A Comparative study of cuttings transport performance of water versus polymer-based fluids in horizontal well drilling

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2015
Allahvirdizadeh, Payam
High drilling fluid circulation rate is often needed for effective transportation of cuttings in horizontal and extended reach wells, which may not be always achievable due to the risk of fracturing the rock by increased bottom hole dynamic pressure and also limit of pumps capacity. Keeping the bottom hole pressure low enough while increasing the flow rate is, therefore, a major challenge in horizontal well drilling operations. A potential solution to this problem would be to use drag reducing additives in drilling fluids. An experimental study is designed and conducted in order to investigate if drag reducing fluid can be effectively used for cuttings transport while drilling horizontal wells. The main objective of this experimental study is to compare the performance of water and a water-based polymer fluid (i.e. PHPA polymer based drilling fluid) in terms of drilled cuttings transportation. Experiments are conducted by using the set-up consisting of a 21 ft long test section with transparent casing with 2.91 ID and an inner pipe of 1.85 OD, which was readily available at the METU-Petroleum and Natural Gas Engineering department laboratories. In this study effect of drilling rate, drilling fluid flow rate and polymer concentration on transportation of the cuttings and pressure losses are investigated while keeping other variables constant. It was observed that using PHPA polymer reduces the frictional pressure losses up to 38% and using the optimum concentration of the PHPA gives the most efficient scenario of transportation of cuttings in horizontal well drilling.
Citation Formats
P. Allahvirdizadeh, “A Comparative study of cuttings transport performance of water versus polymer-based fluids in horizontal well drilling,” M.S. - Master of Science, Middle East Technical University, 2015.