SpoolTree™

Subsea ProductionSystem

Driven by the need to reduce the cost of bringingmarginal fields on stream, a new advance in subseatechnology has been achieved that has the potentialto radically change the way the industry designs,manufactures and operates subsea completions.This new development is the SpoolTree™ SubseaProduction System by Cooper Oil Tool, a division ofCooper Industries. This system utilizes field-provendesigns and presents a new look at the fundamentalrequirements of future subsea production systems.

The industry has been quick to appreciate thebenefits offered by the SpoolTree design and anumber of trees are on order for several projects inthe North Sea and the Gulf of Mexico.

The SpoolTree Subsea Production Systemserves the identical function as a conventionalsubsea tree and maintains the dual primary sealbarrier philosophy of subsea production. The treesystem is essentially a manifold of valves forcontrolling the flow of wellbore fluids and providingvertical downhole communication for workoveroperations. This unique design allows maximumproduction flexibility while reducing costs andimproving operability and safety. The primarybenefits of the SpoolTree are:

• Ability to complete the well with full blowoutpreventer protection at all times

• Ability to retrieve downhole completionswithout retrieving the tree, thereby leaving theflowline connections undisturbed

• Elimination of the need for specializedworkover/completion riser system

• Reduction in the amount of equipmentrequired for handling

• Installation performed with conventional,routine rig procedures

SpoolTree Subsea Production System

The SpoolTree has a different basicconfiguration than the conventional tree. Althoughthe tree is installed on a standard subsea marinewellhead system, the stackup arrangement iswellhead/tree/hanger so that the hanger is landed inthe tree, rather than in the wellhead. This allowsprimary access to the completion without removingthe tree. The SpoolTree tubing hanger is landed ona dedicated load shoulder in the tree. Its elevationand orientation, therefore, can be accuratelycontrolled. The SpoolTree tubing hanger is amono-bore design, allowing the completion to beinstalled on a single work string rather than on acostly conventional dual-bore workover/completionriser. Production seals offered in the tubing hangerare either metal-to-metal seals or the Cooper OilTool metal end-cap seals.

Safety Advantages

The SpoolTree body is machined with an 18-3/4" hub profile on top to allow installation of astandard 18-3/4" drilling blowout preventer (BOP).The ability to interface a standard drilling BOP isprobably the single most important benefit of thesystem because all completion activities can beperformed under conventional blowout preventercontrol. This feature also eliminates the need for anexpensive, specialized completion and workoverriser system.

The SpoolTree also allows direct access to thewellbore irrespective of the condition of thecompletion. That is, even if the well is live underthe tubing hanger due to production tubing failure,safe full-bore access can still be achieved using thedrilling BOP. In a conventional completion, wirelineplugs would be installed in the tubing hanger and

the tree would be removed so that the drilling BOPcould be installed to remove the failed completion.

SpoolTree Valves

All SpoolTree valves are external to the treebody with no vertical valve runs. Production andannulus valves are contained on the exterior of thetree in mini-blocks. Connected to the blocks are theflowloops which provide cross-over and circulationcapabilities.

All SpoolTree valves are Cooper Oil Tool'shighly successful FLS gate valves. The typical valvearrangement consists of a production and annulusmaster valve, production and annulus wing valve (orisolation valve), cross-over valve, workover valveand isolation valves for SCSSV, CIV, etc.

The master, wing and cross-over valves servethe same purpose as on a conventional tree. Theworkover valve, however, allows circulation aroundthe tubing hanger during completion operations.

Conclusion

The SpoolTree Subsea Production System is amajor development in subsea technology. It offersnumerous advantages and operational improve-ments over the conventional approach whileenhancing safety and reliability. The SpoolTree willplay an important role in economically developingfuture marginal fields in both shallow and deepwater applications worldwide.

SpoolTree™ Subsea Production System

Tree Connector

Electro-HydraulicControlPod

Pressure Isolation Cap

Tubing Hanger

Debris Cap

Valves and Actuators

Body

STC-10/STM-15Wellhead System

SD11034-99

SpoolTree™ is a trademark of Cooper Cameron CorporationCameron® is a registered trademark of Cooper Cameron Corporation

©Cooper Cameron Corporation, Cameron Division, P.O. Box1212, Houston, Texas, 77251-1212, Telephone: 713/939-2211, Telefax: 713/939-2620

TC1042, PDF4/96

Cameron

P.O. Box 1212

Houston, TX 77251-1212

Telephone: 713/939-2211

Fax: 713/939-2620

DomesticAnchorage, AlaskaBerwick, LouisianaPatterson, LouisianaVille Platte, LouisianaOklahoma City, OklahomaBrookshire, TexasLiberty, Texas

InternationalZarate, ArgentinaMelbourne, AustraliaEdmonton, CanadaLeeds, EnglandBeziers, FranceCelle, GermanyLongford, IrelandVeracruz, MexicoHoogezand, The NetherlandsPort Harcourt, NigeriaStavanger, NorwaySingapore, Republic of SingaporeAberdeen, Scotland

This list includes major manufacturing and sales locations. Contact your nearest Cameronrepresentative for locations not included on this list.

Manufacturing Plants and Aftermarket Facilities

DomesticBakersfield, CaliforniaWoodland, California Denver, Colorado Lafayette, Louisiana New Orleans, Louisiana Mount Pleasant, Michigan Laurel, Mississippi Oklahoma City, Oklahoma Corpus Christi, Texas Dallas, Texas Houston, Texas Longview, TexasOdessa, Texas Casper, Wyoming Evanston, Wyoming

Sales and Service Locations

InternationalBuenos Aires, ArgentinaPerth, AustraliaKuala Belait, BruneiCalgary, CanadaGrande Prairie, CanadaPunta Arenas, Chile,Pointe-Noire, CongoCairo, Egypt,Great Yarmouth, EnglandLondon, EnglandParis, FrancePau, FrancePort Gentil, GabonJakarta, IndonesiaTokyo, JapanKuala Lumpur, MalaysiaMiri, MalaysiaTerengganu, MalaysiaCiudad Del Carmen, MexicoMexico CIty, MexicoVillahermosa, MexicoThe Hague, The NetherlandsPapakura, New ZealandLagos, NigeriaWarri, NigeriaBergen, NorwayMuscat, OmanMoscow, RussiaAl Khobar, Saudi ArabiaAbu Dhabi, U.A.E.Maracaibo, Venezuela