Reverse Circulation Drilling (RCD)
A managed pressure drilling system, used in conjunction with a continuous circulating device to control wellbore pressure, helped an international E&P company successfully drill a difficult section of an deepwater exploration well in Ghana, West Africa, in 2012. In the view of Derrick Lewis, global operations manager at Halliburton business line Geobalance Measured Pressured Drilling Service, MPD offers considerable benefits in terms of an additional barrier with the RCD, the ability to mitigate lost circulation and well-control incidents, and the ability to tell if the well is taking an influx or ballooning, as well as an increase in rate of penetration (ROP), which is generally experienced with MPD.
MPD is a ten-year-old technology that keeps drilling pressure at, or slightly above, reservoir pressure, which, it is argued, in most circumstances gives better control of the rcd drilling annular pressure profile throughout the wellbore than under-balanced or over-balanced techniques, where the pressure is maintained below or above that in the reservoir.
The installation of a few minor components in the MPD riser stack and rig surface equipment, enabled the rig to rapidly transition from open to atmosphere with RGH” to full MPD capability thus providing a step change in the rig's capabilities - a transition process that saved 12-14 months rig up time.
This integration allows for the installation of a managed pressure drilling (MPD) system that monitors mass flow (flow into and out of the well), providing precise early detection of a hazard, and introduces a means to employ swift preventative measures before a situation escalates into a potentially catastrophic scenario.
The use of advanced drill gas analysis provides an important new tool for reservoir analysis during the early stages of drilling. The component-based RGH easily accommodates MPD service company equipment in addition to AFGlobal MPD systems owned by the drilling contractor or operator.
A below tension ring (BTR) RCD is the first device to be deployed as a subsea riser component. It provides early kick and loss detection and enhances the riser gas-handling system by allowing early detection of riser gas breakout and facilitating pressure control for the same.
With available EC-Drill® equipment, the limiting factor will be rig integration time. LDD has developed one of the largest fleets of reverse circulation, pile-top drilling rigs in the world. There is also application for use on specific platform applications with a surface BOP when a subsea casing hanger system and separate drilling riser is used.
Drilling Contractor is the only viable magazine exclusively covering the global drilling and completion industry, both land and offshore. Because onshore rigs may not have to deal with compressed locations, there is little need to place the equipment items close together.
The system enhanced drilling capabilities and improved safety and efficiency through early kick detection, riser gas handling MPD and pressurized mud-cap drilling—an MPD variant used in total lost-circulation conditions. We are proud to have performed several operations demonstrating the excellence and proven reliability of our products in demanding drilling operations.