Applied annular pressure, for both managed pressure and underbalanced drilling, was born on land decades ago. In fact, the first Rotating Control Device (RCD), the critical component, dates as far back as the 1930's. Simply closing the annulus around the drillstring, and "bottling up" the well, introduced new techniques that enabled wellbore pressures to be managed to drill a better well. In some cases, this was the only way to drill the well.
Typical of the drilling business, innovation is generally derived from repurposing or repackaging technology to address new challenges. Applied annular pressure fits squarely into this arena. The shale boom in North America has pushed all technical limits, striving to squeeze every ounce of lost efficiency out of the program. The lighter your fluid, the more you can pump, the better your rate of penetration, the better you can clean the hole, and the less damage to drilling equipment… efficiencies compound. Lighter fluid introduces more pressure dynamics with the well, however, and these require managing. This is where Managed Pressure Drilling (MPD) came to life as unconventional drilling expanded. As a result, more than 75% of drilling rigs are making hole with RCDs in North America Land today.
Early success of applied annular pressure drilling allowed for migration offshore also. The nature of equipment required to execute limits how easily it can deploy, however. So historically, it has been reserved for the most demanding "undrillable" wells. MPD was typically a technology of last resort, requiring equipment uniquely designed for offshore applications, along with space not commonly available on offshore installations. These barriers eroded over time, however, and MPD is now common on several offshore projects.
Moving into deepwater, the step-change to overcome barriers becomes another significant technology shift. The RCD needs to fit into the drilling riser, and an additional annular is required to manage any gas buildup above the sub-surface BOP. These challenges are dissolving and MPD is picking up pace in deepwater. The motivation remains "undrillable" challenges. However, in order to justify the effort and cost, cracking the "efficiency" drivers that have pushed the shale revolution need to be harvested.
What happens when the efficiency drivers applied in the shale factory start heading to deeper and deeper water? Surprising, the opportunities to harvest efficiency with MPD are even greater, with less effort, in deeper water. The challenge is getting the equipment there.
This paper will explore two parallel universes, showing cases of the technical efficiency gains from real wells. In both arenas, the financial impacts of cost and savings will be normalized. Further opportunities to expand the "efficiency-verse" will also be explored, shining clear light on money well spent.
