Rock Compaction Dynamic Modeling for Unconventional Reservoirs

The quantification of rock mechanics impact represents critical factor for unconventional resources (UR) evaluation and how it contributes into the total UR well's production. This quantification is a vital factor to various reservoir engineering analyses such as history matching, production forecasting, reservoir modeling and reconciling with estimated ultimate recovery (EUR) of fields. To address the rock mechanics impact, a simulation workflow was designed to capture the dynamic change of pore volume and permeability as a function of pore pressure depletion while producing from the basin. The workflow was performed as a pioneer study to integrate advanced core lab experiments that measures different rock compaction scenarios into a dynamic simulation workflow using full physics reservoir simulator. This work used a conceptual dynamic sector model instead of using actual field data. It represents unconventional horizontal wells completed using multi-stage hydraulic fractured stimulation technique. The conceptual model is used to run sensitivity assessment to evaluate different compaction trends. This assessment capitalized on advanced core lab experiments that measure different rock compaction scenarios for unconventional core plugs; i.e., the change the stress dependent parameters (porosity "β" and permeability "α") as function of the pore pressure depletion. As results, this tailored process of integrating lab measurements with dynamic simulation enables the evaluation rock compaction and its impact on wells’ EUR. In general, based on the simulation results, the change of the stress dependent parameters shows different well's EURge. While depleting the reservoir, having higher stress dependent porosity "β" parameter will add more energy into the system and will have a slight increase the EURge. On the other hand, having higher stress dependent permeability "α" parameter, will cause more permeability degradation with pressure depletion and this will reduce the well's EURge significantly.