Abstract
Drilling a well in deep oceans is a daunting task due to both downhole drilling hazards and excessive floating rig package. Traditionally many of these challenging wells are drilled with a low-pressure 21" marine drilling riser stretched from mudline to surface. A huge rig with high weight, space, and tensioning requirement is vital to handle this monster fluid conduit. Moreover, a reliable station keeping system is essential for the rig to keep it in a very tight operating radius to have drilling operations running uninterruptedly.
When we move to deeper waters and harsher environments, it becomes more difficult, and in many cases becomes even impossible to reach reservoir targets in such challenging environments. The problem of narrow formation pressure window also exists and adds up.
Reelwell Drilling Method has been proven by series of tests and theoretical studies to have the potential to alleviate the main drilling challenges by (1) elimination of the marine drilling riser to extend the capability of drilling in ultra deepwaters, (2) providing a closed-loop circulation system to make it possible for the industry to deploy Controlled Pressure Drilling (CPD) techniques and overcome many downhole pressure related challenges including narrow pressure window which is a common problem in deepwaters (Mir Rajabi 2009).
