Investigation of Productivity Index in Natural Gas Reservoir Using an Advanced Reservoir Simulator

With the modern advancement of technology, the use of new reservoir engineering software has increased significantly over the last period, even though the cost of building and running these software is high. Therefore, the question that needs to be answered is whether newly developed software are efficient to support reservoir engineers or not. This thesis will evaluate the efficiency of one of the newest reservoir simulators, called QASR, by assessing the productivity index. This will be accomplished via the use of novel discretization and linearization schemes. Sensitivity studies will also be performed in order to investigate the influence of different reservoir parameters on the calculated productivity index and decide if its correct or not based on the literature review. Some of these reservoir parameters include the skin, well radius, bottom-hole pressure, permeability, and well length. The Peaceman correlation method was chosen to assess the reservoir simulator findings, and three main test cases were modeled and considered to achieve the goal of this thesis. In all the test cases, unstructured grids and permeability were applied via multi-point flux approximation (MPFA). The introduction of different reservoir parameters has yielded a different response on the calculated productivity index using the QASR reservoir simulator. The simulation results for all of the investigated cases indicate that the calculated productivity index using the QASR simulator complies with the literature review performed by the legacy simulators.