Project: Reusing depleted oil and gas fields for CO2 sequestration

Acronym	RETURN
Project Topic	The RETURN project consortium, which was initiated by industry, consists of leading R&D providers in collaboration with several major oil and gas operator companies. The project focuses on unlocking the potential for CO2 storage in depleted oil and gas reservoirs. These sites are promising, as they are well characterized from previous oil and gas activities, and they have large pressure margins for safe storage. There are, however, some technical challenges related to storage in such sites. The low pressure in the depleted reservoirs results in strong cooling and potential freezing of the well and near-well region due to the Joule-Thomson effect and associated phase changes of the CO2. This jeopardizes not only injectivity, but also near-well stability and well integrity. Large depletion can be accompanied by strong stress concentration and hysteresis effect upon re-pressurisation, added to the development of thermal stress. Today's available solutions include heating of the CO2 and gas phase injection (dictating a high number of injectors). This is both expensive and emission-intensive. Novel solutions are thus required, which will be searched for and researched in the RETURN project, and which will ultimately enable safe and cost-efficient re-use of depleted reservoirs for long-term CO2 storage. The targeted research required to reach this goal is addressed in three main scientific work packages focusing on: (i) Coupled well-reservoir flow modelling, (ii) Near wellbore processes, and (iii) Wellbore integrity. The work, comprising both experiments, numerical modelling and larger scale field tests, will focus on understanding how CO2 flows down the well and into the depleted reservoir, and identifying safe operational windows both with respect to the near-well region and wellbores. The output of the project will be several scientific publications, as well as a handbook for industry with input for front-end engineering.
Website	visit project website
Network	ACT
Call	ACT Third Call

Project partner

Number	Name	Role	Country
1	SINTEF AS	Coordinator	Norway
2	Utrecht University	Partner	Netherlands
3	TNO	Partner	Netherlands
4	Technical University of Bergakademie Freiberg	Partner	Germany
5	University of Cambridge	Partner	United Kingdom
6	Shell Global Solutions International B.V.	Partner	Netherlands
7	Equinor ASA	Partner	Norway
8	Wintershall Dea	Partner	Germany
9	EBN B.V.	Partner	Netherlands
10	OGTC	Partner	United Kingdom
11	Containment & Monitoring Institute	Partner	Canada
12	Lundin	Partner	Norway
13	Eni S.p.A.	Partner	Italy
14	Spectrum H2	Partner	Canada
15	Neptune Energy Netherlands B.V.	Partner	Netherlands
16	Chrysaor Production	Partner	United Kingdom
17	Caledonian Midstream Corporation	Partner	Canada
18	bp International Ltd	Partner	United Kingdom
19	Canada's Oil Sands Innovation Alliance	Partner	Canada