Initial review of data and field information recently obtained by Carpathian Energy from Petrom S.A. (the former state owned oil company of Romania), indicates that the oil section beginning at 9390 feet (immediately below the gas section previously analyzed) contains significant commercial recoverable oil reserves. This zone was not previously analyzed by Carpathian and no reserves had been assigned to it.
The field information shows that the oil zone was, in fact, previously tested on several occasions by the state company, but because of different strategies at the time, as well as completion and cementation problems, the zone was only commercially produced out of one well on the edge of the structure, the No. 6 well.
The geological data indicates that the oil zone is field wide and covers an area of at least 860 acres. The data shows the oil column to be at least 71 feet thick, although production tests indicate it could be greater. Porosity is reported to be 7% to 15%, with some shaly sections and fracturing within the sand. Permeability is estimated to be 50 to 100 millidarcies. Gravity of the oil in the field as analyzed from 41 to 52 degrees.
In Romania, the former state owned oil company would often conduct tests of a particular zone and then move up the hole to test other zones, even after a successful test of hydrocarbons. In some instances, especially in a field with multiple zones, the deeper zones would not be returned to and the well would only be produced from the last zone tested. This appears to have been the pattern at Nadlac.
In Nadlac Field, the oil zone at 9390' was previously tested at the top of the section, in the No. 4672 well, at a daily rate of 3,200,000 cubic feet of gas plus 271 barrels of oil, on a 15/64 inch choke. This well was also tested lower in the same zone and flowed at a rate of 3,700,000 cubic feet of gas per day and 170 barrels of oil per day during a test on a 12.5/64 inch choke. The well was then produced from a higher zone and the 9390' zone was plugged off. On the edge of the structure, the No. 6 well produced approximately 133,000 barrels of oil from this same zone when water encroached and the well was plugged. No wells in the field were ever put on pump. If the wells did not flow under their own pressure, they were not produced.
Work is continuing on the cleanout of the No. 100 well, which is situated near the center of the field. Once the well is cleaned out, new logs will be run in the wellbore to fully establish the extent of the oil zone and further evaluate other potential in the field. If bond log analysis shows good cementation, then the 100 well will be tested and completion attempted in the oil zone.
Most Popular Articles
From the Career Center
Jobs that may interest you