MATHEMATICAL MODELING AND RESEARCH METHODS OF HORIZONTAL WELLS HYDRODYNAMIC CLEANING

Abstract

Relevance of the research is determined by the need to understand modern achievements in modeling the processes of sludge transport in real conditions of drilling operations that increase drilling speed and the efficiency of well cleaning; to establish the advantages/disadvantages of existing approaches, modern models and complex methods for describing the dynamics of systems with particles in order to effectively choose the rheological properties of drilling fluids and eliminate the reasons of equipment loss. The aim of this work is to understand the modern experience of modeling the processes of cleaning wells with complex geometries, mainly lying in the horizontal plane; to study the features of the flow of mixtures in the annular space with a circular core; providing recommendations for the practice of modeling and calculating hydrodynamic processes that increase hole cleaning efficiency. Methodology. Theoretical and practical research methods from related fields of hydrodynamics and heat and mass transfer in rheologically and physically complex systems; methods for numerical modeling of laminar and turbulent flows under conditions of direct-flow and swirling flows created by a co-axially or orbitally rotating wall, which affect the formation of a layer of cuttings and the dynamics of particles of a dispersed mixture. Results. The paper introduces the results of modern numerical studies of cleaning wells with horizontal sections and the information on aspects of detailed hydrodynamic and diffusion modeling of complex flows in inclined wells. The applied models and methods used to study the characteristics of flow and heat and mass transfer in homogeneous and heterogeneous media in internal systems are formulated. Aspects of modeling the processes of cuttings transport in the framework of Euler/Lagrangian approaches are discussed, taking into account the features introduced by the effects of interfacial interaction/rotation. The paper introduces the changes in cuttings concentration based on rheological properties (power-law or Herschel–Bulkley), different shapes/sizes of particles, flow regimes and inertial forces. The problems of improving the accuracy of cuttings transport modeling, the possibilities of new technologies, original turbulence models and their two-parameter dynamic bases used for increasing the intensification and efficiency of cleaning processes are analyzed. The authors have given the recommendations for their solution in the considered hydrodynamic and geometric configurations. The results and problems that are of fundamental and applied significance and constitute an independent subject of prospective research are indicated.

Keywords

• cuttings
• well
• cleaning
• modeling
• hydrodynamics
• mass transfer
• rheology
• turbulence
• structure
• forces