ASTEP I.S. – Case Study

ASTEP I.S. GoA 50 km Case Study Field Definition Basis

ASTEP Platform Specification: 50 km Gulf Coast Case Study

Hull and Deck Specification

Normally unattended platform
Proven GVA twin pontoon semi submersible
Deck 64 x 64 m
Hull Displacement: 25,000 Te Draft: 21 m Freeboard: 22.5 m
8 point-mooring

In-line tension chain-poly-chain

suction piles

30-year design life
1 Fuel-gas riser + future riser hang-off
3 umbilicals (1 HV-MPP, 1 HV-ATM, 1 E-H Controls)

Topside Equipment Specification

GTG Power Generation 7.5MW peak demand @ n+1 w/ diesel restart

VSD Subsea Multiphase Pump 3.65MW peak demand

Subsea Heating System DEH with 5.0MW peak demand

Chemical Injection Skid

Hydrate Inhibitor: 75 bbl

Corrosion Inhibitor: 736 bbl

Wax Inhibitor: 0 bbl due to ATM system

Asphaltene/Scale Inhibitor: 435 bbl

Subsea Well Control Module

Control and Communication Module

Utility and Material Handline 1 Pedestal crane Walk to work landing/connection

ASTEP I.S. Case Study Project Execution – Post FID

PLATFORM

SUBSEA

ENGINEERING HOUSTON

Engineering 8 Months

Engineering 8M before steel cutting
Bulk order 5M before steel cutting
Procurement 7M before steel cutting

ENGINEERING

Engineering 2 Months

High-Level FEED completed prior to FID to enable long-lead procurement
Long-lead procurement at FID

FABRICATION FAR EAST

Fabrication 12 Months

Block fabrication and erection
Equipment installation
Commissioning

FABRICATION

Fabrication 18 Months

Long lead billet and forgings control
Includes FAT and SIT

DRY TRANSPORTATION

Dry Transport 2 Months

Far East to Gulf of Mexico (Gulf of America)

INSTALLATION

SPS Installation 2 Months

SPS and flowlines

HOOK-UP AND COMMISSIONING GULF OF MEXICO (GULF OF AMERICA)

Hook-Up and Commisioning 2 Months

Mooring Hook-up
Umbilical Installation
Fuel Gas Riser
Commissioning

First Oil: 24-30 Months after FID

Conventional vs. an ASTEP I.S. Tieback

A GOM Case Study is presented comparing ASTEP I.S. Solution to a conventional tieback approach.

Cost Estimate

ASTEP I.S. 50 km Gulf Coast Case Study Cost Estimate (%)

[1] Pricing based upon Q1 2021 KBR norms and industry pricing [2] All estimates are Class 5 in current dollars and exclude: owner’s costs, escalation/inflation, project level contingency, taxes, duties, DRILLEX and fees [3] Includes Fabricator EPCM and 10% design allowance

ASTEP I.S.

Autonomous Subsea Tieback Enabling Platform Integrated System