Construction of a Comprehensive Static Model Based on The Probability of Reef and Fault for Mishrif Formation-Garraf Oil Field

Mishrif Formation is regarded as the primary reservoir in the selected oil field. It is subdivided into three main units M1, L1, and L2. Based on 107 wells data, the static model construction is the crucial first stage to constructing a dynamic model for any reservoir, and it is here that the significance of this work becomes evident. The primary objective of this paper was to identify the distribution of petrophysical properties throughout the Mishrif reservoir and the initial oil-in-place calculation to assess the viability of working on reservoir modeling and the detection and resolution of reservoir problems, the most important of which is the difference in bubble pressure values within the same formation by verifying the presence of a fault or reef that led to that problem. The static model will be built based on two possibilities, reef and fault, to verify the correct possibility by historical matching with no difference in the distribution of petrophysical properties and the calculation of oil in place in both cases. The significance of developing this field lies in the issue of bubble point discrepancy in Mishrif formation by verifying the presence of faults or not because it may be a significant cause of that discrepancy. At this point, the importance of this research becomes evident. Several studies were conducted in this formation, where the initial oil in the place was calculated according to the available data, among which oil-water contact (OWC) was one of the most uncertain parameters for stock tank oil initially in place (STOIIP) calculation. As a result of drilling more wells and using modern well logging, a deeper OWC level was adopted than in previous studies, which led to a significant increase in the oil used initially, mainly on the eastern side of this formation.