f Hole Enlargenment Operations at Deep Water Wells

The difficulties in deep water drilling have been stimulating new technologies and nem advances. One of the most challenging issue about deep water drilling is certainly that narrow window between fracture gradient and pore pressure. Narrow window between the fracture and pore pressure force to run different size of holes and casings. To use different sizes of casing push engineers for devoloping new drilling tools and advances. The biggest one of these is underream tools that engineers have presented as a solutions . There are two main different systems to operate this kind of tools. The main disparity between these mechanism is activating system of blades. One of is needs a ball to activate or deactivate blades and another of no drop ball mechanism that utilize pressure loss around the blades to activate and disactivate. Rhino Reamer that we used in deep offshore wells needs a ball to activate blades but not necessarily drop a ball to deactivate. Inspite of the fact that there are some advantages and disadvantages when comparing with each other. I want to mention about working principles of Rhino Reamer and its applications at Yassıhöyük-1, Sürmene-1 wells at ultra deep water. As a summary, at Yassıhöyük-1 well, Original hole Enlarged to From To S/N Reamer 18 1/8’’ 22’’ 2815 m. 2950 m. Rhino 1600 16 ½’’ 20’’ 2950 m. 3335 m. Rhino 1600 14 ¾’’ 17 ½’’ 3335 m. 3600 m. Rhino 14250 Sürmene-1 well, Original hole Enlarged to From To S/N Reamer 18 1/8’’ 22’’ 2610 m. 3014 m. Rhino 1600 16 ½’’ 20’’ 3014 m. 4308 m. Rhino 1600.