Abstract: The declining US oil production was turned around in the last decade due to the oil extraction from shales which was made prossible by horizontal drilling and multi-stage hydraulic fracturing. However, more than 90% of the oil remain in shale reservoirs after the primary production due to extreme low permeability (< 1 µd) and porosity (< 5%). The oil recovery can be increased by energizing the oil, increasing oil permeability in the matrix, and enhancing the microfracture conductivity. Chemical blend and gas mixture huff-n-puff energize the oil and increase near fracture matrix permeability. Hydrothermal reactions can generate proppants in situ and increase the conductivity of microfractures. Nanoparticle encapsulated acid treatments can etch the microfractures selectively and increase microfracture conductivity. Laboratory evaluation of these processes would be discussed in this presentation.