Upscaling of Microgel Treatment in Fractured Reservoirs: Experimental and Simulation Investigation

Excess water production through fractured reservoirs is one of the most serious problem for sweep efficiency and oil recovery factor. Gel treatment have been widely used to plug the fractures and reduce excess water production to improve macroscopic sweep efficiency. Field studies showed that gel treatment can be successfully applied in mature oilfield and fracture reservoirs to reduce water production and improved oil recovery factor. The objective of this paper is to understand the preformed particle gel (PPG) propagation through fractures by conducting laboratory work and upscaling these data to filed scale to investigate which parameters can be more affected gel treatment. The semi-transparent fracture model was made of oil-wet carbonate core and acrylic plates with 1.5 mm fracture width. Seawater was used for brine flooding and to prepare the swollen gel. The experimental results showed that the preformed particle gel improved the oil recovery by 12% with 20% water cut reduction. The experimental results were history-matched using UTGEL simulator and an excellent agreement between lab data and simulation data was achieved. The simulation results of the filed scale indicated that the PPG concentration and PPG treatment timing are the main PPG design variables and the conformance control improved when PPG concentration increased and when PPG treatment applied early. Upscaling the laboratory results to filed scale provide a deeper understanding of PPG treatment and can investigate the effect of PPG concentration for PPG application in fractured reservoirs. © 2018, Society of Petroleum Engineers