Fracture Characterization of Margalla Hill Limestone by Using Aerial Photography Near Kenthlaan Road Near La Vista Cafe, Islamabad, Pakistan

Abstract

Fracture characterization in carbonate rocks has always remained very important to evaluate their reservoir properties for both petroleum and water prospects. The manual and classical methods for fracture mapping are laborious and full of challenges. Over the last decade; remote sensing along with aerial photography made it possible to map structure lineation without directly contact with outcrop. This thesis aims to validate this methodology for structure networking characterization by using combination of software and aerial photographs. For this purpose, two outcrops of Margalla Hill Limestone near La Vista Cafe the area was selected. Field photographs were acquired by using a drone and these photographs were stitched together to make a mosaic which were later on georeferenced in ArcGIS. The fractures were then traced by selecting polygons and endpoint files were generated and imported to rock works for drawing rose diagram; and FraNep to evaluate the fracture parameters like intensity, density, orientation and mean length distribution of the fractures. The rose diagrams show 4 sets of fractures are present in the study area confirming both orthogonal and conjugate fractures systems. The fracture density calculated in FraNep was used to calculate fracture porosity for area A1 11.5% and A2-17.38% as well as permeability for Al- 1.009×10° and A2= 1.52×10° millidarcy respectively. It is to be kept in mind that another method namely Circle Inventory method is also used to carry out the research. The results of both methods i.e. FraNep software and circle inventory method has close resemblance which also support accuracy of FraNep software.