Probabilistic Reservoir Simulation Workflow for Unconventional Resource Play: Bakken Case Study

Abstract

It is widely accepted that unconventional resources hold enormous reserve potential. However, complex fluid flow physics and completion/stimulation practices pose a unique challenge in estimating reserves or making long-term production forecast for these unconventional reservoirs, as traditional methods are most often not applicable. This paper proposes the application of a probabilistic reservoir simulation workflow to provide realistic range of production forecasts with successful application in the Bakken unconventional tight oil reservoir. First, geomodels are constructed and ranked. Then, key static and dynamic uncertainty parameters are identified for the subsequent history-matching study (with each of the geomodel realizations) that provides not only production forecast for individual wells but also parameter ranges for experimental design (DoE) for field-level prediction. Then, DoE simulations are conducted to construct proxy equations that are used in Monte-Carlo simulations to generate Low-BTE-High response S-curves for the field-level models. Finally, based on these S-curve results, Low-BTE-High deterministic reservoir simulation models are constructed to generate corresponding long-term production forecast profiles for full-field development and optimization.

Simulation Study of CO2 Huff-n-Puff in Tight Oil Reservoirs Considering Molecular Diffusion and Adsorption

“…Yu and Sepehrnoori [40] have optimized the well spacing and pointed out that four horizontal wells are often drilled in the area of 1 mile × 2 miles. Luo et al [41] found that the number of perforation stages is averagely 30 for each long lateral. Hence, we set a simulation model in the field scale, with the dimension of 10,560 ft, 5280 ft, and 40 ft in x, y, and z direction, respectively.…”

Application of Pressure-Monitoring Data in Land-Based Unconventionals

“…The downhole pressure data is used to optimize artificial lift, maximize well productivity, and identify potential and developing production problems (Luo et al 2011). In special cases, such as liquids-rich unconventional gas reservoirs, real-time downhole pressure and temperature data is used to maintain production conditions in the near-wellbore/fracture region above the dewpoint of gas to avoid condensate drop out in the reservoir that could impair inflow performance (Altman et al 2014).…”