Shifting to a New EOR Area for Sandstone Reservoirs with High Recovery, No Damage, and Low Cost

Attia, Mohamed; Mahmoud, Mohamed; Al-Hashim, Hasan S.; Sultan, Abdullah S.

doi:10.2118/169670-ms

Cited by 13 publications

(9 citation statements)

References 8 publications

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“…One can attribute the reduction in magnesium concentration to the deposition of magnesium carbonate to substitute for calcium carbonate dissolution from the rock surface and (multi-ion exchange). Multi-ion exchange between calcium and magnesium on the rock surface was proved to be one of the mechanisms contributing to the wettability alteration (Austad et al 2009). Water-wetness will increase, and this will increase the oil recovery.…”

Section: Resultsmentioning

confidence: 99%

Chelating-Agent Enhanced Oil Recovery for Sandstone and Carbonate Reservoirs

Mahmoud

Abdelgawad

2015

SPE Journal

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Recently low-salinity waterflooding was introduced as an effective enhanced-oil-recovery (EOR) method in sandstone and carbonate reservoirs. The recovery mechanisms that use low-salinitywater injection are still debatable. The suggested possible mechanisms are: wettability alteration, interfacial-tension (IFT) reduction, multi-ion exchange, and rock dissolution. In this paper, we introduce a new chemical EOR method for sandstone and carbonate reservoirs that will give better recovery than the low-salinitywater injection without treating or diluting seawater.In this study, we introduce a new chemical EOR method that uses chelating agents such as ethylenediaminetetraacetic acid (EDTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), and diethylenetriaminepentaacetic acid (DTPA) at high pH values. This is the first time for use of chelating agents as standalone EOR fluids. Coreflood experiments, interfacial and surface tensions, and zeta-potential measurements are performed with DTPA, EDTA, and HEDTA chelating agents. The chelating-agent concentrations used in the study were prepared by diluting the initial concentration of 40 wt% with seawater and injecting it into Berea-sandstone and Indiana-limestone cores of a 6-in. length and a 1.5-in. diameter saturated with crude oil. The coreflooding experiments were performed at 100 C and a 1,000-psi backpressure. Low-salinity-water and seawater injections caused damage to the reservoir because of the calcium sulfate scale deposition during the flooding process. The newly introduced EOR method did not cause calcium sulfate precipitation, and the core permeability was not affected. The core permeability was measured after the flooding process, and the final permeability was higher than the initial permeability in the case of chelating-agent injection. The coreflooding effluent was analyzed for cations with the inductively coupled plasma (ICP) spectroscopy to explain the dissolution-recovery mechanism. The effect of iron minerals on the rock-surface charge was investigated through the measurements of zeta potential for different rocks containing different iron minerals.HEDTA and EDTA chelating agents at 5 wt% concentration prepared in seawater were able to recover more than 20% oil from the initial oil in place from sandstone and carbonate cores. ICP measurements supported the rock-dissolution mechanism because the calcium, magnesium, and iron concentrations in the effluent samples were more than those in the injected fluids. The IFTreduction mechanism was confirmed by the low IFT values obtained in the case of chelating agents. The type and concentration of chelating agents affected the IFT value. Higher concentrations yielded lower IFT values because of the increase in carboxylic-group concentration. We found that the high-pH chelating agents increased the negative value of zeta potential, which will change the rock toward more water-wet.

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Section: Resultsmentioning

confidence: 99%

Chelating-Agent Enhanced Oil Recovery for Sandstone and Carbonate Reservoirs

Mahmoud

Abdelgawad

2015

SPE Journal

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“…For example, for scale removal process, iron control and matrix stimulation. Recently, they are being used as standalone fluids for enhanced oil recovery, stimulation and water alteration applications 22 .…”

Section: Introductionmentioning

confidence: 99%

Laboratory dielectric measurements to evaluate the conductivity change in the presence of chelating agent with different brines

Alarifi

Mahmoud

2022

Sci Rep

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In the oil and gas reservoirs, the interaction between the injected fluids and the reservoir fluids and rocks plays a major role in the productivity of any oil and gas field. Studying the ion exchange between reservoir fluids and the injected fluids for water flooding or chemical enhanced oil recovery purposes would help in optimizing the oil displacement process and hence the productivity form such secondary or tertiary recovery mechanisms. Chelating agents are used for enhance oil recovery to improve the oil displacement and sweep efficiency by altering the reservoir rock’s surface. When it comes to fluid-rock interaction, conductivity and ionic activity of the injected water will have a great impact on the rock’s surface charge and therefore in the reservoir’s wettability. Dielectric laboratory measurements have the ability to observe the change in conductivity at high frequency due to the presence of free ions and salts in fluids. In this work, observing the effect of chelating agent with different salts on high frequency conductivity using laboratory dielectric measurements has been conducted. Introducing laboratory dielectric measurement could be a valuable tool in the lab as an evaluation technique into the ion exchange that occurs between different fluids from the reservoir with different brines and additives to study the fluid–fluid interaction activities. It can be also utilized to investigate the maximum chelating capacity of different chelating agents with different cations which can be reflected by the change in conductivity.

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“…The low corrosiveness nature of chelating agents enables using it in different aspects of the oil and gas industry including scale removal from electrical submersible pumps in oil production wells [18], Scale inhibition [19][20], Filter cake removal after drilling operations [21]. In addition, aminocarboxylic acids were used to improve oil recovery from subsurface hydrocarbon reservoirs [22][23]. Different chelating agents were also used as standalone stimulation fluids at a wide range of pH values at high-pressure high-temperature (HPHT) conditions [24][25].…”

Section: Chelating Agentsmentioning

confidence: 99%

Reaction Kinetics and Coreflooding Study of High-Temperature Carbonate Reservoir Stimulation Using GLDA in Seawater

et al. 2019

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Well stimulation using hydrochloric acid (HCl) is a common practice in carbonate reservoirs to overcome formation damage in the near wellbore area. Using HCl for matrix acidizing has many limitations at high-temperature (HT) conditions, such as tubulars corrosion and face dissolution due to the fast reaction rate. Chelating agents, such as L-glutamic acid-N,N-diacetic acid (GLDA), are alternatives to HCl to overcome these problems. We studied the effect of diluting GLDA in seawater on the reaction kinetics with carbonate rocks under HT conditions at low pH (3.8). Results of the reaction of carbonate at 1000 psi and 150, 200, and 250 °F with GLDA prepared in both fresh and seawater, GLDA/DI and GLDA/SW, respectively, are presented. The reaction kinetics experiments were carried out in HT rotating disk apparatus (RDA) at rotational speeds ranging from 500 to 2000 revolutions per minute (RPM) at a fixed temperature. Indiana limestone and Austin chalk were used to studying the effect of rock facies on the reaction of GLDA with rock samples. In both GLDA/DI and GLDA/SW, the reaction regime of 20 wt% GLDA (3.8 pH) with Indiana limestone was mass transfer limited. The reaction rate and diffusion coefficient were highly dependent on the temperature. For Austin chalk, at 200 °F and 1000 psi the diffusion coefficient of GLDA/SW is an order of magnitude of its value with Indiana limestone using the same fluid. Diffusion coefficients were used to estimate the optimum injection rate for stimulating HT carbonate formation and compared with coreflooding results. The data presented in this paper will support the numerical simulation of the acid flow in carbonate reservoirs.

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Shifting to a New EOR Area for Sandstone Reservoirs with High Recovery, No Damage, and Low Cost

Cited by 13 publications

References 8 publications

Chelating-Agent Enhanced Oil Recovery for Sandstone and Carbonate Reservoirs

Chelating-Agent Enhanced Oil Recovery for Sandstone and Carbonate Reservoirs

Laboratory dielectric measurements to evaluate the conductivity change in the presence of chelating agent with different brines

Reaction Kinetics and Coreflooding Study of High-Temperature Carbonate Reservoir Stimulation Using GLDA in Seawater

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