Perpustakaan Digital ITB

CO? huff-n-puff (HnP) is an enhanced oil recovery (EOR) method suited to hydraulically fractured shale oil reservoirs, where matrix permeability is too low for continuous gas injection. This study applies CO? HnP as an early-stage strategy, right after hydraulic fracturing and initial flowback, rather than after primary depletion as commonly assumed in prior work. A synthetic Bakken-analog shale oil reservoir was built and simulated in tNavigator using a 6-component compositional fluid model based on Eagle Ford data. A 3³ full-factorial design of experiment tested injection rate (500-2,000 MSCFD), soaking time (7-30 days), and number of cycles (1-3) across 27 scenarios. Cumulative oil production ranged from 10.176 to 15.460 MSTB against a base case of 11.155 MSTB. Number of cycles had the strongest effect on both oil recovery and CO? storage, followed by injection rate, while soaking time showed a trade-off, reducing oil recovery but increasing CO? storage. The optimum scenario (2,000 MSCFD, 7-day soak, 3 cycles) yielded 15.460 MSTB of oil (+38.6%) and 32.650 metric tons of CO? stored, with molecular diffusion confirmed as a primary recovery mechanism.