Mechanisms of foam generation in glass bead packs

Conference · Sun Jun 01 04:00:00 EDT 1986

OSTI ID:5053791

Ransohoff, T C; Radke, C J

Steam flooding is a common thermal technique to recover oil which is too viscous to be displaced by standard waterflooding techniques. Two of the problems associated with steam flooding are ''gravity override'' and ''viscous fingering.'' Gravity override occurs because the steam is much less dense than the oil which it is displacing, causing the steam to ''ride over'' the oil bank. Viscous fingering occurs because the displacing steam is much less viscous than the oil phase, causing channels or ''fingers'' to form. Thus, steam can bypass most of the oil. Fried suggested that these mobility problems might be ameliorated by injecting the steam in the form of a foam. Field tests have in fact demonstrated that foam can significantly increase the efficiency of a steam drive. Foam also holds promise for CO/sub 2/ flooding and as a general mobility-control fluid. The fundamental, pore-level mechanisms of foam generation are investigated in monodisperse bead packs. First, direct visual observations identify the following generation mechanisms: lamella leave behind, gas-bubble snap off, and lamella division. Then, to ascertain the relative importance of these mechanisms, quantitative experiments are pursued on the role of bead-pack permeability (bead sizes from 0.25 mm to 1 mm), gas-phase velocity (0.001 cm/s to 0.8 cm/s), gas-phase fractional flow (0.60 to 1.0), permeability variations, and surfactant type (SDBS, SDS, Chevron Chaser SD1000, and Suntech IV 1035). We discover a critical velocity, above which a ''strong'' foam is generated and below which only ''weak'' foam is formed. The snap-off mechanism is the primary mechanism responsible for the formation of the strong foam. A simple model, based on the concept of a ''germination site'', is developed to predict the onset of snap off at higher gas velocities. 27 refs., 18 figs., 3 tabs.

• Research Organization: California Univ., Berkeley (USA). Dept. of Chemical Engineering; Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5053791
• Report Number(s): LBL-21845; CONF-861080-5; ON: DE87001881
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
BENCH-SCALE EXPERIMENTS
CHEMICAL PREPARATION
COLLOIDS
DISPERSIONS
ENERGY SOURCES
ENHANCED RECOVERY
FLUID INJECTION
FOAMS
FOSSIL FUELS
FUELS
PERMEABILITY
PETROLEUM
RECOVERY
STEAM INJECTION
SURFACTANTS
SYNTHESIS
VELOCITY
VISCOSITY