Subject: Bellaire Oil Company
Kern Front Oil and Gas Field
Location: Kern County, California
Leases: Township 28 South - Range 27 East
Section 15 & Section 27
Kern Front oil field is located adjacently north of Bakersfield, California in the southern San Joaquin Basin. It was discovered in 1912 by Standard Oil of California, but significant development of the field did not take place until years later. Many early wells were completed with an initial potential of several hundred barrels of oil per day until the reservoir pressure declined significantly. Steam cycling was initiated in February of 1964.
The known producing zones of the field and their respective geologic ages are listed below:
Chanac Formation: Mio-Pliocene
Etchegoin Formation: Pliocene
Kern River Formation: Pleistocene
Each formation is composed of marine and non-marine interbedded silts, green/gray clays, and sands. The sands are very fined grained to conglomeratic, poorly sorted, unconsolidated, and lenticular. Porosities range from 25-33%, and permeabilities 1280-1700 millidarcies.
The structure is monoclinal, with a strike of N300W and a dip of 30 to 80 to the southwest. Kern Front is cut by a series of small southwest trending normal faults that do not appear to significantly affect oil production. A large north-south trending fault on the east side provides a reservoir seal in this direction. An up-dip lithology change toward the northeast from sand to silts and clays provides the seal for the majority of the sands in the field.
Oil gravities in the field range from 11.6 to 15.5 degrees. Gas/oil ratios are 60 standard cubic feet of gas per stock tank barrel of oil, and total dissolved solids of the produced water are 500-1200 ppm. All produced water from the leases is delivered to Valley Waste Disposal.
Producing depths range from 1370 to 2400 feet deep. The most common completion practice is to set 7’’ to 8 5/8” pipe above the producing sands, under-ream a 12” hole through the pay zones, land a 5 ½” to 6 5/8” slotted liner across the pays, and gravel pack.
Chevron initiated cyclic steaming (“huff and puff”) and a continuous steam flood drive by drilling many wells mechanically capable of continuous steam injection. Chevron’s stream drive was limited to a pilot project area, and did not produce from all of the many productive sand cycles. The pilot area was located in Section 27, and consisted of 9 steam injection wells and 18 producing wells. This pilot program produced approximately 663,000 barrels of oil from February, 1980 through June, 1986.
The reservoir study by Bellaire Oil Company indicates that the original oil in place (OOIP) for the two sections is over 170,000,000 barrels of oil from the Chanac only, but less than 25,000,000 barrels of oil have been produced to date. It is not uncommon to recover at least 60% of the OOIP with a continuous steam drive. In addition, OOIP calculations have never been made for the Etchegoin formation, or the Kern River formation. The latter two contain multiple sand layers. These sands have never been produced in these two sections, but currently produce form adjacent leases in the field.
Operators at Kern Front and other heavy oil fields in the area, with the implementation of co-generation facilities, have achieved lifting costs at less than $5.00 per barrel of oil. Occidental produces several thousand BOPD in Kern Front with continuous steaming. It is realistic to assume that similar production success could be achieved with these Bellaire leases with adequate low cost steam from co-generation and proper operating techniques. In addition, most wells on the leases have not been completed in all potentially productive sands, and many more wells could be put on production. The possibility for deeper production exists also, although this potential has not been adequately explored. Several wells produced lighter oil from the Upper Miocene age Santa Margarita formation, which underlies the Chanac.