They'll have 3 wells in the A limestone in Costayaco by Dec 31. One on each end and one in the middle so I would expect they get that in the next reserves report.
From RBC report posted here:
Opening Up A-Limestone: Work on mud logs (that exhibited strong kicks when drilling through the A-limestone to deeper target formations) led Gran Tierra to test the A-limestone for the first time on the field in Q3/16. On the Costayaco-19 well (southern extent of the field) 60ft was perforated within a total 100ft net pay that flowed 1,337b/d 30API on natural flow over 26 days and now 2,000b/d with a hydraulic jet pump. The Costayaco-9 well (centre of the field) was perforated (50ft of 70ft net pay) and after acid stimulation averaged 500b/d on natural flow. The next well to be tested through November, Costayaco-7, at the north end could begin to prove up A-Limestone reserves across the length of the field (7km).
Initial Assessment: On a preliminary basis, the A-Limestone could hold around 100-120mmbbls OIP with 20-30mmbls recoverable reserves. We base this on a volumetric assessment of oil in place at Costayaco field. It covers around 9.75km2 and then we assume net pay averages 70ft (70-100ft so far) with application of relatively generic assumptions around porosity (15%), Swc and Bo. The new play could be highly value accretive given Costayaco is fully developed and assuming $7/bbl NPV10 at $65/bbl LT it could be worth $140-210m NPV10 (C$0.47-C$0.71/share).