Defining the wettability state of mixed wet reservoirs: Measurement of critical capillary pressure for crude oils

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:468110

Basu, S; Sharma, M M ^[1]

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1. Univ. of Texas, Austin, TX (United States)

The wetting properties of crude oils are measured using a new technique that measures the capillary pressure required to rupture thin films of brine on mineral substrates. An Atomic Force Microscope is used to record the force required to rupture thin brine films on quartz surfaces. Low values of critical capillary pressure imply that large sections of the reservoir may be rendered mixed-wet because the brine films are unstable. High critical capillary pressures imply water-wet reservoir. The technique also provides a direct indication of the height above the water table, i.e., the capillary pressure at which mixed-wet conditions may be expected in the reservoir. Data presented for a pure hydrocarbon (octadecane) and a Prudhoe Bay crude oil indicate that the critical capillary pressure varies with pH, salinity oil composition and mineralogy. The pH and salinity dependence is explored in some detail in this paper.

• OSTI ID: 468110
• Report Number(s): CONF-961003--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
58 GEOSCIENCES
CAPILLARY FLOW
OIL FIELDS
PETROLEUM
PRODUCTION
PRUDHOE BAY
RESERVOIR ENGINEERING
RESERVOIR PRESSURE
RESERVOIR ROCK