Evaluation of Acid-Gelling Agents for Use in Well Stimulation

1981 ◽  
Vol 21 (04) ◽  
pp. 415-424 ◽  
Author(s):  
C.W. Crowe ◽  
R.C. Martin ◽  
A.M. Michaelis
Keyword(s):  
Reaction Rate ◽  
Guar Gum ◽  
Hydroxyethyl Cellulose ◽  
Gelling Agent ◽  
Fluid Loss ◽  
Well Test ◽  
Reaction Products ◽  
Acid Stability ◽  
Gelling Agents ◽  
Thickening Agents

Abstract Various polymers and other thickening agents have been evaluated as gelling agents for hydrochloric acid (HCl). These materials were compared on the basis of thickening efficiency, acid stability, and residue formation upon spending of the acid. Thickeners tested include xanthan polymers (XP), guar gum (GG), hydroxyethyl cellulose (HEC), carboxymethyl-hydroxyethyl cellulose (CMHEC), polyacrylamide (PAM), polyvinyl alcohol (PVA), polyvinyl-pyrrolidone (P V P), acrylamide/sodium -2-acrylamido-2-methylpropane sulfonate copolymer (PAM/AMPS), and a cationic surfactant that thickens acid when used at high concentrations.Of the thickening agents tested, XP showed the greatest overall potential for use as an acid gelling agent. This polymer is an efficient viscosity builder and has good stability in 15 % HCl at temperatures up to 150 degrees F. Computer model studies, which take into consideration cool-down and gel degradation rate at various stages of acid spending, indicate viscosity is maintained when treating wells that have bottomhole temperatures (BHT's) up to 220 degrees F. Since the gelled acid retains its viscosity during spending, both reaction rate and fluid leakoff are retarded. Laboratory studies simulating downhole spending conditions yield a 3.6-fold increase in spending time for gelled 15 % HCl (22-cp) compared with ungelled acid. Well test results are presented that demonstrate the effectiveness of acid fracturing treatments using HCl with XP. Introduction Gelled acids have been used for many years to improve the effectiveness of fracture acidizing treatments. Gelling the acid allows greater fracture penetration by increasing fracture width, slowing reaction rate, and reducing fluid loss. Unfortunately, most commonly used gelling agents have limited acid stability and are effective only at low-temperature applications. Newer, more acid-stable polymers show promise for use at higher temperatures.When evaluating acid gelling agents, a number of important factors must be taken into consideration. These include the following. Acid Stability. How long is viscosity maintained in the treating acid at various temperatures? Efficiency. What concentration of gelling agent is required to achieve a desired viscosity? Condition of Spent Acid. Is the viscosity of the spent acid low enough to ensure cleanup and are insoluble reaction products formed upon spending of the acid? Acid Stability For an acid gelling agent to be effective, it must be sufficiently stable to retain its viscosity in acid under downhole spending conditions. Tests were performed in which gelling agents were mixed with preheated,]5 % HCl to compare the stability of various acid thickeners. After 1 minute, the initial viscosity was measured with a Fann 35 viscometer at a shear rate of 511 seconds . While maintaining the solution at the test temperature, additional viscosity measurements were made over a period of 1 hour. Table 1 describes the gelling agents that were evaluated, while Figs. 1 and 2 contain the test results.Tests performed at 100 degrees F demonstrate that gelling agents such as GG, hydroxypropyl guar gum (HPG), HEC, and CMHEC have limited stability in 15 % HCl. Consequently, their use at temperatures above 125 degrees F is not recommended. SPEJ P. 415^

Chemically Modified Natural Gum for Use in Well Stimulation

1977 ◽  
Vol 17 (01) ◽  
pp. 5-10 ◽  
Author(s):  
C.J. Githens ◽  
J.W. Burnham
Keyword(s):  
Hydraulic Fracturing ◽  
Apparent Viscosity ◽  
Guar Gum ◽  
Gelling Agent ◽  
Polymer Emulsion ◽  
Gelling Agents ◽  
Chemically Modified ◽  
Well Stimulation ◽  
Fracturing Fluids ◽  
New Material

Abstract A new polymer gelling agent has been developed to help satisfy the growing demand for "clean" hydraulic fracturing fluids. This polymer is a guar derivative that exhibits the desirable characteristics of conventional guar and that leaves low residue upon breaking. The derivatized guar was evaluated for its ability to function as a fracturing-fluid gelling agent in comparison with both a conventional guar and a nonionic cellulose derivative. The guar derivative possesses a number of advantages over both the conventional guar and the cellulose derivative. Laboratory experimental data and field results are presented. Introduction Hydraulic fracturing has been used successfully for oil- and gas-well stimulation for about 27 years. During this time the size of the treatments has grown from the original "tank of oil and sack of sand" to the current massive hydraulic fracturing treatments, entailing several hundred thousand gallons of fluid and large amounts of sand. These massive treatments have become routine in some areas of this country. Although many types of fluids have been used successfully, aqueous fluids have been preferred recently. Because of economic and safety considerations, aqueous fluids will likely continue to be preferred. Treatment designs usually require that the fluids possess a particular apparent viscosity. These stipulated viscosities are particular apparent viscosity. These stipulated viscosities are often many times higher than that of the base fluid in its natural state. The increased apparent viscosities are generally attained by the addition of hydrophilic polymeric "gelling agents." A variety of gelling agents for aqueous fluids is available. Each gelling agent possesses inherent chemical properties that often make it particularly applicable for a special function. These properties are a direct result of the chemical structure and stereochemistry of the repeating unit of the polymer, and the resulting conformation or macrostructure that the polymer assumes in the fluid. Polysaccharides, such as the guar polymer, possess many of the properties desired of a gelling agent. However, the relatively high percentage of insolubles (residue) present in commercial guar has been a matter of serious concern. Many believe that guar-gum residue can contribute to permanent formation and fracture conductivity damage. Because of the complexity of the situation, experimental evaluation of the over-all effect of this residue on the formation permeability and fracture flow capacity is difficult. However, there should be no question that the presence of the residue could result in damage to the formation and the proppant system, and that a reduction in the amount of residue proppant system, and that a reduction in the amount of residue present diminishes this possibility. present diminishes this possibility. A new low-residue, derivatized-guar (derivatized polysaccharide) gelling agent has been developed. This chemically polysaccharide) gelling agent has been developed. This chemically modified guar results in an 85-percent reduction in inherent residue over conventional guar gum, yet retains the desirable properties of the guar polymer. In addition, it provides an properties of the guar polymer. In addition, it provides an extension of guar chemistry and versatility into several new approaches for designing hydraulic fracturing fluids. This versatile polymer has application in most aqueous and polymer-emulsion hydraulic fracturing processes. polymer-emulsion hydraulic fracturing processes. In addition to possessing the obvious advantage of low residue, this new material can be dispersed controllably in aqueous fluids, thereby effectively reducing gel lumping tendencies. The result is a smooth, lump-free gel. It yields equivalent or slightly higher apparent viscosity values in fresh water and the usual brines compared with the old, conventional, guar-gum gelling agents. Alcohol tolerance of this new material is good, and it is readily complexed or crosslinked in water or alcohol-water mixtures with crosslinking agents. Fluids prepared with this new polymer may be manipulated to achieve temperature stability surpassing that of any gelled-water fracturing fluid containing the polysaccharides we have used in the past. SPEJ P. 5

scholarly journals Effect of gelling agents on in vitro development of Amelanchier canadensis ‘Rainbow Pillar’

2013 ◽  
Vol 19 (3-4) ◽  
Author(s):  
A. Fira ◽  
K. Magyar-Tábori ◽  
I. Hudák ◽  
D. Clapa ◽  
J. Dobránszky
Keyword(s):  
Guar Gum ◽  
Growth Parameters ◽  
Shoot Multiplication ◽  
Wheat Starch ◽  
Gelling Agent ◽  
Shoot Cultures ◽  
Gelling Agents ◽  
Shoot Number ◽  
The Media

In vitro shoot multiplication responses of Amelanchier canadensis ‘Rainbow Pillar’ were studied on media solidifi ed with different gelling agents. The media were gelled either with 6.8 g l-1 fi brous agar-agar, or 50.0 g l-1 wheat starch, or 20.0 g l-1 Guar gum, or 15 g l-1 Isubgol or 50.0 g l-1 wheat starch mixed with 0.5 g l-1 Phytagel. Shoot cultures were grown for two months, thereafter the multiplication rates (number of newly developed shoots per explant) were counted and the length of shoots were measured. We found that the highest shoot multiplication of Amelanchier canadensis ‘Rainbow Pillar’ occurred on media gelled with Guar gum, while the longest shoots developed on media with Starch. About four-fold shoot number were obtained on media with Guar gum compared to the weakest results found on media gelled with Isubgol. Finally, considering all factors (shoot growth parameters, costs) the most economical gelling agent for Amelanchier canadensis ‘Rainbow Pillar’ was proved to be wheat starch among the tested alternatives which allows a 75.6% cost reduction.

Decomposition of peroxobenzoic acid in benzene catalyzed by transition metal 2,4-pentanedionates

1984 ◽  
Vol 49 (3) ◽  
pp. 673-679 ◽  
Author(s):  
Pavel Lederer ◽  
Eva Mácová ◽  
Josef Vepřek-Šiška
Keyword(s):  
Transition Metal ◽  
Reaction Rate ◽  
Reaction Products ◽  
Acid Decomposition ◽  
Analogous Experiment ◽  
Catalytic Effects

The decomposition of peroxobenzoic acid in benzene was studied, and catalytic effects of Fe(III), Mn(III), Co(II), Co(III), and Cr(III) on the reaction rate and the composition of the reaction mixture were investigated. An analogous experiment carried out in perdeuterobenzene and determination of the distribution of deuterium in the reaction products provided evidence for the participation of the solvent in peroxobenzoic acid decomposition.

Kinetics of carbon monoxide methanation on a Ni/SiO2 catalyst

1990 ◽  
Vol 55 (7) ◽  
pp. 1678-1685
Author(s):  
Vladimír Stuchlý ◽  
Karel Klusáček
Keyword(s):  
Carbon Monoxide ◽  
Reaction Rate ◽  
Catalyst Activity ◽  
Adsorbed Hydrogen ◽  
Reaction Products ◽  
Co Methanation ◽  
Molar Ratios ◽  
Rate Determining Step ◽  
Higher Temperature ◽  
Kinetics Of

Kinetics of CO methanation on a commercial Ni/SiO2 catalyst was evaluated at atmospheric pressure, between 528 and 550 K and for hydrogen to carbon monoxide molar ratios ranging from 3 : 1 to 200 : 1. The effect of reaction products on the reaction rate was also examined. Below 550 K, only methane was selectively formed. Above this temperature, the formation of carbon dioxide was also observed. The experimental data could be described by two modified Langmuir-Hinshelwood kinetic models, based on hydrogenation of surface CO by molecularly or by dissociatively adsorbed hydrogen in the rate-determining step. Water reversibly lowered catalyst activity and its effect was more pronounced at higher temperature.

scholarly journals Use of Alternative Gelling Agents Reveals the Role of Rhamnolipids in Pseudomonas aeruginosa Surface Motility

Biomolecules ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1468
Author(s):  
Charles D. Morin ◽  
Eric Déziel
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Strong Dependence ◽  
Gellan Gum ◽  
Gelling Agent ◽  
Gelling Agents ◽  
Bacterial Surface ◽  
Solid Media ◽  
Surface Motility ◽  
Wetting Agents ◽  
The Impact

Pseudomonas aeruginosa is a motile bacterium able to exhibit a social surface behaviour known as swarming motility. Swarming requires the polar flagellum of P. aeruginosa as well as the secretion of wetting agents to ease the spread across the surface. However, our knowledge on swarming is limited to observed phenotypes on agar-solidified media. To study the surface behaviour and the impact of wetting agents of P. aeruginosa on other surfaces, we assessed surface motility capabilities of the prototypical strain PA14 on semi-solid media solidified with alternative gelling agents, gellan gum and carrageenan. We found that, on these alternative surfaces, the characteristic dendritic spreading pattern of P. aeruginosa is drastically altered. One striking feature is the loss of dependence on rhamnolipids to spread effectively on plates solidified with these alternative gelling agents. Indeed, a rhlA-null mutant unable to produce its wetting agents still spreads effectively, albeit in a circular shape on both the gellan gum- and carrageenan-based media. Our data indicate that rhamnolipids do not have such a crucial role in achieving surface colonization of non-agar plates, suggesting a strong dependence on the physical properties of the tested surface. The use of alternative gelling agent provides new means to reveal unknown features of bacterial surface behaviour.

scholarly journals Development of Instant Linear Gel for Coal Bed Methane Gas Operations

2021 ◽  
Vol 1 (3) ◽  
Author(s):  
Ramana Murthy RVV
Keyword(s):  
Sodium Acetate ◽  
Guar Gum ◽  
Small Concentration ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Ammonium Persulphate ◽  
Gelling Agents ◽  
Fracturing Fluids ◽  
Degradation Pattern ◽  
Suspending Agents

Previously we prepared fracturing linear gel with fossil diesel, bio-diesel and also used suspending, anti-settling agents and emulsifiers. But through this research, a novel and efficient method for the preparation of linear gel directly mixed with water, guar gum and sodium acetate together instantly. In this instead of diesel, we used water and no need to mix anti-settling agents, suspending agents, emulsifiers that resulted in 30 viscosity linear gel. Ammonium persulphate or Ammonium peroxidisulphate and enzyme-G are used for oxidation purposes to break the gel gradually at a particular static temperature. The degradation pattern observed from the breaker test showed that a reduction in gel viscosity depends on time, temperature & breaker concentration. Observations from experiments revealed that a small concentration of breakers provides rapid break compared to oxidative breakers. This article, designing of fracturing fluids describes how to use the fluid's viscosity generated by the gelling agents like guar gum for CBM operations.

Biodegradation of Guar Gum in Hydraulic Fracturing Fluid under the Action of Enzyme Preparations of Basidiomycetes

2021 ◽  
Vol 37 (4) ◽  
pp. 96-105
Author(s):  
E.Yu. Kozhevnikova ◽  
A.V. Shnyreva ◽  
A.V. Barkov ◽  
Yu.A. Topolyuk ◽  
I.N. Grishina ◽  
...  
Keyword(s):  
Guar Gum ◽  
Schizophyllum Commune ◽  
Petroleum Industry ◽  
Environmentally Friendly ◽  
Gelling Agent ◽  
Fungal Mycelium ◽  
Fomitopsis Pinicola ◽  
Trametes Hirsuta ◽  
Enzyme Preparations ◽  
Fracturing Fluids

Guar gum is a polymer that is widely used as a gelling agent for technological liquids in the petroleum industry. In this paper, we have studied the potential for the environmentally friendly biodegradation of guar gum by enzymes of basidiomycetes for efficient disposal of oil industry wastes. For the first time, we compared the enzymatic activity towards guar gum of seven basidiomycete strains, namely Trametes hirsuta MT-24.24, Lactarius necator, Trametes hirsuta MT-17.24, Schizophyllum commune MT-33.01, Fomes fomentarius MT-4.05, Fomitopsis pinicola MT-5.21, and Trametes versicolor It-1. This comparison showed that the preparation based on Fomitopsis pinicola MT-5.21 fungal mycelium at a concentration of 0.05% provides the most efficient decomposition of a frac fluid containing guar gum. By varying the enzyme concentration in this fluid it is possible to control the decrease in its viscosity over time. The developed enzyme preparation is an efficient and environmentally friendly guar gum biodegradant and can be used to process waste fracturing fluids based on polysaccharides in order to reuse water resources. Key words: biodegradants, basidiomycetes, guar gum, enzymatic hydrolysis, enzyme destructors, fracturing fluids. Funding - The work was financially supported by the National University of Oil and Gas "Gubkin University" (Internal grant no. 120720 "Development of New Biotechnological Methods and Materials for Environmental Protection and Biomedicine").

Rheological and textural analysis as tools for investigation of drug-polymer and polymer–polymer interactions on the example of low-acyl gellan gum and mesalazine

2022 ◽  
pp. 088532822110527
Author(s):  
Piotr Gadziński ◽  
Tomasz Zbigniew Osmałek ◽  
Anna Froelich ◽  
Oliwia Wilmańska ◽  
Agata Nowak ◽  
...  
Keyword(s):  
Profile Analysis ◽  
Polymer Network ◽  
Crosslinking Agent ◽  
Gellan Gum ◽  
Hydroxyethyl Cellulose ◽  
Rheological Analysis ◽  
Gelling Agents ◽  
Texture Profile ◽  
Ionic Crosslinking ◽  
Model Drug

Purpose. In the performed study, the rheological and textural parameters of gellan-based hydrogels were investigated and their dependence on three factors was taken into consideration: ( i) The presence of the model drug, ( ii) The presence and type of the ionic crosslinking agent, and ( iii) the composition of the polymer network. The objective was to compare two analytical methods, regarded as complementary, and define to what extent the obtained results correlate with each other. Methods. The hydrogels contained low-acyl gellan gum or its mixtures with hydroxyethyl cellulose or κ-carrageenan. CaCl2 and MgCl2 were used as gelling agents. Mesalazine was used as a model drug. The rheological analysis included oscillatory stress and frequency sweeping. The texture profile analysis was performed to calculate texture parameters. Results. Placebo gels without the addition of gelling agents had the weakest structure. The drug had the strongest ability to increase the stiffness of the polymer network. The weakest structure revealed the placebo samples without the addition of gelling agents. Texture analysis revealed no significant influence of the drug on the strength of the gels, while rheological measurements indicated clear differences. Conclusions. It can be concluded that in the case of some parameters methods correlate, that is, the effect related to gelling ions. However, the rheological analysis seems to be more precise and sensitive to some changes in the mechanical properties of the gels.

Study on Preparation of Ti Powder by Self-Propagating High-Temperature Synthesis (SHS) with Magnesiothermit Reductive Process

2008 ◽  
Vol 575-578 ◽  
pp. 1086-1092
Author(s):  
Peng Lin Zhang ◽  
Tian Dong Xia ◽  
Guo Dong Zhang ◽  
Li Jing Yan
Keyword(s):  
Reaction Rate ◽  
Combustion Temperature ◽  
Combustion Process ◽  
Green Compact ◽  
Reaction Products ◽  
Technological Parameters ◽  
Solid Reaction ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Ti Powder

The combustion process of Mg-TiO2 system was preliminarily investigated from three aspects of thermodynamics, reaction kinetics and the technological parameters. The result indicates that the adiabatic temperature of Mg-TiO2 system is between 2060K and 2140K because the major existent modalities of TiO2 is the rutile and anatase, this meets the empirical criterion that the SHS reaction will be self-sustaining; The solid-solid reaction occurs at about 767K; Ti powders can be produced only when the ratio between Mg and TiO2 arrives at 2.9:1; The higher the vacuum, the more complete the reaction; The combustion temperature arrives at its peak when the pressure of green compact arrives at 250MPa; the velocity of the combustion wave increases with the augmentation of the pressure of green compact. So the proper control of the technological parameters can change the reaction temperature, reaction rate and the components of reaction products.

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