Investigation of cuttings transport in geothermal wells using computational methods
Date and Time: Jun 26th at 14:15, LSTM Seminar Room
Speaker: Prof. Dr. Gunther Brenner, Technical University of Clausthal
Topic: Investigation of cuttings transport in geothermal wells using computational methods
Abstract: Deep drilling technology for geothermal energy is of great importance for securing the future energy and heat supply. In this context, the drilling process is the main cost parameter which motivates the development of optimized drilling process control and techniques. Fluid mechanics play a decisive role in maintaining safe and efficient drilling operations. In particular, an important parameter is the transport of cuttings under conditions typically relevant in deep wells, i.e. at high pressure and temperature, using drilling fluids with complex rheology and over distances of several kilometers in variable environmental conditions and in wells with vertical and highly deviated or horizontal sections.
In the present work, the two phase flow in a representative section of a typical well is investigated. This consists of a core annulus with a rotating inner wall, which causes Taylor vortices to occur in the flow. Different computational approaches are used, i.e. a classical Euler-Lagrange Model as well as Discrete Element Method (DEM) in combination with an immersed boundary method (IBM). In the latter, the geometry of the individual cuttings particles are resolved in the computational mesh. Besides computational issues, results will be presented to elucidate the effect of operational parameters, fluid and particle properties on the transport efficiency and the occurrence of critical operational conditions.