Rotary steerable systems provide advantages, opportunities

April 1, 2005
Editor’s note: Offshore’s directory of rotary steerable drilling equipment and services includes new and updated product specifications and descriptions provided by the participating companies.

Editor’s note:Offshore’s directory of rotary steerable drilling equipment and services includes new and updated product specifications and descriptions provided by the participating companies. It is organized alphabetically by company, service line, and associated equipment. Although every effort has been made to include all rotary steerable providers, Offshore does not guarantee that thedirectory is an exhaustive list of rotary steerable equipment and services. To participate in future rotary steerable system directories, contact Frank Hartley, Drilling/Production Editor, at [email protected].

Rotary steerable drilling systems are a mainstream service that offer advantages for a number of applications. They offer the ability to drill directionally and continuously without having to stop or slow down to change direction, allowing uninterrupted drilling with continuous weight on the bit, while at the same time providing real-time log data.

These systems have been on the market for over six years with great success and reliability. Rotary steerable systems have demonstrated that with the proper drilling parameters and bit selection, they can produce accurate results with less downtime and produce a faster, cleaner, and smoother wellbore.

Rotary steerable system manufacturers of this year’s equipment directory describe a number of new tools and technology.

Baker Hughes Inteq

Developed jointly by Eni (Agip) and Baker Hughes Inteq, the first-generation AutoTrak Rotary Closed Loop System (RCLS) was introduced in 1997. Since then, over 3,000 jobs have been performed with over 13 million feet of hole drilled. According to Baker Hughes, AutoTrak systems have delivered precise, consistent steerability in formation types ranging from the very weak, unconsolidated formations in deepwater West Africa to the hard rock formations onshore Italy. Well types have varied from >11 km extended reach wells in Asia to complex 3D well paths in the North Sea. The product is now in its third-generation form - a completely new system designed for increased reliability, durability, and capable of integrating advanced formation evaluation LWD and drilling performance improvement systems as close to the drill bit as possible.

More than a rotary steering system, Baker Hughes describes the AutoTrak RCLS as a fully integrated rotary steerable and advanced LWD system. This system integration reduces bit-to-sensor spacing, reduces the number of BHA components, and shortens the overall BHA length. AutoTrak also incorporates a precise, automated directional control system. This closed loop deviation control allows the industries most precise wellbore placement automatically for consistent, pinpoint target interception, the company says. Operators wishing to intersect the most challenging geological targets, including several relief wells have recognized this most precise steering control. Combining the short BHA length and precise directional control with advanced geosteering allows maximum reservoir exposure in each well, resulting in increased production at reduced drilling costs. For one offshore Norway field, the operator has attributed over $6 billion of incremental asset value to the unique contributions of the AutoTrak system.

A further development by Inteq is the AutoTrak X-treme service. This service combines the steering capabilities of AutoTrak RCLS with the high power of their X-treme technology pre-contoured drilling motors. By combining the high rotary speed capabilities of AutoTrak together with the high torque of X-treme technology motors, enormous horsepower is delivered directly to the drillbit. Utilizing the high rotary speed capability of AutoTrak (up to 400 RPM), high string rotation can be used where necessary to maintain efficient hole cleaning. Applications include drilling performance improvement, harsh environment drilling, drilling envelope extension and casing/drillpipe wear reduction. On a recent North Sea well this technology more than doubled offset penetration rates and the well was independently benchmarked as “Best in Class Drilling Performance since records began,” Baker Hughes says.

In 2004, Inteq announced the world’s first successful commercial application of a 3 1/8-in. rotary steerable system. The ultra-slim AutoTrak RCLS was run through 5 1/2-in. casing to re-enter and drill a 4 1/2-in. hole in Bowman, North Dakota. The operator selected the slim AutoTrak to extend the horizontal sections while improving hole quality and placement accuracy. The 3 1/8-in. AutoTrak RCLS was custom-engineered to meet the pass through restrictions in through tubing re-entry applications.

With the addition of the 3 1/8-in. system, INTEQ now offers AutoTrak systems capable of drilling hole sizes ranging from 3 7/8-in. to 18 1/4-in.

Gyrodata

Gyrodata says its Well-Guide RSS is a third-generation rotary steerable system using point-the-bit technology. The system can drill highly accurate trajectories using pre-programmed courses with full downhole closed-loop control.

The system has proven itself in nearly 100 commercial bit runs in a wide range of conditions - from the softer formations in the North Sea, Gulf of Mexico, and offshore California, to the hard and difficult formations of onshore Italy and offshore Netherlands. Applications have included holding vertical, kicking off from vertical, near horizontal drilling, and complex 3D trajectories.

Recent improvements have resulted in run durations averaging 150 bit hours; however, even more significant is that these runs achieved drilling to TD - so that the present run duration limit has not yet been established.

The company is now testing a new RSS tool designed for hole sizes from 8 3/8-9 7/8-in. and allowing a dogleg capability of up to 7°/100 ft. This tool encompasses all of the experience gained from existing tools, and the expectation is for high reliability and long bit runs. Commercial operations are planned for mid-year 2005.

The systems consist of a stationary outer collar through which a rotating shaft drives the drill bit. Steering is accomplished by bending the rotating shaft with hydraulic actuators to point-the-bit in the target direction. According to the company, key features include:

• Kick-off from vertical or in a deviated section

• Steering to highside gravity toolface in magnetic environments

• Fully automated closed-loop downhole control

• Near bit sensors provide continuous 3D azimuth and inclination

• Pre-programmable feature for multiple trajectories

• Trim control from surface while drilling

Full thru-bore provides low pressure loss with no flow rate limitations

Two full-gauge rotating stabilizers for hole cleaning and backreaming

No restrictions on formations, fluid characteristics or bit selection.

Halliburton Sperry-Sun

Using second-generation, point-the-bit technology, Halliburton’s Geo-Pilot rotary steerable system exploits the proven hole quality benefits of extended-gauge bits to deliver the fastest, most trouble-free drilling operation, the company says. Downhole closed loop control coupled with on-the-fly communications produces an invisible drilling system that allows 24-hour ROP by eliminating downlinking interruptions. The centralizing effect of the extended-gauge bit keeps the hole on its true centerline, eliminating borehole rugosity and making all well operations (hole cleaning, tripping, running logging tools, and casing) more efficient, while protecting the cutting structure for maximum sharpness and ROP. The Geo-Pilot system, from Sperry-Sun and Security DBS, works by deflecting a drive shaft midway between two bearings, causing it to flex slightly, which is translated across the lower bearing to become bit tilt.

The Geo-Pilot system was the first point-the-bit tool to be widely commercialized and has completed more than 1,200 runs. The company has seen a growth in wells drilled by 45% year on year and has a 99% efficiency of running pipe to bottom. With successful jobs completed throughout the world, the Geo-Pilot system has drilled vertical, horizontal, multilateral, extended-reach, and high build rate applications. The system is available in a wide range of hole sizes, provides inclination measurements 1 m from the bit, and can be run with an optional at-bit gamma sensor 1 m from the bit for high precision wellbore placement and maximum reservoir exposure. The closed-loop inclination cruise control produces absolutely flat trajectory automatically. In one recent application, two Geo-Pilot systems drilled two horizontal wellbores that intersected deep under a river gorge to provide a pipeline path for stranded gas.

The newest addition to the Geo-Pilot system family, the 5200 Series, adds slimhole capability to the service. The 5200 Series is also a point-the-bit solution, incorporating the extended-gauge bit into the curve generating geometry. While still based on deflection of a rotating drive shaft, the method of deflection has been improved to generate higher dogleg yields. The 5200 Series has demonstrated 10°/100 ft build rate capability and recently completed a 7,145 ft horizontal interval in a single run.

Noble Downhole Technology

According to Noble Downhole Technology, Well Director, a state of the art 3D rotary steerable drilling tool, is capable of meeting the growing demand for advanced directional drilling technology. This step-changing technology provides precise directional drilling control, increased rates of penetration, and a smoother less tortuous well bore, the company says. The tool’s near-bit sensors make continuous adjustments in the azimuth and inclination headings to accurately steer the well to the desired targets. This enables operators to accurately and efficiently drill long horizontal and directional wells that were previously not cost effective. In addition, the use of this tool as a vertical control tool greatly improves the efficiency of drilling deep vertical wells in heavily faulted formations.

Noble says it has significantly upgraded the tool since its acquisition in 2002, including new high temperature (175° C) sensors and electronics. It can be operated in conjunction with other service companies M/LWD and formation evaluation tools, providing increased flexibility when choosing suppliers.

Pathfinder Energy Services

Pathfinder Energy Services says its PathMaker 3D Rotary Steerable system is the culmination of five years of research and development. Its primary application is to provide the operator with the technology to steer the wellbore precisely into the targeted reservoir, without interrupting drilling operations. It replaces the conventional “steerable motor” for all on-shore and offshore drilling applications, while providing the operator with a quality wellbore. The PathMaker is compatible with all of PathFinder’s formation evaluation services.

Some of the features of this system are:

“Point the bit” configuration for improved hole quality

• “Push the bit” configuration available

• Simple and reliable downhole programming without interrupting the drilling operation

• Continually transmits directional position, which is displayed real-time at the surface

• Can be used as a stand-alone device with any MWD system

• Can effectively steer in hole sizes up to 1 in. over gauge

Through contact with the borehole wall, the non-rotating stabilizer blades provide a real-time hole calliper measurement

• Compatible with any/all PathFinder LWD services and BHA’s.

Some of the main benefits gained are:

• Consistent quality and smooth wellbore

• Increased rate of penetration (ROP) by:

• Eliminating sliding and orienting motors

• Consistently doglegging through the curve

• Reducing drillstring torque and drag (smooth well-bore)

Improving hole cleaning (consistent rotation, smooth wellbore.

• Quickerly casing runs (smooth well-bore)

• Improving cement jobs (gauged hole)

• Selecting bits for performance not steerability.

Precision Energy Services

Precision Energy Services says its Revolution service includes the first 4 3/4-in. slimhole rotary steerable system to use point-the-bit technology. In mid-2004 the company introduced its 6 3/4-in. Revolution 675 system for 8 1/2 - 9 7/8-in. holes. Also, field testing has begun for the 8 1/4-in. Revolution 825 system for 12 1/4-in. OD holes, with commercial introduction scheduled for 2Q 2005.

According to Precision, extensive laboratory drilling tests, BHA software modelling and field experience show point-the-bit mode provides better hole quality, longer bit life, and more efficient rock cutting than push-the-bit mode. Point-the-bit mode uses a pivot stabilizer between the bit and rotary steering tool to orient the drill bit axis with that of the hole. This set-up improves wellbore quality by reducing ledging, spiralling, tortuosity, and gauge problems associated with push-the-bit systems.

Simulation and field experience has been used to optimize BHA designs that achieve efficient face cutting of the bit in point-the-bit mode. These designs help the Revolution slimhole RSS maximize penetration rates and eliminate inefficient side-cutting forces, improving bit life and stability while reducing harmful vibration that can damage other BHA components, such as LWD tools.

Point-the-bit systems ultimately drill a smoother wellbore that is more nearly gauge than push-the-bit systems. A smooth wellbore allows the Revolution RSS to consistently steer the bit to the exact target location, extending well sections and improving completions and reservoir optimization.

The Revolution system’s compact design reduces BHA complexity, while placing critical LWD formation evaluation components close to the bit. The result, the company says, is higher than average ROP and fewer doglegs than in wells drilled with conventional drilling motors.

Virtually all rotary steerable systems employ a borehole contacting, or bias, device for providing radial force, the company says, and the orientation and deflection of this device must be measured. The Revolution RSS uses a completely new method of measuring orientation and deflection, employing dynamic measurements from sensors rotating with the drive shaft and having no physical connection with the bias unit. This enables the entire annular space to be used for the sleeve positioning hydraulics.

Rotary Steerable Tools

Rotary Steerable Tools (RST) says it is becoming the leading providerof simply constructed, reliable, effective, and low cost, directional drilling tools, including a rotary steerable system that improves the practice of directional drilling.

RST says its tool design is simple and low cost. The tool has no practical limitations on flow rate, rotary speed, or weight on bit, the company says. Communication to the tool to change toolface heading is made through simple RPM commands. The tool has less than 70 total components and is field serviceable. Operators can select any vendor MWD/LWD to run with the system. The tool is capable of producing a dogleg severity as high as 10°/100 ft, and can also be used for vertical well control. The thru-bore nature of the tool means valuable pump pressure is available for hole cleaning. The simple, low cost features of the RST tool allows the expansion of the proven technical benefits of rotary steerable systems from current high cost, complex well profiles to lower cost environments and more conventional directional well profiles.

The tool is an instrumented, near-bit stabilizer, with three main components: a rotating mandrel, an eccentric inner sleeve, and a weighted, non-rotating outer housing. The tool works by controlling the orientation of the eccentric, inner sleeve, which offsets the mandrel and thus the bit, in the desired direction. The tool is equipped with an internal servo control mechanism called “Active Toolface Control” which uses electronic sensors to monitor housing position and then makes toolface adjustments as required to maintain targeted toolface. Rotation of the inner sleeve to change toolface orientation is made by a geared, brushless DC motor powered by lithium batteries.

Schlumberger

Schlumberger’s suite of full-rotation rotary steerable services - the PowerDrive family - delivers leading-edge technology for all directional drilling environments, the company says. Schlumberger says the products offer exceptional rates of penetration and efficient hole cleaning in the most demanding applications - kickoff from vertical, open hole sidetracks, tangent sections, slimhole extended-reach drilling, long lateral sections, and drilling under harsh conditions at elevated temperatures. All PowerDrive systems share the unique characteristic that every part of the system rotates at drillstring rpm. This enhances hole cleaning efficiency, wellbore quality, and reduces lost-in-hole potential due to mechanical or differential sticking.

Today, a comprehensive range of PowerDrive systems and sizes are available. PowerDrive X5 represents a new generation of tools based on the original PowerDrive concept. It offers automatic inclination hold functionality and near-bit azimuthal gamma ray for optimum wellbore placement, and drilling efficiency. The system has been engineered from the ground up for exceptional or increased reliability, and is capable of drilling hole sizes ranging from 5 3/4-in. up to 26-in. The company says PowerDrive Xceed is a special application tool for harsh, rugged environments, and is ideally suited for openhole sidetracking, steering in overgauge hole and in soft-formations. Minimal wellbore dependence also allows Xceed to be run with bi-center bits. PowerDrive vorteX integrates a high torque power section with rotary steerable technology for performance drilling in hard-rock formations. The system also prevents damaging downhole vibrations and lowers the risk of drillstring fatigue and excess casing wear in hole sections with high doglegs. In addition it is suitable for rigs with lower power specifications, the company says.

Schlumberger says the PowerV is a new fully rotating vertical drilling system that automatically drills an optimized vertical well. When drilling, it senses if hole inclination is building and automatically steers back to vertical. Once vertical, any deviation tendency is corrected automatically. Therefore, little to no directional interaction or supervision is needed to operate the system, the company says. PowerV requires no MWD system to function, the company says, although such systems, or simple inclination-only devices, can be used to provide directional information. The system can also be run below a motor power section. PowerV permits bit selection and weight on bit to be optimized for specific formations rather than be compromised through the need to slide with a conventional motor or to avoid deviating from vertical. Cost savings are realized through increased penetration rates and the elimination of potential correction runs. These savings are further increased due to simplified drilling operations as dedicated rig site supervision needs are largely eliminated. This adds to the system’s cost efficiency and reduces HSE exposure to personnel.

Target Energy Inc.

According to Target Energy, the Target / Smart Drilling Rotary Steerable System (RSS) provides a new generation of downhole closed loop push-the-bit RSS technology for 6 1/8-in. and smaller well bores. The system provides the benefits of improved rate of penetration, better hole cleaning, smoother wellbores, and more accurate well placement, with an overall cost reduction in drilling operations and delivery of superior wellbore quality.

The system is based on proven steering physics and uses four hydraulic pistons combined with a downhole electrical and hydraulic power generation system and magnetometer and accelerometer attitude measurement technology. The system is designed to steer the bit from the current measured point to the desired position along a trajectory at a predefined build rate.

Another rotary steerable system, RockSTar, incorporates the critical benefits of the more complex point-the-bit rotary steerable systems into a cost effective package. Now, the company says, even the most cost constrained projects can benefit from the savings of rotary steerable technology that incorporates:

• No sliding while drilling

Rotational deviation eliminates the need to alter drilling parameters for tool face control

Drilling parameters can be maintained to maximize ROP

No hole spirals or fractional orientation ledging

• Continuous rotation minimizes torque and drag

Continuous rotation improves hole cleaning

• Better hole cleaning reduces ECD

Rotation reduces friction-increasing ROP

Constant drill pipe movement reduces potential for differential sticking

Perform directional control at greater reach

More complex well profiles with lower risk

Elimination of torque effect on toolface that allows slimmer drill strings to greater depths.

Click here to download the2004 Rotary steerable drilling systems directory