Page 295 - Fundamentals of Enhanced Oil and Gas Recovery

Enhanced Oil Recovery (EOR) in Shale Oil Reservoirs 283

Table 9.2 Performance of Water Injection in Reservoirs Located in China [1]
Injection Field Name Permeability Oil Performance
(mD) Viscosity
(cP)
Pulsed An 83, 0.17 1.01 When shut-in, p reduced sharply,
Chang 7 fw not reduced
Asynchronous An 83, Oil production increased
Chang 7
Huff-n-Puff 1 An 83, Oil production increased
Chang 7
Huff-n-Puff 2 An 83, Performance not as good as Huff-n-
Chang 7 Puff 1
Huff-n-Puff 3 An 83, Six wells had one cycle and two
Chang 7 wells had two cycles.
Neighboring nonhuff-n-puff
wells outperformed huff-n-puff
wells. The second cycle
performed not as good as the
first cycle
Huff-n-Puff 4 Chang 6 0.54 4.67 Oil production rate increased. The
scenario was performed for
7 days soaking and well spacing
300 m
Huff-n-Puff 5 0.1 1 Oil production increased from
0.9 to 5 t/day
p, pressure; fw, fractional flow to water.

attracting researchers’ attention. One of the reliable natural gas resources is a shale gas
reservoir. Wood et al. (2011) argue that development of shale gas production as the
huge potential energy resource is a part of clean-burning fossil fuel production, espe-
cially, in many countries where other fossil fuel resources are becoming depleted
[60,62]. Statistical forecasts reveal that the consumption of natural gas is anticipated to
triple by 2035 and large shale gas reservoirs throughout the world have raised expecta-
tions for cheap energy and reliable energy supply [63]. Hydraulic fracturing is the key
technology that has enabled shale gas development. Vidic et al. [64] argue that in
1
hydraulic fracturing operations, a significant amount of fracturing fluid [water and
2
proppants ] is injected under high pressure into low-permeability shale formations to
induce fracturing and improve the mobility of natural gas. Large-scale production of

1
Fracturing fluid: “Fracturing fluid is a special type of fluid that is injected into a wellbore to induce fractures to
facilitate access to the oil and gas resources” [65].
2
Proppants: “Proppants are sand or other granular substances injected into the formation to hold or prop open the
formation fractures created by hydraulic fracturing” [65].