In this sweet spot, hydraulic fracture technology is the major measure to enhance gas production, and it has been widely used in modern petroleum industry, especially in the unconventional oil and gas area, for instance tight sandstone reservoir.
Furthermore, even though tight sandstone gas reservoirs present large gas-bearing areas, their enrichment is controlled by sweet spots and fractures, and they show signs of partial accumulation (Zhao et al. 2004; Yang et al. 2007).
The low magnitudes of minimum horizontal stress indicate less pressure required for hydraulic fracturing (i.e., fracture stimulation sweet spots).
Comprehensive evaluation should focus on source rock, reservoir, overpressure, and fracture for geological "sweet area," on buried depth, rock compressibility, and stress anisotropy for engineering "sweet area," and on resources scale, buried depth and surface conditions for economic "sweet area".
Fracturability Index (FI) is a concept developed for hydrocarbon exploration, particularly useful for fracture placements and sweet spot identification in shale reservoirs.
Pavement Slanted and Enchanted (1992) A shy album bristling with self-assurance, Pavement's debut shrouded its shrewd lyrics in slacker nonchalance and fractured its taut, sweet melodies into shards.
Production is enhanced significantly if hydraulic fractures can connect to sweet spots with enhanced permeability due to the presence of micro- (and induced) fractures.
Purple colours indicate highly strained fractures which indicate geomechanical sweet spots.
At present, priority should be given to favorable source rock, reservoir, overpressure, fracture, and local structure of geological "sweet area," and pressure coefficient, brittleness, crustal stress, and buried depth of engineering "sweet area" (Table 2).
It sounded sweet but just a bit prickly, like fractured Satie.
