Reactive Spacers for Extended Reach Horizontal Cementing
Extended reach wells can be drilled in the 5-10km range with a high degree of reliability. Longer wells are limited by various factors, but many of them are fluid-related, e.g. frictional pressure exceeding pore-frac envelope, inadequate hole-cleaning, etc. In the case of cementing, mud removal becomes increasingly difficult as many of the techniques that work for vertical/inclined wells are no longer sensible. For example, density differences that help push the drilling mud from a vertical hole cause the fluids to slump. Therefore, it is necessary to find new ways of efficiently removing drilling mud In the absence of density differences, rheological differences can be used to increase the efficiency of a displacement flow, e.g. higher viscosities generally displace lower viscosities more efficiently than vice versa. Unfortunately, increasing the viscosity of the displacing fluids reduces the extent of the well before the pore-frac envelope is exceeded. This project focuses on ways in which we may generate beneficial rheological effects, but only local to the displacement front, via any sort of reaction. “Reaction” here is meant loosely, to include a wide range of physico-chemical effects: chemical reactions, flocculation, emulsification, etc.. This project started in 2005, is funded by NSERC via the strategic projects programme, and is also supported by Schlumberger Oilfield Services and Trican Well Services Ltd. We are grateful to our sponsors for their support and continued interest. Contributors: - T. Burghelea - J. Feng - I. Frigaard - M. Martinez - K. Wielage Results are disseminated initially to our sponsors and later in the open literature. Industrial companies interested in the scope of this project are invited to contact Ian Frigaard for details on how to sponsor the project.	Sponsors gratefully acknowledged: