The paper aims to establish a possible link between the sequence stratigraphy and reservoir potential of the Middle Jurassic carbonates of Samana Suk Formation, Kala Chitta Range, North Pakistan. The Samana Suk Formation is comprised of a monotonous sequence of thin- to thick-bedded bioturbated, cross-bedded, ripple marked, sandy, bioclastic carbonates with shale interbeds. The rock unit is the best analog of shallow to marginal marine carbonates due to its pronounced thickness, enhanced lithological variations, and diverse diagenetic features. To establish a possible link between the sequence stratigraphy and reservoir potential of the rock unit, the outcrop and petrographic features are used to record eight microfacies, deposited in a wide range of shallow to marginal marine environments including mudflats, lagoon, back shoals, and sand shoals. Based on the vertical stacking pattern of microfacies in a given time of deposition (170–160 Ma), one second-order local cycle (SLC-1), three regressive systems tracts (RSTs) and two transgressive systems tracts (TSTs) are delineated within the succession. The primary and secondary porosity of selected microfacies from each systems tracts are investigated using petrography, scanning electron microscopy, and energy-dispersive spectroscopy. The direct measurements of porosity and permeability of these microfacies types are carried out using high overburden pressure plug porosity and permeability analyses. Based on these investigations, higher reservoir potential is recorded for mudstones/wackestone microfacies of RST as compared to grainstone microfacies of TST. The higher porosity within RST and higher interconnectivity of available pores both in RST and in TST suggest that the Samana Suk Formation carries good reservoir potential.

本文旨在建立巴基斯坦北部卡拉奇塔山脉萨马纳苏克组中侏罗统碳酸盐岩层序地层与储层潜力之间的可能联系。萨马纳苏克组由单层的薄层至厚层生物扰动，交叉层状，波纹状，砂质，生物碎屑碳酸盐与页岩夹层组成。由于其明显的厚度，增强的岩性变化和多种成岩特征，岩石单元是浅层至边缘海相碳酸盐的最佳模拟。为了在岩石层序地层学与储层潜力之间建立可能的联系，利用露头和岩相学特征记录了八种微相，这些微相沉积在浅浅至边缘的海洋环境中，包括泥滩，泻湖，后滩和沙土。浅滩。根据给定沉积时间（170-160 Ma）中微相的垂直堆积模式，描绘了一个二阶局部循环（SLC-1），三个回归系统道（RST）和两个侵入系统道（TST）在继承之内。使用岩相学，扫描电子显微镜和能量色散光谱法研究了每个系统道中选定微相的主要和次要孔隙度。这些微相类型的孔隙度和渗透率的直接测量是使用高覆盖层压力塞孔隙度和渗透率分析进行的。基于这些研究，与TST的粒岩微相相比，RST的泥岩/砂岩微相的储层潜力更高。