To ensure safe and stable drilling operation, bottom hole pressure (BHP) should be kept within some region. However measurement of the BHP is sometimes not available or reliable, especially when the circulation is low, e.g., during pipe connection procedures. This paper presents the application of a moving horizon estimation (MHE) method for online estimation of the BHP during petroleum drillin...

This paper presents a prototype of a silent, remotely-operated microwave drill (MWD) for concrete. The MWD concept, based on the induced thermal-runaway instability and hotspot formation effects, is pushed here beyond the limit of quarter-wavelength drilling depth. This extension is achieved by a slow mechanical rotation (~20-rpm) of the entire coaxial structure penetrating as a hollow reamer i...

| In this paper we propose a virtual drilling sculpturing algorithm applied on 3-D objects. The 3-D objects can either be simple geometrical shapes such as cubes and spheres or more complicated objects as teeth. In the second case, we consider that we are provided with a sparse set of parallel and equi-distant slices of the 3-D object. With that set of slices we reconstruct the 3-D object using...

Original scientific paper This paper has presented and discussed machinability in the drilling of SMC (Sheet Mould Compound) A-Class composite materials using Taguchi's DoE method. The thrust forces, surface roughness and push-out peel-up delamination behaviour in drilling process for glass fibre reinforced SMC composites have been evaluated. The experimental results and the contribution ratio ...

We report the arthroscopic drilling of classical lesions of osteochondritis dissecans in 11 knees in 10 children with at least six months history and no sign of clinical or radiological improvement. There were eight boys and two girls and the average age at operation was 12 years 11 months. Relief of pain was noticed within days of operation; radiological healing occurred within 12 months in ni...

Oil and gas offshore exploration drilling and production facilities in cold climate and Arctic environmental conditions need various design considerations and operational preparation for intended operations. Offshore winterization of drilling systems and equipment is considered to be one of the essential aspects for ensuring that a facility is capable of and suitably prepared for operations in ...