Case study of thief zones in a California waterflood

Conference · Wed Jan 01 04:00:00 EST 1975 · Soc. Pet. Eng. AIME, Pap.; (United States)

OSTI ID:6685734

Felsenthal, M; Gangle, F J

The thief zone, a common California waterflooding phenomenon, is analyzed from field data collected over a period of 6 yr in the 6,000 to 8,500-ft deep Pico and Repetto formation zones (lower Pliocene) of the San Miguelito field, Ventura County, California. A study of step-rate injectivity tests and injection well profiles indicates that the theif zones had been generated when injection pressures exceeded the parting pressure. Pressure parting gradients ranged from 0.44 to about 0.60 psi/ft in the early life of the flood when reservoir pressure was low and from about 0.60 to 0.71 psi/ft after the reservoir became repressured. Results of 2 well-to-well tracer tests and 10 casing collapses in wells offsetting injection wells indicate that thief zones can grow to well-to-well dimensions. The thief zones are parallel to the bedding planes. Twenty-seven thief zone remedial efforts were attempted with limited success. The best remedy for the problem is to prevent thief zones from being initiated or, if they have been, to reduce injection pressures to below the parting pressure. (22 refs.)

• Research Organization: Continental Oil Co.
• OSTI ID: 6685734
• Report Number(s): CONF-7504112-
• Conference Information: Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Journal Volume: SPE-5363
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
CALIFORNIA
ENERGY SOURCES
ENHANCED RECOVERY
FEDERAL REGION IX
FLUID INJECTION
FOSSIL FUELS
FUELS
GEOLOGIC DEPOSITS
LOSSES
MINERAL RESOURCES
NORTH AMERICA
OIL FIELDS
OIL WELLS
PETROLEUM
PETROLEUM DEPOSITS
PLUGGING
PRESSURE GRADIENTS
PRESSURIZING
RECOVERY
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USA
WATERFLOODING
WELLS