New MTV computer package for hole cleaning design and analysis

A computer package has been developed in the Department of Petroleum Engineering at Heriot-Watt University which provides a useful tool for the field engineer to predict the Minimum Transport Velocity (MTV) required to ensure efficient hole cleaning during drilling operations. The new software package, which operates in a Windows environment, has been designed and built in modules to allow the user to: (a) Predict the minimum circulation rate required for efficient cuttings transport at a given operational condition of hole angle, pipe rotation and eccentricity as well as fluid properties. (b) Model the drilling fluid velocity profile in a defined annular geometry. (c) Define, from viscometer data, the appropriate rheological model (Power-Law, Bingham Plastic, or Herschel-Bulkley) for a drilling fluid. In this paper, the details of the computer package are presented. The paper also describes how the lift and drag forces on the cuttings have been determined and used in the definition of the MTV. Highlights of the theoretical modelling of annular flow of Herschel-Bulkley fluids at different pipe eccentricities and pipe rotary speeds are also presented. Case studies which demonstrate the functionality of the package are also presented.