Optimization of well performance by use of a semi-permanent dynamic desander

By Asle Sandven / Ted Brueren MSc.

SPE SMN European Sand Management Forum 26-27 March 2014

2013-03-26 Classification: Open

Agenda

• Background information

• Sand management challenge

• Solution

• Result

The Gullfaks field

• Located in the northern part of the

Norwegian North Sea

• Production start-up in 1986

• Initial recoverable reserve ~2.1 bn bbl

• Production peak ~605 000 bbl/d in

1994

• Today approx. 110 000 bbl/d

Background information – Challenge – Solution - Result

The Gullfaks field

• The Gullfaks field has been developed by:

− Three large concrete platforms

− Three satellite fields with subsea

wells

• Recovery factor today approx. 62 %

• Recovery ambition 74 %. Obtained by:

− Horizontal and extended wells

− New completion

− EOR technology (f.e. WAG injection)

− Subsea compression

− Sand control technology

Background information – Challenge – Solution - Result

Earlier sand management on Gullfaks C

• Sand trap located at inlet to the test

separator

• Current acceptance criteria per well

(ASR): max.15 g/hr in sand trap

− Sand trap typically captures 1 to 5

% of total sand production

− Criteria corresponds to 0.3 to 1.5

kg/hr of sand per well

Background information – Challenge – Solution - Result

Producer 34/10-C-19

• Drilled and completed in 1993/1994.

Re-completed in 2002

• Sand rate rapidly exceeds ASR criteria

after sand clean-up

− The well flow is therefore choked

back

− The flow may then be too low to lift

out sand to surface

− Over time sand will then

accumulate in the wellbore

− Result: Sand plug formed

Background information – Challenge – Solution - Result

Producer 34/10-C-19

• Once sand plug is formed a sand

clean-up is necessary

• E.g. demanding operations as coiled

tubing (CT) or snubbing

• Sand clean-up in C-19 has been done

almost every 2nd year

• Previous CT sand clean-up was done

February 2012

Background information – Challenge – Solution - Result

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Aug-96 Jan-98 May-99 Oct-00 Feb-02 Jun-03 Nov-04 Mar-06 Aug-07 Dec-08 May-10 Sep-11 Jan-13

Producer 34/10-C-19 - Average Oil rate (Sm3/D)

Background information – Challenge – Solution - Result

CT Sand desander package

• Desander

• Choke manifold

− manually operated

• Control cabin

• 3 x sand skips

• Emergency shutdown valve (ESD)

Background information – Challenge – Solution - Result

Drawbacks of CT Sand desander package

Background information – Challenge – Solution - Result

• Insufficient sand separation

• Well shut-in when emptying

desander

• New rig up for each well

• Sand sent to shore for handling

• Manually operated choke

• Big footprint

• Location in conflict with other

operations

• Qualified as temporary equipment

NORSOK Z-015

• Pressure rated to 100 bar. Not

according to rig specs (345 bar)

Requirements new desander package

Desander functionality

• More efficient separation required

Need of two desanders

Option to flow through

desanders in either series or

parallel

• Constant flow without interruption

Emptying of desander without

shutting down flow

Possibility to bypass

desander

Background information – Challenge – Solution - Result

Requirements new desander package

Operational functionality

• Easy access to all wells

No pipe handling between

each well flowing

Flexibility to route flow to

either HP or LP test separator

• Easy sand handling offshore

No skips for sand storing

• Remote operating of choke

Background information – Challenge – Solution - Result

Requirements new desander package

Desander location

• Avoid conflict with other operations

Need to find new placement

Preferably at production

mezzanin deck (XT-deck)

Background information – Challenge – Solution - Result

Requirements new desander package

Desander location

• Avoid conflict with other operations

Need to find new placement

Preferably at production

mezzanin deck (XT-deck)

• At production mezzanin deck

Limited space available

Limited height available

access through 2x2 m2

opening

Need to reduce size of de-

sander unit dramatically

Background information – Challenge – Solution - Result

Requirements new desander package

Rig requirements

• Not being the weakest link

Pressure tested according to

rig specs

Erosion resistant

Automatic pressure release if

rig shuts down

No emergency shutdown

valve (ESV)

Background information – Challenge – Solution - Result

Solution: semi-permanent dynamic desander

Dual 5kPSI Desander Unit

• Small foot print

− (LxWxH: 2.0 x 2.0 x 3.2m)

• Weight: 8.5 tons

• Dual desander in same frame

− Serie and parallel flow mode

− Option to bypass one desander

• 5000 psi / 345 bar pressure rating

Background information – Challenge – Solution - Result

Solution: semi-permanent dynamic desander

Dual 5kPSI Desander Unit

• Closed system sand handling

− No manual handling of sand

• Separation of solids down to 20 micron

• Monitoring of:

− flowrate

− pressure

− temperature

− amount of sand separated from flow

Background information – Challenge – Solution - Result

Solution: semi-permanent dynamic desander

X-Flow Manifold

• Foot print

− (LxWxH: 2.0 x 2.0 x 1.2m)

• Controls the flow direction

• Enables reversible flow path

• Integrated remote choke

• Integrated flowmeter

Background information – Challenge – Solution - Result

Solution: semi-permanent dynamic desander

Combine Desander unit with X-Flow

• Minimized slot space needed

− LxWxH: 2.0 x 2.0 x 4.4

• Access to wells on both south and north shaft

• Enables flow to either LP or HP separator

• Built with erosion resistant material:

− Duplex UNS31803

− Tungsten Carbide

Background information – Challenge – Solution - Result

Installation of X-Flow and Dual Desander

Lifting

X-Flow Guiding

X-Flow

X-Flow

in

place

Lifting

de-

sander

Guiding

de-

sander

De-

sander

in place

Background information – Challenge – Solution - Result

Installation of X-Flow and Dual Desander

Tie-in points on test manifolds south shaft

Tie-in points on test manifolds north shaft

LP test manifold

LP test manifold

HP test manifold

HP test manifold

Background information – Challenge – Solution - Result

Conventional flow: e.g wells from north to HP

Background information – Challenge – Solution - Result

Producer on

north shaft

New flow path: e.g. wells from north to HP

Background information – Challenge – Solution - Result

Producer on

north shaft

New flow path of wells – animation

2013-12-01 25 Classification: Open

Result: Benefits achieved

Background information – Challenge – Solution - Result

• Operational

− Less jetting work for operators

− Reduced sand problems in process plant

− Only rigging up once

Result: Benefits achieved

Background information – Challenge – Solution - Result

• Operational

− Less jetting work for operators

− Reduced sand problems in process plant

− Only rigging up once

• Cost saving

− Sand handling done offshore by reinjection

− Less need for CT sand clean out

− More time for alternative CT operations

Result: Benefits achieved

• Operational

− Less jetting work for operators

− Reduced sand problems in process plant

− Only one rigging needed

• Cost saving

− Sand handling done offshore by reinjection

− Less need for CT sand clean out

− More time for alternative CT operations

• Improved oil recovery

− Higher flow rate (without exceeding ASR)

− Less down time for wells

− Optimized well performance

Background information – Challenge – Solution - Result

0

100

200

300

400

500

600

700

Aug-96 Jan-98 May-99 Oct-00 Feb-02 Jun-03 Nov-04 Mar-06 Aug-07 Dec-08 May-10 Sep-11 Jan-13

Producer 34/10-C-19 - Average Oil rate (Sm3/D)

Result: Optimized well performance

Background information – Challenge – Solution - Result

Optimization of well performance by use

of a semi-permanent dynamic desander

Ted Brueren MSc.

Well Intervention Engineer

E-mail address: tedb@statoil.com

Tel: +4791151049 www.statoil.com

2013-03-26 Classification: Open