AAPG Bulletin, Vol.89, No.2, 231-254, 2005
The role of outcrop geology in predicting reservoir presence in the Cretaceous and Paleocene successions of the Sulaiman Range, Pakistan
Hydrocarbon exploration in remote, mountainous regions commonly creates a logistical challenge. Remote sensing methods are used to gain an understanding of the geologic evolution of an area. However, over-reliance on these techniques has commonly precluded finer scale observations made in the field, which can significantly reduce exploration risk. The Sulaiman concession lies in the Sulaiman Range, which forms part of the Himalayan fold and thrust belt in the Baluchistan province of northwest Pakistan. Rugged exposures, developed in this semiarid area, provide excellent outcrops of the principal stratigraphy of interest in the concession. To reduce uncertainty associated with reservoir presence, the Upper Cretaceous to lower Paleocene Mughal Kot, Pab, and Ranikot formations were studied. Detailed (centimeter-scale), sedimentological observations enabled the depositional context of these units to be resolved. By recognizing abrupt dislocations in facies tracts and changes in depositional architecture, a low-order stratigraphic framework was established. Furthermore, local, candidate high-frequency surfaces were recognized, which gave an insight into the processes active in the individual facies tracts during periods of relative base-level change. These observations resulted in an integrated model that was used to predict reservoir presence in the Mirawah structure.