As important intermediates generated during surfactant flooding, emulsions are widely acknowledged to be beneficial for enhanced oil recovery. Formation and flow behaviors of W/O O/W have been reported in detail. Nevertheless, W/O/W not sufficiently investigated, which the most common products chemical flooding heavy reservoirs. In this study, two systems with different emulsification tendencies were evaluated by both core microfluidic experiments. Core experiments strong emulsifying (SES)...

The relationship between NaCl concentration and the phase change behavior of microemulsion anionic surfactant was characterized by salinity scan experiments. wettability Winsor I type solution (WI solution) effect NaCL on WI imbibition in oil-wet porous media were investigated microfluidic experiments this study. are similar wetting with stronger than other phases. Two main mechanisms enhancing imbibitions recovery oil wet drive residual solubilization. Under condition microemulsion, has...

Considering the characteristics of carbonate reservoirs in Middle East, a low-viscosity microemulsion acid that can be prepared on site and has an appropriate retardation ability was developed. It compared with four conventional systems (hydrochloric acid, gelled emulsified surfactant acid) through experiments rotating disk, multistage fracturing core flooding CT scanning. The micro-etching conductivity fracture surfaces were clarified, variation saturation field during water invasion...

In order to study the microscopic oil displacement mechanism of polymeric surfactant in chemical cold flooding for heavy oil, indoor visualization experiments were carried out. The experiment was conducted by using water, osmotic modified displacing agent (a kind surfactant) and water-in-oil emulsion (obtained mixing oil) as phases enhance recovery reservoir. experimental results show that can increase viscosity water phase, reduce water-oil mobility ratio, expand swept area, there is no...

To solve the problems of long experiment period and difficult measurement in core imbibition experiments, fracture—matrix microfluidic chips different sizes, boundary conditions wettability regulated by surface property modification were designed to research mechanisms oil-water, oil-surfactant solution oil-Winsor III type surfactant solution. In oil-wettability system process, oil was replaced from matrix through Haines jump, capillary back pressure main resistance blocking flow oil,...

Summary Enhanced oil recovery (EOR) in fractured carbonate reservoirs is challenging because of the heterogeneous and oil-wet nature. In this work, a new application using polymer nanospheres (PNSs) diluted microemulsion (DME) presented to plug fractures enhance water imbibition recover from tight, naturally reservoirs. DME with different electric charges compared through contact-angle core-imbibition tests evaluate their performances on EOR. The cationic chosen it has fastest...

Summary For reservoirs containing oil with a high total acid number, the alkali-cosolvent-polymer (ACP) flood can promote formation of microemulsion rather than viscous macroemulsion and achieve good mobility control. The enhanced recovery (EOR) performance ACP has been studied at core reservoir scale in detail; however, effect on residual still lacks enough research. In this paper, micromodel single channel is used to clarify dynamic effects alkali-cosolvent (AC) solutions after waterflood....

Abstract Recovery in low permeability oil reservoirs is challenging because they are often high fractured and oil-wet. Microemulsion-forming surfactant solutions, which can replace from tight matrix by imbibition, have been verified as effective enhanced recovery fluids for reservoirs. To better understand the mechanisms of oil-wet, rocks using microemulsion-forming surfactants, microfluidic experiments including single channel micromodel tests imbibition could visualize in-situ phase...

The existing researches on surfactant micellar solutions mainly focus the formulation optimization and core flooding test, types mechanisms of cleanup additives suitable for low permeability reservoir remain unclear. flowback efficiencies different were evaluated by experiments, a multi-level pore-throat system micromodel characterizing structures was made, experiments brine salinities conducted with to show oil process in micron pores under effect solution visually reveal enhancing...

The main means of secondary oil recovery is water flooding, which has been widely used in various oilfields. Different flow rates have a great impact on the ratio and occurrence remaining oil. Scholars carried out extensive research it, but mostly macro scale, three-dimensional micro scale also limited by accuracy lack accurate understanding. In this paper, micro-CT core displacement experiments are to intuitively show state under different rates. Through series quantitative image processing...

Abstract Replacing oil from small pores of tight rocks relies on altering the rock wettability with injected fracturing fluid. Among different types wettability-alteration surfactants, liquid nanofluid (LNF) has less adsorption loss during transport in porous media and can efficiently alter wettability; both make LNF a promising candidate to enhance recovery reservoirs. In this study, 2.5-D visualized micromodel micro-sized pore throats is applied elucidate impacts alteration spontaneous...

With the help of digital image processing technology, an automatic measurement method for three-phase contact angles in pore throats microfluidic model was established using water flooding experiment videos as data source. The results new were verified through comparing with manual data. On this basis, dynamic changes under flow conditions clarified by probability density curve and mean value change curve. show that, water-wetting rocks, is acute angle during early stage process, it...

Abstract The formation mechanism and utilization conditions of the remaining oil in high water cut period play significant roles improved tapping potential enhanced recovery. classification is a difficult point, meanwhile burning issue. However, current method mainly through manual to determine boundaries classification, time-consuming has great subjectivity. Machine learning data mining methods recent years have been widely used field petroleum engineering, such as prediction recovery...

Multi-stage acid fracturing can boost productivity in low-permeability limestone reservoirs, with success hinging on differential etching and the strength of undissolved regions to keep fractures open. Traditional rock test methods have strong randomness error. This study explores influence four systems (hydrochloric acid, single-phase retarded gelled emulsified acid) fracture surface based a new continuous method. The weakening variation under different types injection conditions was...

Summary During an acid fracturing treatment, the preflush and spent injected by multistage alternate injection will enter matrix; this part of aqueous phase entering matrix cause serious water blocking damage during crude oil production, hinder migration in matrix, reduce well productivity. There is a large amount small-sized pore throats low-permeability bioclastic limestone reservoirs. The are important channels for hydrocarbon flow more vulnerable to under effect capillary pressure....

Abstract ASP (Alkali/Surfactant/Polymer) flooding has been successfully applied in several field pilots the Daqing oil China. Oil recovery improved by about 20% OOIP over waterflooding. The interfacial tension (IFT) of ASP/crude is one most important factors that control effectiveness flooding. effects alkali, surfactant, polymer and properties on IFT were previously studied. This paper addresses effect injection water quality oil. analyzes inorganic ion compositions organic compounds...

In situ microemulsion, a promising tertiary oil recovery technique, involves injecting surfactant solution capable of forming underground microemulsions (MS) to enhance mobilization. Typically, previous scholars have extensively conducted macroscopic salinity or oil–water ratio scanning experiments examine the static phase behavior in microemulsion. However, there is still limited understanding regarding dynamic formation and transport mechanisms three types dead-end porous media. this...

ABSTRACT: As a novel method of profile control and enhanced oil recovery, polymer microspheres have been applied extensively in the industry. Based on mechanism microspheres, an equivalent numerical simulation is established paper to predict its application performance. The comprehensively considers properties such as expansion, retention, blockage, degradation. And accuracy proven by matching vital data laboratory experiments. Then sensitivity analysis injection parameters carried out...

Abstract The microfluidic experiments were conducted in this paper to clarify the flow dynamics of situ microemulsion and further understand its EOR performances. Two kinds 2.5D glass micromodel with varied depths pore throat are fabricated. One is designed for imbibition tests, which consists two fractures a tight matrix. Another one fractured flooding tests. micromodels originally water wet, can be altered oil wet through surface modification. At same time, three microemulsion-forming...