Indications of uplift from seismic stratigraphy and backstripping of the well data in western Indus offshore Pakistan

Abstract

Two-dimensional regional seismic reflection, oil well data, and biostratigraphic data have been used in integration to study the general structure, stratigraphic architecture, and subsidence history of the part of River Indus offshore Pakistan. The seismic data have been calibrated with the well data by generating the synthetic seismograms to identify the key reflectors indicative of major lithologic horizons. The sedimentary successions on the seismic sections are divided into passive and transpressive margin sediments on the basis of regional tectonics of the area. The western Indian margin is in oblique collision and transpression with Eurasian and Arabian plates creating Kirthar Range onshore and Murray Ridge offshore, respectively. Four mappable seismic sequences are identified within the passive margin sediments and two within the transpressive margin sediments. Due to the complex depositional setting of the basin, certain seismic sequences are not clear on the seismic records. In addition to depositional complexity, the seismic sequences are disturbed by the presence of normal faults generated probably under the action of gravity. It is interpreted from the seismic records that the normal faults were probably reactivated due to the movement of the basement blocks which have generated the push-up structures within the offshore depression area. The subsidence curves show a gentle convex upward trend, which suggest an uplift around 40 Ma probably resulting from the reactivation of the basement blocks. The study could be helpful in understanding the tectonics of the worldwide passive margins dominated by rifting and transpression stages.

Appraisal of reservoir quality for hydrocarbon-bearing deep-water Miocene sandstones incised valley, south-east Asian offshore Indus: An application of seismic attributes and instantaneous spectral porosity quantitative reservoir simulations

“…Therefore, the 2DSSDM could have been applied to the work done by the previous researchers. Based on the conjunction of the present work and those performed by Khan and Liu [ 48 ] and Khan et al [ 50 ], it could have explored the real locations for drilling to possible hydrocarbon-bearing and economically high-rating stratigraphic prospects inside the IOB, Pakistan.…”

“…Recently, robust attempts have been made by researchers to explore the IOB of Pakistan. A very recent development has been carried out by the explorer [ 48 , 50 ]. They have used the back stripping, sequence stratigraphy, and seismic amplitudes-based attributes analysis on this exploration zone.…”

“…Recent studies relying on sequence stratigraphic attributes have revealed possible locations for the exploration of the hydrocarbon trapping areas within the IOB. These studies have initiated a new era of exploration within the IOB of Pakistan, focusing mostly on the most promising zones (particularly from slope to deepwater basin floor fans between ∼10 km distance away from the sedimentary proximal position) for economic development within the IOB [ [48] , [49] , [50] , [51] ]. Moreover, additional studies were conducted for stratigraphic traps of low-stand prograding wedge plays.…”

Multi-level ultra-deep fault-controlled karst reservoirs characterization methods for the Shunbei field

“…Many significant oil and gas discoveries in the Tarim Basin in recent years have been fault-controlled karst reservoirs, emphasizing the need to explore ultra-deep faultcontrolled karst reservoirs. Due to continuous exploration and research in geology, geophysics, drilling, logging, testing and other relevant theories and technologies, remarkable exploration progress has been made in the deep and ultra-deep (7,,000 m buried depth) Ordovician carbonate system in the Tarim Basin and similar other geological provinces (Khan et al, 2020a;Khan et al, 2020b). Ordovician oil and gas resources in the Shunbei field are estimated to have a total of 1.7 billion tons (Ma et al, 2022).…”

Insight to the geological character of the Early Triassic strata in the Western Salt Range, Pakistan: A comparative study

“…Other sedimentological works carried out on this rock unit (i.e., Mianwali Formation) are mostly in the form of confidential reports or unpublished data and are therefore not available. Some of the works were carried out on the Mesozoic–Cenozoic seismic sequential stratigraphy but they are located in the far south (Khan, Liu, Farid, & Ahmed, 2020; Khan, Liu, & Zaheerudin, 2020) and outside the domain of the current study. The present study contributes to the understanding of the Early Triassic marine palaeoenvironments with data from lithofacies, together with sequence stratigraphic interpretations and palaeoclimate of the Zaluch Nala Section (Figure 1).…”