Evaluation of Lower Silurian Source rock H29- NC 115 NW Murzuq Basin SW Libya

Abstract

The basal Tanezzuft Formation (Hot Shale) is recognized as radioactive hot shale and has a high gamma ray response in wireline logs. This is most probably due to the high content of uranium. The lower most Silurian Tanezzuft Formation and Hot Shale are thought to be the main source rocks in the Murzuq Basin. The Lower Silurian Succession during this study and within H 29 - NC115, has been characterized by two main organic Facies, Facies A The Lower Part of the Lower Silurian Succession between intervals 1472 ft. to 1487 ft. which called (Hot Shale). Facies B the Upper Part of the Lower Silurian Succession between interval 1426 ft. to 1468 ft. which is completely different and called (Tanezzuft Shale). The Lower Part of the Lower Silurian Succession distinguished as very rich in organic carbon TOC and highly HI and low OI indicate anoxic environment, which gives opportunity to preserve the organic matter in reducing conditions. representing to Oil Window stage Kerogen type II. The Upper Part of the Lower Silurian Succession based on geochemical information have been evaluated Low Hydrogen Index (HI) which is indicate to the Kerogen type III.