SAMPLE PROJECTS
I. LIGHT OIL AND MISCIBLE FLOODING PROJECTS
CORDONA LAKE, FULLERTON AND MEANS - WEST TEXAS - CO2 FLOODS
TCA was retained by EXXON USA to study the merits of
injecting carbon dioxide into several West Texas carbonate fields. In each of
three separate projects, TCA used its miscible flood simulator to study the
sensitivity of predicted recovery performance to variations in process
variables such as CO2 slug size, injection WAG (water-alternating with-gas)
ratio, waterblocking function, and permeability reduction mechanism. Two and
three-dimensional simulations were then made to investigate the effects of
stratification and areal sweep efficiency on the recovery performance of
pattern flood symmetry elements.
CARSON CREEK NORTH - ALBERTA, CANADA - HYDROCARBON
MISCIBLE FLOOD
TCA was commissioned to study the likely performance of
LPG injection into the Carson Creek North reservoir for Mobil Oil Canada, Ltd.
This study involved a history match of the primary and waterflood performances
in this 300 million-barrel accumulation, and predictions of future performance
for alternatives of continued waterflooding and miscible flooding.
Valuable insights relating to the interaction of the local reservoir geology
and the process characterization were developed over the course of the study.
For example, simulation results suggested that areas of the carbonate reef
reservoir might respond poorly to LPG flooding due to strong gravity override
effects, even though these same regions responded well to waterflooding.
LOWER LAGUNILLAS - LAKE MARACAIBO, VENEZUELA - IMMISCIBLE
GAS FLOOD
TCA was retained by MARAVEN to evaluate the relative
merits of injecting either produced gas, lean gas or inert gas into the Lower
Lagunillas Block III/IV reservoir in Venezuela. Performances expected from
alternative gas injection rates and production policies were evaluated using a
geological and petrophysical model prepared by TCA and MARAVEN. This was a
true compositional problem, involving stripping of intermediates from oil
previously bypassed by the displacement front, as well as shrinkage of oil in
the downdip region. TCA's compositional simulator was used in this work which
culminated with a recommended operating policy for MARAVEN and definition of
infill drilling locations in this 2 billion barrel field.
CORNELL UNIT WASSON SAN ANDRES - WEST TEXAS - CO2 FLOOD
The 200 million barrel Cornell Unit in the giant Wasson San Andres Reservoir
is in an advanced waterflood stage. TCA was retained to evaluate the potential
of the Unit for CO2 miscible flooding. The geological and process models
needed for simulation were developed in the usual fashion, and alternative CO2
enhanced oil recovery processes were evaluated using representative pattern
elements. The results of the pattern element simulations were then scaled to
generate full field project projections using the TCA program FLDPROJ. This
program generates projections of field performance that are often more
accurate than full-field simulations, but cost a small fraction of the cost of
full-field simulations. TCA has used this scaling technique in study projects
for Shell Canada, Mobil U.S.A. and Mobil Canada, as well as for the Cornell
Oil Company study described here.
II. HEAVY OIL PROJECTS
SOUTH BELRIDGE FIELD - CALIFORNIA - STEAMFLOOD
TCA was retained by Belridge Oil Company to
study the potential for improving oil recovery by steam injection from the
Upper and Lower Tulare zones in the South Belridge field. The study involved
working closely with the Belridge staff to develop a suitable geological model
of the productive intervals for input to TCA's Steamflood reservoir simulator.
This work involved reproducing the historical performance of several steam
pilots with the simulator prior to using the simulator to predict the likely
future oil recovery and thermal efficiencies associated with alternative
steamflood well patterns and well spacings.
The simulation results were used by Belridge staff members as a basis for
comparative economic analyses, which led to the recognition and implementation
of a steamflood strategy in the subject reservoir.
PRIMROSE/IPIATIK BITUMEN ACCUMULATION - ALBERTA, CANADA -
CYCLIC STEAM
TCA was retained by Alberta Energy Company, Ltd. and its working interest
partners to design a pilot steam injection
project in the Upper McMurray bitumen sands in an area north of Cold Lake,
Alberta. TCA's Steamflood reservoir simulator was first calibrated by matching
cyclic-steam test results using site-specific geology and hydraulically-
induced fractures prior to predicting ultimate recovery efficiency with the
cyclic steam process.
The cyclic steam process was shown to be capable of achieving commercial rates
of bitumen recovery in the Primrose/Ipiatik area. As a result of the
encouraging predictions, a multi-million dollar pilot project was installed
during 1983 using simulation results as a design-basis. Surface equipment was
sized using adjusted simulation fluid rates and wells were drilled using an
inter-well spacing distance and pattern configuration which accounted for the
heating patterns predicted to develop after multiple steam cycles. This
project is currently in operation.
NORDHORN TAR-OIL FIELD - FEDERAL REPUBLIC OF GERMANY -
STEAMFLOOD
TCA was retained by a German Consortium of oil companies with
project funding provided in part by the European Economic Community to devise
a plan to recover extremely viscous tar-oil from a reservoir in northwest
Germany. After calibration of TCA's Steamflood model using cyclic steam test
results at Nordhorn, the model was used to forecast the recovery efficiency
which might be realized by alternative steamflood pilot designs.
The most promising plan involved the hydraulic inducement of near-horizontal
fractures between an injector and producer well pair with initially-high rates
of steam injection. The well spacing, steam injection rates and well pattern-
type were all design questions for the pilot steam project.
EMLICHHEIM - FEDERAL REPUBLIC OF GERMANY - STEAMFLOOD
TCA has been commissioned on several separate occasions by
WINTERSHALL AG and MOBIL AG to provide reservoir engineering services for both
on-going steam pilot and planned steam expansion projects in the Emlichheim
field. After tuning of TCA's Steam flood simulator by reproducing 40 years of
primary depletion, hot water flooding and recent steam injection history, the
simulator was used to predict future oil recoveries in response to continued
steam injection and aquifer influx.
The simulator was used to select a reasonable rate of steam injection in the
on-going pilot area and to determine a reasonable time to convert from steam
injection to water injection. In the expansion areas, simulation results were
used to recognize infill drilling locations, to design both well patterns and
steam injection rates, and to establish a reasonable operating policy under
conditions of active aquifer influx.
KERN RIVER - CALIFORNIA - STEAM IN HORIZONTAL WELLS
TCA was commissioned during the period 1979 to 1983 by BARBER OIL and CORNELL
HEAVY OIL PROCESS to evaluate the feasibility of steam displacement in the
Kern River series of sediments using a unique set of horizontal wells which
have been drilled from a shaft and positioned along the base of the heavy oil
column. Site-specific geology was input to TCA's Steamflood simulator and
predictions of oil recovery performance and thermal efficiency were made using
different well geometries (well spacings and well lengths) to design an
optimal pilot configuration and operation mode.
The project design installed in the Kern River field was based upon the
simulation comparative predictions. The project was highly successful in a
technical sense and it was operated for several years prior to its shut-in
during 1984.