A “significant” oil and natural gas discovery in South America offshore Suriname has uncorked at least seven distinct plays, joint owners Apache Corp. and Total SA said Tuesday.
The Maka Central-1 well in Block 58 was successfully tested for hydrocarbons in multiple stacked targets in the upper Cretaceous-aged Campanian and Santonian intervals, encountering oil and natural gas condensate.
“The well proves a working hydrocarbon system in the first two play types within Block 58 and confirms our geologic model with oil and condensate in shallower zones and oil in deeper zones,” Apache CEO John J. Christmann said.
“Preliminary formation evaluation data indicates the potential for prolific oil wells. Additionally, the size of the stratigraphic feature, as defined by 3-D seismic imaging, suggests a substantial resource.”
Apache and Total last month agreed to split evenly the interest in Block 58, which comprises 1.4 million acres in water depths of less than 100 meters (328 feet) to more than 2,100 meters (6,890 feet). Apache is operating the first three exploration wells, including the Maka Central-1, and subsequently plans to transfer operations to Total.
The block “offers significant potential beyond the discovery at Maka Central,” Christmann said. “We have identified at least seven distinct play types and more than 50 prospects within the thermally mature play fairway. In partnership with Total, we look forward to advancing both exploration and development of discoveries on the block.”
The South American region is said to be rich in oil and gas prospects.
In Guyana, adjacent to Suriname, ExxonMobil Corp. continued a spate of discoveries last year in the Stabroek Block, including the Tilapia, Yellowtail (oil) and Haimara (natural gas condensate).
ExxonMobil initiated oil and gas exploration activities offshore Guyana in 2008, collecting and evaluating substantial 3-D seismic data that led to drilling Liza-1, the first exploration well, in 2015. The Liza Phase 1 development has estimated recoverable resources of more than 6 billion boe.
The formation evaluation program by Apache and Total in the Suriname waters included logging-while-drilling and wireline logs, formation pressures and preliminary core and fluid analysis. Together with future appraisal wells, the data is to be used to quantify the resource in the Campanian and Santonian formations.
The shallower Campanian interval contained 50 meters (164 feet) of net hydrocarbon-bearing reservoir. Preliminary fluid samples and test results indicated light oil and gas condensate with API gravities of 40-60 degrees. The deeper Santonian interval contains 73 meters (240 feet) of net oil-bearing reservoir. Preliminary fluid samples and tests results indicated API oil gravities of 35-45 degrees.
The Maka Central-1 also targeted a third interval, the Turonian, a geologic analogue to oil discoveries offshore West Africa, according to Apache. Before reaching the interval, the well encountered “significantly over-pressured, oil-bearing reservoirs in the lower Santonian.” A decision was made to end drilling at 6,300 meters (20,670 feet).
“The pressures encountered in the lower Santonian are a positive sign for the Turonian and future drilling will test this interval,” Apache said.
The Noble Inc. drillship Sam Croft, which drilled the Maka Central-1 is to drill the next wells in Block 58, beginning with the Sapakara West prospect. The Sapakara West-1 well, about 12 miles southeast of the Maka Central discovery, is to prospect for oil-prone upper Cretaceous targets in the Campanian and Santonian intervals.