriptive Data Analytics: How to Properly Select the Best Ranges of Viscosity and Flow Rate for Optimal Hole Cleaning?


It is not easy to obtain an optimal hole cleaning for the drilling operation because of the complicated relationship between the drilling parameters influencing hole cleaning. The two viscosity components (e.g. plastic viscosity (PV) and yield point (YP)) and the flow rate (Q) are essential parameters for effective hole cleaning. Thus, understanding the relationship between those parameters will contribute to efficient hole cleaning. The aim of this paper is to explore those relationships to provide optimal hole cleaning. Descriptive data analytics was conducted for data of more than 2000 wells drilled in Southern Iraq. The data were first cleansed and outliers were removed using visual inspection and box plots. The Pearson correlation (PC), a widely used method to measure the linear relationship between two parameters, was utilized to access the relationships between PV and Q, YP and Q, and YP/PV and Q. Moreover, a 10% sensitivity analysis was escorted to quantify and comprehend those relationships. The PCs were calculated to be 0.5, 0.076, and 0.22 for the relationships between YP, PV, and YP/PV with Q, respectively. YP had the highest direct relationship with Q, while PV had the lowest. When the YP increases, a sufficient Q has to be provided to initiate the flow and maintain the mud cycle. In addition, to prevent large solid particles from settling due to the slip velocity, sufficient annular and particle velocities have to be achieved. After initiating the flow, an increase in flow rate to overcome resistance due to PV will not be significant. Therefore, YP has more effect on Q than PV. To maximize hole cleaning, thickening ratio (YP/PV) should be increased. This requires an increase in flow rate, which can be quantified by using the sensitivity analysis provided to achieve the required Q for any increase in YP/PV.

Meeting Name

SPE Eastern Regional Meeting 2019, ERM 2019 (2019: Oct. 15-17, Charleston, SC)


Geosciences and Geological and Petroleum Engineering

Research Center/Lab(s)

Center for Research in Energy and Environment (CREE)

Keywords and Phrases

Correlation methods; Data Analytics; Flow rate; Infill drilling; Microcomputers; Sensitivity analysis; Viscosity, Drilling operation; Drilling parameters; Linear relationships; Particle velocities; Pearson correlation; Plastic viscosity; Thickening ratio; Visual inspection, Cleaning

International Standard Book Number (ISBN)


Document Type

Article - Conference proceedings

Document Version


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© 2019 Society of Petroleum Engineers (SPE), All rights reserved.

Publication Date

01 Oct 2019