Enhanced Oil Recovery (EOR) is a technique for increasing the amount of crude oil that can be extracted from an oil field. Following natural oil production and water injection, respectively primary and secondary oil recovery, the recovery of oil is enhanced with tertiary techniques like injection of CO2, surfactants, polymer injection, etc. or a combination. With polymer injection water soluble polymer is injected into the oil-bearing formation to improve the displacement of the oil and thereby increase the oil recovery. Typically, the polymer is injected in one or more injection wells, displacing the oil to the producing wells. Application of the method, however, is limited to oil reservoirs with relative low temperature and salinity.

Wintershall is preparing for an EOR pilot project to test the application of their newly developed biopolymer, Schizophyllan, in one of their oil fields. This polymer can be applied at significant higher temperature and salinity than commercially available polymers. To advance and optimize enhanced oil recovery techniques it is essential to know the spatial propagation and distribution of the injected fluids in the subsurface. To monitor the distribution of injected fluids in the subsurface, we propose here to develop and test electromagnetic geophysical methods, based on 3D simulations and newly collected natural source and controlled source electromagnetic data.

Time frame (experiment)

• Phase I:  10/2012 - 08/2013
• Phase II: 01/2014 - 12/2015
• Phase III: 01/2016 - 04/2018

Funding

• Wintershall Holding GmbH

Principal Investigators  

• Oliver Ritter (GFZ Potsdam)

Personnel

• Kristina Tietze (GFZ Potsdam)
• Cedric Patzer (formerly GFZ Potsdam)

Cooperations

• Wintershall Holding GmbH (biopolymer@wintershall.com)

Methods & Equipment 

• Magnetotellurics and Controlled Source Magnetotellurics
• Spam Mk IV real time instruments (GFZ)
• Induction coils (Metronix)
• Ag/AgCl electrodes (GFZ)
• CSEM transmitter (Metronix)

Publications/Results

• Tietze, K., Ritter, O., Patzer, C. & Veeken, P. (2017). Borehole CSEM for HC-Saturation Monitoring in the Bockstedt Oilfield (Onshore NW Germany). SPE Reservoir Evaluation & Engineering-Formation Evaluation, 
• Patzer, C., Tietze, K. and Ritter, O. 2017 Time-lapse CSEM inversion using focusing regularization techniques for reservoir monitoring. SEG Technical Program Expanded Abstracts 2017: pp. 5870-5874.
• Tietze, K., Ritter, O. & Veeken, P. (2017). Erratum/Corrigendum: Controlled-source electromagnetic monitoring of reservoir oil-saturation using a novel borehole-to-surface configuration. Geophysical Prospecting, doi:10.1111/1365-2478.12550.
• Patzer, C., Tietze, K. & Ritter, O. (2017). Steel-Cased Wells in Three-Dimensional Controlled Source EM Modelling. Geophysical Journal International, 209(2), pp. 813-826, doi: doi.org/10.1093/gji/ggx049.
• 87th Annual Meeting, Houston, TX, USA. Expanded abstract, accepted for oral presentation.
• Tietze, K., Ritter, O., Patzer, C. & Veeken, P. (2016). Borehole CSEM for HC-Saturation Monitoring in the Bockstedt Oilfield (Onshore NW Germany). ADIPEC The Abu Dhabi International Petroleum Exhibition & Conference, Abu Dhabi.
• Tietze, K., Patzer, C., Ritter, O., Veeken, P. & Verboom, B. (2016). 3D inversion of controlled-source electromagnetic data in the presence of steel-cased wells. 78th EAGE Conference and Exhibition 2016, Reed Messe Wien, Austria, 31 May – 2 June 2016. Expanded abstract, 5 pp.
• Tietze, K., Ritter, O. & Veeken, P. (2015). Controlled-source electromagnetic monitoring of reservoir oil-saturation using a novel borehole-to-surface configuration. Geophysical Prospecting, 63(6), pp. 1468-1490, doi: 10.1111/1365-2478.12322.
• Tietze, K., Ritter, O. Patzer, C., Veeken, P. & Verboom, B. (2015). Borehole Controlled Source Electromagnetic (CSEM) Surveying for Monitoring HC-Saturation in the Bockstedt Oilfield (NW Germany). ADIPEC The Abu Dhabi International Petroleum Exhibition & Conference, Abu Dhabi.
• Tietze, K., Patzer, C., Ritter, O. Veeken, P. & Verboom, B. (2015). CSEM for monitoring reservoir oil-saturation using a borehole-to-surface set-up. Society of Exploration Geophysicists International Exposition and 85th Annual Meeting, New Orleans, LA, USA, 18 - 23 October 2015. Expanded abstract, 4 pp.
• Tietze, K., Ritter, O., Veeken, P. & Verboom, B. (2015): CSEM Monitoring of Reservoir Oil-saturation Using a Novel Borehole-to-surface Configuration - Proceedings, 77th EAGE Conference and Exhibition, Madrid, Spain, 1 – 4 June 2015.
• Tietze, K. & Ritter, O., (2014). Electromagnetic monitoring of the propagation of an injected polymer for enhanced oil recovery in Northern Germany, 76th EAGE Conference & Exhibition 2014, Amsterdam, The Netherlands, 16 – 19 June 2014.

Acknowledgement

• Magnetotelluric instruments provided by the magnetotelluric component of the geophysical instrument pool (GIPP-MT)