Currently some of the most challenging wells being drilled by our industry are located in deepwater zones in the GOM. Many of those wells are in water depths of 8,000 ft. or more and several are targeting reservoirs around 30,000 ft. and beyond.Drilling engineers face many challenges when planning drilling and completion operations for such wells. There are not many rigs available to drill in ultra-deepwater, and even the modern rigs capable of operating in this environment will present limitations ranging from the maximum mud weight possible to be used, due to riser restrictions, to the hook load capability to run very heavy intermediate casings that will easily surpass one million pounds.The well itself will present many problems including high pressure and high temperature formations, the need of multiple casing strings, unstable formations, hole cleaning, unexpected presence of tar zones, huge layers of salt, the need to underream the well, difficult to do an efficient evaluation program etc.On the completion side, the challenges can be even more demanding, with the need to complete multiple zones while trying to minimize future expensive workover operations. This paper presents some practical experiences on dealing with various of the abovementioned problems and also suggestions to make the problems manageable. It might be emphasized that we do not have a perfect solution to all problems and that we are far to have the most efficient solution to drill deep wells located in ultra-deepwater zones in the GOM. However, with daily operational costs reaching one million dollars or more, it is our intention in this paper to discuss the problems, to point out some possible directions, to show some field cases and to open a discussion that might benefit the entire industry.

The objective of this paper is to describe the well management process which includes the design methodology and the well execution procedures utilized by Petrobras International to drill its first ultra deepwater well in a remote and challenging area of the Turkish waters in the Black Sea.Ranked as a well of the highest complexity level, the drilling of this wildcat deepwater well has faced a number of expected hazards such as the presence of shallow gas zones, long abnormally pressurized intervals, low fracture pressure gradient sections, loss circulation zones due to the presence of fractured limestone, great potential for false kicks (breathing formation and ballooning) and the possibility of having gas migration to the riser.In addition to the risks listed above, the well location, in the middle of a remote area of the Black Sea, has been also considered a great challenge in terms of operational logistics. This came from the fact that Petrobras had to plan all its operations from scratch, including moving a huge semi-submersible drilling rig under the bridges located on the Bosphorus Strait.In this work it is also presented the Well Classification Methodology developed by Petrobras. Such method takes into account several factors that includes water depth, number of well drilled in the area, the existence of abnormally pressurized formations and a number of other obstacles. The main idea of this procedure is to establish the proper well design robustness and to define operations actions which should be used to mitigate operational problems that could arise.Despite of all these challenges, the well was executed according to its original plan indicating that the methodology was successfully applied and can be repeated in other wells. A number of lessons learned during the planning and execution phases of this project are also discussed within the scope of this work.