Mathematical modeling of thixotropic drilling mud and crude oil flow in wells and pipelines-A review

Many drilling muds and crude oils are known to be thixotropic. Under a wide range of pressures, temperatures and flow regimes, they display unusual complex flow properties when flowing through wells (crude oils and drilling muds) and during storage and pipeline transportation (crude oils). Understanding and modeling the deviation from Newtonian behavior of drilling muds and crude oils are essential in accurately and optimally designing the flow systems associated with these fluids. Despite an impressive amount of experimental and rheological modeling studies concerning the non-Newtonian drilling mud and crude oil behavior, mathematical modeling studies taking into account their thixotropic properties are rare. In addition, there was no literature review of the knowledge gained to date. Thus, a review paper on studies addressing the mathematical modeling of thixotropic drilling mud and crude oil flow in wells and pipelines will pinpoint the challenges and limitations encountered in such studies. This will hopefully trigger further development and new research topics. This review paper focuses mainly on mathematical modeling studies concerning the well and pipeline flow of thixotropic drilling muds and dude oils. After describing how thixotropy is understood today inside and outside of the petroleum industry community, several mathematical models available in the literature are examined. Finally, challenges, limitations, and potential areas for the development of these models are presented. (C) 2012 Elsevier B.V. All rights reserved.