Expedition 309, “Superfast Spreading Rate Crust 2,” successfully deepened Hole 1256D (6.736°N, 91.934°W) by 503 m to a total depth of 1255.1 meters below seafloor (mbsf) or 1005.1 meters subbasement. The average rate of core recovery for the expedition was 36%. Much higher rates of recovery were experienced in the lowermost section of the hole (~70% average below 1200 mbsf). At the end of Exped...

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...

Hybrid composite-metal stacks (HCMS) combine metal alloys and composite materials are used in the manufacturing maintenance of aircrafts. Drilling is an important process necessary for installing rivets fuselages. This work sought to identify influence cooled compressed air high-speed cutting (HSC) on drilling multi-material joints with different configurations. Among factors observed type (car...

Drilling and blasting have numerous applications in the civil and mining engineering. Due to the two major components of rock masses, namely the intact rock matrix and the discontinuities, their behavior is a complicated process to be analyzed. The purpose of this work is to investigate the effects of the geomechanical and geometrical parameters of rock and discontinuities on the rock mass blas...

Boring trepanning association (BTA) deep hole drilling is widely used in machining tube sheet of steam generator. In order to get a better service integrity, the surface quality after required be higher. this paper, effect mechanism BTA on integrity and machined layer low alloy steel SA508Gr.3Cl.2 for nuclear power investigated. The results show that gradient microstructure can obtained by inne...

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...

The distinctive characteristics of carbon fibre reinforced plastics, like low weight or high specific strength, had broadened their use to new fields. In order to join different components by using bolts, rivets or screws, one of the machining operations needed in composite structures is drilling. Usually, it is accepted that drilling can be carried out using conventional tools and machinery wi...

Parallel manipulators (PMs) have been the subject of study, of much robotic research during the past three decades. A parallel manipulator (PM) is a closed loop kinematic chain mechanism, that is connected to the base via multiple independent chains. The scope of this research work is to perform the position analyses of the three degrees of freedom PMs (TRIPOD and TRI-GLIDE). The present work h...