Design and Experiment Concept of a Cutting Transport Simulation Apparatus for Solid Shape Investigation
Research output: Research › Master's Thesis
Sufficient removal and transportation of solids generated during the drilling process is a major concern in any wellbore. Inefficiencies cause millions of dollars of direct, indirect and hidden costs for oil and gas companies in terms of increased bit wear, low Rate of Penetration (ROP), increased Equivalent Circulation Density (ECD), which may cause formation fracture and high torque and drag, possibly leading to mechanical pipe sticking. Problems related to poor cutting removal and transportation may in the worst case cause a loss of the wellbore. This thesis can be separated into three major sections. The first section provides an overview of previously developed models, including necessary assumptions made to predict and estimate cutting transportation efficiency. It points out the variations for vertical, inclined and horizontal sections of a wellbore and describes the key parameters that influence removal and transportation capabilities of solids and their controllability during the drilling process. The second topic describes the necessary equipment for the experimental setup, like the artificially produced solids, their characteristics and production, the transparent drilling fluid with all its properties and the design of a cutting transport simulation apparatus, which provides the opportunity to investigate the impact of the solids shape on transport and accumulation capacities amongst other factors. The third topic discusses seven experiments, designed to investigate the impact of the cuttings shape on parameters like the particles slip velocity, the Minimum Transport Velocity (MTV) for desired flow patterns, the Cutting Bed Height (CBH) and the necessary duration of circulation with predefined flow rates to erode a cutting bed. The experimental data obtained with help of these experiments allow the validation of the advantages or disadvantages of both investigated shapes on removal and transport characteristics. Those results will further enable the adjustment of drilling parameters to optimize the overall drilling process.
|Award date||1 Jul 2016|
|State||Published - 2016|