Oil Country Tubular Goods

Expandable technology growth is changing drilling practices

Here’s what is offered, what is being developed and where this technology is headed

Robert E. Snyder and Perry A. Fischer

Recent years have seen an explosion of technologies related to expandable metals, and that trend has not abated. Much has been written about the potential sea change that this technology could have on well construction. The so-called monobore well, for example, when perfected, has the potential to reduce well costs and extend a reasonably large, non-telescoping ID to unprecedented depths. It is possible, perhaps likely, that this technology will someday be used in a majority of wells; and in the case of some items such as expandable screens – someday soon.

Just keeping track of what is offered can be a chore. So, World Oil compiled the present offerings of companies supplying expandable technology. In addition, we asked about the near and distant future of this technology. The companies featured are: Weatherford, Enventure, Halliburton, Baker Oil Tools, Schlumberger and READ Well Services.

The first section is an overview describing what is available now and how it is used, including brief examples of installations. The next section answers the question, “What are you working on that is in testing and development?” The last section asks about the future vision of these technology providers.

I. STATUS OF EXPANDABLE TECHNOLOGY

WEATHERFORD

Since 1998, Weatherford has led the industry in commercializing/installing Expandable Sand Screen (ESS*) technology that is rapidly becoming standard practice for reducing costs and enhancing production. It is now working toward the end game of providing a range of solid tubular expansion technologies that make the single-diameter (or monobore) well a reality, both for high-end, challenging applications and lower profile wells. The company’s Expandable Tubular Technologies are classified into three categories: Expandable Slotted Tubulars (EST), Solid Tubular Expansion (STE), and Expansion Systems, as explained here.

Expandable slotted tubulars (EST). The following discussions describe three sub-categories of EST: Expandable Sand Screens (ESS), Alternative Borehole Liners (ABL); and Expandable Completion Liners (ECL).

   Expandable Sand Screens (ESS). As a major contributor to ESS technology, Weatherford has completed more than 225 installations worldwide with its range of expandable products, including 22.5 mi of ESS screen (Fig. 1), and the world’s longest expansion, more than 4,900 ft of a 7,000-ft ESS. This track record verifies the growing adoption of ESS as a reliable, high-productivity sand control method.

Fig. 1. Weatherford has expanded more than 22.5 miles of ESS screen in hundreds of jobs worldwide, including a record 4,920-ft ESS installation.

ESS is being used extensively in a wide range of applications, including open-hole (74%), cased-hole (26%), multizone reservoirs and the world’s first deployment in a multilateral North Sea well. Proven benefits include productivity improvements of up to 70%, compared to alternative sand control methods, and cost reductions of more than 20%.

Weatherford has a long ESS track record. An ESS screen first installed over 3-1/2 years ago in a North Sea, subsea, high-rate gas producer is still stable, sand-free and producing consistently.

A notable milestone was achieved in late 2002, when successful installation of 5-1/2-in. ESS with enhanced connectors for ConocoPhillips in Bohai Bay, marked the 150th global application. This was a multiwell project in Peng Lai field. The first six wells included two with cased-hole perforations (no sand control completion) and four with perforated casing, then ESS completions. The openhole deviated completion proved successful, leading to three additional wells being completed in the same manner.

ESS (Fig. 2) is available in sizes ranging from 2-7/8 in. to 5-1/2 in. It is the only compliant expandable screen that offers: borehole support; a large ID; high collapse resistance; and a large open area that resists plugging. With ESS screens, there is no need to use additional mud and fluids that can damage the screen; there is no rearrangement of produced sand into a low-permeability pack; and there are no hotspots.

Fig. 2. The ESS design includes a large flow area and optimum strength and stability.

Alternative Borehole Liners (ABL). The ABL has also proved successful, with a strong and growing track record. Operators in many producing areas must set casing strings earlier or higher than desired due to problematic geological zones. Unstable formations can also prevent casing runs from reaching the target depth, resulting in need to run contingency casing strings. In both scenarios, as a result of being forced to run an additional string, wellbore diameter through the reservoir could be compromised, resulting in a well unable to meet production expectations, or even reach planned depths.

The ABL, a cemented, expandable slotted liner, can be used as a metal-to-rock solution to overcome these potential problems. For example, if a 9-5/8-in. casing string with a 8.681-in. ID is set higher than planned, an ABL can be installed below the string. This isolates the problem zone, but retains throughbore of 8.681 in. or larger. As a result, operators are able to retain hole size through the next section of the well, which could make the difference between the well being commercially viable or not.

Expandable Completion Liners (ECL). Weatherford has also developed breakthrough ECL technology that can replace conventional slotted liners or cemented/perforated liners. The technology provides increased borehole stabilization, selected isolation and treatment capability, and reduced hole size.

It can be particularly useful in completing reservoir zones in through-tubing sidetracks, achieving a limited reservoir interval while avoiding difficult overall cementing and perforating work. Other benefits to operators include: 1) increased field output, since in certain cases, the larger wellbore created will produce higher flow area; 2) extended well life and increased viability of older wells, since it allows for a return to the reservoir for carrying out future remedial work; 3) flexibility to return to the reservoir to shut off and isolate water breakthrough, by inserting plugs or packers inside definite bore rather than an open hole; and 4) wide-hole-size operating range from 3-1/2 in. to 9-1/2 in.

Solid Tubular Expansion (STE). Under this second category of the company’s three contribution areas, two sub-categories, Expandable Liner Hangers (ELH) and the MetalSkin* Casing Repair System are described, as follows.

   Expandable Liner Hangers (ELH). The ELH provides a means of deploying ESS and other non-cemented liners. It also provides the hanging for the MetalSkin Casing Repair System. ELH is expanded using a rotary compliant technique (see expansion systems section) that delivers a metal-to-metal fit with the parent casing, resulting in a maximized throughbore for future intervention access.

  MetalSkin Casing Repair System (Fig. 3). In mid-2003, the company successfully installed four compliantly expanded Solid Expandable MetalSkin casing repair systems for Imperial Oil Resources at its Cold Lake field in Alberta, Canada. The successful installations returned the four wells to service. The new technology is a metal-to-metal expandable casing system designed to solve problems that occur when reservoir and fluid production conditions have changed, or when the casing has been worn, corroded or damaged.

Fig. 3. Example well schematic shows MetalSkin assembly deployed to isolate thief zone comprised of perforations and corroded casing.

At Cold Lake, the system was applied using the company’s Compliant Rotary Expansion System (CRES*) to repair casing leaks. This technique forms the MetalSkin to the casing being repaired, accommodating irregularities within the parent casing. This provides metal-to-metal contact around the entire circumference of the casing and a tight seal. After expansion, the system becomes an integral part of the casing string, allowing the wells to be returned to active production.

Expansion systems. In addition to the traditional EST expansion cone, which is a tapered tool used in conjunction with an expansion mandrel, and is designed to swage and expand various slotted tubular products, a fundamental advantage of Weatherford’s systems is the use of compliant expansion techniques, such as the two systems described here.

   The Axial Compliant Expansion System (ACE*) is designed to expand slotted tubulars. It offers single-trip, metal-to-rock compliant EST expansion, which is the key to elimination of the annulus, provision of borehole support and prevention of particle migration. It is the single-trip system that improves wellbore contact, allows access through restricted ID and improves tool life. ACE features a compliant top-down expansion tool, a retrievable system and a field re-dressable tool. The expansion tool comprises two sections: a fixed roller nose to initiate expansion, and compliant axial rollers to complete the expansion process. The tool is compliant in that pistons can extend or retract as the hole profile changes.

   The Compliant Rotary Expansion System (CRES) tool is a hydro-mechanical tool designed to expand solid tubulars. When used with an Expandable Liner Hanger (ELH) deployment tool, it sets and expands the ELH. It is also used to expand long lengths of solid tubulars for the MetalSkin system. CRES provides a top-down, low-axial-load expansion operation that is tolerant to internal casing anomalies. The tool can fit through unexpanded tubulars for easy retrieval and offers a selective expansion capability. Rotary compliant expansion provides a metal-to-metal contact that maximizes burst resistance, with low rolling friction and low axial loads, and maximizes the throughbore.

HALLIBURTON

Halliburton offers both expandable screen systems (PoroFlex* System) and expandable liner hanger/packer systems (VersaFlex* System). Both have undergone extensive development testing in lab and test-well environments.

   PoroFlex Expandable Screen Systems (Fig. 4) have been installed in eight wells on four continents to date. The system is rapidly gaining acceptance due to its reliable design, installation and expansion methodology. The system has been used in both cased- and open-hole completions and has been selected by major operators based on four primary features of the system, as outlined here.

Fig. 4. Halliburton’s PoroFlex Expandable Screen System offers dual expansion methods on the same trip with the same tool and has been used in multiple commercial wells with no failures of base pipe, screen or connections.

Perforated, or near-solid, base pipe is employed as the flow conduit. This provides high collapse resistance and offers a broad range of remediation and accessory installation. Packers, plugs and intelligent well equipment can be installed reliably in the post-expansion base pipe. In addition, unperforated blank pipe can be run to isolate shale sections or trouble zones in the wellbore to improve zonal isolation.

Filtration is achieved with the only one-piece, 360° expandable screen available. The screen is based on Purolator-Facet’s Poroplate* design, which does not change micron rating during or after expansion, although flow area through the screen is increased.

Integral-joint threaded connections are used, which make up like casing on the rig floor and allow the screen to be rotated in the hole, if necessary. This reduces rig time during installation and, when combined with the perforated base pipe, provides the same functionality during installation as traditional screen installations.

The screen is expanded hydraulically, which makes the process virtually weight-independent. This is ideal when running in extended-reach or horizontal wellbores. The fixed-cone expansion process provides a known internal diameter for the length of the completion, which is fully expanded in one trip. Extensive testing, in combination with customer design reviews, confirms no failure of any base pipe, screen or connection and no reported sand production.

The operational history of the Poroflex line, which is available in both 6.125-in. and 8.5-in. (post-expansion) sizes, has demonstrated the need to approach expandable screen completions with a total systems approach. Efficiency/performance of the completion is very much linked to quality of the wellbore drilled, drilling fluids and knowledge of the producing interval. Halliburton has therefore developed this technology in close association with Sperry Sun and Baroid to tune systems which improve effectiveness of expandable screen completions.

The VersaFlex Liner System combines industry leading expandable solid tubular technology with Halliburton’s best-in-class cementing, casing attachment and float equipment to deliver a reliable liner hanger system. With liner top failure rates reaching up to 30% in some cases, cost of remediating this problem can be high. The primary cause of these failures is mechanical failure of either the liner hanger or liner top isolation packer, or the inability of the cement sheath to isolate the liner lap.

The system has major mechanical advantages over conventional liner hanger/packer systems. Most important, the liner hanger/packer has no moving parts or exposed hydraulic ports. To further ensure liner-top integrity, the integral liner hanger/packer, which also includes an integral polished-bore receptacle, deploys five independent elastomeric elements to provide annular isolation. The expansion process is such that pre-setting of the expandable liner hanger/packer is virtually impossible.

To ensure greater reliability of the cement sheath, the system allows for increased circulation rates so that turbulent flow is achieved. This is possible as the run-in outside diameter is reduced when compared to conventional liner hanger equipment. In addition, Halliburton has developed, in its association with Enventure Global Technology’s SET development, proprietary, patented, tuned cement designs that reduce or eliminate the potential for channeling and gas migration through the cement. Combining Halliburton’s cementing expertise with its casing attachments and float equipment provides not only the VersaFlex system, but also improved cement integrity.

Liner lengths over 5,000 ft have been installed in five wells, with additional installations scheduled. It should be noted, however, that the expandable liner hanger/packer has been installed over 140 times, as this part of the system is virtually identical to Enventure’s anchor joint. Anchor joints are routinely pressure tested in each installation, so the operational reliability of the device is well documented. Four sizes are available in alloy metallurgy at this time: 5 x 7 in., 5-1/2 x 7 in., 7 x 9-5/8 in. and 7-5/8 x 9-5/8 in.

   Near Bit Reamer (NBR). Halliburton’s Security DBS product service line provides associated services to the expandable products market with its NBR device, Fig. 5. The current technology can pass through existing casing and – following a standard drill bit – open the hole size below casing up to 20% larger than the bit below it. The NBR has been utilized in more than 500 drillstring assemblies all over the globe.

Fig. 5. Halliburton’s Security DBS Near Bit Reamer is designed for optimum performance in directional applications where traditional hole enlargement techniques have been difficult.

ENVENTURE

Enventure’s Solid Expandable Tubular (SET*) Technology consists of the Openhole Liner (OHL*) System, FlexClad* System, Cased-Hole Liner (CHL*) System, and Openhole Clad (OHC*) System.

Since its inception in 1999, Enventure has installed 147 SET Systems and expanded 3,680 connections and more than 141,000 ft of pipe for 40 operators globally. Enventure’s system reliability factor of 95% is based on the expansion cone exiting a usable liner.

   The OHL System has been used frequently in older fields being re-worked or remediated, to reach deeper reserves and to isolate water zones that have been penetrated by horizontal re-entry wells. Enventure has installed and expanded this system in conditions that included mud weights up to 18.1 ppg, a horizontal well angle in excess of 100° and expansion depths greater than 26,000 ft.

OHL can be installed and expanded through a qualified window, eliminating cutting and pulling casing, and redrilling hole section, Fig. 6. The most recent window exit was for Kerr-McGee in the Gulf of Mexico, where a 7-5/8 in.by 9-5/8-in. OHL system was installed inside 9-5/8-in., 53.5-ppf casing. The 2,000-ft+ OHL System was expanded over 1,900 ft below the window, allowing the operator to maintain completion size at TD. The operator estimates savings in excess of $2,000,000 were gained by using the window exit application.

Fig. 6. Enventure’s window exit capability increases the versatility of its Openhole Liner System, and is flexible enough to accommodate horizontal, vertical and high-angle holes.

   FlexClad Systems. The company has installed six 3-1/2 in. by 4-1/2-in. and one 5-1/2 in. by 7-in. FlexClad Systems. Installation of the latter system had a setting depth of over 20,000 ft. These systems have successfully sealed off perforations and provided a competent wellbore for high-pressure fracturing across a lower interval.

   CHL Systems. In 2002, Enventure set records and established milestones with its CHL System, including: A new length record for the low-carbon steel casing system to convert a Sarawak Shell Berhad well to a monobore completion and to avoid exposing the existing casing to sour gas production. The following additional records occurred in this same well, i.e., the first: 1) successful integration of completion products with SET Systems; 2) application of a CHL used to increase production in tubing-constrained gas wells; 3) application of a CHL in Asia-Pacific; 4) installation of a CHL to successfully use a wireline retrievable plug; 5) installation of a horizontal CHL in a 1,000-ft+ workover project off the NW coast of Borneo; and 6) application of corrosion-resistant alloy (CRA) SET Systems in a producing gas well in the Netherlands for Shell NAM, setting a new length record of more than 6,000 ft.

Enventure and Brunei Shell Petroleum installed the world’s first horizontal CHL in a 1,000-ft+ workover project off the NW coast of Borneo. The system was perforated across three separate oil producing zones. The elastomer seals had to be positioned within a tolerance of 6 6.6 ft due to the proximity of the gas to oil-bearing zones. The liner was run “uphill” in an inclination of 105° to get to a hole depth of almost 13,123 ft. The well has had a 30% increase in production and a 33% reduction in gas-oil-ratio (GOR).

   OHC Systems. Enventure installed the first OHC in 2002. This application was also the first clad installation set in a horizontal well section. To date, nine systems have been installed, with a 100% success rate for openhole water shutoff.

The company’s installation of the first OHC System in a horizontal well section consisted of two systems positioned from 5,930 to 6,017 ft and from 6,181 to 6,220 ft to shut off about 400 bpd of produced water. Production results since the installation indicate that net oil rate has sustained an increase to over 100 bpd from 50 bpd and that watercut has decreased substantially.

   SlimWell* Process (SWP). During the past year, Enventure commercialized the SlimWell Process that comprises two or more solid expandable casing strings planned in a single well, Fig. 7. It implemented the first SlimWell in Chesapeake Energy Corp.’s Wellman 3-H in South Texas in mid-2001. A 5-1/2 in. by 7-in. expandable OHL system was run and expanded inside a previously installed 6 in. by 7-5/8-in. expandable system. This expandable “nesting” process minimized the reduction of hole size at 12,470 ft TD.

Fig. 7. A SlimWell plan illustrates the telescoping effect it avoids, compared with a conventional well plan.

SWP comprises a combination of expandable/conventional tubulars. Enventure has successfully installed this type of configuration in four wells, allowing operators to preserve valuable hole size.

BAKER OIL TOOLS

   Expandable liner hanger systems. Baker Oil Tools has been providing clients with expandable metal solutions since 1994. Its first commercially available expandable product was the ZXP liner packer system, of which well over 12,000 systems have been installed in almost every part of the world. This expandable system can provide high pressure (10,000 psi) and high temperature (400°F) integrity.

The company has continued developing expandable technology breakthroughs. In January 2002, a FORMlock* Expandable Liner Hanger was run in a well in Prudhoe Bay, Alaska. The hanger was set at 10,335-ft MD with a liner length of 1,100 ft. This was the first expandable liner top completion, with the completion string stabbed into the liner top. Since this installation, these expandable liner hanger systems have been installed in over a dozen wells in Brazil, Indonesia, Malaysia and North America. Fig. 9 illustrates Baker’s expandable offerings.

Fig. 9. The complete line of Baker Oil Tools’ expandable technology includes a multilateral junction system; liner extension, hanger and packer, casing cladding; expandable packer; and expandable sand screen.

   Level 6 junction multilateral completion system. The FORMation* junction system was used to complete the world’s first Level 6 multilateral well, in 1998 in California’s Belridge field, and has subsequently been used successfully throughout the world. To date, 10 of these junction systems have been run in Africa, Asia, Europe and North and South America, making this perhaps the most widely run Level 6 junction system. Formed-metal technology enables the junction system to pass through standard casing sizes, then have one leg re-formed downhole, using a fixed cone. The resulting hydraulically sealed, full-size multilateral junction can be conventionally cemented, drilled and completed.

   Expandable open hole completion system. EXPress* is an expandable openhole completion system. It comprises an expandable sand control screen that can reduce or eliminate the annular space between the screen and the wellbore. Although the expandable screen offers many advantages, its greatest potential to add value is in horizontal openhole sand control applications. It combines the sand control ability of the company’s EXCLUDER2000* screen with metal expansion technology. The screen area that is open to flow is large before expansion and even larger afterward, allowing the screen to function as a premium screen even if it is not expanded.

The company designed the expandable screen with drilled-hole base pipe and filter membrane construction. The filter membrane construction allows conditioned mud solids to be produced with less risk of screen plugging, while maintaining effective sand control capabilities. The mechanical structure of the drilled pipe design offers better collapse resistance than slotted configurations. Such collapse resistance is particularly advantageous in projects where the use of electric submersible pumps may create drawdowns exceeding 1,000 psi.

Numerous systems have been installed worldwide and, like the liner hanger systems, there have been a number of “world firsts.” In March 2002, the company installed the world’s first, second and third one-trip expandable completions for Chinese National Oil Co. offshore Indonesia. The expandable completions, in three wells in the Intan field, were accomplished using the company’s expandable openhole completion system, configured with the expandable sand control screen, the FORMlock Express expandable liner hanger, EXPress solid expandable blank pipes and FORMpac XL* openhole isolation packers.

The completions isolated the production zone and provided cost-effective sand control without gravel packs. The running procedure also saved rig time by eliminating several trips compared to conventional completion operations. The three Intan wells have been placed on production, with productivity indexes that have been significantly greater than offset wells in the same reservoir.

In July 2002, the expandable openhole completion system was used again, this time in the world’s first single selective completion inside an expandable sand screen completion, in a 6-1/8-in. openhole wellbore that penetrated both oil- and gas-producing zones, Fig 8. The operator wanted the ability to produce the oil zone first, and later open the system to the gas zone.

Fig. 8. Baker’s Single Selective Completion set inside EXPress Expandable Screen System.

In March of 2003, Baker Oil Tools deployed the world’s first variable swage in a system based on solid expandable pipe and EXPress screen. The North America location was in a shallow gas field drilled 20 m from a well that was abandoned due to severe sand production. Traditional sand control methods were unsuccessful because of non-uniform, poorly sorted and very fine formation sand. Two reservoir zones were present, separated by a small shale barrier with a need for zonal isolation capability since the lower sand had a water contact. All of the equipment was expanded using a variable swage, with the expandable completion equipment and the expansion tools run in the same trip in the well. Pre- and post-installation calipers confirmed that the screen was successfully expanded as designed. The well is producing with no sand production.

   Cladding system for cased and open hole. EXPatch* Casing Cladding is used to selectively line finite lengths of existing wellbore casing to provide several advantages during production. In cased-hole completions, it can blank off perforations in short sections to minimize water inflow and can repair damaged or corroded casing in long sections. In sand control completions or to shut off water inflow, it can be placed between FORMpac XL openhole packers in the company’s openhole completion system to help the packers create a mechanical fluid flow barrier for selective blank-off of a wellbore section. The cladding creates a definitive anchor/sealing section with the host casing. Its setting mechanism does not rely on the integrity of the surrounding medium to place the clad, and its length can be adjusted to fit exact wellbore applications.

   Expandable packer. The FORMpac XL expandable packer prevents annular flow around openhole liners and screens while maintaining maximum wellbore ID. The expandable packer redirects flow through the screen to eliminate the threat of hot spots that could promote erosion. The packer’s unique element delivers expansion performance that has been successfully tested to 1,000 psi differential pressure and 250°F. Consequently, it eliminates the need for cement to create a permanent contact force as in traditional ECP applications. The FORMpac XL is manufactured on a solid pipe mandrel to allow for re-entry should cladding procedures become necessary for zonal isolation.

SCHLUMBERGER

The prefabricated RapidSeal* multilateral completion system for Level 6 junctions was developed through a joint R&D project between Agip and Schlumberger. The system combines two 7-in. outlets below 9-5/8-in. casing or two 9-5/8-in. outlets below 13-3/8-in. casing to form a junction. The two outlets are compressed in the prefabrication process.

When the system is deployed at depth, a wireline-conveyed expansion tool reforms the outlets to their original size and shape using hydraulic-driven pistons, Fig. 10. The reforming process takes about 45 min. and is monitored and controlled in real time. Service pressure ratings are 1,200 and 2,200 psi for 9-5/8-in. and 13-3/8-in., respectively. The 9-5/8-in. junction was installed for Petrobras in Brazil, Agip in Nigeria and CNOOC in Indonesia. Schlumberger will be installing its 13-3/8-in. expandable junction in the near future.

Fig. 10. Schlumberger’s TAML Level 6 junction is installed as follows: 1) Drill main borehole; Underream and enlarge junction location; Set RapidSeal system on primary casing. 2) Position wireline expansion tool and complete reforming process. 3) Set wireline-conveyed cement retainer and cement junction. Drill out cement; drill and complete each lateral.

READ WELL SERVICES

There are interesting niche requirements where innovative use of expandables have a role to play. For example, achieving a downhole metal-to-metal seal between two tubulars with no internal well restriction, rated to the burst/collapse and the tensile/buckle of the tubulars to be connected, has been one of the most sought after of all downhole tubular connection or repair systems.

A new tie back system has been tested and proven to achieve this demanding specification for the connection of two tubulars. UK-based READ Well Services developed its Hydraulic Expandable Tubular System (HETS*) tie back in partnership with several major operating companies. To meet the specification of current contracts, hydraulic testing to 10,000 psi, gas testing to 3,000 psi and a 200-t load test have been successfully completed on connections made with a HETS expansion tool.

An example operation is shown in the schematic, Fig. 11. During well planning, two clients separately identified considerable risk of the 14-in. casing not reaching planned TD due to possible hole conditions on HPHT wells under construction. The drilling contingency in place involved a costly sidetrack. The HETS solution was chosen as an alternative to sidetracking the well. It offered a metal-to-metal seal, no internal well restriction and the ability of the connection to withstand the considerable loadings applied due to thermal expansions within the wells when put on production.

Fig 11. READ’s metal-to-metal liner connection is used as follows: 1) Casing stuck shortly before it is landed; 2) Cut and dress casing below hanger; 3) Run and land new casing section with HETS* Overshot; 4) the connection is expanded and swaged with HETS Swage Tool.

In the contingency plan, the stuck casing is cut a short distance below the hanger and new casing is run with a READ-supplied overshot attached to the bottom. The new casing is spaced out and landed in the hanger. The HETS tool is run with a spear on drill pipe. The spear is located in the cut casing and tension applied (e.g., 200 t) to pre-tension the casing. The HETS tool is operated hydraulically from surface. Two high-pressure seals are activated and water is pumped into the annulus between the seals and the casing, Fig. 11(4) The hydraulic pressure yields the inner casing, plastically deforming the casing into a specially designed overshot, the final internal swage pressure being in the order of 25,000 psi. The process takes about one hour. The pressure is released and the drill pipe removed, leaving a completed tie back connection.

II. TECHNOLOGIES IN TESTING OR DEVELOPMENT

WEATHERFORD

Weatherford has made a considerable investment in rapid commercialization of its patented expandable technologies, and can call on its resources to fast track the process. In April 2003, it opened a new, global, Expandable Technology Centre in Aberdeen, Scotland, to support the ongoing investment in new expandable products. The Centre houses a manufacturing facility with equipment capable of producing over 7,000 ESS joints per year. Additional equipment includes the world’s only four-head laser cutting machine, and the world’s largest abrasive water-jet facility.

The company also has two of the world’s largest R&D, testing/training facilities in Houston and Aberdeen. Downhole Technology Ltd. in Aberdeen is a major R&D/testing center for offshore well services, and Weatherford has designed and built a unique expansion rig to carry out controlled bench tests for all of its expandable technology products. The unit has a full data acquisition suite, and power capability equal to that of a full-scale drilling rig.

The data acquisition suite is networked to Weatherford’s design and engineering offices, with a video system on hand to video-stream tests as they are conducted. It is possible to carry out specific tests that model actual conditions. And for field trials and final product evaluation, the team can use the drilling units in Houston and Aberdeen.

For 2003 commercialization projects, the following systems would apply:

• Slimbore* openhole liner. With a 7-5/8-in OD, the liner has the capacity to expand to 9-5/8 in., and its development significantly enhances the company’s ability to provide a “slim-well” construction solution.
• The MetalSkin casing repair system, currently available as 5-1/2 in., expandable to 7 in., is under development, with three additional sizes in the pipeline: 4-1/4 in. to clad a 5-1/2-in.; 7-5/8 in. to expand into 9-5/8 in.; and a prototype for a 6 in. to expand to 7-5/8 in.
• Ongoing development of ESS screens will ensure that there is an ever-increasing range to meet application demands. Work is progressing on enhancement of the smaller 2-7/8-in. screen through development of a new compliant tool, to meet the demand for sand control in smaller wellbores – such as the Gulf of Mexico market – and remedial and sidetrack applications.

A one-trip system is also ready for commercial use, as an enhancement to the proven 4-in. and 4-1/2-in. ESS screen. This will enable deployment and expansion in a single trip, providing significant cost savings in areas where there are high rig rates, such as West Africa, Gulf of Mexico and the North Sea. The first application is expected by mid-year 2003.

HALLIBURTON

By mid-summer 2003, a corrosion-resistant alloy version of the 8.5-in. PoroFlex Expandable Screen System will be available, with the 6.125-in. version available soon thereafter. Extensive development work on variable open-hole annular barriers is in process, with production versions of the tool commercially available in late 2003. Further enhancements to reduce rig time and protect formation integrity are also in process, which will be unveiled as the development progresses. With interest in Halliburton’s expandable screen technology increasing, inventory is being produced for all sizes of the product.

Two additional “standard” VersaFlex Expandable Liner System sizes are undergoing developmental testing and will be available by 3rd quarter 2003. Additional sizes suited for deepwater work will be available early 2004. The entire size range will be available in 13 chrome metallurgy in 2004. Plans for critical-service, corrosion-resistant alloy systems are in process; however, their scheduled availability is uncertain at this time.

Security DBS is developing specially sized drill bits and accessories to complement Enventure’s line of solid expandable tubular products, with delivery expected soon.

ENVENTURE

While SlimWell reduces the telescoping effect in traditional well design, the MonoDiameter System eliminates telescoping, allowing operators to slim down the top of the well while increasing well diameter at TD.

The first field application of a MonoDiameter* Drill Liner (MDDL) in September 2002 was a collaborative effort between Enventure, Shell Exploration & Production Co. (SEPCo) and Shell International Exploration & Production Inc. (SIEP) in a South Texas Well. For this installation, 11-3/4-in. casing was set prior to running a 9-5/8-in. MDDL. The liner was expanded to a 9.9-in. ID and the liner lap was hung and sealed with elastomers. Then the shoe was drilled out and a top-down cone expanded the casing to a 10.4-in. ID. A subsequent hole section was underreamed to 12-1/4 in. and another 9-5/8-in. Monodiameter Liner was run and expanded. A drift run to TD confirmed the expanded diameter. Both liners tested successfully to 4,000 psi.

The MDDL is being developed in various sizes. The next evolutionary step will be the development of the MonoDiameter Production Liner.

Enventure’s future system enhancements for its basic expandable technology (OHL, FlexClad, CHL and OHC Systems) include longer expanded lengths, shorter millout times, higher-collapse-rated pipe, higher-efficiency connections and even higher system reliability. Enventure continues to work toward improving burst and collapse properties of the pipe and connections that will allow expansion of 30%.

Another future application of SET technology will combine casing drilling with expandables. This capability will provide constant circulation and allow the operator to maintain the current hole condition.

BAKER OIL TOOLS

Now in development, with availability by third-quarter 2003, the LinEXX* Expandable Liner System effectively blocks off problem drilling zones and isolates production zones without reducing casing ID as in traditional telescoping well programs. Placed below an intermittent casing string, the new liner is expanded to maintain the same throughput ID as the liner string located above it. The new system can be used to block off unexpected problem sections or it can be part of the initial well design.

READ WELL SERVICES

READ’s HETS application of expandable technology offers new solutions to other well construction problems, since it is not limited to the tie back application. Solutions for liner hangers, isolation plugs and internal expandable patch systems are under development. Solutions for elastomer-free liner hangers, high-differential isolation plugs and internal expandable patch systems for coiled tubing deployment are under development.

III. WHAT’S IN THE FUTURE?

WEATHERFORD

The company is continuing to build its range of solid tubular technologies that will ultimately make the single-diameter well a reality for a variety of applications. The commercialization of MetalSkin is just one more example of how it is getting closer to reaching this goal. The Optiwell System* is available and field proven. It offers an estimated 70% to 80% of the benefits expected from single-diameter technology.

Solid Tubular Expansion (STE) technology offers the drilling industry the opportunity to access smaller deepwater reservoirs that were previously uneconomical due to traditional high costs of deepwater operations. STE also offers significant cost savings in conventional well construction and well remediation.

Research estimates that STE technology has the potential to: significantly reduce the rig footprint by up to 75%; and reduce drilling muds by 20%, drill cuttings by 50% and cement by 50%. In the not too distant future, early adopters will be using STE to reduce operating costs and drill wells that were considered impractical, i.e., too deep, too hot, too depleted, too expensive, too remote, or in waters that were too deep or too environmentally sensitive.

In well construction, STE can minimize well tapering, which can optimize well design. This allows operators to construct the well with smaller tubulars in the upper portion of the wellbore, while still penetrating and producing the reservoir with production tubing optimum for maximum hydrocarbon recovery. The ultimate goal is to develop STE systems that will eliminate the telescopic effect in well engineering and construction.

The Optiwell System is actually a precursor to the single-diameter well. Such a system, constructed similarly to a conventional well, has a less-severe telescoping effect, and creates a wellbore that has a higher degree of diametric efficiency. Essentially, it employs one or more STE liners strategically planned into the well to extend its reach. The only diameter lost from each section is twice the wall thickness of the casing being expanded, plus any elastomer that the system may use for sealing subsequent expanded drilling liners to the previous casing string.

Using STE technology provides a more optimum well design and enables the operator to reduce drilling vessel size required to drill in deep water (1,500 to 5,000 ft) or ultra-deep water (below 5,000 ft). This means that instead of being forced to use costly fifth-generation rigs, the operator could use a third-generation rig, and well construction cost savings would be tremendous.

HALLIBURTON

Expandable technologies will become the norm in the near future. While expandable screens do not represent a one-for-one replacement for gravel packing, the benefits associated with their use are simply too economically attractive to ignore. Operators will continue to search for the proper application of this technology. Expandable sand-control-screen systems must consistently provide high levels of reliability to allow realization of their potential in the industry.

Operators in various areas have avoided running liners due to the inherent reliability risks associated with standard liner-hanger equipment. The dramatic increase in reliability and the consequent reduction in installation risk associated with expandable liner hangers will make their use even more routine, while increasing liner usage in areas previously stung by wellbore integrity issues.

ENVENTURE

Enventure expects that the SlimWell application will be the normal drilling process for land and offshore wells. Although the full economic advantage of expandable tubulars lies in being planned into the initial well design, SET Technology will continue to have an important role in addressing unexpected drilling and completion problems that no other technology can solve.

Commercial rollout of the MonoDiameter System will bring new opportunities to reduce costs and develop reserves that previously were not economically viable. Enventure continues to drive the evolution of SET Technology into products that will go farther, last longer and cost less.

BAKER OIL TOOLS

Baker Oil Tools is averaging more than one expandable system installation per day. However, there are still many opportunities for development and new applications. From an industry perspective, additional development needs to be conducted on corrosion-resistant alloys, reliable gas-tight threads, and enhanced solid-pipe collapse resistance after expansion, to name a few. Baker will continue to invest in expandable developments to provide the full breadth and depth of expandable solutions. The future for expandable technology applied to wellbore construction is bright because it has the ability to provide value to the operator in the form of reduced Capex and Opex

READ WELL SERVICES

READ perceives that the main thrust of development in the industry will be toward the volume market of total well construction. As a specialist niche provider, READ must follow a different agenda, and plans to concentrate on development of particular and specialized completion components, aimed on one hand at the mature sectors of the industry that require cost-effective remedial and slot-recovery options, and on the other at the ultra-deep and HPHT sector, where elastomer-free metal-to-metal technology is critical.  

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