CT Study of Liquid Diversion with Foam

Nguyen, Quoc Son; Zitha, Pacelli L.J.; Currie, Peter K.; Rossen, W.R.

doi:10.2523/93949-ms

Cited by 9 publications

(22 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Gas within and surrounding the liquid fingers dissolves into unsaturated liquid over time. This is consistent with findings in earlier core-flood studies (Kibodeaux et al 1994, Nguyen, et al 2009. We also reported in that study gas injectivity after foam and the liquid injectivity after a prolonged period of gas injection following foam.…”

Section: Introductionsupporting

confidence: 93%

Injectivity of Multiple Gas and Liquid Slugs in SAG Foam EOR: A CT Scan Study

Gong

Vincent-Bonnieu

Bahrim

et al. 2019

IOR 2019 – 20th European Symposium on Improved Oil Recovery

View full text Add to dashboard Cite

Surfactant-alternating-gas (SAG) is often the injection method for foam enhanced oil recovery (EOR) in order to improve injectivity. However, liquid injectivity can be very poor once foam is created in the near-wellbore region. In a previous study, we reported core-flood experiments on liquid injectivity after foam flooding and liquid injectivity after a period of gas injection following foam. Results showed the importance of the gas slug to subsequent liquid injectivity. However, the effects of multiple gas and liquid slugs were not explored. In this paper, we present a coreflood study of injectivities of multiple gas and liquid slugs in a SAG process. We inject nitrogen foam, gas and surfactant solution into a sandstone core sample. The experiments are conducted at a temperature of 90°C with 40-bar back pressure. Pressure differences are measured to quantify the injectivity and supplemented with CT scans to relate water saturation to mobility. We find that during prolonged gas injection in the first gas slug following foam, a collapsed-foam region forms near the inlet due to the interplay of evaporation, capillary pressure and pressure-driven flow. This region slowly propagates downstream. During subsequent liquid injection, liquid mobility is much greater in the collapsed-foam region than downstream, and liquid sweeps the entire core cross section there rather than a single finger. In the region beyond the collapsed-foam region, liquid fingers through foam. Liquid flow converges from the entire cross section to the finger through the region of trapped gas. During injection of the second gas slug, the liquid finger disappears quickly as gas flows in, and strong foam forms from the very beginning. A collapsed-foam region then forms near the inlet and slowly propagates downstream with a propagation velocity and mobility similar to that in the first gas slug. Behavior of the second liquid slug is likewise similar to that of the first liquid slug. Our results suggest that, in radial flow, the small region of foam collapse very near the well is crucial to injectivity because of its high mobility. The subsequent gas and liquid slugs behave like the first slugs. The behavior of the first gas slug and subsequent liquid slug is thus representative of near-well behavior in a SAG process.

show abstract

Section: Introductionsupporting

confidence: 93%

Injectivity of Multiple Gas and Liquid Slugs in SAG Foam EOR: A CT Scan Study

Gong

Vincent-Bonnieu

Bahrim

et al. 2019

IOR 2019 – 20th European Symposium on Improved Oil Recovery

View full text Add to dashboard Cite

show abstract

“…CT scan experiments of liquid injection directly following foam (Nguyen et al 2009) confirmed that liquid penetrates foam in one or two fingers in the core and displaces gas within the fingers, leaving foam outside of the fingers trapped in place. Unlike conventional fingering, with an increasingly non-uniform front as it advances, eventually forming fingers, liquid displaces foam only in these fingers directly from the inlet of the core.…”

Section: Introductionmentioning

confidence: 97%

“…Most of the literature specifically on liquid injectivity following foam is related to matrix acid diversion (Kibodeaux et al 1994;Zeilinger et al 1995;Nguyen et al 2003;Nguyen et al 2009). The objective in an acid stimulation process is to maintain low water relative permeability and reduce liquid injectivity to the greatest extent possible.…”

Section: Introductionmentioning

confidence: 99%

Laboratory Investigation of Liquid Injectivity in Surfactant-Alternating-Gas Foam Enhanced Oil Recovery

et al. 2019

View full text Add to dashboard Cite

Surfactant-alternating-gas (SAG) is a favored method of foam injection, in part because of excellent gas injectivity. However, liquid injectivity is usually very poor in SAG. We report a core-flood study of liquid injectivity under conditions like those near an injection well in SAG application in the field, i.e., after a prolonged period of gas injection following foam. We inject foam [gas (nitrogen) and surfactant solution] into a 17-cm-long Berea core at temperature of 90°C with 40 bar back pressure. Pressure differences are measured and supplemented with CT scans to relate water saturation to mobilities. Liquid injectivity directly following foam is very poor. During prolonged gas injection following foam, a collapsed-foam region forms near the inlet and slowly propagates downstream, in which water saturation is reduced. This decline in liquid saturation reflects in part liquid evaporation, also pressure-driven flow and capillary effects on the core scale. In the collapsed-foam region, liquid mobility during subsequent liquid injection is much greater than downstream, and liquid sweeps the entire core cross section rather than a single finger. Mobility in the region of liquid fingering is insensitive to the quality of foam injected before gas and the duration of the period of gas injection. This implies that at the start of liquid injection in a SAG process in the field, there is a small region very near the well, crucial to injectivity, substantially different from that further out, and not described by current foam models. The results can guide the development of a model for liquid injectivity based on radial propagation of the various banks seen in the experiments.

show abstract

“…Foam fluid has been widely applied in many fields, especially in the fields of drilling, well completion and oil recovery in the petroleum industry, and has achieved good results in many aspects, such as enhanced oil recovery, profile control, matrix acidizing, plugging removal, fracturing, etc. [1][2][3][4][5][6][7][8] Foam flow in porous media is a special gas-liquid two-phase flow and is a process of migration, rupture and regeneration of a series of liquid films. Foam can sharply decrease the mobility of gas and improve the sweep efficiency of flooding fluid in the formation, thus enhancing oil recovery.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Dynamic Texture and Flow Characteristics of Foam Transport in Porous Media Based on Fractal Theory

Wang

et al. 2019

Fractals

View full text Add to dashboard Cite

Foam fluid has found wide applications in oilfield development, such as profile control, water plugging, gas channeling control, fracturing, and so on. As a non-Newtonian fluid, the successful application of foam is significantly influenced by its structure. The foam texture, however, is complex and irregular, and becomes even more complicated in porous media by the boundary effects. Therefore, the description of dynamic foam structure is crucial and a quantitative description method for foam fluid is worth exploring. In this paper, the fractal characteristics of foam in porous media are verified and combined with foam microdisplacement experiment, and the fractal rule of foam is found. The relationship between fractal dimension and pressure is also discussed. The results show that foam has dynamic fractal characteristics during transport in porous media and the box-counting fractal dimension ranges from 1 to 2. Furthermore, the dynamic change of foam fractal dimension during transport in porous media could be divided into three stages. In the first stage when no foam forms, the fractal dimension is about 2; in the second unsteady foam stage, the fractal dimension is reduced from 1.9 to 1.6; the last one is the steady stage and the fractal dimension is almost constant (about 1.6). Besides, the fractal dimension of foam fluid is closely related to displacement pressure. Low pressure corresponds to higher fractal dimension, and high pressure corresponds to lower fractal dimension. Pressure is negatively linearly correlated with fractal dimension. These results are expected to enrich the understanding of the foam dynamic characteristics in their advanced applications.

show abstract

CT Study of Liquid Diversion with Foam

Cited by 9 publications

References 0 publications

Injectivity of Multiple Gas and Liquid Slugs in SAG Foam EOR: A CT Scan Study

Injectivity of Multiple Gas and Liquid Slugs in SAG Foam EOR: A CT Scan Study

Laboratory Investigation of Liquid Injectivity in Surfactant-Alternating-Gas Foam Enhanced Oil Recovery

Investigation of Dynamic Texture and Flow Characteristics of Foam Transport in Porous Media Based on Fractal Theory

Contact Info

Product

Resources

About