Hydraulic evaluation of drilling fluid performance on hole cleaning for different rheological models
Date
2005-08-03
Journal Title
Journal ISSN
Volume Title
Publisher
Society of Petroleum Engineers
Abstract
Bottom hole cleaning is an important function of drilling fluid that needs special attention during a drilling operation. Good hole cleaning results in an
increase in penetration rate and, at the same time, reduces the operating drilling cost. One of the effective steps towards reducing operating cost is to have a well designed drilling hydraulics program that will optimize the energy used at the mud pumps. A variety of hydraulic optimization designs are available depending on the cutting structure and the formation to be drilled but a common objective is to maximize the available hydraulics to provide optimum hole cleaning. Many authors have discussed various ways of effecting proper hole cleaning using different approaches and methods. Fluid velocity, pump rate, fluid rheology, drill pipe eccentricity, pipe rotation and particle settling velocity, among others were used at various times to evaluate effective hole cleaning. The economic appraisal of hole cleaning using hydraulic horsepower and jet impact force by Wright et al (2003) have proved that both can be used for the design of optimum hydraulic programs on the basis of minimum drilling cost. In this study, basic hydraulic models for vertical oil wells were used to determine the pressure drop in a drill string circulating system and hence, the equivalent circulating density (ECD) using both the Bingham plastic and Power law fluids’ rheological models. From the slip velocity relationships, the transport efficiency of the cuttings for both models was determined. An economic evaluation of the hydraulics from the energy and horsepower requirements for both models showed that the power law fluid model provided a better transport efficiency, and hence more economical in terms of minimum drilling cost.
Description
This work contains figures and tables.
Keywords
Bottom hole cleaning, hydraulic, hyraulic optimization, drilling cost, operating cost, Department of Petroleum Engineering
Citation
Duru, U., Chukwu, G. A. & Obah B. (2005). Hydraulic evaluation of drilling fluid performance on hole cleaning for different rheological models. Society of Petroleum Engineers.SPE 98792