Microscopic Visualization with High Resolution Optical-Fiber Scope at Steam Chamber Interface on Initial Stage of SAGD Process

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractExperiments and numerical simulations on initial stages of the steam-assisted gravity drainage (SAGD) process were carried out. Experimental studies used two-dimensional scaled reservoir models to investigate fluids flow characteristics in the steam chamber and production fluids. The rise and growth of the initial steam chamber were observed and visualization of micro-phenomena at inclined interface on the side of the steam chamber with a high-resolution optical-fiber scope was carried out. Very fine water droplets of 0.01 mm order in size were observed at the interface between steam and heavy oil phases. These droplets entered into heavy oil phase and created emulsion together with the heated oil, which flowed down and was produced from the production well. It was successfully demonstrated that these micro phenomena has an influence on chamber expansion rate in horizontal direction and oil production rate.The numerical simulation of the SAGD process was also performed. The thermal simulator, CMG's STARS TM , was used to simulate the experimental steam chamber growth at the initial stage. The simulation used the two-components (water and heavy oil) black oil, three-phase (water, heavy oil and steam) and three-dimensional numerical model for the physical model. The results from the history-matched numerical simulation were found to be in good agreement with those of the experiments for oil production and steam chamber shape by using the Intermediate3-Stone1 wettability model represents fluids behavior cumulating the microscopic phenomena at the chamber interface. Furthermore, a new process named Surfactant-SAGD injecting a surfactant before starting steam injection to enhance the communication between two wells and mobility of the production fluids was tested.

Pore-level Investigation of Heavy Oil Recovery using Steam Assisted Gravity Drainage (SAGD)

“…Very fine water droplets produced at the chamber interface due to the condensation would move likely into the oil face (which has already been mobilized as a result of direct steam heating) immediately after generation. This microscopic invasion of very fine water droplets (in the order of 0.005 to 0.01mm in diameter) into the bitumen-filled region would likely create water-in-oil emulsions which should be drained under the resultant force of gravity-capillarity interaction [28]. This emulsification hypothesis on a plane interface is illustrated schematically in Figure 4a.…”

“…The topic of "emulsification phenomenon" during the typical SAGD process was covered in the literature based on the experiments conducted using scaled physical models as well as field-scale data [24,[26][27][28][29][30][31]. According to the field-scale trials of the SAGD process, the produced liquid is in the emulsion state composed of mobilized oil and water (either stable or unstable depending on the physicochemical characteristics of the interacting liquids as well as process operating conditions).…”

“…847 Drag forces applied from the moving oil film to the water droplet Schematic representation of a) pore-scale emulsion creation in SAGD process focusing on the near interface events (modified from [28]), and, b) engulfing phenomenon at the pore-scale. an oven (60°C) and under a backup pressure (i.e.…”

Measurement of Viscosity Alteration for Emulsion and Numerical Simulation on Bitumen Production by SAGD Considering In-situ Emulsification

“…An excellent review of current status and future issues on SAGD was presented by Al-Bahlani and Babadagli [1] in terms of experimental and numerical studies. As mentioned in their review, Sasaki et al [3] suggested the in-situ emulsification mechanism in the SAGD process as shown in Fig. 1.…”

“…In addition, the surface action of oil D DAVID PUBLISHING Fig. 1 Mechanism of SAGD process and in-situ emulsification modified from Sasaki et al [3].…”