New Agent for Formation-Damage Mitigation in Heavy-Oil Reservoir: Mechanism and Application

Abstract

Migration of formation fines has been shown to cause production decline in many wells, especially for sand production wells in heavy oil reservoir. Filter cakes in wire wrapped liner, which were formed by the attachment of viscous crude oil blended with formation fines, may block the flow paths of viscous oil. The solution to this problem is appropriate treatment to mitigate this type of formation damage.In this paper the performance at laboratory-scale of a new type of agent for formation damage mitigation is presented and some guidelines for its application including the injected pore volume and injection concentration are provided.The mechanism for damage mitigation with this type of agent in heavy oil reservoir was introduced in detail, it mainly include that this type of agent can reduce interfacial tension between crude oil and water and change the wettability of rock surface, which may lead to the breakaway of resins and asphaltenes attached to the rock surface.By simulation experiments and core flood tests the effectiveness of this type of agent to mitigate the damage in heavy oil reservoir was identified. Simulation experiment results show that, damage mitigation in cores with the permeability higher than 1μm 2 , is more effective than those with the permeability lower than 1μm 2 , and core flood experiment results also indicate that this type of agent with the concentration of higher than 5% can remarkably increase recovery factor for cores with the permeability higher than 1μm 2 . Finally some results on the behaviour of its application in heavy oil reservoir are presented.

Experimental Investigations of Behaviour of Biosurfactants in Brine Solutions Relevant to Hydrocarbon Reservoirs

“…A closely related surface activity was observed with all the brine solutions and slight increase in surface activity. The results of the combined salinity and temperature effect on surface activity and stability of rhamnolipid and Greenzyme show that the trend of surface activity is a function of brine composition but their respective surface activity is stable with increase in temperature which is consistent with other studies [11,17,[44][45][46]. Raheb and Hajipour [46] also observed rhamnolipid stability up to 100 • C, while Amani et al [44] and Amani [17] observed rhamnolipid stability at 120 • C. More so, Xu et al [45] also observed increase in surface activity of six protein samples investigated over a range of 23-60 • C temperature.…”

“…They have also been identified as a good substitute for chemical surfactants in most applications in various fields such as environmental, biotechnological, food, medical processes as well as oil industries [3,7,8]. Also, past studies have reported enhanced oil recovery (EOR) potential of biosurfactants (e.g., [9][10][11][12][13][14][15][16][17]). However, most of these studies were not conducted with brine composition and salinity relevant to hydrocarbon reservoirs.…”

“…They have been extensively studied due to their wide applications in other processes such as soil remediation. Greenzyme is a water soluble protein-enzyme produced using DNA of selected oil-eating microbes [11,24]. Greenzyme has not been extensively studied, although there are some recent studies (e.g., [13,25]) on its EOR applications but limited studies have been reported on its physicochemical properties.…”

A Synergy between Controlled Salinity Brine and Biosurfactant Flooding for Improved Oil Recovery: An Experimental Investigation Based on Zeta Potential and Interfacial Tension Measurements

“…Hence, there has been increased research on biologically generated surfactants (biosurfactants) as substitute for chemical surfactants and studies have reported the biosurfactants to be as efficient as chemical surfactants in different applications [27]. Also, past studies have reported EOR potential of biosurfactants (e.g., [22,[28][29][30][31][32][33][34]) but effect of biosurfactants on zeta potential of CORB system has not been explored. The main objective of this study, therefore, is to investigate the potential of synergy between CSB and biosurfactants for further improvement of oil recovery and to investigate their effect on rock-fluid interactions.…”

A Review of Enzyme-Induced Calcium Carbonate Precipitation Applicability in the Oil and Gas Industry

“… Wang et al (2008 ) conducted three core flooding experiments on three different handmade cemented rock samples using three enzyme concentrations (1, 2, and 5%). The oil was recovered from flooding in 90–95% of cases, and there was no significant recovery difference among the three enzyme concentrations; however, the most recovery was accomplished with 5%.…”