Exploring the Ortoire Syncline, Southern Basin, Trinidad

Author(s): Xavier Moonan (presenter), Connie McLaren, Lynn Anderson, Touchstone Exploration

Touchstone Exploration is the operator of the 184 sq km Ortoire Block onshore south eastern Trinidad. Structurally the block covers the open east facing Ortoire Syncline which entails Late Miocene Lower Cruse to Pleistocene Mayaro Fm deltaic fill. These passive fordeep infill deposits sit conformably onto a south easterly verging Early to Middle Miocene fold belt. As such throughout the breadth of the Ortoire Block there are numerous tear fault dissected WSW to ENE trending anticlines. These anticlines were the result of the oblique collision between the northern margin of the South American plate with the leading edge of the Caribbean Plate culminating in the Middle Miocene. Historical exploration within the area by United British Oilfields of Trinidad (UBOT) and Shell, had been focussed on Middle Miocene Herrera amalgamated channelised slope to base of slope deepwater turbidites of the Cipero Formation and Late Miocene Lower Cruse base of slope sheet like turbidite fans. Considered shallow water deposits at the time, the results of many of those wells were considered disappointing or uncommercial. Mapping on various 3D seismic surveys and numerous 2D seismic lines, integrated with surface geology, regional well data and fold and thrust belt models have revealed numerous Middle Miocene Herrera plays within the block. From north to south, Touchstone Exploration has identified an eastern extension of the prolific Penal Barrackpore oilfield in the Cascadura area, a subthrust north verging anticline at Coho, a south easterly verging subthrust anticline at Royston and an eastern extension of the Carapal Ridge north verging subthrust anticline in the Chinook area. Two of these structures, Coho and Cascadura have been successfully explored todate by Touchstone Exploration. At COHO-1 and CAS-1 ST1, extended tests have been completed and commercial discovery notifications have been submitted to the Ministry of Energy and Energy Industries. Touchstone has spud its 3rd exploration well, Chinook-1 in August 2020 and will then drill CAS Deep-1 to test further thrust sheets in the Cascadura area.

Bio:

Xavier Moonan, Touchstone Exploration

Xavier Moonan is a Senior Geoscientist at Touchstone Exploration in Trinidad & Tobago. He has an MSc. in Structural Geology with Geophysics at the University of Leeds, UK, and was awarded a ‘Top Ten Presentation’ by AAPG for his poster presentation on the Penal Barrackpore Anticline at AAPG ICE Conference in Milan, 2011.

He served as the Convener for the 20th Caribbean Geological Conference Trinidad 2015, as Programme Committee Trinidad Representative for AAPG ICE Cartagena, 2013, and as General Co-Chair for AAPG GTW Trinidad 2014, GTW Guyana 2017 and GTW Suriname 2019.

Xavier is Vice President of the AAPG Latin America & Caribbean Region. He is a member of the Geological Society of Trinidad & Tobago, the Houston Geological Society and the Society of Petroleum Engineers.