Geostock
| Company type | Subsidiary |
|---|---|
| Industry | Engineering, Energy storage |
| Founded | September 23, 1965 |
| Founder | BP France, Shell, ELF Union, Total (initial shareholders) |
| Fate | Integrated into Vinci Construction group |
| Headquarters | France , France |
Area served | International |
Key people | Pascal Baylocq (Chairperson, 2017–2025) |
| Products | Subterranean energy storage solutions (liquid, liquefied, gaseous hydrocarbons, hydrogen, compressed air) |
| Owner | Vinci Construction group |
| Parent | Vinci Construction group |
Geostock is a French engineering firm established in 1965, currently integrated within the Vinci Construction group. The company focuses on subterranean energy storage solutions, handling liquid, liquefied, and gaseous hydrocarbons, as well as hydrogen and compressed air. Its operations extend internationally through various subsidiaries.
Establishment
Amid the aftermath of the 1956 Suez Crisis and the oil crises of the 1970s, prominent French oil refiners, with governmental backing, founded Geostock on September 23, 1965. Initial shareholders included BP France, Shell, with later participation from ELF Union and Total.
Geostock’s first major undertaking involved creating its inaugural salt cavern storage facility, known as Géosel, located in Manosque. This site currently consists of 30 salt caverns. Since 1969, Geostock has been responsible for managing this installation along with its connected pipeline infrastructure.
In 1971, the company expanded its portfolio by developing the Lavéra facility near Martigues, focusing on mined caverns for LPG storage under the Géogaz initiative.
Growth and Development
Throughout the 1970s, Geostock broadened its scope by designing, constructing, and operating underground storage installations and acquiring businesses within the same industry sector.
In 1972, Géomines initiated a diesel storage operation utilizing a former iron ore mine at May-sur-Orne (Normandy), which remained active until its closure in 1993. This approach involved repurposing abandoned mining cavities for geological storage purposes.
The firm’s international footprint began with Loenhout in 1975, conducting its first geophysical survey aimed at natural gas storage within porous geological formations by developing an aquifer-based storage system.
The Geovexin site near Paris opened in 1977 as a propane storage facility using mined cavities; these were originally excavated for heavy fuel oil. This installation functioned for three decades before ceasing operations in 2012. That same year, Geostock also constructed a mined-cavity propane storage facility at Donges.
By 1984, Géogaz had incorporated commercial and chemical butane storage within mined caverns. Two years later, in 1986, a salt cavern butane storage site was commissioned in Mohammedia, Morocco; an additional cavern was added there in 2013.
In 1989, a collaboration with Gaz de France led to the design of the Manosque salt cavern natural gas storage site, which became operational in 1993. In 1996, Butagaz was established at Sennecy-le-Grand featuring propane storage in mined caverns. A year later, in 1997, Geostock formed Gester—a joint venture with Simecsol—focused on soil remediation.
The acquisition of German firm Untergrundspeicher und Geotechnologie Systeme (UGS) in 1999 doubled Geostock’s turnover and shifted the company’s primary focus toward underground natural gas storage rather than oil.
Vinci increased its ownership stake in Geostock by purchasing Total’s 40% share in 2011, raising its holding to 90%. By 2021, Vinci had fully acquired Geostock, making it a subsidiary under VINCI Construction Grands Projets.
In 2014, Geostock designed and implemented a liquid hydrocarbon storage facility within mined caverns at Jurong, Singapore; this installation remains active today.
Also noteworthy is Geostock’s leadership role in the European Hystories project initiated in 2021—a European Union-funded scientific research program exploring hydrogen storage solutions within porous geological formations such as depleted reservoirs and aquifers. The consortium comprised universities, research centers, engineering companies, and energy operators working together to develop technical methodologies and socio-economic evaluations for geological hydrogen storage. This project spanned from January 2021 through June 2023.
Chairpersons
- 1965–1975: Etienne Schlumberger
- 1975–1985: André Clerc-Renaud
- 1985–1992: Claude Tourolle
- 1992–2007: René Le Marchand
- 2007–2017: Jean-Michel Noé
- 2017–2025: Pascal Baylocq