Federal Register of Legislation - Australian Government

Primary content

Bookmark

This gazette
Administered by: Industry
Published Date 05 Feb 2015

COMMONWEALTH OF AUSTRALIA

 

Section 708

Offshore Petroleum and Greenhouse Gas Storage Act 2006

 

APPLICATION FOR VARIATION OF A PETROLEUM PIPELINE LICENCE

 

I, GRAEME ALBERT WATERS, the National Offshore Petroleum Titles Administrator, on behalf of the Commonwealth–Western Australia Offshore Petroleum Joint Authority hereby give notice pursuant to section 708 of the Offshore Petroleum and Greenhouse Gas Storage Act 2006 (the Act) that an application has been received from

 

Apache Northwest Pty Ltd

(ABN 58 009 140 854)

 

Santos (BOL) Pty Ltd

(ABN 35 000 670 575)

 

for a variation of Petroleum Pipeline Licence WA-11-PL, located in the offshore area of Western Australia, as set out below.

 

Pursuant to subsection 226(3) of the Act, a person may make a written submission to the Titles Administrator about this application within 30 days from the date of this notice.

 

This notice takes effect on the day on which it appears in the Australian Government Gazette.

 

Made under the Offshore Petroleum and Greenhouse Gas Storage Act 2006 of the Commonwealth of Australia.

 

 

GRAEME ALBERT WATERS

TITLES ADMINISTRATOR

ON BEHALF OF THE COMMONWEALTH-WESTERN AUSTRALIA

OFFSHORE PETROLEUM JOINT AUTHORITY

APPLICATION FOR VARIATION OF

PETROLEUM PIPELINE LICENCE WA-11-PL

 

John Brookes Pipeline

 

SCHEDULE

 

(B) Basis of Design

 

The pipeline design is based on the following parameters:

 

Item

Item Description

Details

1

Outside diameter of pipe and riser

457.2 mm (18 in)

2

Wall thickness of pipe inclusive of riser (only for carbon steel)

15.9 mm (KP21.2 to KP48.1 and pipeline riser);

17.5 mm (KP48.1 to KP53.9);

15.9 mm (KP53.9 to KP54.4) pipeline repair spools

3

Length

33.2 km (approximate)

4

Internal Corrosion Allowance

5.5 mm (except for the riser and spools up to the subsea isolation valve where 2.5 mm 316L cladding is provided) and the pipeline repair spools (where
2.5 mm Inconel 625 cladding is provided)

 

External Corrosion Allowance

3 mm (applies only to the riser in the splash zone)

5

Pipeline and Riser Steel Grade

DNV-OS-F101 Grade 450

6

Pipeline Specification

DNV-OS-F101 High Frequency Weld

7

Minimum yield strength of pipe steel

450 MPa (SMYS)

8

Pipeline Design Pressure

13.75 MPag

9

Maximum Allowable Operating Pressure

13.75 MPag

10

Normal Operating Pressure

8.7 MPag

11

Minimum field test pressure

Hydrotest pressure (minimum) for the existing pipeline is Design Pressure x 1.05 x 1.1 = 15.89 MPag

12

Normal Maximum Inlet Pressure

10 MPag

13

Normal Minimum Outlet Pressure

(Varanus Island)

6 MPag

14

Maximum Pipeline Design Temperature

100°C upstream of the repair connector and 55°C at the repair connector

15

Maximum Riser and Spool Design Temperature

120°C

16

Design Capacity

The pipeline capacity is a function of the available pressure drop, fluids and any future tie-ins at a distance down the pipeline. The current capacity based on: known likely fluids; current maximum offshore export pressures, is 235 mmscfd (240 TJ/d). The design capacity for the Pipeline Repair Project is 267 mmscfd (273 TJ/d)

17

Stabilisation

KP21.2 to KP53.9 – Concrete Weight Coat

KP53.9 to KP54.4 – Gravity Anchors

Existing Tie-in Spool – Gravity Anchors

18

External Coating Specification

KP21.2 to KP48.1 – 5.5 mm Asphalt Enamel Coating

KP48.1 to KP53.9 – 2.5 mm 3 Layer Polypropylene

Tie-in Spool and Repair Spools – 350 microns Thermally Sprayed Aluminium

Riser Submerged Zone – 350 microns Thermally Sprayed Aluminium

Riser Splash Zone – 13 mm EPDM

Riser Atmospheric Zone – 350 microns Thermally Sprayed Aluminium

19

Field Weld Joint Coating

The existing pipeline field joints have heat shrink sleeve or cold applied tape wrap overlaid by either marine mastic or high density polyurethane foam and the existing riser and tie-in spools have TSA coated field joints. The repair spools to be fabricated onshore will be TSA coated at each joint forming the straight and tie-in spools.

20

Weight Coating Design and Specification

Concrete density 3040 kg/m3

KP21.2 to KP23.0 – 120 mm

KP23.0 to KP48.1 – 70 mm

KP48.1 to KP53.9 – 70 mm

21

Characteristics of substance proposed to be conveyed

Wet gas (approximate 85.5% methane saturated with water at reservoir conditions)

22

General plans and descriptions of pump stations, tank stations or valve stations and their equipment

  • Subsea isolation valve located adjacent to
    John Brooked platform, which is provided with dropped object protection frame and
    1 electrical cable and 1 hydraulic pack

 

General plans and descriptions of pipeline repair

  • The inclusion of a 520 m (nominal) length comprising straight spools and tie-in spools to form a cooling spool downstream of the SSIV as the replacement for the existing CS pipeline
  • Straight spools to be ANSI flange jointed (WN/swivel-ring pairs) as 4 joint lengths (nominally 46 m long), externally coated with TSA
  • Tie-in spools to be ANSI flange jointed (WN/swivel-ring pairs) as varying lengths, externally coated with TSA
  • Straight spools, tie-in spools and flanges to be CRA (Inconel 625) clad internally
  • Straight and tie-in spools to be stabilised by gravity anchors
  • Cooling spool cathodic protection by sacrificial anodes affixed to the gravity anchors and cable connected to the straight and tie-in spools
  • Straight and tie-in spool welded joints to be TSA coated
  • SSIV structural modification to accommodate the new spool configuration
  • Downstream tie-in of the cooling spool via mechanical connector
  • Removal of the existing RPCM probe and dummy spool immediately downstream of the SSIV
  • Installation of a temperature probe in the vicinity of the mechanical connector

23

General plans and description of pigging facilities

Provision for offshore pig launcher located at the platform and an onshore pig receiver at Varanus Island

24

Design life

20 years (approximate)

25

The provisions for cathodic protection of the proposed pipeline

  • For pipeline, sacrificial Aluminium Zinc Indium bracelet anodes spaced at the following intervals:

KP21.2 to KP23.0 – Type A4, every 16 joints and double anode at every 1.0 km as
KP marker

KP23.0 to KP48.1 – Type A3, every 15 joints and double anode at every 1.0 km as
KP marker

KP48.1 to KP53.8 – Type A2, every 6 joints and double anode at every 1.0 km as
KP marker

KP53.8 to KP53.9 – Type A2, every 3 joints and double anode as KP54 marker

KP53.9 to KP54.4 – Cooling spool provided with cathodic protection via sacrificial anodes affixed to the gravity anchors and cable connected to the straight and tie-in spools

  • For each rock bolt anchor assembly, anode is provided on each assembly

26

Crossings

None

 

27

Marine Growth Allowance

30 mm

28

Location of offtake tees for future use

None