P. 14 Technology in Focus dec | 09 Weatherford International Ltd. Introduction to Weatherford’s Expandable Technology: Expandable tubular technology is a system in which diameter of a casing, liner or sand screen is increased by a certain percentage (depending upon the material) after it has been deployed in the well bore. One main objective is to reduce the telescopic effect that traditional casing & well designs have. Figure-1 is an example of Monobore Expandable open hole liner where you can achieve zero loss in hole size and thus benefiting deep drilling because wells can reach greater depth without a loss in final well bore diameter. Why use expandable Technology? • Allows exploitation of previously untapped resources • Improved Sand control • Increased productivity from larger bore • Better skin • Reduced cost • Selective isolation between zones Below are a few applications of expandable technology that can reduce development cost and enhance well bore productivity. Application -1 Cased Hole Expandable Liner for Casing Repair • Casing in older wells can sustain damage during the normal course. • It can get worn out or corroded by well effluent properties. • In such cases repair is required to continue drilling or production. • The cost of repair and subsequent reliability of such repair can severely affect the well economics. • Various procedures are applied to repair the damaged casing and the type of remediation operation can prolong the life of the well. • Conventional approaches to resolve these problems such as Cement Squeeze is effective only in short term in sealing off the damage and the need to re-squeeze and the possibility long term, breakdown can limit the economic viability. • Cased Hole expandable liners can quickly and permanently solve this problem with out much loss in ID. • Elastomeric sealing element placed along the length of the expandable liner provide effective zonal isolation. Figure-1 Monobore expandable open-hole liner Weatherford system. Figure -2 Expansion Process
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P. 14Technology in Focus
dec | 09
Weatherford International Ltd.Introduction to Weatherford’s Expandable Technology: Expandable tubular technology is a system in which diameter of a casing, liner or sand screen is increased by a certain percentage (depending upon the material) after it has been deployed in the well bore.
One main objective is to reduce the telescopic effect that traditional casing & well designs have.
Figure-1 is an example of Monobore Expandable open hole liner where you can achieve zero loss in hole size and thus benefiting deep drilling because wells can reach greater depth without a loss in final well bore diameter.
Why use expandable Technology?• Allowsexploitationofpreviouslyuntappedresources• ImprovedSandcontrol• Increasedproductivityfromlargerbore• Betterskin• Reducedcost• SelectiveisolationbetweenzonesBelow are a few applications of expandable technology that can reduce development cost and enhance well bore productivity.
Application -1 Cased Hole Expandable Liner for Casing Repair
• Variousproceduresareappliedtorepairthedamagedcasingandthetypeofremediationoperationcanprolong the life of the well.
• ConventionalapproachestoresolvetheseproblemssuchasCementSqueezeiseffectiveonlyinshortterm in sealing off the damage and the need to re-squeeze and the possibility long term, breakdown can limit the economic viability.
Weatherford International Ltd.Application-2 Expandable Monobore Openhole clad.
Monobore open hole clad is a contingency drilling liner and is run in hole and expanded in situ to selectively isolate troubled zones. Monobore open hole clad is a proposed solution for dealing with drilling hazards such severe loss circulation or well bore collapse. Conventionally following methods were adopted either individually or a combination of two. I. Cement squeezeII. Increasing Mud weightIII. Addition of lost circulation material. One more approach a more proactive approach in well design is to run additional casing/liner string. This again drives the well construction costs. Additionally the additional string also slims the well.
Application-3 Expandable Sand Screen
Expandable Sand screen technology is a simple and innovative sand control technique to. The slim nature of the design facilitates easy deployment in various open hole applications. After deployment the screen is expanded to eliminate the annulus. This eliminates the need for additional gravel packing normally required in areas of reactive shales, low frac gradient formations.
An expandable sand screen consists of multiple overlapping rectangular sheets of metal-weave filters attached to an expandable base pipe and encased within a protective metal shroud. It can be expanded by a solid expansion cone followed by a compliant expansion tool. During expansion, the base pipe and the protective shroud’s slots open to expose a flow area through the metal-weave filters, which accommodate the expansion by sliding away from each other while maintaining a tight overlap at all times. The effective filter aperture remains constant and unaffected by the expansion process.
Application-4 Annular Swellable Packers
Swellable Elastomer is a rubber that swells when immersed in well fluids, water, hydrocarbon or mixture of both.
If Wellbore fluids are not present at the time of deployment. An expansion fluid can be used to perform the activation.
