Reservoir Evaluation Technology Package #1: Ensemble-based History Matching and Its Applications to Estimating Petrophysical Properties for Hydrocarbon Reservoirs

Novel and pragmatic techniques have been developed to dynamically, implicitly, and inversely estimate multiple petrophysical properties by history matching production data with the ensemble-based techniques. The newly developed techniques have been validated by accurately evaluating multiple petrophysical properties in numerical and real core flooding experiments, 2D synthetic heterogeneous reservoirs, a 3D standard test case (PUNQ-S3 model), and a field case under various conditions, respectively. In particular, the newly developed techniques have been improved to accurately and dynamically evaluate multiple petrophysical properties for unconventional resources where traditional methods find their limits. Recently, our research group has improved the techniques for determining three-phase relative permeability for water-alternating-gas processes and CHOPS processes, respectively. Also, a pressure-gradient-based sand failure criterion has been proposed and validated with laboratory experiments to quantitatively determine sand production and characterize the corresponding wormhole growth and its propagation during CHOPS processes, and then extend its applications for real field production. The newly proposed sand failure criterion is convenient to be incorporated with any numerical reservoir simulator and thus to be useful for field cases.

Reservoir Evaluation Technology Package #2: Optimization of Displacement Efficiency and CO2 Storage Capacity under Uncertainty

Experimental and theoretical techniques have been developed to not only optimize displacement efficiency for maximizing oil recovery, but also maximize CO2 storage capacity under uncertainty. CO2 Huff-n-puff processes has been experimentally and numerically evaluated in the Bakken formation, while CO2 injection is found to increase injectivity in tight oil formations for enhancing oil recovery and CO2 storage capacity. Water-alternating-CO2 processes together with horizontal well configuration can be used to enhance oil recovery and CO2 storage in thin heavy oil reservoirs. Also, integrated techniques have been developed to maximize oil recovery and CO2 storage under uncertainty, while scaling criteria have been respectively developed for waterflooding and immiscible CO2 flooding in tight formations and heavy oil reservoirs.

Reservoir Evaluation Technology Package #3: Evaluation of Reservoir Performance for Unlocking Unconventional Resources

Experimental and theoretical techniques have been developed to evaluate reservoir performance for unlocking unconventional resources. More specifically, techniques have been developed and verified to determine dynamic dispersion coefficients of solutes flowing in a single fracture, a circular tube, and a tube-bundle model under different source conditions. Ensemble-based techniques have been improved to accurately and dynamically evaluate multiple petrophysical properties for unconventional resources where traditional methods find their limits. As for tight formations, experimental and numerical techniques have been developed to respectively evaluate non-Darcy flow behaviour and CO2 huff-n-puff processes in the Bakken formation, while a mathematical model has been formulated to determine vector well patterns, minimum permeability plateau and characteristic length, and fracture conductivity with non-Darcy flow behaviour, respectively. Then, a novel slab source function has been formulated and successfully applied to accurately evaluate performance of a hydraulically fractured horizontal well in a tight formation with and without fracture mechanics. CO2 injection is found to be an effective agent to increase injectivity and thus oil recovery in such tight formations, while experimental techniques have been employed to determine static and dynamic characteristics of microscopic pore-throat structure and residual oil distribution in tight oil formations. As for thin heavy oil reservoirs, both water-alternating-CO2 processes implemented with horizontal wells and the enhanced cyclic solvent process have been found to improve oil recovery.