Development of subsalt pay zones in deepwater GoM typically includes drilling long intervals of halite formation. Despite the relatively low UCS, salt drilling presents a unique challenge due to its plastic nature and tendency to creep. These factors coupled with complex deepwater casing programs necessitate the use of hole enlargement while drilling techniques. The difficulties of HEWD in salt is further magnified in deviated wellbores where maintaining the directional wellplan becomes a key performance objective.Using a 4D modeling program has resulted in improved HEWD ROP and directional control in salt on several deepwater GoM projects. The software allows engineers to model various RSS BHAs, optimize the bit/reamer cutting structure and prepare operating parameter recommendations tailored for the directional plan.Well A A Mississippi Canyon j-shaped well called for maintaining tangent at 44degrees through a 100% salt 14.5 x16.5 interval. Using a new reamer cutting structure design with a selected PDC allowed the operator to drill 7852ft at an ROP of 54.7ft/hr. The directional objective in the 12.25x14.75 interval of the same MC well was to hold tangent at 44 degrees before dropping to 15degrees. A new cutting structure design with a selected PDC was employed on the RSS/BHA. The 6022ft interval was drilled in one-run with an average ROP of 80ft/hr. Well BMaximum ROP was the primary objective in an 8877ft, 14.75x16.5 section of a s-shaped well which included building and holding at 35 degrees before dropping back to vertical in 100% salt. Bit and reamer recommendations and drilling parameter recommendations to maximize ROP were developed by calibrating the data from the offset well, Well A. The new cutting structure and pre-job planning resulted in a total run ROP of 97.5 ft/hr with an average on-bottom ROP of 129.1 ft/hr, an 80% improvement compared to offset.

With well depths more commonly surpassing 30,000 ft below the mudline and ever-increasing water depths, exceedingly high-pressure environments present a new and challenging frontier for both operators and service companies. These new environments demand advances to existing technology to endure such pressure extremes while also accurately positioning the wellbore in the reservoir and obtaining critical geological information as the well is drilled. A recent example in this pressure regime in the deepwater Gulf of Mexico will be reviewed. Pressure limits of the currently available technology are extended while successfully meeting drilling and evaluation goals. The drilling and evaluation technologies delivered real-time formation pressure and geological information, along with continuous directional control, enabling the operator to make vital decisions while drilling and for sidetrack evaluation. This real-time decision-making capability reduced the time required to execute casing point selection and subsequent sidetrack plans. Emphasis is placed on the need for operators and service companies alike to focus on thorough pre-job planning while paying close attention to complete system requirements high-pressure evaluation tools and detailed reviews. Newer drilling opportunities, particularly in the deepwater arena, involve operating in extreme environments such as ultrahigh pressures, and demand different approaches to ensure flawless execution. This paper presents the variety of challenges, critical success factors, and lessons learned when drilling these ultra-high pressure wells in the demanding waters of the Gulf of Mexico. With downhole pressures approaching 30,000 psi and ever-increasing rig costs, the need for dependable drilling systems and integrated advanced formation evaluation technology is needed now more than ever. The case results showcase the ability to set a new performance standard, extend the conventional operating envelop farther, and deliver answers while drilling.