The use of hole opening tools in conjunction with Rotary Steerable Systems (RSS) has increased dramatically in the past few years. Although excellent performance has been delivered with the mainstream commercial tools, alternate options have been developed to enable an RSS to drill the pilot hole in conjunction with a string tool to open the hole in a single run. The most popular current option involves a weight or hydraulic activated underreamer. However, fixed blade, multi-diameter reaming tools have recently been developed for use within Rotary Steerable (RS) assemblies:An eccentric string reamer that will pass through a small pilot hole but then drill and produce a larger hole. This provides a significantly lower-cost hole opening option.A concentric string reamer that utilizes a tapered design incorporating a mid and main reamer section. This innovative design uses a mid-reamer that enlarges the pilot hole to an intermediate size and stabilizes the main reamer above it on its gauge pads. Because of its unique design, the mid reamer is able to stabilize the tool even if the pilot hole is of poor quality or is overgauge. This is particularly beneficial with RS tools in soft formations, leading to improved borehole quality and BHA stabilization. It also enables the use of smaller RS tools, thus providing greater directional potential. Additionally, a single RSS can be used to drill multiple hole size intervals, minimizing BHA changes, which in turn increases rig floor safety and lowers costs. Several distinct applications are documented where these fixed bladed solutions, in combination with both Push and Point RS tools, have proven extremely successful. This has provided greater flexibility with regard to tool selection and well planning options, delivering lower cost per foot in RS projects. Case studies are presented from the Far East, Norway, and the Gulf of Mexico. Introduction Hole opening tools fall into two main categories; Eccentric and Concentric. Eccentric reamers are fixed reamers that are dominated by bicenter drill bits or 'wing-like' string reamer tools using PDC cutters. They are developed for applications where hole enlargement is required but the tool has to pass through a smaller diameter restriction than the required final hole size. The concentric tools are more diverse and consist of fixed designs such as concentric drill bits and string tools (that could be either PDC or roller cone cutting structures), to more complex tools that open on demand by either mechanical or hydraulic control. The growth in the use of hole opening devices over the last few years was driven predominantly by the growth of deepwater drilling. The lessons learned from innovations in the deepwater have extended those applications to shallower waters and even to selected land wells. Hole opening while drilling devices have enabled operators to set larger strings of casing deeper in holes where hole stability, lost circulation and high-pressure zones are a constant problem. This has the obvious advantage of eliminating trips while leaving sections of open-hole exposed over shorter durations, as well as providing a larger annulus for better cement jobs. The ability to reach extremely deep reservoirs with 12 1/4", 10–5/8", and 8 ½" well bores enables operators to run larger and more complex production strings, and this in turn has had an enormous impact on exploration and production economics.

The Wisting Field is located offshore in the Barents Sea north of Norway. The field development requires drilling and completion of horizontal wells in a narrow pressure window, which is challenging for conventional technology. The Reelwell Drilling Method (RDM) provides a solution for managed pressure drilling (MPD) to mitigate these challenges. Based on the use of dual-channel drillpipe, RDM enables the pressure gradient in the openhole section to be held constant and nearly independent of the drilling fluid flow rate. RDM provides low-energy drilling, i.e., efficient drilling and hole cleaning when using low flow and low-drillstring rotation speed. This allows drilling of horizontal sections within a small pressure window and limits drillstring fatigue in high-dogleg applications. In order to start qualification of RDM for the Wisting Field, a horizontal trial well was drilled in fall 2018 at the Ullrigg Drilling and Well Test Centre, located at the NORCE Norwegian Research Centre in Stavanger, Norway. The goal for this trial well was to prove the dual-channel drillpipe capability to perform low-energy drilling, i.e., low-rotary speed, low flow, and stable downhole pressure gradient. The trial well had a challenging geometry with up to 14°/30-m build rate, as required for the field. The 9½-in. horizontal section was drilled in order to check the performance of the RDM and start the qualification of the RDM for the Wisting Field. The trial well was drilled with a low-flow motor, i.e., with flow rates around 700 lpm. The string rotation speed was held lower than 5 rpm to limit drillstring fatigue in the high-dogleg section of the well. Efficient drilling and hole cleaning of the 9½-in. horizontal hole section was demonstrated. The results from the trial confirm the predicted performance for the RDM. The results indicate that RDM can keep well pressure gradient within the required window and mitigate the drilling challenges for the Wisting Field. The RDM architecture with return flow in the inner string represents a major advantage to avoid cuttings build up in the well, challenges with laminar return flow, formation wash-outs, mechanical down hole dynamics and ECD control by low energy drilling.

This paper documents the results of a customer demonstration of a digital network powered from surface deployed on a wired drillpipe system downhole. The objectives of the trial were to: demonstrate the ability of the system to power multiple tools from surface without the need for batteries or power generation turbines downhole concurrently, provide high speed bi-directional telemetry between downhole tools and surface without the need for mud pulse, E-Mag signals or repeaters Over 100 joints of the powered and wired drillpipe were mobilized to a land test rig. Two runs were planned for the customer demonstration well: the first with a service company's bottom hole assembly equipment, the second utilizing a Measurement-Whilst-Drilling (MWD) tool replacement specifically designed to make use of the full potential of the high speed telemetry and electrical power available. In setting up the system, the rig was fitted with a top drive adapter, allowing data and power to be transmitted from surface to the drillpipe and downhole tools. During the trial, typical operations were conducted to validate system handling times, operational aspects and to demonstrate overall power/network uptime and reliability. Handling, racking and tripping operations were conducted, showing that the wired pipe string could be manipulated in the same way as regular drillpipe. Make/break and slips to slips timings showed similar periods to regular drillpipe handling on the same rig. No damage was observed and no special handling or thread doping techniques were required. A total of 96 pipe joints [3058ft] were run in hole on two successive runs, drilling a granite formation whilst circulating with a water based fluid. Run #1 demonstrated the ability of the system to interface to and supply power to a service company's drilling mechanics BHA without the need for lithium batteries downhole. Tools were pre-assembled, torqued and pre-programmed before arrival at the rigsite and could be run directly into the wellbore. Run #2 demonstrated power delivery to and high speed real-time telemetry with a custom designed MWD tool providing continuous directional surveys, tool-face, annular and internal pressures, shock and vibration and gamma ray measurements at >61,000bps data rate. During the runs, power and real-time measurements were monitored whilst circulating, drilling on bottom and tripping. Both runs included a distributed in-string sub to measure annular pressure, temperature and string vibrations, communicating and taking power from the string concurrently with the other downhole tools. 189hrs of operations were recorded during the demonstration, witnessed by customers at the rigsite, and streamed globally to those remote. 100% uptime was recorded for both the power and telemetry transmission over the digital network. Overall, the trial results demonstrated the ability of the system to be handled in a similar way to a regular drillstring. Power was supplied to downhole tools thus eliminating the need for downhole batteries and turbines. A high speed, reliable digital network was deployed allowing multiple tools and sensors to communicate on the same transmission path as the power without the need for in string signal repeaters.