Evaluating the Lower Cruse and Navet Formations Within the Wd-8 Lease Operatorship Block

Abstract

Lease Operatorship block WD-8, lies within the Forest Reserve oilfield. Forest Reserve is known for having the ENE-WSW trending, south easterly verging Forest Reserve anticline which plunges into NW-SE trending Los Bajos Fault. Regionally to the south of the Forest Reserve anticline lies the south westerly plunging Siparia syncline and to the north of the Forest Reserve anticline is the Morne L′ Enfer syncline. WD-8 is situated on the northern flank of the Forest Reserve anticline with the axis of the anticline occurring within the southern part of the block. Prior to 2018, TETL last drilled within the WD-8 block in the year 2014. Drilling within the WD-8 block pre-2018 was mainly in the southern portion of the block. The year 2018 saw TETL drill five wells in the northern part of the WD-8 block. The results from these wells prompted an evaluation within the Northern portion of the WD-8 block to determine the structure and extent of the Lower Cruse and Navet reservoirs. Field wide mapping post 2018 drills within the block highlighted the sand trend at the Cruse level is in a WSW-ENE direction and that these sands in northern WD-8 are very narrow with maximum widths ranging between 100 ft – 150 ft. Additionally, it showed that by using a smaller well spacing, wells would encounter different producing sand bodies not seen in adjacent wells. Differences in the sand character between wells in the Southern part of the block to wells in the northern part of the block at the Lower Cruse level were also seen. The Lower Cruse section in the southern part of the WD-8 block tends to have thick stacked slope channel sand deposits, while the northern part of WD-8 has relatively thin stacked slope/base of slope channel deposits. Structurally, the presence of an ENE-WSW fault which separates the southern wells from the northern wells was also revealed. Abnormal stratigraphy was also found in Northern WD-8 where the Eocene Navet formation was encountered below the Late Miocene Lower Cruse formation. Two (2) wells in the northern portion of the block found the Navet formation resistive with only one well testing this reservoir. This then presents a new under exploited target reservoir with the block. Mapping of the Navet Formation indicates that this reservoir trends in a WSW-ENE direction. This updated geological model for the WD-8 block resulted in six infill developmental wells being identified to further exploit the remaining reserves within the Lower Cruse and Navet Formations in the WD-8 block.