Modelling and numerical calculation of the multiphase transport in deep drilling technology

该项目的目的是利用数值方法研究粘塑性流体中颗粒的输运，并在工程模型中汇总推导出的结果。本课题的背景是深钻技术中岩屑的运移。深钻技术对保障未来能源供应具有重要意义。这涉及到矿物燃料的使用以及地热能的生产。在这两种情况下，钻井过程都是最重要的成本参数，因此需要高效、时间优化的过程控制。出于生态原因，井眼的完整性对于防止钻井液泄漏到地质地层中尤为重要。上述目标只有通过基于模型的钻井过程系统优化和自动化才能实现。从流体力学的角度来看，岩屑从井眼中运移是很重要的。这必须在合适的模型中量化，以适应典型的深钻条件，即高压和高温，使用具有复杂流变性的钻井液，以及在可变环境条件下进行数公里的钻探。在本项目中，这种方法是基于最先进的计算技术来分析液体中的粒子输运。根据需要对这些方法进行了扩展，并在实验数据的基础上进行了验证。这将使量化二次流或液体流变对颗粒输运的影响成为可能，而这些影响目前尚未得到研究。在这个项目中，过去几年在申请人小组和在克劳索尔工业大学的工作将得到延续和扩展。本项目将有助于澄清和更好地量化深钻过程的水动力过程。然而，与其他技术领域有许多相似之处，其中出现了类似的问题。例如流化、过滤、造纸、废水处理或食品技术。

The aim of this project is to investigate the transport of particles in viscoplastic fluids using numerical methods and to aggregate derived findings in engineering models. The background of the project is the transport of cuttings in deep drilling technology. Deep drilling technology is of great importance for securing the future energy supply. This concerns the use of fossil fuels as well as the production of geothermal energy. In both cases, the drilling process is the most important cost parameter, so that efficient, time-optimised process control is required. For ecological reasons, the integrity of the borehole is of particular importance in order to prevent unwanted leakage of drilling fluids into the geological formation. The above goals can only be achieved by model-based, systematic optimization and automation of the drilling process. From the point of view of fluid mechanics, the transport of cuttings from the borehole is important. This must be quantified in suitable models for the conditions typical of deep drilling, i.e. high pressures and temperatures, the use of drilling fluids with complex rheology and over distances of several kilometres under variable environmental conditions.This approach in the present project is based on state-of-the-art computational techniques for the analysis of particle transport in liquids. These methods are extended as required and validated on the basis of experimental data. This will make it possible to quantify the effects of secondary flows or the rheology of the liquid on particle transport that have not been studied up to now. In this project, the work of the last years in the group of the applicant and at the TU Clausthal will be continued and extended.The present project will contribute to the clarification and better quantification of the hydrodynamic processes for the deep drilling process. However, there are numerous parallels to other fields of technology in which similar questions arise. Examples are fluidisation, filtration, paper processing, waste water treatment or food technology.