September 2008

GPA Europe AGM and Gas Storage Session 

Thursday 20th, November, Marriott Marble Arch, London

Thursday Morning

• 09:30 
  An Introduction to Underground Gas Storage Including Underground Technologies, Planning Requirements, Safety Case Preparation and Commercial Issues.
   
  Garth Raybould and Evan Passaris, Atkins Design and Engineering Solutions
   
  After a brief review of the commercial and geopolitical factors driving the need for more underground gas storage (UGS) in the UK, Garth and Evan will describe the underground technologies involved in the identification and development of UGS facilities, in both salt caverns and depleted reservoirs.  They will focus particularly on the geological and geomechanical aspects of facility investigation, design and operation.  Their presentation will consider some of the planning, environmental and safety issues involved and the reasons for the progression from onshore to offshore facilities.   Safety issues will include reference to the potential for gas escape and migration on geological pathways, the geomechanical factors involved in safe containment and the application of RAM (reliability, availability maintainability) principles to design and operation.  In view of the increasing interest in investment in UGS developments, key factors in due-diligence auditing of facilities will be reviewed.
   
• 12:30 Networking Lunch sponsored by Costain Oil Gas and Process
  
• 14:00 - 14:30 GPA Europe Annual General Meeting 2008

Thursday Afternoon Technical Meeting
14:30 Gas Storage Issues

• Cavern Storage and Process Facilities
  Guenter Behrendt & Dirk Heyer,
  PSE Engineering GmbH, Hanover, Germany
  A)   Caverns – Big Tanks in the Salt: Development and status of cavern storage technology
  In times of declining energy resources and increasing demand, people and economies are looking for stable energy supplies. For decades, salt cavern storage has contributed to Europe’s supply security. From the early beginnings up to now, storage requirements in respect of volume and availability have dramatically changed. In former times, storage facilities were only used to handle supply peaks in winter time, but now they are also trading instruments in the unbundled gas market. The influence and developments due to these new challenges for surface and subsurface installations (e.g. Leaching Facilities, Gas Drying Facilities, Compression Facilities, etc.) are highlighted in detail in the presentation.
  B)   Compression Systems A discussion on reciprocating compressor technology and plant solutions based on Ariel reciprocating compressors.
  A flexible and stable solution for the necessary gas compressors is important. Nowadays turbo compressors and reciprocating compressors are the main types for cavern storage, but due to the development from the pure storage to a trading instrument, reciprocating compressors have experienced a  “renaissance” for new storage projects!
• LRC Storage^â An Innovative and Efficient Underground Gas Storage Technology
  Dominik Uznanski, GdF Suez, Paris, France
  The Lined Rock Cavern (LRC) technology allows storage of natural gas under high pressures in one or more caverns excavated in solid rock at a shallow depth. Each cavern is equipped with a steel liner, which serves as an impermeable container for the gas, which means that the surface facility does not need gas treatment facilities such as dehydrators. The cavern size and depth is adapted to actual geological conditions.
  LRC storages can be located in many places where there are no traditional underground storage formations, such as salt deposits or depleted reservoirs, because the caverns are made of solid rock. The working gas volume can be close to 90% of the total volume and gas can be injected and withdrawn frequently, which offers an optimal answer to peak-shaving needs.
  LRC is the fruit of 18 years of thorough R&D, testing and industrial implementation, carried out by GDF SUEZ and E.ON Sverige. The Skallen LRC storage, a successful demonstration project in southwest Sweden close to Halmstad, has been in commercial operation since early 2004. More recently, efforts have been undertaken to develop a compressed air energy system, in which the LRC storage allows a timely and cost efficient production of electricity using air turbines.
  Today, GDF SUEZ wants to help implement the LRC technology worldwide and offer an interesting strategic gas storage alternative to traditional underground storages and LNG peak-shaving plants, as well as provide a means of producing electricity from compressed air.
• Underground Gas Storage in Cheshire: the Costain Experience
  Mike Healy, Costain Oil, Gas and Process, Manchester, UK
  Costain Oil, Gas and Process has been involved in two large UK underground gas storage projects in Cheshire. The gas is to be stored in salt cavities some 600m deep, which have been leached specifically for the projects. The brine is a commercial product and the leaching process is constrained by the demands of the downstream processes.At 600m deep, the storage pressures within the caverns straddles the NTS pressure and results in gas compression being needed for injection and withdrawal during different parts of the trading cycle. The NTS gas is injected into the cavern dry, however moisture is picked up during storage and this needs to be removed before the gas is re-injected into the NTS.
  The commercial and strategic reasons for underground gas storage are understood and widely reported. Some of the key design issues such as the choice of compressor, compressor driver and dehydration technology are important decisions and as they are long lead items need early decisions. Another technical area that needs special consideration is the amount of water that will be picked up in the cavern, as this sets the design for the hydrate control and corrosion control strategies.
  This paper gives a brief overview of these two projects, the wider planning and environmental issues, and finally covers some project specifics