Abstract: Petrophysical Properties and OOIP from a Predominantly Old E-log Suite, Huntington Beach Field, California
BEDARD, ROBERT, EarthQuest Technology, Inc, Bakersfield, CA; DEBORAH OLSON, Digital Petrophysics, Inc., Bakersfield, CA
Quantitative values for reservoir properties are an essential part of a reservoir
characterization. However, obtaining this information is a challenge in many older fields
that lack modern logs. Reliable data for reservoir properties were obtained for the Upper
Main Zone at Huntington Beach through the development of an empirical model for clay and
shale volume, porosity, and permeability calibrated to core data and to the modern log
suites that were present. Water saturation for OOIP calculations was derived from a
capillary pressure-based model referenced to the rock properties calculated from the
empirical model. First, the modern logs were analyzed using the clay volume and Dual Water
saturation models incorporated in the Symbiolog log analysis system. Parameters were
verified and calibrated to core data where available. Clay volume was derived only
from SP supplemented by GR, curves which were available in the predominating E-log and IES
log suites. Then, effective porosity was derived from clay volume. Silt index was
calculated from the shallow resistivity, and a permeability curve was developed from the
silt index, calibrated to laboratory air permeability from core. Available laboratory
capillary pressure curves were analyzed and incorporated into a model that assigned a
value of Swi to each level in the reservoir based on its computed properties. The entire
E-log only model was constructed within the user-programming module of Symbiolog. The
reservoir properties were summed and used to generate volumetrics, thus producing the
first measure of OOIP in this reservoir based on quantitative well log data. This
methodology is more interpretive
than modern log analysis techniques and the best results
are obtained by involving both geological and petrophysical expertise in the execution of
the analysis.
AAPG Search and Discovery Article #90911©2000 AAPG Pacific Section and Western Region Society of Petroleum Engineers, Long Beach, California