Gran Tierra Energy Inc., Calgary, is designing a test program to measure whether it has a commercial discovery at its Bretana Norte 95-2-1XD exploratory well in Peru’s Maranon basin, which appears to have confirmed a 1974 heavy oil find on Block 95.
Bretana Norte encountered oil shows at the top of the target Vivian reservoir, and the company recovered oil-saturated core over 90% of the oil column and in the underlying water column.
Log interpretations and MDT fluid and pressure sampling indicate the presence of an oil-bearing reservoir in the Vivian sandstone beginning at 9,408 ft measured depth, 8,851 ft true vertical depth, with an approximate gross oil column thickness of 99 ft and 53 ft of net pay thickness.
The well encountered the oil column 48 ft higher than at the 1974 Bretana-1 discovery well 4 km away. Bretana-1 tested 18° gravity oil at rates of 807 b/d on natural flow and was never placed on production (OGJ Online, Dec. 14, 2012).
Meanwhile, on the Chaza block in the Putumayo basin in Colombia, Gran Tierra said its Moqueta-8 appraisal well tested on a hydraulic jet pump at rates of 651 b/d of 28.2° gravity oil with 0.4% water cut on a 57-hr test of Caballos perforations at 5,361-5,538 ft, 925 b/d of 27° gravity oil at 0.4% water cut on a 16.4-hr test of the T sandstone at 5,153-5,256 ft, and 24 b/d of 16.3° gravity oil with a 0.4% water cut in 24 hr from the U sandstone at 4,866-4,911 ft.
Gran Tierra is completing Moqueta-8 as a production well and drilling the Moqueta-9 appraisal well in the northern part of Moqueta field.