Process for improving waterflood performance in heterogeneous clay-sensitive formations

Patent · Tue Oct 23 04:00:00 EDT 1984

OSTI ID:6143083

Sydansk, R D

A freshwater containing polyvalent cations and relatively few or no monovalent cations is injected into a heterogeneous clay-sensitive subterranean hydrocarbon-bearing formation via a well. The polyvalent cation solution displaces the saline connate water in the near wellbore environment and contacts a first water-sensitive clay. The polyvalent cation solution exchanges polyvalent cations for monovalent cations in the first clay causing little clay damage while producing a monovalent cation solution which is thereafter displaced into the far wellbore environment. The monovalent cation solution contacts a second water-sensitive clay in the relatively highly permeable zones of the far well-bore environment to effect clay damage and reduce the permeability of the highly permeable zones in the far wellbore environment. The process results in improved waterflood sweep efficiency.

• Assignee: Marathon Oil Company
• Patent Number(s): US 4478283
• OSTI ID: 6143083
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
CATIONS
CHARGED PARTICLES
CHEMICAL COMPOSITION
CLAYS
DISPLACEMENT FLUIDS
ENGINEERING
ENHANCED RECOVERY
FLUID INJECTION
FLUIDS
HETEROGENEOUS EFFECTS
ION EXCHANGE
IONS
OIL WELLS
PERMEABILITY
RECOVERY
RESERVOIR ENGINEERING
RESERVOIR ROCK
SWEEP EFFICIENCY
VALENCE
WATERFLOODING
WELLS