Foam to Optimize Gas Injection Development Scheme: Labs Evidence and Simulation Forecast of Gas Control Efficiency
C. Topini, M. De Simoni, L. Dovera, F. Rotelli, M. Bartosek, A. Abrar, D. Renna and E. Braccalenti
Event name: IOR 2019 – 20th European Symposium on Improved Oil Recovery
Session: Modelling Foams
Publication date: 08 April 2019
Info: Extended abstract, PDF ( 2.61Mb )
Price: € 20
The present work aims to assess the potentialities of foam in mitigating the gas injection issues foreseen during water alternating gas injection (WAG) scheme, such as premature gas breakthrough at producers and gas cycling. Main objective is to demonstrate foam efficiency for an offshore oil field by integrating extensive dedicated laboratory testing, accurate reservoir modeling and preliminary facilities feasibility, key steps for field EOR application. The adopted workflow focused on the close integration of different analyses allowing the characterization of the different phenomena and criticalities that may arise during foam injection application. Lab tests started with an accurate in bulk surfactants screening to identify the best performer for the candidate reservoir. Eleven foamers were tested and the best one was selected for the following core flood tests. Core flood tests were performed at reservoir pressure and temperature conditions. Berea cores were first flooded under WAG scheme and then adding also a buffer of the optimized foamer solution (FAWAG scheme). Core flood results showed that injection of foam decreases gas and fluid mobility. The reduction of foamer performance in presence of oil was also evaluated. Core floods results were matched and main foam parameters were obtained to perform field scale foam injection simulations. Two sets of parameters matching the available lab data were defined. Both of them were applied providing an optimistic and a pessimistic scenario. Field scale simulations highlighted that foam injection provided a positive effect on field oil production and GOR reduction; the best scenario highlights additional reserves of about 3% after 15 years of production associated with a 30% GOR reduction. The pre-feasibility study identified the most suitable injection scheme and it assessed no major show stoppers from flow assurance. The preliminary cost estimate per incremental barrel associated to the implementation of the technology was also done. Main conclusion of the study was that laboratory tests, numerical simulations and preliminary facilities assessment confirm the potentialities of foam injection for the candidate reservoir. An integrated and comprehensive workflow was set-up to estimate the efficiency and benefits of foam injection. The presented workflow is currently being applied to assess foam injection potentiality for other fields within the company’s portfolio.