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Technology Applications

Chris Carpenter, JPT Technology Editor

Dart-Activated Hydraulic Pipe-Recovery System

The HyPR HoleSaver from Churchill Drilling Tools is the first full-strength hydraulic pipe-recovery system. The tool consists of a full-strength sub positioned in the drillstring, which is ­severed by a HyPR jetting dart in just a few hours. Traditional methods of pipe recovery can take many days and often use explosives or other high-energy sources. By using dart-activated technology, the HyPR HoleSaver is a faster, simpler, and safer way to recover stuck pipe for many applications. Churchill Drilling Tools, in its effort to create new technology to reduce cost and enhance performance, has made considerable investments in research and development to produce HyPR darts that are capable of delivering cutting power in excess of 1,000 hydraulic hp, with jet velocities of over 300 ft/sec (Fig. 1). To activate the system, either a fishing or cementing dart is pumped down the string. Once landed in its intended location, this dart will quickly part the full-strength sub. This process can also be accelerated with torque or overpull from the surface. Depending on the dart selected, the user is left with either a perfect fish-neck or immediate side-track cementing capability. Up to three HyPR HoleSavers can be positioned at multiple points throughout the string for maximum contingency options. The tool is an ideal partner for Churchill’s DAV MX circulating sub, which can be used in packoff situations to recover circulation before cutting the string. Stuck-pipe situations currently cost the drilling industry millions every year. Churchill Drilling Tools was therefore committed to develop this low-cost, simple, and effective solution to the recurring issue. The HyPR Hole­Saver now enables operators to effectively insure against excessive costs by running the tool in their drillstring to recover quickly from stuck pipe should it occur. The compact and portable nature of the system makes it ideal for remote locations where stuck-pipe situations are likely to have even higher cost implications. The low cost of running the tool, combined with its rapid recovery time, brings significant cost reductions for operators globally.

Hydraulic Long-Stroke Pumping Unit

The Weatherford EnviroLift hydraulic long-stroke pumping unit is a new lift solution that is well-suited for multiwell pads, environmentally sensitive areas, and populated areas. It provides capabilities similar to those of a conventional pumping unit—but in a more compact, environmentally friendly package that enhances safety—and eliminates problems associated with other hydraulic technologies. The unit is suited for deviated and horizontal wellbores and for liquid production up to 1,200 B/D (191 m3/d). The unit comes in three parts that require no site preparation and install quickly: the wellhead, cylinder assembly, and power unit. The 240-in. stroke unit is rigidly bolted and supported on the integrated wellhead—eliminating guy wires while enabling the unit to withstand 100‑mph winds—and contained in a single cylinder with no exposed moving parts. The design eliminates the stuffing box to avoid leaks. With a maximum skid size of 11×6 ft (3.4×1.8 m), the unit enables higher well density and increased productivity in multiwell pads and provides plenty of work space. Additionally, with options for camouflaging and noise reduction to blend into the surrounding landscape, the unit can be aesthetically pleasing.

High-Performance Elastomer

Rubberatkins’ high-­performance perfluoro (FFKM) elastomers enable customers to realize sealing solutions not previously possible with other traditional FFKM elastomers. This advance is made possible by unique compounding techniques used to stretch the boundaries of these elastomers in often hostile chemical environments and extreme temperatures. Because of the nature of perfluoro elastomers, their mechanical properties are low at elevated temperatures. However, the Rubberatkins’ Vermanite perfluoro elastomers have been engineered for improved performance and longevity at challenging downhole conditions. Vermanite is one of Rubberatkins’ many materials specifically compounded for extreme downhole applications (Fig. 2). Sealing solutions for high-expansion, ultrahigh-­temperature (650°F) geothermal application and extreme sour-gas environments are just a few applications where Vermanite has been used successfully. Products molded from Vermanite include O-rings, T-seals, V-seals, packing elements, and expandable seals. In addition to the performance and longevity aspects of Vermanite, Rubberatkins has been able to bond these inert materials successfully to various substrates.

Reamer Tool

Superior Drilling Products’ Drill-n-Ream tool is a dual-stage eccentric reamer that increases the wellbore drift by 1/16 in. or ⅛ in. over bit size while rotating during horizontal and vertical drilling operations (Fig. 3). The two reamer stages spaced approximately 5 ft apart act in unison to force each other into the formation while reducing ­ledges, doglegs, and wellbore tortuosity. Each reamer includes four blades with numerous polycrystalline-diamond-compact (PDC) cutters, which are designed in a progressive pattern to minimize torque. Diamond domes are also placed strategically on the reamers to eliminate pipe damage and protect the PDC cutters while rotating in casing. The profile relief located near the blades entices the formation into the PDC cutting structure to maximize the amount of formation that is contacted while conditioning the wellbore.

Annular Barrier

It is estimated that tens of thousands of wells currently suffer from surface annular pressure (SAP), and cement cannot overcome this challenge. Similarly, in increasingly challenging completions, cement fails to fulfill its primary purpose. The Welltec Annular Barrier (WAB) was developed with the primary application of segregating production between different reservoirs in cementless lower completions. The WAB functions by applying pressure from within the completion string to the engineered sleeve through the valve system and hydraulically conforming the sleeve to the formation (or casing) within which it is set. Once conformed to the encircling structure, the WAB seals off the annulus around the liner upon which it is mounted, preventing undesired pressure migration across the WAB along the wellbore. The WAB gives users the ability to protect themselves against SAP by overcoming the use of cement as the only primary well barrier. The WAB builds upon solid-expandable knowledge Welltec has developed in the last half-decade but augments the material strength of expanded steel with transferred annular pressure. This technique of repurposing pressure to create a more robust seal is a novel approach to an old problem.

Cement-Evaluation Service

Baker Hughes introduced its Integrity eXplorer cement-evaluation service. Existing evaluation techniques, which have been used for more than 30 years, are acoustic-based and may not provide the accuracy needed when faced with current challenges. This new electromagnetic/acoustic technology allows operators to assess the integrity of cement bonds directly in any current wellbore environment or cement mixture. Operators in the upstream sector rely on the accuracy of cement-bond logs to make critical decisions that can affect long-term well integrity and the environment (Fig. 4). While cement compressive strength has typically been used as a key indicator of cement quality, today’s challenging environments require a more-detailed assessment. The Integrity eXplorer service provides operators with accurate and comprehensive data about the properties of the respective cement, thereby enabling them to make critical decisions to help protect their assets, reduce nonproductive time, and minimize unnecessary remediation.

Downhole-Fluid-Recovery Service

Flowco’s NitroGEN Services rapidly recover downhole fluids. Nitrogen is efficient, inert, and noncorrosive, and works seamlessly with all Flowco gas lift valves. NitroGEN operates in three ­stages. First, a low-pressure air compressor pulls atmospheric air to the membrane separator; next, the membranes separate air into rich, inert nitrogen gas at greater than 95% purity and oxygen waste. Finally, high-­pressure booster compressors discharge nitrogen-gas volumes up to 600 scf/min at 5,000 psi. Applications include well jetting and unloading, de­watering, well testing and cleanout, reservoir-pressure maintenance, and gas supply for gas lift systems (Fig. 5). New-well activity applications for NitroGEN include completions and drillouts. NitroGEN is ideal for pipeline purging and pressure testing. 24-hour supervision and daily reporting are available with NitroGEN.