Data-Driven Sequence Stratigraphy of the Cretaceous Depositional System, Punjab Platform, Pakistan

Abstract

The Punjab Platform is a gently dipping monocline that has been drilled since the 1960s with a low success ratio. Most of the drilling targets in the past were based on the structural interpretation. Furthermore, the exploration focus remained in Paleozoic sequences, and little attention has been paid to the Cretaceous systems. In this paper, a prograding Cretaceous (Sembar-Goru) mega-sequence is subdivided into three sequences using a semi-automated and integrated workflow. A data-driven chronostratigraphic chart is prepared, which revealed several regressive stages in the study area. The sands developed during these stages are laterally sealed by shales and claystones that form a stratigraphic play. The stratigraphic play area lies in a shoreface environment where shoreface sands are expected to be charged by underlying Lower Cretaceous black shales. A prominent gas cap above the proposed stratigraphic play further increases the confidence on the presence of a reservoir. This paper is the first attempt to study the Cretaceous deltaic sequences in the study area, which has remained unexplored for the last six decades.