Experimental and Modeling Study of the Transport of Chromium Acetate Solutions Through Carbonate Rocks

SPE Journal ◽  
2010 ◽  
Vol 15 (02) ◽  
pp. 349-367 ◽  
Author(s):  
F.. Chen ◽  
C.S.. S. McCool ◽  
D.W.. W. Green ◽  
G.P.. P. Willhite
Keyword(s):  
Chromium Concentration ◽  
Reservoir Rock ◽  
Water Production ◽  
Polymer Systems ◽  
Common System ◽  
Recovery Processes ◽  
Rate Controlled ◽  
Hydrolyzed Polyacrylamide ◽  
Dolomite Rock ◽  
Chromium Acetate

Summary Gelled polymer systems are applied to oil reservoirs to reduce water production and to increase sweep efficiencies in recovery processes. A common system consists of hydrolyzed polyacrylamide with a chromium (III) crosslinker. Transport of these chemicals through the reservoir rock is essential for a successful treatment. In carbonate reservoirs, dissolution of the carbonate raises the pH of the gelant to levels where chromium precipitates, robbing the gelant of crosslinker. The transport of chromium acetate solutions through dolomite rock material was studied by injecting various solutions through short cores and measuring Cr, Mg, and Ca concentrations and pH in the effluent. Chromium retention in the cores caused by precipitation was a rate-controlled process. A mathematical model was developed that described convection, dispersion, kinetic reactions of carbonate dissolution and chromium precipitation, and chemical equilibrium for reactions between aqueous components. Experimental data from this work and taken from literature were simulated by the model. One rate equation with one set of parameters described the steady-state values of chromium concentration exiting the cores after the breakthrough of the injected solutions.

A new injectable biphasic hydrogel based on partially hydrolyzed polyacrylamide and nanohydroxyapatite as scaffold for osteochondral regeneration

RSC Advances ◽  
2015 ◽  
Vol 5 (12) ◽  
pp. 9089-9096 ◽  
Author(s):  
Newsha Koushki ◽  
Ali Asghar Katbab ◽  
Hossein Tavassoli ◽  
Azadeh Jahanbakhsh ◽  
Mohammad Majidi ◽  
...  
Keyword(s):  
Partially Hydrolyzed Polyacrylamide ◽  
Osteochondral Repair ◽  
Nanocrystalline Hydroxyapatite ◽  
Hydrolyzed Polyacrylamide ◽  
Osteochondral Regeneration ◽  
Novel Scaffold ◽  
Chromium Acetate

Fabrication of an injectable biphasic hydrogel based on partially hydrolyzed polyacrylamide (HPAM), nanocrystalline hydroxyapatite (nHAp), and chromium acetate (Cr(iii)) as a novel scaffold for osteochondral repair has been attempted.

scholarly journals Polymer gels for controlling water thief zones in injection wells

2012 ◽  
Vol 5 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Gustavo-Adolfo Maya-Toro ◽  
Rubén-Hernán Castro-García ◽  
Zarith del Pilar Pachón-Contreras. ◽  
Jose-Francisco Zapata-Arango
Keyword(s):  
Oil Recovery ◽  
Water Injection ◽  
Injection Wells ◽  
Recovery Processes ◽  
Injection Water ◽  
Secondary Oil Recovery ◽  
High Concentrations ◽  
Low Efficiency ◽  
Hydrolyzed Polyacrylamide ◽  
Positive Results

Oil recovery by water injection is the most extended technology in the world for additional recovery, however, formation heterogeneity can turn it into highly inefficient and expensive by channeling injected water. This work presents a chemical option that allows controlling the channeling of important amounts of injection water in specific layers, or portions of layers, which is the main explanation for low efficiency in many secondary oil recovery processes. The core of the stages presented here is using partially hydrolyzed polyacrylamide (HPAM) cross linked with a metallic ion (Cr+3), which, at high concentrations in the injection water (5000 – 20000 ppm), generates a rigid gel in the reservoir that forces the injected water to enter into the formation through upswept zones. The use of the stages presented here is a process that involves from experimental evaluation for the specific reservoir to the field monitoring, and going through a strict control during the well intervention, being this last step an innovation for this kind of treatments. This paper presents field cases that show positive results, besides the details of design, application and monitoring.

Effects of Gelant Composition and Pressure Gradients of Water and Oil on Disproportionate Permeability Reduction of Sandpacks Treated with Polyacrylamide-Chromium Acetate Gels

SPE Journal ◽  
2006 ◽  
Vol 11 (02) ◽  
pp. 145-157 ◽  
Author(s):  
Tuan Q. Nguyen ◽  
Don W. Green ◽  
G. Paul Willhite ◽  
C. Stanley McCool
Keyword(s):  
Steady State ◽  
Water Permeability ◽  
Polymer Gels ◽  
Permeability Reduction ◽  
Pressure Gradients ◽  
Water Production ◽  
Petroleum Reservoir ◽  
Fractional Flow ◽  
Gel Composition ◽  
Chromium Acetate

Summary For some polymer gels applied in reservoirs to control water flow, a favorable disproportionate permeability reduction (DPR) occurs in which permeability to water is reduced to a much greater extent than it is to oil. Permeability reduction in sandpacks by partially hydrolyzed polyacrylamide-chromium acetate gels was studied as functions of gel composition and the pressure gradients imposed on the gels. For the range of parameters studied, increased gel composition increased the factors by which the permeabilities to water and oil were reduced. Increased gel composition also increased selectivity, a measure of the water-permeability reduction with respect to oil-permeability reduction. Applied pressure gradients during steady-state flows had little effect on oil permeability and a moderate effect on water permeability. Material balances on phases and components in the sandpacks provided insights into mechanisms responsible for the development of flow channels through gelled sandpacks and mechanisms contributing to favorable DPR. Increased pressure gradient during channel development decreased the selectivity of the treatment. Introduction High water production is a major concern in mature hydrocarbon reservoirs. Costs of handling and disposing of water produced from oil reservoirs often shorten the life of a production well. Disposal of the water is also an environmental concern. In order to reduce water production, polymer gels have been used to modify the mobility of water and oil in petroleum reservoirs. When some gels are placed in a petroleum reservoir, permeability reduction occurs to a much greater extent for water than for oil. This phenomenon is known as favorable DPR. Reduced permeability to water can lead to decreased production of water, and sometimes increased oil production, thereby prolonging the useful life of the reservoir. Results reported in the literature have shown that the application of several polymer gel systems can result in DPR. Mechanisms for DPR have been debated, and the magnitude of the effect has been unpredictable from one application to another. Mechanisms for DPR that have been proposed and studied by several researchers are shown in Table 1. The usual method to study DPR is to saturate a porous medium with gelant, allow time for gelation to occur, and then inject oil and water to steady-state conditions and determine permeabilities at 100% fractional flow of each fluid. One aspect of this procedure that most of these experimental works do not describe or examine is the process that occurs when oil or water is first injected into the gel-treated porous media. It is our experience that the medium has very little permeability at the start of injection and that considerable time is required for the injected fluid to develop channels or flow paths through the system before a steady state is approached.

GELATION KINETICS ACCOUNTING WHEN MODELING ENHANCED OIL RECOVERY METHODS

2020 ◽  
Vol 6 (4) ◽  
pp. 101-126
Author(s):  
Alexey A. Ishkov ◽  
Ruslan F. Mazitov ◽  
Alexey S. Shlyapkin ◽  
Evgeniy N. Malshakov
Keyword(s):  
Oil Recovery ◽  
Injection Rate ◽  
Reservoir Rock ◽  
Design Parameters ◽  
Residual Resistance ◽  
New Approach ◽  
Technological Efficiency ◽  
Software Product ◽  
Gel Composition ◽  
Chromium Acetate

This paper presents a new approach to modeling flow deflectors. The developed approach takes into account changes in rheology properties of gel compositions depending on time and temperature. The effects of changes in the residual resistance factor of the reservoir rock depending on the gel composition concentration and permeability are also considered. In addition, the general concepts included in the developed injection software product used to calculate the geometry of gel screens placement and the effects of their application are shown. All rheological characteristics of gel composition used in the software product are obtained by laboratory means at the stage of free volume studies and on filtration core models. The developed product allows correctly simulating the processes of gel screen formation in the bottomhole formation zone and evaluating technological efficiency depending on the treatment design. The following characteristics can be used as variable design parameters: concentrations of polyacrylamide and chromium acetate cross-linked, the sequence of increasing/decreasing polyacrylamide and chromium acetate cross-linked concentrations, the volume of both the composition as a whole and individual rims, pressure and injection rate.

A Novel Branched Polymer Gel System with Delayed Gelation Property for Conformance Control

SPE Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Tao Song ◽  
Qi Feng ◽  
Thomas Schuman ◽  
Jie Cao ◽  
Baojun Bai
Keyword(s):  
Gelation Time ◽  
Polymer Gels ◽  
Environmental Concerns ◽  
Water Production ◽  
Polymer Gel ◽  
Conformance Control ◽  
Branched Polymer ◽  
Chelating Ability ◽  
Hydrolyzed Polyacrylamide ◽  
Gel System

Summary Excessive water production from oil reservoirs not only affects the economical production of oil, but it also results in serious environmental concerns. Polymer gels have been widely applied to decrease water production and thus improve oil production. However, traditional polymer gels such as partially hydrolyzed polyacrylamide (HPAM)/chromium (III) gel systems usually have a short gelation time and cannot meet the requirement of some conformance control projects. This paper introduces a novel polymer gel system of which crosslinking time can be significantly delayed. A branched polymer grafted from arginine by the surface initiation method is synthesized as the backbone, chromium acetate is used as the crosslinker, and no additional additives are used for the gel system. The results show that the gelation time of this system can be delayed to 61 days at 45°C and 20 days at 65°C because of the rigid structure of the branched polymer and the excellent chromium (III) chelating ability of arginine. The polymer gels have been stable for more than 150 days at 45 and 65°C. Coreflooding and rheology tests have demonstrated that this branched polymer has good injectivity and shear resistance in high-permeabilityrocks.

Controlling Water Production Using Gelled Polymer Systems

2008 ◽  
Vol 11 (03) ◽  
pp. 454-465 ◽  
Author(s):  
G. Paul Willhite ◽  
Richard E. Pancake
Keyword(s):  
Water Production ◽  
Polymer Systems

Polymer Systems for Water Shutoff and Profile Modification: A Review Over the Last Decade

SPE Journal ◽  
2013 ◽  
Vol 19 (01) ◽  
pp. 135-149 ◽  
Author(s):  
Khalid Saad El-Karsani ◽  
Ghaithan A. Al-Muntasheri ◽  
Ibnelwaleed A. Hussein
Keyword(s):  
Oil And Gas ◽  
Water Injection ◽  
Gelation Time ◽  
Field Application ◽  
Injection Wells ◽  
Polyelectrolyte Complexes ◽  
Polymer Systems ◽  
Water Shutoff ◽  
Wide Range ◽  
Hydrolyzed Polyacrylamide

Summary Unwanted water production is a serious issue in oil- and gas-producing wells. It causes corrosion, scale, and loss of productivity. One method of treating this problem is to chemically reduce unwanted water. This paper discusses the use of polymer systems for this purpose and presents a thorough review of available literature over the last decade. In this paper, field-application data for various polymer systems are summarized over the range of 40 to 150°C (104 to 302°F). These applications cover a wide range of permeabilities from 20 to 2,720 md in sandstone and carbonate reservoirs around the globe. Moreover, the review revealed that the last decade of developments can be categorized into two major types. The first type is polymer gels for total water shutoff in the near-wellbore region, in which a polymer is crosslinked with either an organic or an inorganic crosslinker. The second type is concerned with deep treatment of water-injection wells diverting fluids away from high-permeability zones (thief zones). These thief zones take most of the injected water, which results in a large amount of unrecovered oil. For the total-blocking gels, various systems were identified, such as polyurethane resins, chromium (Cr3+) crosslinking terpolymers, Cr3+ crosslinking foamed partially hydrolyzed polyacrylamide (PHPA), and nanoparticle polyelectrolyte complexes (PECs) sequestering Cr3+ for elongation of its gelation time with PHPA. In addition, polyethylenimine (PEI) was identified to crosslink various polyacrylamide- (PAM-) based polymers. The Petróleos de Venezuela S.A. (PDVSA) Research and Development Center developed a PAM-based thermally stable polymer and an organic crosslinker. The system is applicable for a wide temperature range from 50 to 160°C (130 to 320°F). For the deep modification of water-injection profiles in water-injection wells, two systems were identified: microspheres prepared from PAM monomers crosslinked with N,N′-methylenebisacrylamide and microspheres produced by crosslinking 2-acrylamido-2-methylpropane sulfonic acid (AMPS) with diacrylamides and methacrylamides of diamines (thermally activated microparticles known as Bright Water). This paper highlights all major developments in these areas.

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