IN
INTTRODUCTRODUCTION TO ION TO RLWRLWI CONCEPT I CONCEPT AND EQUIPMAND EQUIPMENTENT
22 March 2007
Introduction
Introduction
• • AvAvereragage ree recocovevery fry facactotor on tr on the Nhe Nororwewegigian Can Conontitinenetatall ShShelelf f (NCS) is 50%. (NCS) is 50%. • • AvAvereragage re rececovoverery fy facactotor fr for or susubsbseaea wewelllls os on Nn NCS CS is is 2020%%lower than for platform wells (44% vs. 55%).
lower than for platform wells (44% vs. 55%).
•
• ThiThis is is res resulsultinting fg from rom highigher her intinterverventention ion coscost (pt (platlatforform cm costost
~10
~100’0’ NOKNOK/da/day, try, tradiaditiontional sual subsebseaa coscost ~4-t ~4-5 MNO5 MNOK/dK/day) aay) andnd
lack of su
lack of suitable initable interventtervention union units for suits for subseabsea wells lewells leading toading to
lower fr
lower frequencequency of intery of interventiovention operatn operations foions for subsr subseaea wells (wells (11
intervention per year for platform wells vs. 1 intervention
intervention per year for platform wells vs. 1 intervention
ever
every 12ty 12th yeah year for sr for subsubseaea welwells)ls)..
•
• ArArouound nd 5050% o% of pf proroduductctioion cn comomes es frfrom om susubsbseaea wewelllls os on tn thehe
NCS.
Introduction
• The goal is to get the recovery factor from subsea wells up to same level as for platform wells today (from 44% to 55%). A 10 percent point increase in recovery factor from subsea wells could lead to an increase of 1,500 Mbarrels of oil at the NCS. • To achieve this goal production logging and other measures
needs to be initiated and performed at a lower cost than traditional methods (from 4-5 MNOK/day to 2 MNOK/day). • This could be done by the use of a dynamically positioned
(DP) vessels with intervention equipment installed which can operate at a lower cost than drilling rigs (due to day rate, mooring etc).
Introduction
-
Worldwide possibilties-146 412 289 343 847 146 412 289 343 847W ireline operations
• W i re li ne ( sl ick l in e o r braidedline)
• Pull and set plugs
• Well monitoring/ running production logging tools (PLT)
• M ake a w ell diagnosis
R iserless Light W ell I ntervention (R LW I )
FMC w ill by the use of the RLWI concept aim tow ards reducing the cost of intervention on subsea w ells, and increasing both the intervention frequency and recovery ratio.
Riserless system
Riserless systems mean that there is no use of riser during intervention in a subsea well. The equipment can be installed or retrieved both by use of a guideline system (GL) or by a guidelineless system (GLL). Guideline, often called guidewire, is a line connecting the subsea equipment to the vessel,
guiding the equipment in place. The GL system is normally used on water depths down to 500 metres and the GLL system from 500 metres downwards.
The FMC RLWI system is deployed from a monohull vessel (Island Frontier).
System overview
*Note: Composite cable is not in use yet, customary wireline is still in use
RLW I System – General Introduction
• Main system features
– 10 000 psi system
– Subsea flushing, no well fluid to surface – Riser back-up as contingency
– Control system redundancy
– Tool string length up to approximately 22 m – Compatible with both HXT and CXT
– 7 1/16” bore
RLW I System
• Pressure Control Head (PCH)
• Upper Lubricator Package (ULP)
• Lubricator Tubulars (LUB) (3, 6 & 9 m – maks 18 m)
• Tool Trap
• Lower Lubricator Package (LLP)
• Lower Intervention Package (LIP)
• LIP/XT connector (CPI) 30 m
50 t 17 t
Upper stack
Subsea Equipment
Main features LIP:
· Main barrier element (Safety Head –function)
· 13 5/8” connector towards CXT and 18 3/4” connect towards HXT.
· Two 7 1/16” gate valves in main bore
· One 7 1/16” shear seal ram with high cutting capacity.
Low er lubricator package (LLP)
Main features LLP:
· 13 5/8” connector to LIP
· 10” connector towards lubricator
· Mounting base for control module and umbilical termination. · Control module with 44 functions
· EQD (Emergency Quick Disconnect) facility of umbilical connection · Well kill connection
· EDP (Emergency Disconnect Package) functionality for riser mode
Tool trap
The purpose of the tool trap is to protect in particular the SCSSV and prevent
unintentional dropping of the tool string into the well bore.
The tool trap is positioned between the 10” compact connector and the lubricator
tubular and has bores through, which enables distribution of hydraulic control functions to Upper Lubricator Package and Pressure Control Head and circulation of well fluids/lubricator contents.
The tool trap includes a hydraulically
operated flapper, but this function is today disabled. The UPIV in the LIP is used as tool trap for this operation.
Because of this, the tool traps only function is to act as a mechanical connection
between the LUB tubular and the LLP. 13 5/8” Speedlock
Soft land funnel
Guide arms with funnels
Upper Stack
The Upper Stack comprises the follow ing main elements:
Pressure Control Head (PCH)
Upper Lubricator Package (ULP)
Lubricator tubular (LUB, high pressure flanged)
Lubricator Tubular (LUB)
In order to get the toolstring into the pressurised well there have to be some kind of intermediate storage facility, capable of holding the length of the entire toolstring. The LUB act as this intermediate storage facility, and is capable of holding toolstrings up to 22 meters in length.
The toolstring is installed inside the lubricator, the lubricator is then sealed off and pressure tested. The valves isolating the toolstring and LUB from the well are then opened, and the toolstring can enter the well.
Upper lubricator package (ULP )
The ULP provides one of the barrier elements required in order to be able to secure the well at all stages of the
intervention. The Wireline Shear Seal Valve (WSSR) in the ULP is capable of cutting wireline or slickline only, and sealing the wellbore
afterwards.
The ULP has a 10” connector towards the PCH.
Pressure control head (PCH)
The PCH act as a barrier element in the RLWI system and provides a sealing function around the moving wireline. The seal is obtained by means of injecting viscous grease into the flow tubes ensuring a dynamic hydraulic seal between the wireline cable and the flow tubes. The grease injection pressure must be higher than the well head pressure.
The PCH has a lower dual stuffing box at the bottom of the flow tubes and a single stuffing box and line wiper above the flow tubes. The stuffing boxes, allows a static seal of the wireline cable should the grease injection into the flow tubes fail. The line wiper, wipes off excess grease from the wireline to minimise grease spill to sea. At the bottom of the PCH there is a tool
catcher where the wireline tool can be hung off, during deployment of the PCH and wireline tool.
Topside contr ol system
The RLWI topside control system consists of the following main components:
· Main Umbilical
· CIU (Chemical Injection Unit) Pump and Tote Tank skids · EH-WOCS (Electro Hydraulic Work Over Control System) · Service Umbilical
· Test HPU
· GIU (Grease Injection Unit) 3rd Party
All systems included in the topside control system are
autonomous units that can be mobilised and tested as stand-alone units.
U m b i li c a l s y st e m
The RLWI system requires a number of
communication and service functions during a well intervention. The main umbilical provides a control link between the surface control system and the subsea equipment.
The control system is based upon both hydraulic and electrical functions. The umbilical carries both hydraulic and electrical cables.
The umbilical is designed as a self-containing umbilical for a water depth of 500 meter +20% spare capacity.
EH WOCS, H y d r a u l i c Po w e r U n i t (H PU )
The control and operation of the RLWI system is being performed from the EH-WOCS. Steering of the grease injection system and running of the wireline winch are performed from external units. All emergency functions related to the RLWI system can be triggered from the EH-WOCS, which acts as the central control room for the operation.
Inside the EH WOCS there is a hydraulic power unit and a PC based control system.
Chemical Injection Unit (CI U)
In order to circulate the content of the LUB out, before and after every run in the well some kind of pump skid is
required. The CIU provide the pumping capability of the RLWI system.
The water in the LUB are being pumped into the sea before opening the well, and replaced by glycol. After the toolstring has returned to surface the content of the LUB has changed to well fluid. The well fluid is then flushed back into the
wellbore or into the production system.
The CIU is also used for pressure testing and pressure
Service Umbilical
The Service Umbilical is used for running and pulling Tree Cap and for contingency operations.
For example after an emergency disconnect the service
umbilical is used to normalize RLWI operations. A ROV is then used to connect the service umbilical to the subsea
Summarizing
The RLWI concept is based upon performing conventional wireline operations by means of the RLWI system operated from a monohull vessel or rig.
The RLWI system is planned to be used on X-mas trees from different manufacturers, both vertical and horizontal systems. One of the main objects are to reduce intervention costs and to increase the oil recovery from any subsea well in order to make subsea wells more profitable.
FMC will act as main contractor and single point of contact for this new service.