PEMEX has implemented an extensive campaign to drill deepwater wells along the Gulf of Mexico (Mexican region) as part of their exploration program. One of the challenges in this region is the presence of salt, which affects the subsurface geology and creates a very complex structural environment. In this case study, a well was drilled beneath a salt dome in the southeast area of the Gulf of Mexico. This area presented a very strong structural complexity as a result of the salt tectonics of this dome. The 3D surface seismic analysis revealed the possible shallow gas hazards in this area, which added further constraints to the well placement. Perforating the well presented additional challenges beyond those of previously deepwater wells drilled because the presence of salt generates tectonic forces produced by the salt movement during migration to shallower zones, and in particular, because the well could cross salt sediments in the top part of the dome. We will present the results obtained after apply seismic-while-drilling technology to reduce some of the uncertainties produced by the presence of salt. We will also show how this information was used to look in front of the drill bit and measure the distance from the well to the salt flank in real time, allowing for decision making while drilling to optimize the drilling process.

Technical Paper presented at 15^th Rio Oil & Gas Conference, held on Sep 13 -16^th 2010 at Rio Centro/RJ.