Deep offshore gas fields: a new challenge for the industry

Transcription

1 Deep offshore gas fields: a new challenge for the industry Emil Gyllenhammar Aker Solutions PAU, FRANCE 5 7 APRIL 2016

2 The challenge Remote gas fields in offshore depths of up to 3000 m Far away from the nearest coast Little or no oil and gas infrastructure Finding cost effective field development strategies Subsea processing opens up new possibilities 2

3 Subsea processing toolbox Currently three separable categories of subsea processing exists in operation. The categorization is based on what the main purpose of the system is: Subsea processing Subsea boosting Subsea separation Subsea raw seawater injection (pressure support) Vision: Subsea gas dehydration and CO2 removal Pumping Separate gas and liquids into separate pipelines (production boosting) Compression Produced water reinjection (de-bottlenecking) Slide 3

4 Stand alone subsea solutions for gas fields Autonomous subsea field development solution No surface facilities Tie back to shore / a surface facility far away subsea compression needed Power generation Control All electrical control system Subsea processing Subsea chemical storage 4

5 Long tie backs and distance dependent cost Field development CAPEX Conventional surface facility with processing and export Minimum interface to shore: pipeline Subsea tie back Minimum interface to shore: pipeline(s) and umbilical Step out At a certain distance the cost of pipelines and umbilical will dominate 5

6 Hybrid subsea/floater solutions for gas fields Support from a small surface facility with reduced topside size, complexity, manning and cost compared to a conventional processing platform/fpso Power generation Control Condensate handling and storage Chemical storage Subsea processing and gas export 6

7 DEPTH for Gas Fields case overview DEPTH (Deep Export, Production and Treatment Hub) for Gas Fields is a joint effort between Total an Aker Solutions with the aim of identifying cost effective subsea field development solutions with long distance tie backs to shore for deep offshore gas fields. Gas field: 500MMScf/d (CGR=40) 300 km step out 2500m water depth No surface facilities tie back to shore Slide 7

8 Subsea compression in DEPTH Subsea compression from day one enables the selection of smaller pipelines Maximum pipeline inlet pressure with subsea compression Maximum pipeline inlet pressure Pipe diameter 1 < Pipe diameter 2 < Pipe diameter 3 Åsgard Subsea Compression flow diagram Pipeline design capacity Production rate Two options for the installation of subsea compression: 1. Subsea compression installed late life / when minimum flow is reached to increase production 2. Subsea compression installed from day one to reduce pipeline size and cost Slide 8

9 Åsgard Subsea Compression On Stream MCE Deepwater Development 2016 Contract AWARD Dec 2010 Template Manifold station Topside module System integration test Installation First Gas 17 th Sept 2015 Compressor module test operates like a Swiss watch 9

10 Subsea gas dehydration in DEPTH Removing both free water and water solved in the gas: Remove the need for continuous MEG injection from shore Reduce pipeline material requirements and avoid corrosion Reduce pressure drop and increase turndown flexibility Adsorption Water removal using beds of solid desiccants Batch process No chemical required Technologies not requiring glycol for dehydration Require regenerations of the solid desiccants Membrane Water removal with selective membrane Continuous process No chemical required Low pressure drop Supersonic separation Water removal with low temperature Continuous process No chemical required High pressure drop Gas dehydration module Wellstream Gas/Liquid separation Compressor Hydrocarbons to host Liquids to host AA LDHI from subsea storage Pump Detailed screening of technology, system design and technology qualification planning performed Slide 10

11 Conclusion MCE Deepwater Development 2016 Subsea processing offers alternative development options for deep offshore gas fields with cost saving potential With subsea compression installed and operating; it can now also applied in greenfield developments from day one to reduce pipeline cost Subsea dehydration removes the need for continuous MEG injection and offers advantages in pipeline operability and material cost Slide 11