With the oil carbonate reservoirs exploration and exploitation around the world and the Brazilian coast, new challenges for well drilling are found which requires new techniques to be developed. The carbonate reservoirs can present fractures with high conductivity along its structure, often accompanied by geological faults. When associate with scenarios where the reservoirs are depleted, due to the ongoing production of these oil fields, may lead to fluid severe losses into the formation during the news well construction. For decades, in case of total loss at offshore wells drilling, the proposed solution has been to pump sealing material into the formation and, persisting the losses, to end it with a cement plug in open hole and make another attempt to drill the interval. When these procedures were not effective, the wells were often abandoned. On one side, it should be emphasized, that pumping sealant material and cement into the producing reservoir is undesirable, due to the possibility of damaging the intervals of greater permeability and production potential which may bring reduction in productivity (or injectivity) of the well. On the other side, continuing the drilling with fluid total loss may be intolerable from the operational safety point of view, as it is not possible to use conventional kick detection methods, that are mainly based on drilling fluid mass control. Facing these difficulties of drilling wells in reservoirs characterized by fractured and depleted carbonates, the FMCD (Floating Mud Cap Drilling) technique was developed. The technique consists of drilling with continuous pumping of fluid both through the drilling column and the well annulus, injecting all fluid and formation cuts into the reservoir.