Subsea Christmas Trees

Transcription

1 ACCESS TM Certified System Components SpoolTree Subsea Christmas Trees

2 SpoolTree subsea Christmas trees from Cameron: completions and workovers with full BOP protection and full-bore vertical access without removing the tree. SpoolTree operational and cost advantages Wells can be completed and worked over with full BOP protection at all times; Downhole completions can be retrieved without removing the tree, leaving the tree connector gasket, flowline connection and production control umbilical undisturbed; Completions and workovers can be performed with a standard drilling riser and BOP. The need for a specialized completion/workover riser system is eliminated; Wireline tools are not run through the tree valves, greatly reducing the risk of damage; When Cameron invented the horizontal tree in 1992, it was a revolutionary concept. Now the patented SpoolTree Christmas tree is one of the most widely used (and often imitated) trees in the world s offshore fields. Subsea field development has changed fundamentally as a result of this technology. Cameron created a tree with significant operational advantages by re-engineering field-proven components. It features Cameron FLS Gate Valves and Cameron Willis subsea chokes, for example, the industry s most trusted brands. SpoolTree tubing hangers and running tools are proven in numerous wells. SpoolTree Christmas trees have working-pressure ratings of up to 15,000 psi. They mate to any of Cameron s STM and STC wellhead connection profiles hub, mandrel or deepwater high capacity and can be adapted to other wellhead profiles. SpoolTree Christmas trees are integrated with Cameron s MOSAIC subsea production systems, which provide options for current and future field development unavailable anywhere else. The amount of equipment required for handling offshore is reduced; Installation is performed with familiar equipment and routine rig procedures; Overall height of the completion is substantially lower; SpoolTree Christmas trees are fully integrated with Cameron s modular, high-performance MOSAIC production systems. SpoolTree systems reduce rig time, not only during workovers, but also during initial completion operations. SpoolTree Christmas trees deliver unique performance benefits in every type of offshore well Subsea oil or gas production Subsea gas or water injection Subsea aquifer Platform tie-back* Mudline completion* *See page 7 for more information. Cameron introduces the SpoolTree Christmas tree Cameron SpoolTree receives approval from Health Safety Executive (HSE) and Minerals Management Service (MMS) Unique wellhead-tree-hanger stackup is the key difference between SpoolTree Christmas trees and conventional trees. How SpoolTree Christmas trees are different from ordinary trees SpoolTree technology turns conventional Christmas tree technology upside down. Instead of the typical wellhead-hangertree stackup, the SpoolTree design has a wellhead-tree-hanger stackup. In this configuration, the Christmas tree consists of a concentric bore spool with a wellhead connector below and a wellhead connector profile on top. The tubing hanger is hung off inside the spool First Gulf of Mexico SpoolTree is installed in 650 ft of water. Two 3 x 2 10,000 psi WP trees were used on a two-well subsea template with production manifold Cameron installs the world s first SpoolTree Christmas tree in 350 ft of water in the North Sea. Fourteen 5,000 psi WP trees were installed in a system of subsea satellite wells tied back to a floating production facility. Well types included oil producers, water injectors, gas supply and gas injectors First mudline SpoolTree is installed in 150 ft of water in the North Sea. Three 5 x 2 5,000 psi WP trees were used in a diver-assisted satellite completion on drill-through mudline wellheads. 2

3 on a dedicated load shoulder, and the valves are situated on the side of the spool. No valves are in the vertical bore of the wellhead/tree system. The completion is run after the tree is installed, and the completion can be pulled with the tree in place and flowline connections undisturbed. Reduced costs, increased safety In re-thinking traditional Christmas trees, Cameron s goals were to shorten rig time, reduce capital equipment costs and increase safety. Eliminating the need to remove the tree to pull production tubing saves rig time (see chart below), especially for completions that require frequent retrieval of downhole equipment. Eliminating the need for an expensive, dual-bore workover and completion riser system cuts equipment costs. Christmas Tree Rig Time Comparison Water Depth 1000 ft (305 m) 2000 ft (610 m) 3000 ft (914 m) 4000 ft (1219 m) 5000 ft (1525 m) First platform SpoolTree is installed in the North Sea. A total of twenty-nine 5 x 2 5,000 psi WP SpoolTrees were installed using 13-5/8 10,000 psi WP compact wellheads. SpoolTrees were used on every well type. And SpoolTree Christmas trees are safer than ordinary trees. All completion and workover activities can be performed under full BOP control using a standard drilling riser and blowout preventer, which connects to an 18-3/4 profile on top of the SpoolTree body. Because tubing is installed after the tree is in place and the BOP connected, there is uninterrupted BOP protection from the moment the well is perforated. With conventional equipment, the tubing must be installed before removing the BOP and installing the tree. The SpoolTree design has earned the approval of major regulatory bodies governing its use including the Minerals Management Service for the Gulf of Mexico and the Health and Safety Executive for the North Sea. Rig Time (Hours) SpoolTree is awarded patent in U.S. SpoolTree Completion Conventional Tree Completion SpoolTree Workover Conventional Tree Workover First guidelineless SpoolTree run in 3,638 ft of water, Campos Basin, Brazil Modular Subsea And Integrated Completion systems: The MOSAIC concept MOSAIC systems are the result of a design philosophy that eliminates the usual tradeoffs you expect with a pre-engineered, modular system. With MOSAIC systems, you gain simplified installation procedures, reduced personnel training and faster delivery. Unlike ordinary systems, you don t have to give up flexibility, expandability and desirable product features and benefits. The ordinary approach to modularity is fixed assemblies run progressively to large structures, which are not appropriate for many applications. MOSAIC systems are modular at the component level, standardized to work together in many combinations. The result is a cost-effective system that can be adapted to virtually any subsea job. The MOSAIC system is more easily expanded as field development needs evolve, and its components contain the technology that provides the performance you need. Cameron s SpoolTree Christmas trees are an integral part of the MOSAIC system. They re the perfect fit for today s subsea economics First deepwater SpoolTree is installed in 2150 ft of water in the Gulf of Mexico. Three 3 x 2 10,000 psi WP trees were tied back to a 24-slot subsea template, producing to a floating production facility through a free-standing production riser system. First Australian SpoolTree trees are built by Cameron for the Timor Sea area. 3

4 Modular SpoolTree Christmas trees: The foundation of a production system with endless possibilities. SpoolTree Christmas trees can be configured with a wide array of component choices. The benefits of Cameron s MOSAIC concept modularity at the component level can be seen here in sharp focus. The possible combinations of component choices, available pressure ratings and sizes are virtually endless. Which means you get equipment precisely suited to your current requirements and flexible expansion options as your development plans evolve. Spool body The Spool body provides outlets to attach production, annulus and isolation valves for downhole functions and the electrical penetrator bonnet assembly. The tubing hanger landing shoulder is specially ported to accept control stabs and provides hydraulic continuity between the production control system and downhole hydraulics. Basic Chemical Injection Annulus Crossover Valve assemblies Valves are contained both as an integral part of the spool body, and in mini-blocks external to the vertical bore of the tree. A typical valve cluster includes production and annulus master valve, production and annulus wing valve, crossover valve, workover valve and isolation valves for SCSSV, CIV and other requirements. Assemblies are available for 3 7 completions. Production Choke Gas Lift Choke Tree connector The tree connector is capable of providing approximately 3 million pounds of preload when operated by the Tree Running Tool (TRT). Tree installation is diverless. The TRT contains all hydraulic tree connector functions, leaving the tree connector with no hydraulics exposed to the subsea environment. Flowline and pipeline connections Vertical, horizontal, diver assist and ROV-driven connections are available. Common interfaces allow a variety of different types of connection systems to be used. Control module Within the advanced CAMTROL control pod, the controls circuitry and hydraulics are also modular. Up to 32 hydraulic control points, in multiples of four, can be included in the pod. These control points can be used not only for traditional tree valves but also for functions such as manifold valve control, choke adjustment, position indication/feedback and accommodating smart well technology. 4

5 Debris cap The debris cap covers and protects the spool top, and need not contain pressure. The cap is mechanically weight set and is run and retrieved with drillpipe. When landed, the cap latches to the external profile on to the top of the SpoolTree body. The design allows the top of the spool and the inside of the cap to be filled with corrosion inhibitor. Internal tree cap and wireline plugs The SpoolTree design follows Cameron s dual pressure barrier philosophy. The primary pressure barrier is a plug in the tubing hanger. The Internal Tree Cap (ITC) provides a secondary barrier above the tubing hanger. The ITC is run and retrieved through the BOP stack using the tubing hanger tools. The cap seals and locks into the tree using the same mechanism as the tubing hanger. Two versions of the ITC are available: either solid or bored for a wireline plug. The plug option allows access to the tubing ID using wireline tools. The ITC plug is metal sealing with an elastomer backup. Tubing hanger The modular design allows up to six hydraulic and two electrical penetrations. Available for 3 7 completions, the tubing hanger has a concentric bore and side production outlet. During installation, the hanger orients, lands and locks to the bore of the SpoolTree spool body. At the bottom of the hanger, an orientation sleeve with a helix engages a key in the tree, which provides 180º of passive orientation to positively align the hanger outlet with the spool body. This design makes precise orientation simple, sure and automatic. Tubing hanger seals are either metal-to-metal or Cameron s CAMLAST Metal End-Cap (MEC) seal. The SpoolTree tubing hanger allows multiple penetrations for SCSSV, CIV, DHPTS, smart well, etc.. Retrievable subsea chokes Retrievable subsea chokes from Cameron Willis provide flexibility to replace worn trim or change it out based on the well production profile. Plug-and-cage and external-sleeve trim types are available. Chokes are offered for diver-assist and diverless installation and retrieval. Retrievable subsea chokes can be specified with crown or clamp connectors. Guidebases SpoolTree Christmas trees can be easily configured for template or satellite installation. They can be run with guidelines on drilling guidebases or guidelineless. Completion guidebases for satellite installations can be customized with a variety of connection types and other features to fit field development requirements. 5

6 SpoolTree Christmas trees outperformed ordinary trees in these projects. Imagine how they ll perform in yours. Campos Basin, Brazil Water Depth: 1,109 meters (3,638 ft) Problem: Using electrical submersible pumps (ESP) in deepwater subsea wells and reducing intervention costs. Solution: In the world s deepest commercial application of electrical submersible pumps in subsea wells, SpoolTree Christmas trees were chosen because their modular design and unique wellhead/tree/hanger stackup provided the right combination of features to make interventions faster and easier than with ordinary trees. Subsea trees were installed in water depths up to 1150 meters, but the operator wanted the flexibility to locate the production platform in shallow water. This called for the use of ESPs because long horizontal flowlines made reservoir pressure and gas lift insufficient. The ESP can also withstand high flow rates. Although the ESPs have proven reliable, their presence almost always means that more interventions will be required. The operator chose the Gryphon Field, North Sea Campos Basin, Offshore Brazil SpoolTree design because it dramatically simplifies interventions. And it provides full-bore access to accommodate electrical connections. SpoolTree s monobore design also allows more penetrations than conventional types. SpoolTree modularity allows an easy conversion from gas lift to ESP. Another benefit: a custom flowline connector designed by the operator was a simple retrofit. The SpoolTrees used here were the first with eccentric tubing hangers. This was also the first guidelineless SpoolTree installation. Gryphon Field, North Sea Water Depth: 112 meters (370 ft) Problem: Economically develop a marginal field with four types of wells. The water injection wells used in this project required a high volume of water production. In addition, the operator did not want to acquire an expensive, dual-bore riser system. Solution: SpoolTree modularity gave the operator the flexibility to control eight production wells, four water injection wells, one gas injection/production well and one water production well with only one basic tree type. The operator was able to reduce costs substantially by drilling only one water production well. Using ordinary trees, more water production wells would be required to match the flow rates of the water injectors. Because the SpoolTree Christmas tree s design allowed water production from a 9-5/8 concentric bore, no additional water producers were required. The oil and gas wells were tied to a purpose-built, permanently moored FPSO in the North Sea. 6

7 SpoolTree modularity and operational advantages had a dramatic impact on delivery and installation times. The first tree was delivered only nine months from receipt of the purchase order. And installation time was considerably reduced, which allowed earlier production and also represented a significant cost savings for the operator. Because SpoolTree Christmas trees allow all completion and workover activities under the control of a conventional BOP, an expensive completion/workover riser system was not necessary. Such a system can cost as much as three Christmas tree assemblies. Cauvery Basin, Offshore India Water Depth: 90 meters (295 ft) Problem: Re-enter and complete two wells that had been drilled with Cameron WS-1 Lo-Torque subsea wellheads and abandoned 10 years earlier. Drill and complete two additional wells in the field for a total growth. In addition, the permanent guidebases on the old wells were not recoverable and not designed to provide production flowline support. Solution: The conventional approach in such a situation is to utilize a tubing spool assembly to provide new seal surfaces for the BOP and for the tubing hanger system. The dual bore tree can then be run on top of the spool. This spool assembly can also provide a structure for the flowline support base. But this solution was impractical because in addition to the cost of a separate tubing spool, it would have required a large capital expenditure for a dual bore completion riser just to complete four wells. The SpoolTree Christmas tree alleviated all these problems. The spool part of the SpoolTree allowed the establishment of new seal surfaces for the BOP and tubing hanger system, in essence combining the spool and the tree into one assembly. The SpoolTree did not require an expensive Platform and mudline SpoolTree configurations All the advantages and versatility of subsea SpoolTree Christmas trees are also present in platform and mudline versions. On platforms, SpoolTree valve arrangements, low height and compact overall size allow tighter spacing. Because mudline SpoolTrees are compact and sit close to the seabed, damage from fishing trawl boards and nets can be minimized. Both versions retain easy access to the completion with full BOP protection. Mudline SpoolTree Cauvery Basin, Offshore India of four wells producing to an FPSO off the east coast of India. Favorable development economics and a fast schedule where crucial for the success of this project. Since the condition of the sealing surfaces of the two old wellheads was unknown, it was important to minimize the effects of seal surfaces that may have been corroded, damaged or covered with marine completion riser system. Cameron engineers designed a simple flowline support structure that interfaced with the existing guidebase, without requiring a spool assembly for only that purpose. The result was an economical solution to a problem that would have been far more expensive to solve with conventional equipment. Platform SpoolTree 7

8 Western Hemisphere Cameron PO Box 1212 Houston Texas Tel Fax Eastern Hemisphere Cooper Cameron (U.K.) Ltd. 5 Mondial Way Harlington Hayes UB3 5AR Tel Fax subsea@camerondiv.com Asia Pacific/Middle East Cooper Cameron (Singapore) Pte. Ltd. No. 2 Gul Circle, Jurong Industrial Est Locked Bag Service No. 3 Jurong Town Post Office Singapore Republic Of Singapore Tel Fax subsea@camerondiv.com MOSAIC, SpoolTree, Cameron, CAMLAST, STM, STC, CAMTROL and Cameron Willis are trademarks of the Cooper Cameron Corporation, Cameron Division. Cooper Cameron Corporation, Cameron Division, Printed in USA, 3/99, HG/7.5M, WR6565/TC1265