Two Clocks Beneath the Leeward Antilles: Petroleum Systems and Potential of the Bonaire Basin

This study tests and amends the author's earlier petroleum-system model of the Bonaire Basin, the Cenozoic trough between the Leeward Antilles (Aruba, Curaçao, Bonaire) and the Falcón coast of north-western Venezuela, against the structural chronology of Gorney et al. (2007), AAPG Bulletin 91(5), 653–684, doi:10.1306/11280606002. That paper integrated BOLIVAR and industry reflection seismic with on-land geology and defined three Cenozoic phases: late Eocene–early Oligocene N–S opening of a 3–6 km deep basin on E–W normal faults; NW-striking normal faults forming deep submarine rifts with up to 4 km of fill, mainly late Oligocene–early Miocene and active to the present; and middle Miocene inversion with a 175 km offshore La Vela fold-thrust belt carrying at least 7 km of shortening. The test corpus is eight essays and two companion essays by the author (June–August 2026), the GLIAG Bonaire Basin Petroleum-System Atlas (August 2026) and a targeted external literature set. Four results follow. (1) The trap model now carries three generations: T1 (late Oligocene–early Miocene; Gorney et al. 2007), T2 (middle–late Miocene inversion) and T3 (Pliocene–Quaternary NW–SE anticlines; Hippolyte & Mann 2011). (2) The Agua Clara shale is upgraded from seal and minor source to a proven Falcón source, because Cumarebo oils correlate with Agua Clara bitumens (del Ollo 1993). (3) The El-Mowafy et al. (2007) study of the Aruba and western Curaçao basins, which places only their south-western part in the oil and gas window, corroborates an immature Aruba–Paraguaná barrier and makes maturity in the western K5 kitchen unproven. (4) A first-order heat-flow scaling of four Atlas pseudo-wells (ln Ro = −1.797 + 0.443z) places the primary-source oil window (Ro 0.6–1.3%) at 2.9–4.7 km for 55 mW/m² and at 3.6–5.7 km for 45 mW/m². Combining the onshore heat-flow history of Baquero et al. (2009) with these results defines two charge clocks and two critical moments (~20–17 Ma and ~8 Ma). Applying the resulting timing penalty to the Atlas risk matrix lowers the composite chance of success of the three leading plays from 55% to 49%, 50% to 47% and 25% to 21%, and their risked P50 from about 912 to about 846 MMboe at 6 Mcf/boe (analytical, not PRMS, as of 29 October 2026). The basin is interpreted as charged but under-imaged. A fifteen-item amendment register corrects the author's earlier published record, and a falsification programme specifies the seismic, heat-flow and geochemical observations that would confirm or reject the model. Document ID GLIAG-BB-2026-PS-005, Revision 1.1. Analytical volumes only; not reserves or resources under SPE-PRMS. Text and data mining reserved under Article 4(3) of Directive (EU) 2019/790.