Oil Country Tubular Goods

Expandable technology developments zero in on practical applications

Five companies show both new products and how development and testing are making applications field usable.

Perry A. Fischer, Editor, and Robert E. Snyder, Executive Engineering Editor

In this annual report of July 2004, World Oil reviewed contributions of six companies, which presented over 12 new developments covering applications such as: expandable casing patches; sand control screens; and openhole and cased hole liners.

In this article, World Oil continues its annual expandables update, featuring contributions of both new and updated technologies that improved the systems previously introduced. The focus of another 12 products is on: sand screens, zonal isolation, casing patching, liner hangers, expandable openhole liners and a multilateral system. The five companies represented include: Weatherford, Baker Oil Tools, Halliburton, READ Well Services and TIW.

A separate and related article overviews an important onshore-Texas well test of single-diameter wellbore construction developed by principal participants Shell and Enventure Global Technology. This test highlighted key technologies for which further development will accelerate practical and economic field applications.

WEATHERFORD

Weatherford’s innovative combination of its field proven expandable sand screens (ESS)* with its newer expandable zonal isolation (EZI)* system provides the best of both worlds, i.e., openhole productivity with cased-hole functionality.

Combining ESS and EZI. Limitations of openhole completion techniques have resulted in most wells with multiple producing zones being cased and perforated. While offering good zonal isolation, this approach does not always realize the well’s true production potential. Now, with this field-proven expandable technology, all the zonal isolation capabilities of a cased and perforated completion can be achieved, along with openhole productivity levels.

A reservoir containing multiple zones requiring hydraulic isolation from one another is traditionally cemented and perforated. In vertical or slightly deviated wells, this can provide good, long-term zonal isolation, albeit with extra expense.

In longer horizontal wells, cementing and perforating can become problematic as the longer annulus becomes difficult to cement, and perforating gun strings become long and complex; thus costs can quickly spiral. If the reservoir requires sand control – usually gravel packing – the completion can become complex.

Understanding the challenges associated with both multizonal isolation and sand control, Weatherford developed products that can remove the need for cased-hole gravel packs.

For instance, the proven 5-1/2-in. ESS system has been improving sand control for more than five years, increasing well productivity and reducing gravel placement costs. It has been especially successful in long, single-zone reservoir sections. The ESS section is expanded compliantly against the wellbore, eliminating the annular space and providing borehole support and filtration, thus removing the need to place gravel for formation sand filtration.

However, the 5-1/2-in. system is less suited for complex, multizonal reservoir completion sections that may require several zonal isolation devices.

Adding MetalSkin.* Combining ESS technology with the proprietary MetalSkin solid expandable tubular system, which can be compliantly expanded against the formation, provides a simple/ cost-effective alternative to cementing/ perforating. This modular completion system enables improved well designs unlimited by number of formation layers or degree of sand consolidation, Fig. 1.

Fig. 1. Multi-zone well completion with ESS expandable sand screens over the gas producing zones, and productive zones separated by expandable zonal isolation EZI sections with elastomer seals.

The MetalSkin section can be expanded against the openhole to seal against impermeable strata, preventing unwanted production flow along the annulus. The product was adapted by bonding multiple elastomer sections to the expandable pipe to provide reservoir isolation, Fig 2. The new product is now known as the MetalSkin EZI* expandable zonal isolation system, or simply the EZI system.

Fig. 2. Expandable zonal isolation joints, 7-in. diameter, with elastomer seal sections, awaiting trial well installation.

The combination of ESS and EZI sections, spaced out with blank pipe, makes this system modular and easily adaptable for many applications. The blank pipe sections provide the controlled bore required for setting conventional isolation packers, flow control devices, or an intelligent completion for future reservoir management. If sand control is not required, a section of expandable completion liner (ECL)* can replace the ESS section to provide hole stabilization for the production interval between the EZI isolated sections.

A major advantage of the combined ESS-EZI system, noted earlier, is its ability to complete a long, high-angle or horizontal reservoir in a multi-zone formation.

Field results. The world’s first 7-in. Expandable Reservoir Completion (ERC), a combination ESS and EZI completion, was successfully installed by BP in a trial well in South Texas. The completion comprised two ESS joints and five EZI joints, deployed and expanded in a single round trip in a vertical well at 6,600-ft MD. Analysis of surface/ downhole load-torque-pressure data and caliper logs shows that the expansion tools worked successfully, and all expandable components are compliant with the wellbore and are providing  isolation to the level required by the original design. Two further installations have now been carried out in water injection wells, a single zone application in the Caspian Sea and a multi-zone application in Alaska. Early indications are that planned well objectives have been met.

BAKER OIL TOOLS

Baker Oil Tools updates its comprehensive inEXX* system, and discusses its FORM 5* multilateral. And a new version of the EXPress* expandable screen is introduced.

inEXX* expandable liner system. This established system employs the industry-preferred methodology of one-trip, top down expansion systems to extend a casing string while maintaining the same casing drift. Applicable as part of the initial casing design, the system enables the operator to drill deeper exploration wells with larger hole sizes at the reservoir. As a contingency plan, the system provides the ability to isolate downhole conditions such as reactive shales, subsalt environments, or low fracture gradient formations. It provides an optimized, cost-effective casing configuration without the drop in hole size encountered in typical casing programs or other solid expandable systems on the market.

The linEXX system comprises six primary components:

• RC9* series casing shoe – Recessed shoe installed with intermediate casing string provides means to tie back expandable liner to casing string. Available in two versions: for cemented (RC9-R) or un-cemented (RC9) applications.
• FORMlock* hanger – Expandable hanger set in RC9 shoe that ties linEXX liner to casing string.
• linEXX* casing – Run below FORMlock hanger and expanded to equivalent drift of conventional casing.
• FORMpac* open hole packer – Used in un-cemented applications. Has bonded elastomer sections which, once expanded, create zonal isolation of open hole, sealing liner above RNX shoe.
• RNX* guide shoe – Installed at bottom of linEXX string to guide liner in open hole. During expansion, guide shoe is engaged and retrieved back to surface with catEXX assembly, following complete expansion, leaving no restrictions in linEXX string to be drilled out.
• catEXX* system – Hydraulic expansion tool used to carry in and swage liner assembly. System relies on pressure contained within drill pipe to expand solid tubulars without string weight.

The system begins with the RC9 series shoe installed on the bottom of the casing and run and cemented in the well. After casing is set, the shoe is drilled out and the openhole section is drilled using either ream while drilling (RWD) technology or a hole opener to provide an under-reamed hole section for liner expansion. Once drilling is complete, the linEXX liner is run and swaged to the same drift as the previous casing string with the catEXX system, Fig. 3. When the swaging assembly reaches the liner bottom, the RNX guide segment is engaged and retrieved with the catEXX tool back to surface. Full liner expansion is now complete, and the liner can be cemented, or drilling operations continued.

Fig. 3. General deployment of linEXX system. Intermediate liner run to depth with contingency casing shoe (1). Expandable liner run to depth (2,3) and expanded, creating continuous ID through liner string (4).

FORM 5 re-formable, corrosion-resistant multilateral system. This system is the first corrosion-resistant alloy (CRA) re-formable multilateral junction, and the first re-formable junction designed as a completion, rather than a drilling template, Fig. 4. It is also the first to be compatible with gravel packs and 9-5/8-in. casing/ completion programs. The system comprises a main bore and two cased legs, of which one is pre-formed. The system is deployed in casing and then re-formed in a casing window, providing a mechanically sound Level 5 junction with integral hydraulic integrity.

Fig. 4. Baker Oil Tools FORM 5 multilateral junction comprising main bore and two cased legs, one pre-formed.

Previous Level 5 multilateral junctions have been limited by reduced flow from the laterals, complex installation methods, or a lack of access to laterals for remedial operations. Using formed metal technology to re-form the leg in the casing window increases the branch-parent diameter ratio and, thus, substantially increases effective flow area over conventional Level 5 multilateral completions.

This new approach to constructing a junction also simplifies installation. In one trip, the operator can install extended lengths of liners or sand control screens immediately below the pre-formed leg and install the lateral completion with the multilateral system. The system can be integrated with various conventional cased and openhole completion methods, such as gravel packs, screens and liners and final completion designs such as intelligent completion systems. The system can be used in producers and, to some extent, in injector wells.

Manufacturing the FORM 5 from nickel alloy 718 (UNS N07718) provides good machining/ weldability properties. It also optimizes heat treatment for strength and for plastic de-forming/ re-forming. The material provides outstanding ductility and mechanical strength, as well as a high level of corrosion and environmental cracking resistance. The system has played a key role in enabling Statoil to increase production, add reserves and control water in Glitne and Heidrun fields.

EXPress* expandable screen. Baker Oil Tools now offers a version of its EXPress expandable screen for 9-1/2-in. open hole. The new screen size is designed for normally pressured gas wells and heavy oil.

HALLIBURTON

Halliburton now offers several additions to its PoroFlex* and VersaFlex* systems. Significant enhancements to the first system are development of the Variable Reach Annular Barrier Technology, variable expansion capability, and single trip deployment.

PoroFlex expandable screen completion system. This technology has been enhanced with several additions. Innovative Variable Reach Annular Barrier Tools (ABT-VR) are now available. This technology, as well as the Fixed Reach (ABR-FR) version, are available in various configurations; all share the common feature of a circular post-expansion base pipe, thereby maintaining a higher collapse rating, Fig. 5.

Fig. 5. Halliburton PoroFlex Fixed and Variable Reach Annular Barrier tools for expandable pipe sealing in open hole.

The variable reach tool provides sealing capabilities in holes with variable diameters up to 20% above gauge. Two versions are available – mechanical and chemical configuration, Fig. 5. The first provides reliable openhole isolation by deploying a compliant 316L stainless steel cylinder with an elastomeric coating against the rock face. The chemical variable-reach tool combines functionality of the mechanical tool with a chemical sealant in the openhole annulus that isolates intervals adjacent to the tool. When combined with internal isolation devices, such as intelligent well equipment, which has been accomplished multiple times, the result is a true expandable completion. As opposed to a simple expandable screen, an expandable completion system will provide cased-hole functionality in an openhole completion; a true step-change for sand control.

Halliburton’s original PoroFlex system utilizes a two-trip expansion method that allows circulation through the system while running it into the hole. A single-trip system, which has now been commercially installed, reduces installation time and system complexity. The expandable completion is carried in the wellbore on the expansion tool. Once on depth, the screen suspension tool is expanded inside the support casing and the expansion tool releases from the completion string for further expansion on the same trip.

Variable expansion capability for the 8.5-in. PoroFlex system is in final development stages. With this capability, the post-expansion base pipe OD may be placed in more intimate contact with the wellbore. The resultant profile will remain circular to maintain the higher collapse resistance of the system, while allowing the OD to vary as much as 1 in./ft. The system continues to maintain high reliability, with zero failures of base pipe, screen or connection, and no reported sand production in any installations to date. The number of jobs completed with the system has increased significantly with multiple installations awarded from new and existing users.

VersaFlex expandable liner system. Halliburton’s liner system continues to maintain the lead in the expandable liner hanger market by offering a true step-change in liner hanger deployment and sealing technology. With over 90 installations, quality processes continue to capture ideas for improvements which drive the enhancements to the service and product line, Table 1.

Additional sizes are under review. Two types of corrosion-resistant alloy systems are in development and are scheduled for commercial availability by year-end. Global installations of drilling/ production liners have exceeded 90 jobs, with liner lengths from 160 ft to 6,590 ft, while maintaining a record of no pre-setting, 100% liner-top pressure integrity, and no instances of difficulty entering the liner top to drill the next interval.

Recently, a 100% successful liner drilling application in the Gulf of Mexico involved a 97-ft, 6-1/8-in. hole section drilled, cement job pumped, and a 7-5/8-in. VersaFlex liner hanger set and tested. This development sets the stage for future liner drilling applications and continued market growth.

Halliburton’s SSR-II cementing plug set using HWE (High Wiping Efficiency) technology along with High Pressure Super Seal float collars and float shoes has assisted in successful installations by allowing 100% sealing on bumping plugs and 100% sealing on flow back testing in all applications where the plug was deployed.

READ WELL SERVICES

The Hydraulic Expandable Tubular System (HETS)* system developed by UK-based READ Well Services (READ) uses directly applied hydraulic pressures in excess of 20,000 psi to permanently expand components into the well architecture. Particular advantages of this technique are the single-trip deployment and highly compliant expansion offered, combined with the inherent metal-metal sealing capability of these devices, as introduced in World Oil’s 2003 and 2004 reviews.

This year sees READ building on successful development of the HETS CT Patch, a coiled-tubing deployed, hydraulically expanded internal patch. Gradually, the entire HETS vision is coming to maturity – to eventually deliver a range of products that will enable slim-well construction using conventional tubulars. Introduced below are slim-well product developments for 2005 – 2006.

Close-clearance expandable liner hanger. READ is contracted to deliver an expanded liner hanger using the HETS technique for a DWC (Drilling With Casing) offshore application in early 2006. This will be the first in a series of “close-clearance” liner hanger developments that can be incorporated into conventional casing completions. The monobore well may be eluding the industry for the time being, but there is a viable alternative to be found in slim wells.

Deployment system development. Moving expandables onto coiled tubing was a first step in the HETS strategy for live wells – early 2006 will see completion of the wireline-deployed expandable patch, Fig. 6, and liner hanger. While drill pipe deployment remains an option, the DWC liner hanger will be deployed on a purpose-built heavy duty umbilical. Operational flexibility is the name of the game.

Fig. 6. Hydraulic Expandable Tubular System (HETS) wireline-deployed expandable patch system.

Zonal isolation. Applying innovative and creative thinking, READ is developing the Zonal Isolation Barrier (ZIBS)* which will provide an inflatable stainless steel packer to seal off the annulus between casing and formation, giving life-of-well durability.

Cementless liner system. Cementing operations, particularly in highly deviated wells, TTD (Through Tubing Drilling) applications, and with close-clearance casing, are often fraught with difficulty. The HETS zonal isolation barrier system (ZIBS) provides a solution. With onshore tests already underway, it is expected that this part of the slim-well concept will be available later this year. Like its sister-products, the strength of the new isolation barrier is in its use of conventional tubulars.

The main thrust of development behind HETS is targeting “bottom up” well design. Selecting the optimum production liner and tubing from the bottom of the well up, and incorporating HETS products, results in slimmer surface casing strings, yielding considerable cost savings. The above descriptions overview the dynamic development underway at READ to provide the industry with a new toolbox of well-construction techniques that aims to transform the way it looks at slim-well construction.

TIW

TIW is developing a complete line of expandable liner hanger products. The TIW XPAK* expandable hangers will be available for both standard cemented liner applications along with drill-down versions.

As with the company’s successful 2T XPatch* system, the XPAK expandable hanger will be hydraulically set with a multi-stage setting tool using conventional surface pumps. The expandable hanger system has been designed to offer the highest liner top pressure ratings in the industry, along with increased hanger load capabilities. Tie back capabilities will be a standard feature on both versions.

Shop testing is nearing completion on the expandable hanger product line, with field testing scheduled in mid-2005. This will be TIW’s third product in the expandable line, which follows the 2T XPatch, and the XPAK whipstock packer anchoring system.

ENVENTURE

Enventure Global Technology and Shell recently announced successful completion of major tool testing for their MonoDiameter* System, a well-construction process that eliminates drillstring tapering. Verifying individual downhole tools in this field application brings the single-diameter well closer to reality. This test is reviewed in the accompanying article, “Field tests of the next phase of monobore construction further validates its practicality.”

To date, Enventure has performed 340 installations and expanded more than 72 mi of pipe for 76 operators globally. And it holds or has pending, more than 600 patents for its proprietary systems. 

Click here for a complete list of World Oil’s annual expandable technology reports.