Petrophysical Evaluation of Mishrif Formation Using Well Logging in North Nasiriya Oil Field

Abstract

The Mishrif Formation (Cenomanian – Early Turonian) is an important geologic formation in southern Iraq due to its petrophysical properties and geographic extensions, making it a good reservoir of hydrocarbons. Petrophysical properties of the Mishrif Formation in the current study at the Nasiriya oil field were determined from the interpretation of three open-hole logs data of (NS-1, NS-2, and NS-3) wells. The results of the Mishrif petrophysical evaluation showed that the formation consists of five variable units (CRI, MA, CRII, MB1 and MB2), each one characterized by distinct petrophysical characteristics. The upper (MA) and lower (MB) units were determined using electrical, porosity and gamma-ray logs. A shale seal separates the two units (CRI and CRII). The main reservoir units in the formation are MB1 and MB2 characterized by high moveable hydrocarbon compared with the residual hydrocarbon. These units are separated by barrier rocks (BR) consisting of marly limestone.