RLWI

IN TRODUCT RODUCTION ION TO RLW I CONCEPT AND EQUIPM ENT

22 March 2007

Introduction • Aver Averag age e reco recove very ry fac facto torr on the the Nor Norwe wegi gian an Con Conti tine neta tall Sh Shel elf  f  (NCS) is 50%. • Aver Averag age e rec recov over ery y fac facto torr for for su subs bsea ea we wellllss on on NCS NCS is 20 20% % lower than for platform wells (44% vs. 55%). • This This is is resul resultin ting g from from hig higher her int interv ervent ention ion cos costt (plat (platfor form m cost cost ~100’ ~10 0’ NOK NOK/da /day, y, tradi tradition tional al subse subsea a cos costt ~4-5 ~4-5 MNOK/d MNOK/day) ay) and and lack of suitable suitable intervent intervention ion units units for subsea subsea wells leading leading to lower frequenc frequency y of interventio intervention n operations operations for for subsea subsea wells (1 (1 intervention per year for platform wells vs. 1 intervention every ever y 12th 12th year year for subs subsea ea wel wells) ls).. • Arou Around nd 50 50% % of of pro produ duct ctio ion n com comes es fr from om su subs bsea ea we wellllss on on the the 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-

847

343

289

146

412

Total producing wells: 2037

W 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 • Perforating/re-perforating

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).

I sland 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  – Hydraulic override of all valves on ROV panels

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)

Upper stack

30 m

17 t

50 t

Lower 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.

Lower Intervention Package (LIP)

Lower Intervention Package

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

Lower lubricator package

Tool t rap 13 5/8” Speedlock

Guide arms with funnels

Tool trap body

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.

Soft land funnel

Because of this, the tool traps only function is to act as a mechanical connection between the LUB tubular and the LLP.

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)

Tool Trap

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.

U p p er s u bs e a st a c k

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 standalone 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.

Um bilical System

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 equalizing. The CIU pumps the glycol through the umbilical.

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 equipment.

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.