A Newly Developed Mathematical Model to Predict Hydrolyzed Polyacrylamide Crosslinked Polymer Gel Plugging Efficiency in Fractures and High Permeability Features

2018 ◽  
Author(s):  
Sherif Fakher ◽  
Baojun Bai
Keyword(s):  
Mathematical Model ◽  
Polymer Gel ◽  
High Permeability ◽  
Crosslinked Polymer ◽  
Hydrolyzed Polyacrylamide

Freeze-etch TEM of aqueous polymer gel network morphology

1986 ◽  
Vol 44 ◽  
pp. 796-797
Author(s):  
J. A. N. Zasadzinski ◽  
R. K. Prud'homme
Keyword(s):  
Metal Ion ◽  
Polymer Network ◽  
Polymer Gels ◽  
Polymer Gel ◽  
Deformation History ◽  
Crosslinked Polymer ◽  
Aqueous Polymer ◽  
History Of ◽  
Gel Network ◽  
Network Morphology

The rheological and mechanical properties of crosslinked polymer gels arise from the structure of the gel network. In turn, the structure of the gel network results from: thermodynamically determined interactions between the polymer chain segments, the interactions of the crosslinking metal ion with the polymer, and the deformation history of the network. Interpretations of mechanical and rheological measurements on polymer gels invariably begin with a conceptual model of,the microstructure of the gel network derived from polymer kinetic theory. In the present work, we use freeze-etch replication TEM to image the polymer network morphology of titanium crosslinked hydroxypropyl guars in an attempt to directly relate macroscopic phenomena with network structure.

Understanding the Plugging Performance of HPAM-Cr (III) Polymer Gel for CO2 Conformance Control

SPE Journal ◽  
2020 ◽  
Author(s):  
Xindi Sun ◽  
Baojun Bai ◽  
Ali Khayoon Alhuraishawy ◽  
Daoyi Zhu
Keyword(s):  
Pressure Gradient ◽  
Low Permeability ◽  
Far Field ◽  
Polymer Gel ◽  
Co2 Flooding ◽  
High Permeability ◽  
Conformance Control ◽  
Gel Treatment ◽  
Plugging Performance ◽  
Breakthrough Pressure

Summary With the demand for conformance control in carbon dioxide (CO2) flooding fields, hydrolyzed polyacrylamide-chromium [HPAM-Cr (III)] polymer gel has been applied in fields for CO2 conformance control. However, the field application results are mixed with success and failure. This paper is intended to understand the HPAM-Cr (III) polymer gel plugging performance in CO2 flooding reservoirs through laboratory experiments and numerical analysis. We conducted core flooding tests to understand how the cycles of CO2 and water affect the HPAM-Cr (III) polymer gel plugging efficiency to CO2 and water during a water-alternating-gas (WAG) process. Berea Sandstone cores with the permeability range of 107 to 1225 md were used to evaluate the plugging performance in terms of residual resistance factor and breakthrough pressure, which is the minimum pressure required for CO2 to enter the gel-treated cores.We compared the pressure gradient from the near-wellbore to far-field with the gel breakthrough pressure, from which we analyzed under which conditions the gel treatment could be more successful. Results show that HPAM-Cr (III) polymer gel has higher breakthrough pressure in the low-permeability cores. The polymer gel can reduce the permeability to water much more than that to CO2. The disproportionate permeability reduction performance was more prominent in low-permeability cores than in high-permeability cores. The gel resistance to both CO2 and brine significantly decreased in later cycles. In high-permeability cores, the gel resistance to CO2 became negligible only after two cycles of water and CO2 injection. Because of the significant reduction of pressure gradient from near-wellbore to far-field in a radial flow condition and the dependence of breakthrough pressure on permeability and polymer concentration, we examined hypothetical reservoirs with no fractures, in which impermeable barriers separated high- and low-permeability zones and in which the gel was only placed in the high-permeability zone. We considered two scenarios: CO2 breaking through the gel and no CO2 breakthrough. No breakthrough represents the best condition in which the gel has no direct contact and can be stable in reservoirs for long. In contrast, the breakthrough scenario will result in the gel’s significant degradation and dehydration resulting from CO2 flowing through the gel, which will cause the gel treatment to fail.

scholarly journals PEG/PPG-PDMS-Adamantane-Based Crosslinked Terpolymer Using the ROMP Technique to Prepare a Highly Permeable and CO2-Selective Polymer Membrane

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1674
Author(s):  
Dongyoung Kim ◽  
Iqubal Hossain ◽  
Yeonho Kim ◽  
Ook Choi ◽  
Tae-Hyun Kim
Keyword(s):  
Ring Opening ◽  
Polymer Membranes ◽  
Crosslinking Density ◽  
Polymerization Process ◽  
Separation Performance ◽  
High Permeability ◽  
High Solubility ◽  
Crosslinked Polymer ◽  
Precursor Molecules ◽  
Gas Separation Performance

In this study, precursor molecules based on PEG/PPG and polydimethylsiloxane (PDMS), both widely used rubbery polymers, were copolymerized with bulky adamantane into copolymer membranes. Ring-opening metathesis polymerization (ROMP) was employed during the polymerization process to create a structure with both ends crosslinked. The precursor molecules and corresponding polymer membranes were characterized using various analytical methods. The polymer membranes were fabricated using different compositions of PDMS and adamantane, to determine how the network structure affected their gas separation performance. PEG/PPG, in which CO2 is highly soluble, was copolymerized with PDMS, which has high permeability, and adamantane, which controlled the crosslinking density with a rigid and bulky structure. It was confirmed that the resulting crosslinked polymer membranes exhibited high solubility and diffusivity for CO2. Further, their crosslinked structure using ROMP technique made it possible to form good films. The membranes fabricated in the present study exhibited excellent performance, i.e., CO2 permeability of up to 514.5 Barrer and CO2/N2 selectivity of 50.9.

Low-Salinity Chase Waterfloods Improve Performance of Cr(III)-Acetate Hydrolyzed Polyacrylamide Gel in Fractured Cores

2015 ◽  
Vol 19 (02) ◽  
pp. 331-339 ◽  
Author(s):  
Bergit Brattekås ◽  
Arne Graue ◽  
Randall S. Seright
Keyword(s):  
Fluid Flow ◽  
Water Phase ◽  
Polymer Gel ◽  
Low Salinity ◽  
Gel Swelling ◽  
The Matrix ◽  
Rupture Pressure ◽  
Salinity Water ◽  
Hydrolyzed Polyacrylamide ◽  
Blocking Capacity

Summary Polymer gels are frequently applied for conformance improvement in fractured reservoirs, where fluid channeling through fractures limits the success of waterflooding. Placement of polymer gel in fractures reduces fracture conductivity, thus increasing pressure gradients across matrix blocks during chase floods. A gel-filled fracture is reopened to fluid flow if the injection pressure during chase floods exceeds the gel-rupture pressure; thus, channeling through the fractures resumes. The success of a polymer-gel treatment, therefore, depends on the rupture pressure. Salinity differences between the gel network and surrounding water phase are known causes of gel swelling (e.g., observed in recent work on preformed particle gels). Gel swelling and its effect on fluid flow have, however, been less studied in conjunction with conventional polymer gels. By use of corefloods, this work demonstrates that low-salinity water can swell conventional Cr(III)-acetate hydrolyzed polyacrylamide (HPAM) gels, thereby significantly improving gel-blocking performance after gel rupture. Formed polymer gel was placed in fractured core plugs, and chase waterfloods were performed using four different brine compositions, of which three were low-salinity brines. The fluid flow rates through the matrix and differential pressures across the matrix and fracture were measured and shown to increase with decreasing salinity in the injected water phase. In some cores, the fractures were reblocked during low-salinity waterfloods, and gel-blocking capacity was increased above the initial level. Low-salinity water subsequently flooded the matrix during chase floods, which provided additional benefits to the waterflood. The improved blocking capacity of the gel was caused by a difference in salinity between the gel and injected water phase, which induced gel swelling. The results were reproducible through several experiments, and stable for long periods of time in both sandstone and carbonate outcrop core materials. Combining polymer gel placement in fractures with low-salinity chase floods is a promising approach in integrated enhanced oil recovery (IEOR).

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.

scholarly journals An Optimization Study of Polyacrylamide-Polyethylenimine-Based Polymer Gel for High Temperature Reservoir Conformance Control

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Zulhelmi Amir ◽  
Ismail Mohd Saaid ◽  
Badrul Mohamed Jan
Keyword(s):  
High Temperature ◽  
Raw Materials ◽  
Gelation Time ◽  
Quadratic Equation ◽  
Quadratic Model ◽  
Polymer Gel ◽  
Performance Information ◽  
Conformance Control ◽  
Crosslinked Polymer ◽  
Optimization Study

This paper presents optimization formulation of organically crosslinked polymer gel for high temperature reservoir conformance control using response surface methodology (RSM). It is always desirable to approach an optimal polymer gel formulation study with adequate performance information related to viscosity and gelation time to minimize excessive water production. In this paper, the effects of polymer and crosslinker concentrations and their influences on gelation time and viscosity were investigated. Central composite design (CCD) was used to determine the optimized organically crosslinked polymer gel formulation. Concentrations of two main raw materials, namely, polyacrylamide (PAM) and polyethylenimine (PEI), were varied in a suitable range. This was to obtain the formulation with the desirable two vital responses, which are viscosity and gelation time. It was found that the results fitted the quadratic equation. Statistically, the quadratic model is reliable and adequate perfectly the variability of the responses obtained from the experimental data. In addition, gelation time and gel viscosity may be controlled by adjusting both polymer and crosslinker concentrations. The optimum formulated organically crosslinked polymer gel with significant desirability factor conditions was achieved at 1.5% w/v of PAM and 0.3% v/v of PEI.

Water Shutoff and Zonal Isolation for High Permeability Depleted Reservoir Using Organically Crosslinked Polymer Sealant System

2020 ◽  
Author(s):  
Nasser Al-Azmi ◽  
Salem Al-Sabea ◽  
Abu-Eida Abdullah ◽  
Milan Patra ◽  
Nakul Khandelwal ◽  
...  
Keyword(s):  
High Permeability ◽  
Crosslinked Polymer ◽  
Water Shutoff ◽  
Zonal Isolation ◽  
Polymer Sealant
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