Komar University of Science and Technology, Iraq
This paper investigates the gas and water breakthrough time using sector model (SM) in the naturally fractured (NF) carbonate reservoirs located in Northern Iraq. The naturally fractured reservoirs have complex pore system since rock formations are susceptible to diagenetic process such as dissolution, dolomitization and mechanical fracturing. As a result the reservoir quality may be enhanced or occluded through cementation. The complexity of a fracture network typically leads an anisotropic permeability distribution within the reservoir. Thus ultimate recovery can be achieved with carefully planned reservoir management strategies through conducting an accurate reservoir modeling and simulation.
In this work a sector model was developed based on the studied example field. The field produces from four NF compartments; the average reservoir height is around 95m in which the WOC and GOC located at depth 685m and 590m, respectively. The reservoir rock properties modeled using a dual-porosity with single-permeability system. This model was based on the layercake Petrel model. Furthermore, a sensitivity study also conducted with the aim to investigate the dependences of the well and field-performance.
Results showed that matrix permeability and fracture dimension have great effect on early water and gas breakthrough. While aquifer size and permeability and WOC have moderate effect on both water breakthrough and ultimate recovery when compared to previous parameters.