## 2 Location of the Study Area and the Geological Background  
This study focused on three wells (BK1, E-AJ1, and E-CB1) located in the southeast of the Bredasdorp Basin, offshore from South Africa (Figure 1). The Bredasdorp Basin lies on South Africa's south coast, southeast of Cape Town in the Western Cape (WC) province and west-southwest of Port Elizabeth in the Eastern Cape (EC) province. It is among the four sub-basins of the Outeniqua Basin that is located on the south coast, is surrounded by the Infanta Embayment, Agulhas Arch, and is southwest of Mosselbay [5; 29; 30; 31; 32]. It spans approximately 18,000 square kilometers (km\({}^{2}\)) with sequences of stratigraphy exceeding 5000 m thickness, extending from Cape Town to the Agulhas/Falkland Fracture Zone in the Indian Ocean [33]. The Bredasdorp Basin contains syn-rift continental and marine layers from the Upper Jurassic to Lower Cretaceous periods and divergent rocks formed during the post-Cretaceous and Cenozoic eras [34; 35]. This study's formation of interest lies between the Lower Cretaceous and early Upper Cretaceous period (Barreman to early Cenomanian) between 93 and 112 Ma. The basin's sediments were derived from the Cape Supergroup and Karoo Supergroup sandstones and shale erosion [36]. The Cape Supergroup sediments are sequences from shallow marine, transitional, and deep-sea environments. The basin is thought to have undergone a sequence of structural deformations (drift and rift activities) during the separation of Gondwanaland and the other southern hemisphere continents [5; 37; 38; 39; 40]. The basin's structural deformation and sediment addition from the coastal zone are adequate to produce an average to good source rock [5; 32; 41]. It also comprises half grabens (Figure 1) that dip slightly to the south, with geological pinch-outs completing the basin's hydrocarbon trapping mechanisms [42].  
Tectonic history of the Bredasdorp Basin  
South Africa's offshore basins are classified into three types of tectonostratigraphic regions: the eastern offshore region, southern margins (which include the Outeniqua Basin), and the passive margin encompassing the western border [39; 43]. The Bredasdorp Basin is classified as a passive margin basin associated with the early Cretaceous of the South Atlantic opening [44; 45]. This basin's sedimentary filling pulses are associated with distinct contemporaneous tectonic occurrences [37]. The slope and basin system evolved concurrently due to fine-grained density and suspension deposits, leveed slope and basin floor turbidite fans, and fine-grained turbidite systems [38]. This evolution  
Figure 1: Map showing the location of the studied wells in the Bredasdorp Basin and the major tectonic elements in the Outeniqua Basin. The schematic cross section (A) illustrates the horsts, grabens and major faults associated with sediments from the syn-rift (Jurassic) to recent in the Bredasdorp Basin [29]. WC = Western Cape province, EC = Eastern Cape province.  
allowed for the classification of the sedimentary history of the Bredasdorp Basin into four tectonostrigraphic stages: pre-rift, syn-rift, transition, and drift (Figure 2) [5; 34; 46]. Each tectonostrigraphic phase is closely related to a particular unconformity or unconformities.  
The pre-rift phase is associated with the basement rocks and sequences deposited before the Valanginian-aged (~139 Ma) 1 At1 uncomformity.