Fractional Flow Behaviour and Transport Mechanisms During Low salinity and Protein Enzyme Bio-surfactant EOR Flooding

Abstract

The focal point of this project is to investigate and assess the potentiality of an enhanced waterflooding process by a naturally generated surfactant (Protein-Enzyme bio-surfactant). The effect of low salinity (LSW), and LSW combined with a bio-surfactant (Protein-Enzyme) in a tertiary mode flooding comparatively. A high salinity water (HS) (0.75 M) was used to flood in the secondary mode after aging the crude saturated core with an initial water saturation of 19%, a recovery of 68.15% oil initially in place (OIIP) was recovered until no further recovery. Upon flooding with a LSW (90% dilution of HS), a further incremental recovery of 11.1% OIIP was produced. Enhancing the LSW with bio-surfactant in a third flooding sequence, an additional 3.75% OIIP was recovered. Analysing the mechanism of LSW bio-surfactant with fractional flow, a high recovery of 0.583 PV (pore volumes) at breakthrough was estimated. Thus, an alteration in ionic strength (salinity) by a 90% dilution and combination of bio-surfactant, saw an incremental recovery, which indicates the potential of LSW bio-surfactant on recovery of residual oil saturation.

Mechanisms of Waterflood Inefficiency: Analysis of Geological, Petrophysical and Reservoir History, a Field Case Study of FWU (East Section)

“…For example, when a calcium ion (Ca 2+ ) is exchanged, a little molecule of thickness of a well-ordered layer of water is adsorbed by the clay. In the case of sodium ion (Na + ), disordered layers of water are adsorbed, leading to an indefinite swelling of the clay [2,25,49]. Fragmentation of smectite or mixed-layer smectite and illite occurs when the clays swell.…”

“…Waterflooding is dominant amongst fluid injection methods and responsible for high levels of oil production (over fifty percent of recovery worldwide) [1][2][3]. This technique is employed to increase hydrocarbon recovery when there is a significant decline in primary production resulting from the depletion of the reservoir pressure [4,5].…”

“…This popularity hails from the general availability of water, relative ease of injectivity due to the possession of hydraulic head in injection wells, ability to spread within reservoirs, and its efficiency in oil displacement. The performance or success of waterflooding varies from one reservoir to another with factors such as reservoir stratigraphy and geology, as well as fluid and in situ static and dynamic properties, accounting for most of this variation [2,8]. The North Finn in 1989 recorded a number of waterflooding failures in its North Carson Muddy oilfield, accounting for more than half of its cash flow.…”

Experimental and Numerical Evaluation of Enzyme-Assisted Hot Waterflooding Performance for Heavy Oil Reservoirs

“…Moreover, enzyme has been proved with its good EOR potential in various reservoirs such as low permeability reservoirs (Liu and Zhang, 2011), conventional reservoirs (Jain and Sharma, 2012), and heavy oil reservoirs (Feng et al, 2009). In addition, enzymes have been tested with good EOR performance under a wide range of formation water salinity (Feng et al, 2007;Morgan et al, 2020a) and reservoir temperature (Feng et al, 2007). Also, it has been found that enzyme could potentially be used as an effective additive for different EOR processes including cold heavy oil production, CSS, waterflooding, and CO2 or nitrogen injection (Ott et al, 2011).…”