A new design of nonlinear model predictive controller (NMPC) is proposed for managed pressure drilling (MPD) system. The NMPC is based on output feedback control architecture and employs offset-free formulation proposed in [1]. NMPC uses active set method for computing control inputs. The controller implements an automatic switching from constant bottom hole pressure (CBHP) regulation to flow c...

INTRODUCTION Groundwater plays an important part in many regolith processes (chemical weathering, solute dispersion, etc.), but collecting groundwater data usually requires drilling that can be: a) expensive analyses for porosity, permeability, etc in addition to drilling costs; b) problematic rig availability and access to remote sites; c) under-sampled entire groundwater regimes characterised...

Stick-slip vibrations present at the bottom hole assembly (BHA) of a generic oilwell drillstring subject to dry friction are studied. Different nonlinear differential equations-based models of a drillstring are analyzed. The drillstring models presented are oriented to avoid simulation problems due to the discontinuities originated by the presence of dry friction. The influence of different dri...

The vibration phenomenon represents the cause of many problems in metal cutting processes. It has a big influence on the quality of the machining operation, tool life and machine precision. Drilling operation is a common metal cutting process where quality of the hole form is often a critical issue. Therefore, it was necessary to predict these vibrations. The first part of this paper deals with...

Introduction: Commercial drilling, even deep-sea or remote, depends on human teleoperation. Lightspeed delays mean that coring and drilling beyond the Moon requires automation in order to not get stuck or risk mission failure. The Drilling Automation for Mars Exploration (DAME) is a NASA project for developing critical-path drilling software technologies. The DAME project’s purpose was to devel...

This study investigates the effect of focal plane variation using vibration in a femtosecond laser hole drilling process on Invar alloy fabrication quality for the production of fine metal masks (FMMs). FMMs are used in the red, green, blue (RGB) evaporation process in Active Matrix Organic Light-Emitting Diode (AMOLED) manufacturing. The taper angle of the hole is adjusted by attaching the obj...

[1] We report new drillstring packer permeability tests conducted during Integrated Ocean Drilling Program (IODP) Expedition 327 in upper oceanic basement in Hole U1362A on the eastern flank of the Juan de Fuca Ridge. Hole U1362A lies within a closely spaced array (40–2460 m separation) of six holes in well-sedimented 3.5–3.6 m.y. old crust that were drilled, tested, and instrumented with boreh...

NIOSH continues to conduct respirable dust control research for surface mine blasthole drilling operations. Research areas have included testing variables (shroud leakage area, drill deck cross-sectional area, shroud height, collector-to-bailing airflow ratio, etc.) that have the most impact on respirable dust control, development of a dust collector inlet hood, development of a dust collector ...

Control of well drilling operations poses a challenging issue to be tackled. The loss of well control could lead to the occurrence of blowout as a severe threat, involving the risk of human lives and environmental and economic consequences. Conventional proportional-integral (PI) controller is a common practice in the well control operation. The small existing margin between pore pressure and f...