Polymer Injection Start-up in a Brown Field - Injection Performance Analysis and Subsurface Polymer Behavior Evaluation
M. Spagnuolo, M. Sambiase, F. Masserano, V. Parasiliti Parracello, A. Lamberti and A. Tiani
Event name: IOR 2017 - 19th European Symposium on Improved Oil Recovery
Session: Pilot & Field Cases
Publication date: 24 April 2017
Info: Extended abstract, PDF ( 5.63Mb )
Price: € 20
A robust analysis of a polymer flooding inter-well pilot start-up in a brown oil field was performed. The objective was to analyze the polymer injection performance to verify the in-situ preservation of the injected viscosity, key condition for the expected EOR effect. The adopted workflow focused on the integration of different analyses. Indeed, several phenomena may occur during polymer injection, such as complex injectivity behavior due to polymer non-Newtonian rheological nature, formation damage caused by particles adsorption, fractures opening, and mechanical degradation of the solute. Our injection performance analysis considered the following aspects: literature studies, polymer laboratory tests, shear stress through perforation evaluation, diagnostic plots, injectivity test interpretation, well test analysis, and fracturing investigation. Eventually, numerical simulations allowed us to integrate the different disciplines, thoroughly capturing the subsurface polymer behavior. Main conclusion is that injection under fracturing conditions occurred during pilot start-up. These small-scale fractures are localized in the near-wellbore zone and lead to a satisfactory well injectivity. Furthermore, no evidence of mechanical degradation was detected. The evaluation of the subsurface polymer behavior during an inter-well pilot is crucial to verify the correct polymer injection process. Robust reservoir monitoring is ongoing and preliminary promising effects are now being shown.