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Technology Applications

Coiled-Tubing Drilling

Polaris is AnTech’s largest tool in its family of bottomhole assemblies for coiled-tubing drilling. With a 5.0-in. diameter, it is designed for drilling hole sizes in the 6-in.-and-larger range. The electrically powered orienting tool (Fig. 1) enables precise adjustment of the drill-bit and motor orientation. Its purpose-built drive train provides the force required to change direction and, at the same time, withstand the reactive torque from the drilling motor (i.e., direction can be changed while drilling ahead). Drilling both the curved and the straight sections is possible without pulling out to adjust the motor bend. The gyrosteering tool and optional sensors use wireline telemetry to provide real-time feedback. Information about the downhole conditions, tool position, and the formation is relayed to the display panel at the surface to aid drilling decisions. The tool is suitable for applications in unconventional gas shales, coalbed methane, and underground coal gasification.

Geomodeling Update

Blueback Reservoir provides software plug-ins and 3D-geomodeling services for oil/gas exploration and production and has announced the release of its Toolbox v11. The suite of plug-ins for Schlumberger’s Petrel contains functionality features not available in the standard version. The plug-in suite contains modules for geology, geophysics, project management, reservoir engineering, and seismic reservoir characterization. The plug-in suite delivers high-end geophysics tools to assist reservoir characterization. The new content focuses on estimating seismic net pay for thin-bed reservoirs and classification of seismic data using amplitude-variation-with-offset (AVO) analysis to help identify hydrocarbons. The functionality ranges from the seismic net-pay workflow to AVO seismic classification to functionality for creating connected volumes of the extracted seismic-attribute bodies. The net-pay workflow involves a series of steps from analyzing the acoustic-impedance/gradient-impedance slope through colored inversion and creation of seismic net-pay maps.

High-Temperature Roller-Cone Bit

Smith Bits, a Schlumberger company, introduced its Kaldera advanced roller-cone bits for geothermal and high-temperature (HT) drilling applications (Fig. 2). Advanced materials technology provides an engineered sealing and lubrication system for drilling HT wells. The seals are made from fabric-reinforced fluoroelastomer composites that provide thermal stability and wear resistance. An innovative grease compound was developed from synthetic-based oils and functional additives to increase the load capacity at elevated temperatures to ensure adequate lubricity of the bearing/sealing system. In a recent geothermal well in Italy, where temperatures can exceed 277°C, bits with the new sealing system were run successfully. A new field record was established, drilling 77 hours in a single run, a 37% increase of on-bottom drilling hours compared with offset runs. At the end of the run, all seals and bearings were graded as still effective.

Downhole Motor

Mpact Downhole Motors launched its 4¾-in. downhole motor with an 18% increase in load capacity. The higher capacity improves reliability and allows increased weight on bit, which enables higher penetration rates. The heavy-duty thrust bearing can handle the increased load capacity. The tool’s tensile strength matches or surpasses that of the rest of the motor, providing integrity in the downhole motor. The proprietary adjustable housing adjusts between 0 and 4° in the field. The adjustable housing features a wear pad approximately 120° around the adjusting ring at the bend point. The eccentric motion of the rotor is connected to concentric rotation in the bearing assembly by a drive shaft fitted at each end. The bearing assembly is oil lubricated, sealed, and pressure balanced. The pressure-balancing method ensures zero pressure-drop across the seals, allowing the seals to act only as a barrier between the oil and the drilling fluid. The maximum recommended pressure drop across the bit is 1,500 psi. The radial bearing is designed to accommodate a larger-diameter drive shaft, allowing it to withstand extreme radial and torsional loads. The temperature rating is 400°F.

Bridge Plugs

Peak Well Systems has extended the range of its SIM System technologies for flow control with its 5- and 5½‑in. products, including the SIM Retrievable Bridge Plugs (Fig. 3). This system comprises a plug and an expandable seal (requiring no landing profile), which can be set by mechanical tool-string manipulation. The system uses a slickline-conveyed running tool that enables setting the tool-string at any desired depth within the tubing. A radial indexing mechanism activates a set of slips to anchor the running tool to the tubing wall. Then, the device is set by downward jarring that activates and expands the sealing element. Then, an overpull is applied to confirm that the deployed component has been set fully. Once set in place, the running tool is released from the device by upward jarring. The product range has interchangeable modular components including plug systems (both retrievable and permanent), mechanical leak-detection tools, gas lift straddles, and large-bore gauge hangers, all of which can be set on slickline.

Formation Testing in Hostile Environments

The new Schlumberger MDT Forte qualified rugged system and the MDT Forte-HT high-temperature version deliver robust downhole-fluid analysis, fluid sampling, and transient testing to meet the challenges of oilfield operations (Fig. 4). The two new platforms have been fully redesigned and reengineered to tolerate excessive vibration at all stages of use: from low-frequency shaking during transit to high-impact shock and vibration downhole at extreme temperatures. The redesigned electronics system incorporates surface-mounted components on a ruggedized chassis that overcomes conventional fragility of electronics when operating in tough logging conditions. Qualified for 100 operating hours at temperatures up to 400°F, the system is suited for operations in the most challenging environments, including deep water, drillpipe conveyance, high-pressure/high-temperature wells, and remote operations. These systems extend the reliability, efficiency, and applicability of the system platform while minimizing operational risks.