Research on Water-Flood Law of Diamictite Reservoir in Iraq F Field

The Asmari Formation of F Oilfield in Iraq develops sandstone, limestone, dolomite and diamictite rocks. At present, most wells in the oilfield are experiencing water flooding and the water content is increasing rapidly. However, there is a lack of research methods and systematic understanding of the law of water flooding. This paper analyzes the reservoir connectivity and water flooding rule. Detailed research work is as follows: the reservoir physical properties and distribution characteristics, the interlayer, the horizontal and vertical depletion of formation pressure in each oil zone, the water breakthrough time of single well at different structural positions, and the water flooded layer proportion. The results show that the dolomite in the member A of Asmari Formation is mainly a medium-low porosity and low permeability reservoir, and the physical properties of sandstone in member B are mainly medium-high porosity, medium-high permeability and ultra-high permeability. The interlayer between two members is a physical interlayer dominated by dolomite, and the plane distribution is not stable which has a certain permeability. Microfractures are widely developed in Asmari Formation, which increases reservoir space and improves connectivity. The Asmari reservoir has good connectivity within and between layers, vertically and horizontally, but the degree of connectivity is different due to the heterogeneity of the reservoir. Through research, there are four water flooding modes in F oilfield, and the edge water advance of high permeability sandstone is the most important one. The research results of this article have guiding significance for the distribution of remaining oil, deployment of new well locations, perforation plans, and formulation of measures.