Page 151 - Primer on Enhanced Oil Recovery

Chemical EOR
12

Abstract

Currently, up to 90% of oil (it is very much region dependant) is produced using water-
flooding. The amount of water injected into the reservoir significantly exceeds the level
of oil produced. However, the average level of oil recovery coefficient (recovery factor)
does not exceed 50%, i.e. up to 50% of oil is left in the formation after waterflooding.
This shows the urgency in finding new technologies to increase oil recovery from the
reservoirs. Chemical Enhanced Oil Recovery allows to modify water properties, induce
chemical reactions in the reservoir, change reservoir fluid properties and transform fluids-
rocks interactions in order to increase oil recovery.

Chapter outline

12.1. Polymer flooding 142
12.1.1. Polymer flooding applicability criteria 146
12.1.2. Polymer flooding completed projects 147
12.1.3. Implementation Technology 149
12.2. Alkaline flooding 150
12.2.1. Alkaline flooding applicability criteria 153
12.2.2. Alkaline flooding completed projects 157

Currently, up to 90% of oil (it is very much region dependant) is produced using
waterflooding. The amount of water injected into the reservoir significantly exceeds
the level of oil produced. However, the average level of oil recovery coefficient
(recovery factor) does not exceed 50%, i.e. up to 50% of oil is left in the formation
after waterflooding. This shows the urgency in finding new technologies to increase
oil recovery from the reservoirs. The technical ambiguity in the water flooding is
that reservoir pressure maintenance requires the injection of large volumes of water,
while the injection of a large amount of water leads to the creation of the instability
of the displacement front and early breakthrough of water to the production wells.
Overcoming this problem is possible with the use of chemical compounds that
change the rheological properties of the fluid and surface interaction energies. In
some cases both methods are employed. In all cases, if used appropriately, chemical
water injection can provide high reservoir pressure and the displacement front
stability.

Primer on Enhanced Oil Recovery. DOI: https://doi.org/10.1016/B978-0-12-817632-0.00011-6
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