Drilling engineering is a high input and risk underground project, which needs the real-time down-hole diagnosis and forecast technique. Drilling string vibration signals contain full and complex vibration waves, which contains the vibration of the drilling string by itself, the vibration stimulated by the interaction of bit and the formation, the vibration induced by colliding between drill st...

Introduction. Radical procedures like calcanectomy and amputation performed for calcaneal osteomyelitis are regarded as effective in eradication of infection even though potentially functionally disabling. Bone sparing procedures offer better functional result at the expense of potentially worse infection control. The aim of the study has been to assess the influence of the surgical radicalism ...

Bone drilling is a major part of modern orthopaedic surgery which involves the internal fixation of fractured bones. The investigation of bone drilling described in this paper demonstrates the contribution of automation technology towards the study of bone strength. The aim of this preliminary investigation is to establish a relationship between bone drilling forces and measurements of bone min...

Oil and gas drilling operations use drilling fluids (mud) to lubricate the drill bit and stem, transport formation cuttings to the surface, and seal off porous geologic formations. Following completion of the well, waste drilling fluid is often applied to cropland. We studied potential changes in soil compaction as indicated by cone penetration resistance, pH, electrical conductivity (EC(e)), s...

This paper designs an integrated estimator and L1 adaptive control scheme to address the two main challenges involved in the Managed Pressure Drilling (MPD) system: first, the bottomhole states are updated at a low rate, which can be viewed as unmeasured and thus need to be estimated in real time; and second, the drilling process is subject to uncertainties including unknown parameters (e.g., f...

The interaction between friction and vibration is a widely recognised source of inefciency in all mechanical systems. The nature of this interaction is very dependent on the dynamic environment and its control requires a detailed understanding of the mathematical structure governing the stability of this environment. Although the fundamental causes of friction-induced intermittent motion have b...

today’s energy reauiraments have produced an increase in drilling activities all around the world. among this situation is the fact that all the operators are trying to minimize cost without reduction in quality. so, they are looking for new types of contracts between all drilling companies, contractors and suppliers until that with make agreement between them have successful operations. in thi...

1Department of Mechanical Engineering, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands 2Department of Civil, Environmental & Geo-Engineering, University of Minnesota, Minneapolis, USA 3Delft Center for Systems and Control, Delft University of Technology, Delft, The Netherlands 4Well Engineering Design, Nederlandse Aardolie Maatschappij B.V. (NAM), The Netherlands 5Wells ...

This paper details the online-identification-based adaptive design of a stick/slip minimization algorithm and top-drive servo control for Rotary Steerable System (RSS) directional drilling tools. Stick/slip in this context refers to the downhole angular velocity variation of the bit about a nominal value. The basic pole placement controller designs are SISO linear but recursively evaluated base...

Resonant Sonic Head drilling (RSHD) induces axial vibrations along the drillstring system which affect the accuracy and quality of pre-reinforcement required to tunnels excavation in complex soils. The main goal of this paper is to control these vibrations in order to improve this process. First, an infinite dimensional equations as vibration model are elaborated with Neumann boundary condition...