Modeling of a long sand-pack for heavy crude oil through depletion tests utilizing methane gas

Abstract

With the enormous increase in the demand for crude oil, and decrease in the resources of conventional oil reservoirs, there is a great need to understand heavy or foamy oil-gas drive mechanism to maximize the oil and gas production. To analyze the real movement of non-viscous heavy oil flow, the characteristic features of the oil-gas mixture has to be estimated to forecast the future potential supply from a heavy oil reservoir. An important question in heavy oil flow under solution gas drive is whether the behaviour of depletion tests can be simulated to model the heavy oil flow behaviour. The main objective of this research is to develop a reliable numerical model for modelling heavy oil flow calibrated with controlled solution gas drive experiments, and that makes a novelty in this manuscript. In this paper, CMG-STARS model which is capable of simulating solution gas drive tests that matched the research experiments. This heavy oil recovery model can determine the relative permeability curves for oil and gas in the dual-phase system using Corey’s relations. At a depletion rate of 0.0418 psi/min, the maximum cumulative oil and gas production was observed to be 13,000 cm 3 and 8500 cm 3 , respectively. The results from the bottom hole pressure and the block pressure simulation runs indicate that the fluid properties such as surface tension plays a significant role in the gas bubble formation. These results are promising, and helps to understand the complex behaviour of heavy oil reservoirs and thus can improve heavy oil recovery.