Petrophysical Analysis and Formation Evaluation of a Gas Field

Abstract

For the hydrocarbon exploration of the study area, the petrophysical study has been carried out in well X. In this study we applied various techniques, i.e. mud logging, wireline logging, well testing, core analysis and production testing. In this study the two formations are evaluated, the lower Ranikot (LRK) Formation and Pab Formation, which have the reservoir potential. These two formations were focused for the evaluation purposes. Five distinct lithological layers were identified through the petrophysical analysis. Such as Ranikot Formation (a), Ranikot Formaion (al), Ranikot Formation (b), Ranikot Formation (c), and Pab Formation. The Ranikot Formation (a) is rich in shale fragments. The Ranikot Formation (al) is the lime marker which is used for the geological correlation. The petrographic study also identified the heavy minerals such as zircon, pyrite, iron oxide, utile and hematite. Ranikot Formation (al) can be distinguished from Ranikot Formation (a) by its low gamma ray, low porosity and high resistivity. The Ranikot Formation (b) zone is designated to the first sands below the Ranikot Formation (a). The Ranikot Formation (c) zone applied to the section, where gamma ray increased significantly compare to Ranikot Formation (b). The Pab Formation layer applied to all of Pab Formation. The Pab Formation was cored in both wells. The petrographic study identified ankerite as the predominant cementing material and siderite as the predominant heavy mineral. Feldspar and sandstone are also present in this formation. The reservoir quality of the Pab Formation was much better as compared to the low Ranikot Formation in terms of clean sand porosity, water saturation and permeability.