Ocean Drilling Program Leg 201 was the first ocean drilling expedition dedicated to the study of life deep beneath the seafloor. Its seven sites were selected to represent the general range of subsurface environments that exist in marine sediments throughout most of the world’s oceans. In water depths as great as 5300 m and as shallow as 150 m, the expedition drilled as deep as 420 m into ocean...

Because neurosurgery and orthopedic surgery often require the drilling of bones, this paper attempts to solve the problem of bone drilling. The goal is to realize a control system, which is able to drill with a contact drilling force and can automatically stop drilling at the moment of breaking through. In particular, both the de drilling mntor control and the feed rate control are driven by fo...

Bone drilling is widely used in orthopaedics and surgery; it is a technically demanding surgical procedure. Recent technological improvements in this area are focused on efforts to reduce forces in bone drilling. This study focuses on forces and a torque required for conventional and ultrasonically-assisted tool penetration into fresh bovine cortical bone. Drilling tests were performed with two...

In this research, finite element analysis of the conventional drilling and vibration assisted drilling is carried out. The ABAQUS software is employed for FE analysis. The Johnson-Cook models for both plastic deformation and damage are employed for FE simulation.The results of the FE analysis are then verified with experimental results in both conventional and vibration assisted drilling on Al ...

drilling fluid is the most important lifeline of the drilling operation, that main task is facilitate the cuttings removal of the drilling. there are varieties of drilling fluids such as sodium bentonite based-drilling fluid is called “mud” and drilling foam or surfactant based-drilling fluid is called “soap”. the present work aims are study on the modified drilling mud properties by using the ...

The relationship between production rates of large diameter geothermal production wells, and slimholes, is studied. The analysis is based on wells completed in liquid-dominated geothermal fields, where flashing occurs either in the wellbore or at the surface. Effects of drawdown in the reservoir, and pressure drop in the wellbore, are included; heat losses from the wellbore to the formation are...

The aim of this investigation is to devise a robust detection method for drill bit break-through when drilling into long bones using an automated drilling system that is associated with mechatronic assisted surgery. This investigation looks into the effects of system compliance and inherent drilling force fluctuation on the profiles of drilling force, drilling force, drilling between successive...

Due to the shortcomings of the traditional drilling way, as well as the complexity and difficult mathematical model of the drilling process, etc, this paper briefly analyses the principle of auto-drilling system on AC frequency conversion and the relationship among all factors that affects on the auto-drilling and puts forward a technology that combines parameters' self-tuning fuzzy control wit...