ABSTRACT
Unconventional hydrocarbon exploration is needed in the current oil and gas crisis scenario. Therefore, the development of conditions for unconventional hydrocarbon exploration is needed. In the Upper Indus Basin (UIB), Pakistan, the Patala Formation is one of the potential candidates for this unconventional exploration. It is a proven source rock at the regional level in the Kohat-Potwar sub-basin of UIB. This study aims to evaluate the shale gas potential of the rock in the Minwal-Joyamair area of the sub-basin. Developing a shale rock physics model is important for exploring and developing shale reservoirs due to the difference between unconventional shale and conventional sand reservoirs. These differences include mineral types, mineral characteristics, matrix pores, and fluid properties. To achieve the study's objectives, an integrated strategy provides for evaluating rock physics parameters, petrophysics, and geochemical analyses. This integrated approach indicates that the Patala Formation is a good potential reservoir for shale gas exploration. The Formation has a significant thickness (around 40-50 m), higher total organic carbon content (02-10%), higher brittleness index (0.44-0.56), and relatively shallow depth (2136-3223 m). These research findings suggested that the presence of organic and quartz-rich lithofacies can be considered as highly favorable "sweet spots" for shale-gas exploration in the UIB, Pakistan. Through proper understanding of the spatial and temporal distribution of these "sweet spots", shale-gas exploration can be developed as an effective strategy to exploit shale gas.
ABSTRACT
Upper Indus Basin has been a valuable asset as the complexity of structure and hydrocarbon production is the leading producer of oil and gas in history and still to date. Potwar sub-basin has significance in the light of oil production from carbonate reservoirs or Permian to Eocene age reservoirs. Minwal-Joyamair field is very significant and has unique hydrocarbon production history with complexity in structure style and stratigraphy. The complexity is present for carbonate reservoirs of the study area due to heterogeneity of lithological and facies variation. In this research, the emphasis is on integrated advanced seismic and well data for Eocene (Chorgali, Sakesar), Paleocene (Lockhart), and Permian age (Tobra) formations reservoirs. This research's primary focus is to analyze field potential and reservoir characterization by conventional seismic interpretation and petrophysical analysis. Minwal-Joyamair field is a combination of thrust and back thrust, forming a triangle zone in the subsurface. The petrophysical analysis results suggested favorable hydrocarbon saturation in Tobra (74%) and Lockhart (25%) reservoirs in addition to the lower volume of shale (28% and 10%, receptively) and higher effective values (6% and 3%, respectively). The main objective of the study is the re-assessment of a hydrocarbon producing field and describe the future prospectively of the field. The analysis also includes the difference in hydrocarbon production from two different type of reservoir (carbonate & clastic). The findings of this research will be useful for any other similar basins around the world.
