Alderley

Technical excellence: delivered

Application NotesNatural Gas Metering

Project Name:Quad 204 Project

Location:Quadrants 204 and 205 of the UKCS, approx. 130km west of Shetland

EPC Contractor/Consultants:Hyundai Heavy Industries

End User:BP

Scope of ApplicationThe Quad 204 FPSO is a replacement for the Schehallion FPSO and will be located west of Shetland. The Schehallion field is one of the largest in the UKCS and is located in one of the most challenging offshore environments in the sector.

The scope of supply consists of one natural gas metering system, comprising 2 x 100% export meter streams, utilising 4” ultrasonic meters and one import meter stream. A remote gas analyser house containing gas chromatographs and other analytical equipment was supplied, along with an associated control system.

Alderley has also supplied an oil metering system and a single deoiling hydrocyclone vessel to the Quad 204 FPSO.

Quad 204 FPSO

Alderley

www.alderley.com

Rev. 09.01.17

Applicable Standards

AGA 8: Super Compressibility Calculation of Natural Gas and Other Related Hydrocarbon Gases

AGA 9: Measurement of Gas by Multipath Ultrasonic Meters

AGA 10: Speed of Sound in Natural Gas and Other Related Hydrocarbon Gases

API MPMS Chp. 14: Natural Gas Fluids Measurement

BS ISO/TR 12765: Measurement of fluid flow in closed conduits - Methods using transit-time ultrasonic flow meters

ISO 5168: Measurement of fluid flow - Procedures for the evaluation of uncertainties

ISO 6976: Natural gas - Calculation of calorific values, density, relative density and Wobbe index from composition

• Single skid 10.2m long x 3.3m wide x 3.4m high

• 2 x 100% export streams 4” 1500# hub connections ultrasonic meters c/w control valves and isolation valves

• 1 x 100% import stream 4” 1500# hub connections ultrasonic meters c/w control valves and isolation valves

• Pressure and temperature instruments

• Small bore drain pipe and valves

• Control system including S600+ flow computers

• Separate sample cabinet c/w 2 x gas chromatographs, HC dewpoint analyser, H2S analyser, moisture analyser, grab

sample system with carrier gas

Main Equipment