Reelwell (Norway)

Technology Update The Reelwell Drilling Method (RDM) is a new technology developed to solve certain drilling problems and improve the operation margin for various applications. The technology uses a specially designed dual drillpipe (DDP), shown in Fig. 1, that has two flow channels, one for the flow of drilling fluid into the well down to the bit and the other for the return flow of fluid from the bottom of the well back to the surface. Developed in Norway, the RDM has been field tested at various locations in the past several years. The technology has features for pressurized mud cap drilling (PMCD), managed pressure drilling (MPD), and extended reach drilling (ERD). The RDM enables PMCD with cuttings return MPD with a constant well pressure profile ERD with reduced torque and drag, no equivalent circulating density (ECD) in the wellbore, and no cuttings in the hole The DDP is available in 6?-in. steel and 5?-in. to 7½-in. aluminum pipe diameters. With a pressure rating of 5,000 psi, the DDP contains a concentric inner pipe with a stab-in connector and is handled in the same way as a conventional drillpipe. The RDM can be adapted to a standard drilling rig, with the following tools and arrangements: A top drive adapter—a swivel directing the fluid return through a second standpipe and mud hose An inner pipe valve—a bottomhole assembly (BHA) tool for the isolation of the drillstring during connections A flow control unit—a skid with a control valve system for flow and pressure control A rotary control device—a standard tool at the blowout preventer for MPD The RDM uses standard BHA components and drill bits, and the tools operate on reduced flow rates.

Abstract Managed Pressure Drilling has been proven to be a tool for extending access to previously unattainable drilling targets in many deepwater areas across the world, such as deepwater Gulf of Mexico. 21" Low-Pressure risers do not allow for application of Constant Bottom Hole Pressure (CBHP) technique by floaters. Since it is not designed to hole the pressure, it prevents setting up a closed circulation loop in our drilling system which is an essential tool for MPD.A high-pressure riser along with a surface Rotating Control Device is required to perform CBHP drilling technique. However, we know that deployment of such high pressure risers in long lengths and harsh environments has not come to be practical.An alternative drilling method from floaters at any water depth proves to be Reelwell Drilling Method (RDM). Reelwell AS, Shell, StatoilHydro, and the Research Council of Norway launched a JIP in 2005 to develop RDM, which is a riserless drilling method based on concentric drill pipe. Mud is circulated in a closed loop in this system. The pressure and flow of mud is dynamically controlled by a computer system on the return path on the surface. Many tests including the latest pilot test in March 2009 has proven that the downhole pressure can be controlled precisely and that the system fits perfectly for CBHP.Deployment of this technology by smaller floating rigs is possible with no limitation on water depth as huge and long 21" LP riser is eliminated from the system. The volume of mud is limited to bring about even more cost and rig space savings.