Redesigning a Drilling Test Facility for a Drill String Prototype
Research output: Research › Master's Thesis
This thesis discusses the reconstruction of a drilling test stand, formerly used for dual- body bits, by extending its testing capabilities onto specific testing conditions, designed to test the performance of a drill string prototype. Both testing platforms are merged into one drilling facility, offering the possibility to conduct the former and new testing functions with the least possible facility adjustments. Its design is presented in form of a system architecture covering its modular components and functions in a well arranged manner. The main modular extensions consists of test well, a customized well head and drill site surface equipment. By conducting a brief geomechanical study based on seismic data of the Trofaiach basin, the far field stresses acting upon a borehole with 300 m depth are investigated. Within the cased hole, a 9 5/8 in casing is immersed in completion fluid, capable of receiving injected liquid and gaseous influxes. The well is provided with a completion fluid circulation heating system, to accelerate the curing process of the test cement within the 9 5/8 in casing, which is drilled. The completed facility extension allows overbalanced drilling with well control interventions and managed pressure drilling, while tracking the dynamic drilling performance of the prototype under these conditions. The subsurface as well as surface components are designed within the practical disciplinary design methods in drilling and mechanical engineering. The tri-axial Van Mises failure criterion is utilized during the design, heating as well as the test phases, to monitor the casing stresses, in order to guarantee its integrity. A register of the acquisition costs of the entire facility as well as the costs of the demonstrated test runs are included. Furthermore, steps are introduced to upgrade the designed facility to conduct sensory tests for high pressure, high temperature wells.