On 1 November 2018, Gran Tierra Energy (GTE) reported it increased its working interest from 55% to 100% in the PUT-1 Block of the Putumayo Basin. The PUT-1 Block contains the Vonu 1 multi-zone oil discovery well, drilled by GTE in 2017, along with potentially prospective areas where the prolific Cretaceous Villeta group is developed. Gran Tierra remains operator of the acreage where former partner Lewis Energy held 45% interest.  Background information  Only two wells were previously drilled on the PUT-1 Block. Texaco spudded the Alguacil 1 NFW on 23 September 1969 in a 50/50 partnership with Gulf Oil. The well was P&A as a dry hole at a depth of 10,628 ft (3,239 m) in Cretaceous age section on 23 September 1969. There were no recorded tests run in the well. The second well was drilled by the same partnership. The Tucan 1 NFW was spudded on 10 July 1969 and was P&A as a dry hole with shows on 17 September at a depth of 9,920 ft (3,024 m) in Cretaceous age section. No well tests were reported  The PUT 1 block covers 465 sq km and it was awarded to Lewis Energy Colombia (100%) on 31 March 2009.Â  Gran Tierra Energy Colombia farmed into the block and assumed operatorship on 24 August 2014. The current ownership of the block is GTE 55% and Lewis Energy Colombia 45%. The block has been under suspension due to community protests since early 2015.  On 5 June 2017 GTE announced a multi-zone oil discovery in its Vonu 1 new-field wildcat (NFW) located on the PUT-1 Block. Log interpretation indicated oil saturation within six separate reservoirs having a cumulative pay thickness of some 157 ft true vertical depth (TVD). The well encountered 8.2 ft of net oil pay in the Villeta N Sand Member, 3.4 ft of net oil pay in the Villeta M1 Limestone Member, 8.7 ft of net oil pay in the Villeta M2 Limestone Member, 91.1 ft of net oil pay in the Villeta A Limestone Member, 15.3 ft of net oil pay in the Villeta U Sand Member and 30.7 ft of net oil pay in the Villeta T Sand Member. GTE expects to test all zones individually during June 2017. The Vonu 1 NFW was spudded on 6 May 2017 aimed at the multi-zone structural prospect defined on 3D seismic as separate from the adjacent Costayaco field. The directional well targeted the Caballos Formation, the Villeta U, T and N Sand Members and the Villeta A Limestone Member. Gran Tierra is operator with 55% interest and Lewis Energy holds the remaining 45%.
GTE (Gran Tierra Energy) reported it increased its working interest from 55% to 100% in the PUT-1 Block.