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Technology Applications

Environmental Qualification

Baker Hughes has added drilling and completion fluids, production chemicals, and additives used in cementing and stimulation operations to its SmartCare family of environmental solutions. Before awarding the designation, a team of chemists and researchers evaluates and rates the components of a chemical product for potential environmental and health effects. Insights gained from the evaluation also guide research and development of increasingly sustainable solutions. Products must undergo rigorous assessment of intrinsically hazardous properties. This assessment is conducted through a single, integrated chemical-evaluation process that examines each product at both holistic and component levels for health, safety, and environmental acceptability, and for performance and compatibility. The result is a relative numerical rating that ranks the product or component according to three major hazard categories and 12 subcategories. This scientific method—based on the United Nations Globally Harmonized System for Classification and Labeling of Chemicals—produces credible, transparent, and documented information for customers, regulators, investors, and the public. The evaluation enables comparison of functional groups of chemistries (such as surfactants, clay stabilizers, and corrosion inhibitors) so that the most environmentally preferred option can be selected. Compliant products then can be combined to create fit-for-purpose solutions.

Intelligent Intervention

The ReSOLVE instrumented wireline intervention service from Schlumberger allows operators to perform many major well-intervention operations without a rig or coiled-tubing unit. The advanced capabilities of the tools, coupled with the speed and small footprint of electric-
wireline deployment, give operators intervention options to address production problems quickly, safely, and noninvasively. The new tools use downhole sensors and high-speed telemetry to provide instantaneous monitoring of tool operation, responsive real-time control of all tool functions, and positive confirmation of intervention actions. The family of tools includes a high-force anchor and linear-actuator tool (Fig. 1) for pushing and pulling operations and an optional high-expansion universal shifting tool (UST) for shifting completion components selectively. A milling tool operates in combination with the company’s TuffTRAC cased-hole tractor to mill through built-up scale and other well obstructions. A nonexplosive setting tool sets bridge and tubing plugs, packers, and other devices while providing a record of the setting force to confirm the setting operation. The services are deployed on standard wireline cables and surface equipment, with optional tractor conveyance. During operations, the tools are directly controlled at all times by the engineer at the surface, who can see feedback of all tool operations in real time. The linear-actuator tool anchors in tubing and precisely applies a controlled gripping of up to 45,000 lbf. The UST deploys shifting keys on command, even below restrictions. The milling tool uses the company’s AutoMill control system to vary weight on bit autonomously to maintain a constant bit torque to prevent stalling. The tool uses a custom polycrystalline-diamond-compact bit designed by Lyng Drilling specifically for scale-milling operations. The setting tool provides a fully controllable setting speed with a constant setting force of up to 78,000 lbf, without the use of explosives.

Downhole Pressure Testing

Churchill Drilling Tools has deployed its mechanical extrusion (MX) and Smart Dart (Fig. 2) systems in drillstring pressure testing. The extrusion system allows use of the rigid darts for multicycle control in high-pressure/high-temperature environments. The system provides a simple accurate method to test a drillstring to a specific preset pressure and enables regaining circulation between each test. This system allows multiple tests at various pressures in a single run. The pressure-test subassembly can be run in any length of pipe, at any angle or temperature, and with any type of circulation fluid. The subassemblies have fully tapered internals, provide unrestricted circulation, and have a full through-bore before the first cycle. The dart is dropped and pumped into place, with the load transmitted through pins in the dart into the subassembly. The pins determine the shear-out pressure. Pressure can be held at the required test level for as long as necessary. When testing is completed, a small increase in pressure is used to shear out the dart into the catcher below. This system enables multiple test cycles, full circulation between tests, and a shear-out point that can be modified accurately by altering the dart’s pins before it is dropped. The system has demonstrated shearing accuracy of 99.6% and has been used for leak detection in drillstrings and in pre-emptive integrity tests before ultracritical high-pressure phases.

Progressing-Cavity Surface Pumps

Moyno progressing-cavity pumps are capable of handling thick, abrasive, and corrosive heavy oil effectively, even with viscosities higher than 1,000,000 cp. There are models capable of generating flow rates up to 2,500 gal/min and pressures up to 2,100 psi. These pumps are low maintenance and have a long service life. The progressing-cavity design results in a low-shear discharge with no-pulsation flow. Progressing-­cavity pumps for lease-automatic-­custody-transfer (LACT) applications (Fig. 3) provide accurate transfer of ownership of liquid hydrocarbons between a buyer and a seller through an LACT unit into a pipeline.

Water-Based Fluid System

Baker Hughes has introduced its LATIDRILL water-based drilling-fluid system to enhance wellbore quality and increase drilling efficiency in extended-lateral sections in unconventional shale plays. The drilling-fluid system is more environmentally favorable than oil-based systems and offers the hole stability, drilling speed, and performance usually associated with invert-emulsion systems. The drilling-fluid system improves wellbore stability by controlling clay hydration typically associated with the use of a conventional water-based fluid. Clay hydration can lead to sloughing shale and borehole enlargement. This ­drilling-fluid system uses a proprietary wellbore stabilizer that maintains wellbore integrity mechanically and limits nonproductive time associated with hole-stability issues. By delivering a more-stable wellbore in long horizontal sections, the drilling-fluid system reduces pore-pressure transmission, minimizing or eliminating mud losses. This drilling-fluid system improves drilling efficiency by use of specially purposed lubricants that coat metal surfaces, drill cuttings, and formation walls to reduce torque and drag, particularly in high-pressure/high-temperature applications. The lubricants also enable delivery of greater amounts of hydraulic horsepower to the drill bit, resulting in faster penetration rates. Because the drilling-­fluid system is water based, disposal of oily cuttings is unnecessary and cleanup time on the rig can be reduced by as much as 2 days compared with that of oil-based systems. Operators can realize greater value by packaging the drilling-fluid system with the full range of the company’s shale solutions, including the StarTrak imaging tool, the AutoTrak rotary-steerable system, and the Hughes Christensen Talon 3D polycrystalline-diamond-compact bit.

Gate-Valve Seals

Worldwide Oilfield Machine (WOM) has successfully completed an extreme-­temperature test of its patented Dual-Seal Gate Valve with Magnum Seal Assembly (Fig. 4). The test included operating the gate valve through 200 cycles of extreme temperatures ranging from −20 to +450°F under a constant pressure of 15,000 psi. This test ensures that the gate valve meets the American Petroleum Institute 6A Annex F-PR2 performance requirements. After completion of the test, inspection of key seal components within the valve’s upstream and downstream sides revealed no abnormal abrasion or deformation. Test results demonstrated that mechanical integrity was maintained on the upstream- and downstream-seal assemblies, the gate faces, and the stem packing. The company’s dual-seal technology forms a bubble-tight seal against the valve gate, which is maintained through the most-extreme conditions, such as those occurring in Arctic and ultradeepwater drilling and production.

Seal-Change-Out Tool

SECC Oil & Gas developed a system that allows operators to replace elastomer seals subsea. The two-part system combines a seal-change-out tool with a replacement inner-piston-seal cartridge (Fig. 5) for the company’s Hot Make Hot Break connector and provides permanent injection solutions with connect/disconnect capability. This combination can provide direct access to a well from a manifold or tree by way of a vessel, making it a viable connector for scale-squeeze and gas-compression projects. The connector uses a pressure-balanced full-bore external-check-valve design to remove the risk of pollution and protect offshore personnel and equipment in a drive-off emergency. It achieves this by instantly and automatically sealing each end of the bore when disconnecting under pressure, eliminating high-­pressure fluid loss or seawater ingress at the point of connection/disconnection. However, its elastomer seals, which are essential to its pressure-balanced design and automatic disconnection and reconnection capability, are not considered by the industry to last the 25-year life time required of permanent connectors. The new technology is built around a removable cartridge or inner piston that is integrated into the connector’s permanently installed female component and is simply removed and replaced by use of a remotely operated vehicle (ROV). The ROV lowers the change-out tool into the female receptacle and twists out the inner-­piston cartridge, replacing it with a new one.

Y-Type Strainer

Spirax Sarco has released its Fig 18HP alloy-steel Y-type strainer rated to American Society of Mechanical Engineers Class-2500 standards. The strainer is designed to protect equipment from pipeline debris such as scale, rust, jointing compound, weld metal, and other solids in flowing liquids or gases in high-pressure applications. This range of strainers has a large screen area providing a high flow coefficient and low pressure drop, reducing the blowdown frequency for cleaning. The strainer is capped, drilled, and tapped to enable a blowdown valve to be fitted to drain and clean the screen while it is in service, reducing system downtime. The strainer screens are available in several materials, perforations, and mesh sizes. The standard stainless-steel screen in the ½- to 2-in. size range has 1/32-in. perforations.

Mooring-Monitoring System

The Inter-M Pulse (Fig. 6) from InterMoor, an Acteon company, is a ­mooring-monitoring system that electronically monitors the inclination and tension of mooring lines. Robust, ­purpose-built sensors are used in the mooring connectors. The collected data are sent to the topside-control-room interface acoustically, where they are displayed by use of a traffic-light system with automatic threshold alarms to warn of any issues that could cause problems. Developed with Pulse Structural Monitoring, the system has important safety and environmental benefits that aim to prevent floating production units from breaking away from their moorings, thereby safeguarding the lives of workers and preventing oil spills. Additionally, it could help mitigate the cost of lost production. In 2011, the system completed a 6-month trial in the North Sea. During a winter drilling campaign, a 76-mm, 800-t-minimum-break-load mooring line was installed over the stern roller of an anchor-handling vessel for the Ocean Nomad semisubmersible rig. The trial provided tension data for the line from the ultralow-power long-life system in a range of sea states.

ICD Reservoir Management

Inflow-control devices (ICDs) are designed to improve completion performance and balance inflow throughout a horizontal wellbore, enabling the reservoir to drain more efficiently while optimizing production and maximizing ultimate recovery. Weatherford’s FloReg ICD (Fig. 7) has been used effectively in more than 100 wells since 2005. The technology continues to be advanced with new variations to improve functionality and reservoir control (RC) and to reduce risk without sacrificing flow assurance. The RC function enables shut-off capabilities for wells requiring selective injection or production, or for wells with uncertain reservoir conditions. The tool combines RC with the company’s ZoneSelect monobore sliding-sleeve technology. As production requirements change or the well depletes, flow can be adjusted by closing or opening sleeves selectively. Life-of-well functionality delivers operational flexibility to enhance reservoir-management capability. A radio-frequency-identification device (RFID) enables running the RC string in the well with each device closed. This method eliminates the need to run washpipe, while providing the ability to operate the hydraulically actuated tools uphole and operate the monobore sliding-sleeve technology without intervention. It then is possible to open individual RCs in any sequence by circulating RFID-coded tags, by generating modulated pressure pulses, by use of a preset time, or by a combination of all three. A mechanical-shifting option is available in the event that it is needed.