Shale Oil Potential of Patala Formation in Balkassar Area, Potwar Basin, Using integrated Wire-line logs, 3-D Seismic Inversion and Attributes Analysis

Abstract

Balkassar field is located in Chakwal district, Punjab Province of Pakistan. Geologically, the area is in Potwar Basin which is eastern part of Upper Indus Basin. The Basin is heavily thrusted and folded because of collisional tectonics regime. The stratigraphic sequence is composed of pre-Cambrian to recent deposits. The prime purpose of this study is to examine and evaluate the Shale oil prospective of Patala Formation in Balkassar area. In this dissertation, seismic 3-D data and well log data of Balkassar-OXY-01 well are used. Seismic 3-D data is used for delineation of the sub-surface features. The 3-D Seismic cube given by the Directorate General of Petroleum Concessions is interpreted by using Kingdom Software. The general structural trend in the study area is northeast to southwest, however, the seismic interpretation of available 3-D cube does not show any fault. The seismic reflectors show almost planner behavior because the available 3-D cube belongs to one of the limb of the fold where there is no fault has been encountered, which is also confirmed by the seismic attribute analysis. For Petro-Elastic or Petro-Mechanical properties well log data of the Balkassar-OXY-01 is used. Using shear Sonic log (DT), properties such as brittleness Index, Young’s modulus and Poisson’s ratio are calculated which shows that the Shale of Patala Formation is brittle and suitable for hydraulic fracking. Geochemical Parameters such as TOC, Vitrinite reflectance, LMI and Kerogen volume depicts that the Patala Formation’s Shale is enough mature and can produce economic quantity of Shale oil. P-wave impedance is calculated through Model Based Inversion and Band Limited Inversion. Due to the absence of frequency control in the Model Based Inversion, Band Limited Inversion resolved Patala Formation with relatively better accuracy.