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Vol. 59 No. 6

June 2007

Technology Applications

Dennis Denney, JPT Technology Editor

Constant-Rheology Synthetic-Base Mud

Baker Hughes Drilling Fluids has introduced Rheo-Logic constant-rheology synthetic-based drilling fluid. It is designed to minimize downhole mud losses through reduced surge pressures and equivalent-circulating-density management in deepwater wells (Fig. 1). The system mitigates the effects that cold-water temperatures and pressures have on the rheological properties of conventional synthetic-based mud.The system uses a viscosifying package to build a constant-rheological profile over a wide range of temperatures and pressures. The viscosifiers provide viscosity at low temperatures without building progressive gel strengths with increasing temperature. The system can be formulated with multiple base fluids, and its properties can be modified easily with the company’s drilling-fluid products.

For additional information, visit www.bakerhughes.com/drillingfluids.

Fig. 1—With its constant, low-energy gel structure, pressure spikes associated with initiating circulation are virtually eliminated with Baker Hughes Drilling Fluids’ Rheo-Logic system.

Tool and Equipment Tracking

Merrick Systems and BJ Services completed a pilot of downhole radio-frequency identification (RFID) tags. The Rig-Hand and Tool-Hand software work in conjunction with the unique identifiers contained in the RFID tags for surface and downhole drilling equipment to track and manage equipment through inspection, transportation, and operations. The tags are small, ranging from the size of a small button to the size of a bottle cap. They can be mounted mechanically, epoxied, or screwed into components—depending on criteria such as available wall thickness, component diameter, and the intended use or reuse of the component, such as drillpipe, casing, and bottomhole-assembly components. The system comprises RFID tags, ruggedized handheld computers with built-in tag readers and software modules for handhelds, PCs, and inspection stations. The system is designed for consistent collection of information on downhole equipment for drilling, workover, and completion operations. The solution contains information about components but is configurable to accommodate virtually any user-specific information for which tracking is desired. The tagging system provides rig operations, inspection services, storage yards, and the transportation sector with immediate access to component information. Accurate dimensions, certifications, inspection records, or even sales and use history are available to the software modules and to a variety of existing third-party applications.

For additional information, visit www.merricksystems.com.

Laser Coating

Laser Cladding Services announced its laser-coating technology to increase component reliability in harsh environments for offshore applications. Laser coating is used to improve wear resistance and performance of downhole oil and gas tools (Fig. 2). This new application of the technology equates to better protection of critical offshore components by significant reductions in abrasion and corrosion. The company transferred developments from specialized cladding projects for the rocket-engine- testing program at the Stennis Space Center in which copper was applied to a stainless-steel substrate through laser cladding to create a durable and effective seal. Laser cladding is a metal-surface-enhancing process performed by applying a powdered metal material onto the base surface with controlled heat from a laser. Laser cladding provides a strong metallurgical bond with minimal dilution of the base material. This process is performed with minimal heat input, which also results in a small heat-affected zone. A small zone of base material is melted with the cladding to create the metallurgical bond. The thermal input can be controlled precisely, thus yielding minimal dilution and only a small heat-affected zone. This lower amount of heat input prevents distortion, and the base-material properties are affected minimally.

For additional information, visit www.lasercladding.com.

Fig. 2—Laser Cladding Services’ cladding of dissimilar metals on a drill bit.

External Steel-Pipe Corrosion Protection

Duoline Technologies’ Ricewrap is a protective wrap of glass-reinforced-epoxy (GRE) material applied externally and bonded to steel pipe (Fig. 3). It is used for external corrosion protection on downhole tubing that typically is used between injection mandrels and/or packers in multiple zones. The nominal thickness of the externally applied GRE is 0.100 in., with a working envelope between -20 and 250°F. Externally coated GRE tubing also can be lined internally to offer both internal and external corrosion protection. An external corrosion-barrier ring is used to protect the connection threads and is compressed during field makeup.

For additional information, email bward@duoline.com.

Fig. 3—Duoline Technologies’ Ricewrap protective GRE wrap with an external corrosion-barrier ring to protect the connection threads.

Wheeled Rod Guide

Wheeled Rod-Guide Couplings from Oilfield Improvements centralize the rod string in the tubing. Wheels are set vertically in slots at 45° phasing along the axis of the guide/coupling body. This design ensures centralizing at all rod couplings. The rolling action of the wheels inside the tubing walls produces significantly less friction, and less wear, than does the rod string rubbing or slapping directly against the tubing walls. The wheel size and placement in the guide/coupling body are designed to ensure smooth spanning of tubing couplings, which reduces the shock effect that is characteristic with many rod-coupling devices when they bump tubing shoulders at the couplings. Wheels are set on stainless-steel journals and roll pins to ensure smooth rolling action and are easily field-replaceable with just a common hammer and punch. With proper use and effective chemical-treatment programs, several operators have extended, by an average factor of four, the operating periods between servicing wells because of sucker-rod or tubing wear.

For additional information, email info@rodguides.com.

Absolute Encoder

Dynapar introduced its Acuro AX71 absolute encoder, a compact, high-resolution unit tough enough for use in the oil and gas industry (Fig. 4). Absolute encoders increase accuracy and reduce downtime compared to standard incremental encoders that provide motion feedback in racking systems, roughnecks, draw works, and top drives. The 70-mm-diameter encoder provides up to 17 bits of single-turn resolution and 12 bits of multiturn resolution. An input-voltage range of 10 to 30 VDC allows the encoder to be used almost anywhere in the world, and it is compatible with many communication protocols. This absolute encoder was designed with the help of a major drilling-services firm to operate reliably under conditions of severe mechanical shock and vibration, in high temperatures, and in explosive environments. This unit can withstand high shock loads of up to 100 g. High ambient temperatures combined with radiant heat from the sun can raise the temperature inside a tightly sealed encoder to weaken its electronic components. The electronics of this unit incorporate special substrates and diodes that ensure reliable operation to 60°C. In addition, the encoder is self-grounding to prevent shorting out. The core of the new encoder technology is an advanced optical-application-specific integrated circuit that provides high resolution, accuracy, and diagnostic capability.

For additional information, visit www.dynapar-encoders.com.

Fig. 4—Dynapar’s Acuro AX71 explosion-proof absolute encoder.

Flowsheet-Based Material Balance Module

The SimSci-Esscor unit of Invensys Process Systems has introduced simulation and modeling software that converts raw process data into consistent and reliable information to support asset-performance management strategies. The new Material Balance Module for the company’s Advanced Real-time Performance Modeling suite uses mass and volume reconciliation to reveal sources of random error, bias, and gross error that jeopardize the accuracy of real-time plant data. The material-balance software combines reconciliation methodologies within a flowsheet tool to automate creation of daily material-balance reports for each major unit, identify bad flow instrumentation, and aid in pinpointing material-loss locations. The module is highly scalable. A user can, for example, create a simple material-balance representation of plant streams and units and then extend the platform later to achieve more-rigorous heat and material-balance calculations, on-line performance monitoring, and operations decision-support modeling that may be needed for advanced closed-loop optimization or real-time enterprise control.

For additional information, visit www.invensys.com/ps.