Hydraulic Fracturing
HYDRAULIC FRACTURING
In addition to the recovery processes featured in this series of drawings, hydraulic fracturing is included as an example of
technologies that contribute to improvements in oil production.
Hydraulic fracturing is used to create additional passageways in the oil reservoir that can facilitate the flow of oil to a producing
well. “Tight” reservoirs, those whose oil-containing rocks have restricted pore volume and connectivity that impede the flow
of oil through the reservoir, are commonly fractured by injecting a fluid containing sand or other “proppant” under sufficient
pressure to create fractures in the rock through which the oil can more easily flow. Care is also taken to contain the fracturing
within the oil reservoir to avoid intersecting adjoining aquifers that would introduce excess water into the oil-producing zone.
DOE research has developed several alternative fracturing techniques designed to accomplish specific tasks:
Tailored pulse fracturing is employed to control the extent and direction of the produced fractures. Precise quantities of solid
rocket fuel-like propellants are ignited in the wel bore to create a control ed pressure "pulse" which creates fractures in a more
predictable pattern.
Foam fracturing, using foam under high pressure in gas reservoirs, has the advantage over high-pressure water injection
because it does not create as much damage to the formation, and wel cleanup operations are less costly.
CO /sand fracturing increases production by eliminating much of the inhibiting effects of pumped fluids such as plugging by
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solids, water retention, and chemical interactions.
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