Grant: Collaborative Research and Development Grants

Canada is the 3rd-largest producer of natural gas & 8th-largest producer of crude oil in the world. The upstream sector is the largest single private sector investor in Canada. Many operations required before oil & gas can be produced from a well involve sequential pumping of fluid stages along a circular pipe, e.g. plug cementing, primary cementing, pumping of sand & proppant suspensions, waxy crude oil pipeline restarts. These processes are physically complex for many reasons: pipes are inclined; there may be large density differences between fluids; fluids often exhibit strongly non-Newtonian properties; pumping rates range from slow-laminar flows to fully turbulent flows. Although the hydraulics of a single phase flow of any one of these fluids is quite well understood, multi-phase flows of such liquids are very far from being understood. This fluid mechanics understanding is crucial for the successful design of industrial processes such as those above. In each process the efficiency can be severely compromised if the fluid stages significantly mix and/or by-pass one-another. Non-piston-like displacement & mixing can lead to contamination or to the placement of incorrect or substandard fluids. Potential consequences include a significant impact on well productivity, destruction of the near-well ecosystem, pollution of the environment and safety hazards. The main scientific problem is a lack of basic knowledge of mixing and displacement flows of non-Newtonian fluids in pipes. This makes it hard to predict the degree of mixing between 2 fluids traveling in a pipe, and hence to accurately design fluid volumes, properties and flow rates for any of these operations. The scientific aim of this project is to begin to provide such knowledge, via a concerted study of the fluid mechanics involving experimental and computational methods. Our technological objective is to use the knowledge that we develop, to enhance well construction & servicing operations worldwide.