WFT055774

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Controlled Pressure Drilling (CPD®)

Providing technology, techniques and support to safely drill wells, whether you need to drill faster, reduce nonproductive time, or enhance well productivity and reservoir recovery. Weatherford's CPD service is simply… A better way to

Drill

The CPD® wheel To read the wheel, select a CPD technique and then read outward to understand the general area of application, the definition of the technique, the operator's intentions and the primary key to achieving success.

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© 2007–2009 Weatherford. All rights reserved.

A full circle of service from the CPD industry leader

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It's no accident that the Weatherford name is synonymous with Controlled Pressure Drilling (CPD) technology and its subsets, underbalanced reservoir drilling (UBD), managed-pressure drilling (MPD) and air drilling. We saw the necessity for CPD technologies and services back in 1998, dedicated the resources, realized our vision, and now lead the industry with many more successful CPD wells than all of our competitors combined.

1998–2001: Assembling the right equipment Weatherford aggressively acquired and developed key technology, from proprietary rotating control devices to nitrogen-generation units and patented fluid and foam technology. Taking our new tools to the field, we proved that CPD techniques could be applied safely while preventing formation damage. Using reservoir characterization during UBD has enabled the discovery of new reservoirs previously overlooked with overbalanced technologies. 2002–2003: Defining the processes In 2002 we launched our CPD specific quality, health, safety and environmental (QHSE) management system, now recognized worldwide as a model of excellence. In 2003 our new Suitable Underbalanced SM Reservoir Evaluation (SURE ) process offered clients both quick screening tools and detailed evaluation models to help assess the suitability of CPD techniques for their wells. 2003–2005: Integrating everything We focused on strengthening our overall client service and support system, expanding our engineering staff and well planning, operating procedures, post-job review and incident management across all CPD operations. At the same time, we enhanced our air-drilling and well-testing capabilities with additional organic and acquisition-based growth. This strategy added proprietary new tools to our MPD lineup to adapt the technology for offshore operations. Today, Weatherford CPD technology, techniques and support help you safely drill your wells, whether you need to drill faster, reduce nonproductive time or enhance your productivity and reservoir recovery.

© 2007–2009 Weatherford. All rights reserved.

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More than one better way to drill

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Whichever CPD approach is right for your wells, we have the technology, systems and support to help you safely drill your wells, whether you need to drill faster, reduce nonproductive time or enhance your well productivity and reservoir recovery.

Managed pressure drilling (MPD) More productive drilling. Weatherford coined the term MPD to cover situations in which the well is not intentionally encouraged to flow during drilling but the wellbore pressure profile is tightly controlled with a closed and pressurizable mud-return system. Rather than relying on mud weight alone, MPD systems control wellbore pressure profile by combining a rotating control device with surface control of annular returns pressure.

Underbalanced drilling Less pressure, more flow. In underbalanced reservoir drilling (UBD), the emphasis is on protecting the formation, particularly in low-pressure, depleted reservoirs. Encouraging the reservoir to flow while it is being drilled avoids creation of “skin” and its associated negative impact on well productivity and reservoir recovery. Lower pressure in the wellbore also increases ROP, prolongs bit life and prevents fluid loss into the formation, making differential sticking unlikely. Overall results: enhanced production and reservoir recovery.

Air drilling Getting there faster. West Texas operators have relied on air drilling for decades to get through hard fractured limestone formations quickly and without costly fluid losses. Air drilling uses mist or foam as the drilling fluid, increasing ROP and lengthening bit life. Although air drilling is an “old” technology in the U.S., it holds bright promise in other areas of the world.

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© 2007–2009 Weatherford. All rights reserved.

Better drilling results Minimize mud losses and eliminate costly nonproductive time. In one area offshore Indonesia, one well out of every five was a financial disaster as a result of near-total loss of drilling mud. A Weatherford pressurized mudcap drilling (PMCD) system solved the problem. The Transocean Sedco 601 semi-submersible rig, equipped with this technology, has now drilled more offshore wells in surface-BOP mode than any other rig in the industry.

ROP more than doubles at Wild River. Weatherford helped an operator realize a 250 percent ROP increase and an overall cost saving of 18 percent compared to previously drilled offset wells. In addition we helped cement and case the well in a near-balanced state, avoiding formation damage and achieving the operator's “best” cement job in the area.

Cutting drilling time in half. By using concentric casing nitrogen injection, Weatherford's UBD program in the Algerian Hassi Messaud field reduced the drilling time for horizontal wells from approximately 30 days to 12 to 15 days. Subsequent improvements—drillpipe injection and EM MWD—have since cut the time to less than 10 days.

ROP improved to 94 percent. The Chinese were trying to complete 54 new gas wells from the Puguang field in time for the 2008 Olympics, but the wells were taking more than 300 days each to drill. Weatherford's air-drilling services came to the rescue; four wells were drilled using an engineered approach to foam technology, resulting in savings of 60 days per well in the top-hole section and a 94 percent increase in ROP.

Studies sponsored by the Minerals Management Service and the American Petroleum Institute concluded that between 25% to 33% of all remaining underdeveloped reservoirs were not drillable using conventional overbalanced drilling methods. This is because of the increased likelihood of drilling and well control problems such as lost circulation, kicks and blowouts.

© 2007–2009 Weatherford. All rights reserved.

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Six elements to drilling a better well

At Weatherford, finding a better way to drill doesn't stop with drilling. It includes every aspect of how we run our operations. Our QHSE program has already been recognized throughout the industry as a model of excellence. Now add to that the Six E's—the way we drill your wells:

Evaluation. We provide basic and detailed reservoir screening and engineering evaluation to select and quantify the potential benefits of CPD® technology for your wells. Our evaluation protocols include everything from basic air-drilling techniques through UBD reservoirs to advanced MPD techniques for offshore rigs.

Engineering. A full-time global staff of more than 100 experienced reservoir and well engineers helps ensure that every Weatherford project lives up to its potential. Our engineers add a layer of CPD expertise and understanding to your staff that you won't get any other way.

Equipment. We have the largest fleet of surface and subsea CPD equipment in the world, including rotating control devices, fit-for-purpose drilling fluids and foams, nitrogen, compression, separation systems and more. This huge “toolbox” ensures that you get exactly the right tools for your project.

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© 2007–2009 Weatherford. All rights reserved.

For an operator in south Texas, Weatherford's SM

SURE process screened out two prospects that were not good CPD candidates. The third prospect was drilled with minimal formation damage and higher productivity compared with other wells in the area.

Weatherford engineering used constant bottomhole pressure (CBHP) MPD techniques to reduce drilling time from 30 days to 5 days while totally avoiding lost circulation in a 12,457-ft (3,797-m) well in the Gulf of Mexico. The client has now made MPD its standard operating procedure in this field.

In Venezuela, a client faced drilling through sandstone with shale intercalations— formations with vastly different properties. We used our downhole deployment valve ™

(DDV ) to drill the well underbalanced without the lost circulation, sticking, kicks and blowouts that had plagued other wells in the field. In addition, the CPD approach improved the ROP by 84 percent in one formation and 174 percent in the other.

Experience. Weatherford's experience and global database help ensure that you benefit from best practices, methods and results from around the world. Our performance tracking system manages incident reporting, tracking, investigation and resolution. The system also provides client-specific key performance indicators to help you maintain your own continuous improvement program.

Execution. Our staff of project managers, wellsite engineers, wellsite supervisors and equipment specialists has more CPD training and field experience than any other team in the industry. These are the people who make sure that the CPD value we've projected is delivered to you on location. Their success has built ours.

Exploitation. Our goal is to help you exploit the full potential of your reservoir and your wells. Our clients—and our track record—tell us we're succeeding.

A jackup rig offshore Angola was having serious problems drilling through a fractured carbonate reservoir with a low bottomhole pressure and up to two percent H2S in the gas, mud losses of 1,400 bbl/hr, and low ROP (1,400 ft/427 m in 35 days). We applied PMCD and eliminated mud losses, prevented H2S from reaching the surface, and increased the ROP from 40 ft/day to 220 ft/day.

In a depleted field of Venezuela, we deployed complete CPD systems—including nitrogen and four-phase separation—to successfully complete 18 wells that today produce approximately 2,000 to 4,000 bbl/d of 34° API oil. The client plans to continue drilling in this area with the same technology and equipment.

Weatherford brought CPD coiled-tubing directional drilling to a mature North Sea field, drilling through three reservoir sand units with a field-record ROP. Result: economically viable production from a previously subeconomic zone.

The Six E's encapsulate our commitment to you as your global one-stop CPD service provider. We look forward to working with you to optimize your drilling and reservoir development programs and helping you realize real gains in NPV. We think you should expect nothing less. Whichever CPD approach is right for your wells, we have the technology, systems and support to help you safely drill your wells, whether you need to drill faster, reduce nonproductive time or enhance your well productivity and reservoir recovery. It's simply…

A better way to drill

© 2007–2009 Weatherford. All rights reserved.

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A better way to drill

515 Post Oak Blvd., Suite 600 Houston, Texas 77027 Tel: 713-693-4000 weatherford.com

Weatherford products and services are subject to the Company's standard terms and conditions, available on request or at weatherford.com. For more information contact an authorized Weatherford representative. Unless noted otherwise, trademarks and service marks herein are the property of Weatherford. Specifications are subject to change without notice. Weatherford sells its products and services in accordance with the terms and conditions set forth in the applicable contract between Weatherford and the client. © 2007–2009 Weatherford. All rights reserved.

Brochure 4562.01