January 27, 1987
UNOCAL
2700 "F" Street
Bakersfield, CA 93301
Attn: Mr. Akbar Sheriff
Dear Akbar,
Thanks for giving me the opportunity to present the
Diatomite Analysis on your well McKittrick Front #415. As
per your request, I have put together a short summary of the
main points which were covered. You will note that I have
included many of the observations which were made from the
dipmeter. In the future, ResTech would be pleased to
process your dipmeters and integrate their interpretation
with the standard Diatomite and Monterey Analysis. In the
event that you decide to purchase this combined service, a
member of ResTech's staff who specializes in dipmeter
interpretation will prepare a full written report of the
results.
I hope that either you or members of your staff will be
able to drop by our computing center, the next time that you
are in Ventura.
Sincerely,
Harold Crawford
HC:pm
DIATOMITE ANALYSIS
INTRODUCTION
This report summarizes the discussion of the Diatomite
Analysis held in the UNOCAL office in Bakersfield,
California on January 26, 1987, on the following well:
UNOCAL
McKittrick Front #415
Cymric
Kern County, California
CUSTOMER OBJECTIVES
The Diatomite Analysis was made to identify potentially
productive zones in the Reef Ridge Diatomite and the
Antelope Shale. In these formations, the non-detrital
silica is in Opal-A and Opal-CT phases. In addition, the
McDonald and Devilwater Shales were examined. The non-
detrital silica is in the quartz phase in these deeper
shales.
METHODOLOGY
1) Use Dual Induction and Neutron/Density log data to
calculate the total fluid-filled porosity of the rock
and the bulk volume of hydrocarbons present within
the pore space.
2) Use the Neutron/Density log data to determine the
crystalline phase of the non-detrital silica.
3) Use the dipmeter to explain any apparent accumulations
of hydrocarbon.
INTERPRETATION OF RESULTS
The silica was zoned as follows based upon observation
of the Neutron/Density log data:
| Depth | Description |
| Surface - 1090 Ft. | Detrital Quartz |
| 1090 Ft. - 1395 Ft. | Opal-A |
| 1395 Ft. - 1580 Ft. | Opal-A and Opal-CT (transition zone) |
| 1580 FT. - 3775 Ft. | Opal-CT |
| 3775 Ft. - TD | Quartz |
1090 Ft. - 1395 Ft.
Low water saturation and heavy crude.
The trapping mechanism is the
unconformity at the top of the
Diatomite.
1395 Ft. - 1580 Ft.
Total water saturation increases.
However, most of this additional water
is associated with the silica phase
change from Opal-A to Opal-CT.
Permeability is far better in this zone
than the zone directly above. Thus,
this zone is probably better than the
pure Opal-A zone directly above.
Hydraulic fracturing will be required
for commercial production.
2660 Ft. - 2915 Ft.
Although water saturation is high, this
zone may be capable of commercial
production in the 150 BOPD range. A
high initial water cut is not expected
since most of the water is bound (clay)
water and water of crystallization.
However, in order to minimize the water
cut, the intervals of highest total
water saturation (2855-2875 ft. 2888-
2896 ft.) should not be perforated. The
dipmeter indicates that the oil is
trapped against an unconformity at 2660
ft. A hydraulic fracturing job will be
required for commercial production.
3480 Ft. - 3700 Ft.
This zone has the lowest total water
saturation of the oil bearing zones
located in the Opal-CT. Since it is the
deepest, it should also have the best
permeability. The dipmeter indicates
that the oil is trapped by a strat trap
which is associated with the decline in
formation dip over the interval 3480 ft.
- 3510 ft. Although some production in
the order of 20 or 30 BOPD can be
expected without a hydraulic fracturing
job, a hydraulic fracturing job will be
required for commercial production since
the silica is in the Opal-CT phase.
3775 Ft. - 3900 Ft.
This accumulation of oil is located at
the top of quartz phase shale. Total
water saturation increases with depth
over the zone suggesting isolation from
zones directly below. Since the silica
is in the quartz phase, the
permeability of this rock is expected to
exceed the permeability of the rock
directly above it. The dipmeter
indicates that an increase of dip
magnitude is associated with the silica
phase change at the top of the zone. A
hydraulic fracturing job is not required
for commercial production from this
zone. However, industry experience
indicates that acidization will greatly
enhance production.
4060 Ft. - 4205 Ft.
This zone has slightly lower total
porosity than the zone directly above
it. Water saturation increases below
the zone, suggesting zone isolation.
The dipmeter indicates that a decrease
of dip magnitude is associated with the
top of the zone. A hydraulic fracturing
job is not required for commercial
production from this zone. Acidization
is recommended.
4300 Ft. - 4435 Ft.
This zone has slightly lower total
porosity than the zone directly above
it. The dipmeter suggests that the rock
may be well fractured since this zone is
characterized by increasing dip scatter.
Total water saturation increases with
depth below this zone suggesting an
oil/water transition. A hydraulic
fracturing job is not required for
commercial production from this zone.
Acidization is recommended.
DISTRIBUTION
Due to the confidential nature of this report,
distribution has been restricted. Only three copies have
been printed. All three copies are being sent directly to
Mr. Akbar Sheriff by Federal Express.
PREPARATION
This report was prepared for ResTech California by:
Harold Crawford
Interpretation Specialist
In making interpretations of logs, our employees and consultants will give the customer the benefit of their best judgment, but since all interpretations are based on inferences from electrical or other measurements, we cannot, and we do not guarantee the accuracy or the correctness of an interpretation. We shall not be liable or responsible for any loss, cost, damages, or expenses whatsoever incurred or sustained by the customer resulting from any interpretation made by any of our employees or consultants.