An Optical Method for Immediate Evaluation of Microfoam Stability in Foam Sclerotherapy

2021 ◽  
Vol 34 (3) ◽  
pp. 128-134
Author(s):  
Taoping Bai ◽  
Wentao Jiang ◽  
Lin Liang ◽  
Yalan Li ◽  
Yubo Fan
Keyword(s):  
Half Life ◽  
Optical Method ◽  
Clinical Performance ◽  
Foam Stability ◽  
Life Time ◽  
Optical Methods ◽  
Foam Sclerotherapy ◽  
Drainage Rate ◽  
Short Period ◽  
The Stability

<b><i>Objectives:</i></b> The objective of our study was to develop an optical method that instantly evaluates the stability of sclerosing foam, which would enable early predictions of the clinical performance of the foam and reduce the occurrence of clinical side effects. <b><i>Methods:</i></b> Based on the principle of light scattering, we developed a method to optically test foam stability and verified it experimentally using sodium morrhuate (2 mL; 0.05 g/mL) and carbon dioxide. A self-made foam preparation instrument was used to achieve a preparation speed of 275 mm/s. The liquid-gas ratios were considered as 1:3, 1:4, and 1:5. Curves of illuminance with respect to the drainage rate and decay time were obtained. By fitting the curve, the relationship between foam half-life time (FHT) and foam decay was obtained. Thus, foam stability was evaluated using the initial illuminance value; the foam transfer time was approximately 3 s. <b><i>Results:</i></b> The experimental FHT varies between 205 and 232 s. Illuminance is exponentially related to drainage rate and linearly related with time. FHT can be expressed by the initial illuminance and illuminance curve fitting coefficients. The half-life of the foam decreases as the initial illuminance value increases, for the same sclerosing drug. The suitability of foam stability is determined by the position of the initial value in the chart. <b><i>Conclusion:</i></b> Optical methods are feasible for evaluating foam stability over a short period of time. Clinically predicting the stability of freshly prepared foam can reduce number of incidences of further complications. This will promote the development of foam sclerotherapy and provide a basic understanding of the internal mechanical properties of foam.

An investigation on the influence of glycerin on sclerosant foam stability

2011 ◽  
Vol 26 (6) ◽  
pp. 232-234 ◽  
Author(s):  
J D Peterson ◽  
M P Goldman
Keyword(s):  
Half Life ◽  
Foam Stability ◽  
Varicose Veins ◽  
Injection Technique ◽  
Foam Sclerotherapy ◽  
System Technique ◽  
Negative Effect ◽  
Sodium Tetradecyl Sulphate ◽  
Time Required ◽  
Disposable Plastic

Background Foam sclerotherapy is an increasingly popular modality in the treatment of varicose veins. Foam stability varies according to foam composition, volume and injection technique. Materials and methods A disposable plastic connector was used to create foam from 0.50% sodium tetradecyl sulphate (STS) mixed with varying volumes of glycerin. As a measure of foam stability, the half liquid time was defined as the time required for half of the original volume of sclerosing solution to settle. Three recordings were determined for each of the three mixtures of sclerosant foam. Results The time for sclerosing solution to settle to half of its initial volume was found to be 89 seconds for 0.50% STS alone, 117.7 seconds with the addition of 0.1 mL of 72% glycerin, and 114.7 seconds with the addition of 0.2 mL of 72% glycerin. Conclusion The small volumes of glycerin added to STS prolonged the half liquid time of STS foam up to 35%. As glycerin alone is unable to be foamed with the double-syringe system technique there may be a point at which further addition of glycerin has a negative effect on the half-life of foam.

Laboratory Studies For Design of a Foam Pilot For Reducing Gas Channeling From Gas Cap in Production Well in Messoyakhskoye Field

2021 ◽  
Author(s):  
Emil Rinatovich Saifullin ◽  
Chengdong Yuan ◽  
Maiia Vladimirovna Zvada ◽  
Mikhail Alekseevich Varfolomeev ◽  
Shinar Kayratovna Shanbosinova ◽  
...  
Keyword(s):  
Half Life ◽  
Foam Stability ◽  
Polymer Concentration ◽  
Life Time ◽  
Injection Well ◽  
Production Well ◽  
High Permeability ◽  
Optimal Injection ◽  
Gas Channeling ◽  
Polymer Stabilizers

Abstract Messoyakhskoye field, operated by Gazprom Neft, is currently experiencing gas channeling from gas cap in production wells because of strong heterogeneity. Foam for a long has been considered as a good candidate for gas blocking, (Svorstol I. et al., 1996), (Hanssen, J. E., & Dalland, M. 1994), (Aarra, M. G. et al., 1996). However, foam injection for gas blocking in injection well is different from that in production well, where it is necessary to selectively and long-term impact on gas-saturated highly permeable areas without affecting the phase permeability of oil in the reservoir. This paper provides detailed laboratory studies that show how to determine suitable foam systems for gas blocking in production well. For gas blocking in production well, a long half-life time is required to sustain stable foam because a continuous shear of surfactant solution/gas can't be achieved like in injection well. Therefore, reinforced foam by polymer is chosen. Four polymer stabilizers and five foam agents were evaluated using bulk test to determine foaming ability, foam stability, and effect of oil by comparing foam rate and half-life time to determine the suitable foam system. Furthermore, filtration experiments were conducted at reservoir conditions to determine the optimal injection mode by evaluating apparent viscosity, breakthrough pressure gradient, resistance factor, and residual resistance factor. Polymer can significantly improve half-life time (increase foam stability), and the higher the polymer concentration, the longer the half-life time. But simultaneously, a high polymer concentration will increase the initial viscosity of solution, which not only decreases the foam rate, but also increases difficulties in injection. Therefore, an optimal polymer concentration of about 0.15-0.2 wt% is determined considering all these influences. Filtration experiments showed that the apparent viscosity in core first increased and then deceased with foam quality (the ratio of gas volume to foam volume (gas + liquid). The optimal injection mode is co-injection of surfactant/polymer solution and gas to in-situ generate foam at the optimal foam quality of about 0.65. Filtration experiments on the different permeability cores showed that gas-blocking ability of polymer reinforced foam is better in high-permeability cores, which is beneficial for blocking high permeability zone. It should be also noted that under a certain ratio of oil to foam solution (about lower than 1 to 1), the presence of oil slowly decreased foam rate with increasing oil volume, but significantly increased half -life time, which is favorable for foam treatment in production well. This work highlights the difference between foam injection for gas blocking in production well and injection well, and emphasizes the use of polymer reinforced foam. Moreover, this work shows systematic experimental methods for choosing suitable foam systems for gas blocking in production well considering different factors, which provides a guide regarding what kinds of foaming agents and polymer stabilizers should be used and how to evaluate them for designing a pilot application.

AVALIAÇÃO DO TEMPO DE MEIA-VIDA DE ANTOCIANINAS DE UVAS CABERNET SAUVIGNON EM “SORBET”

2004 ◽  
Vol 22 (2) ◽  
Author(s):  
ELIANA FORTES GRIS ◽  
LEILA DENISE FALCÃO ◽  
EDUARDO ANTONIO FERREIRA ◽  
MARILDE T. BORDIGNON LUIZ
Keyword(s):  
Vitis Vinifera ◽  
Half Life ◽  
Life Time ◽  
Vitis Vinifera L ◽  
Cabernet Sauvignon ◽  
Natural Pigments ◽  
Color Retention ◽  
Uv Visible ◽  
The Stability

O objetivo deste trabalho foi avaliar a estabilidade e a viabilidade da aplicação de antocianinas de casca de uva Cabernet Sauvignon ( Vitis vinífera L.) como corante natural em “sorbet”. As amostras foram monitoradas pela medida da absorbância em espectrofotômetro (ultra-violeta visível) durante 7 semanas. Foram realizados cálculos de tempo de meiavida e percentagem de retenção de cor desses pigmentos em “sorbet”.O experimento foi realizado com três repetições em triplicata. Os resultados demonstraram que a utilização desses pigmentos em “sorbet” é viável, apresentando tempo de meia-vida de aproximadamente 8 meses e percentagem de retenção de cor de 87,7 % ao final do experimento. EVALUATION OF HALF-LIFE TIME OF ANTHOCYANINS OF CABERNET SAUVIGNON GRAPES IN SORBET Abstract The aim of the present work was to evaluate the stability and viability of anthocyanins application in the husks of Cabernet Sauvignon ( Vitis vinifera L.) grapes as natural pigments. Samples were monitored by absorbance measure in spectrophotometer UV-visible during 7 weeks. Half-life calculations and color retention percentual of this pigments in sorbet were realized. The experiment was accomplished with three repetitions in three replicates. The results demonstrated that the utilization of this pigments in sorbet is viable, showing half-life of approximately 8 months and color retention percentual of 87.7% at the end of the experiment.

scholarly journals Laboratory Analysis of Foam Generating Surfactants and Their Thermal Stability for Enhanced Oil Recovery Application

2020 ◽  
Vol 39 (2) ◽  
Author(s):  
Muhammad Khan Memon ◽  
Ubedullah Ansari ◽  
Habib U Zaman Memon
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Foam Stability ◽  
Sodium Dodecyl ◽  
Life Time ◽  
Alpha Olefin Sulfonate ◽  
Alpha Olefin ◽  
Secondary Oil Recovery ◽  
The Stability ◽  
Brine Salinity

The residual oil after primary or secondary oil recovery can be recovered by the methods of EOR (Enhanced Oil Recovery). The objective of this study is screening the surfactants that generate maximum stable foam in the presence of brine salinity at 92oC. Laboratory experiments have been performed to examine and compare the stability of generated foam by individual and blended surfactants in the synthetic brine water. AOS C14-16 (Alpha Olefin Sulfonate) and SDS (Sodium Dodecyl Sulfonate) were selected as main surfactants. Aqueous stability test of AOS C14-16 and SDS with brine water salinity 62070ppm was performed at 92oC. AAS (Alcohol Alkoxy Sulfate) was blended with SDS and AOS C14-16. The solution was stable in the presence of brine salinity at same conditions. Salt tolerance experimental study revealed that AOS C14-16 did not produce precipitates at 92oC. Further, the foam stability of surfactant blend was performed. Result shows that, the maximum life time of generated foam was observed by using blend of 0.2wt% SDS+0.2wt% AOS+0.2wt% AS-1246 and 0.2wt% AOS+0.2wt% IOSC15-18+0.2wt% AAS surfactants as compared to the foam generated by individual surfactants. The success of generated foam by these surfactant solutions in the presence of brine water is the primary screening of surfactant stability and foamability for EOR applications in reservoirs type of reservoirs.

scholarly journals Static and flow behaviors of supercritical CO2 foam stabilized with betaine surfactant for mobility control application

2021 ◽  
Vol 76 ◽  
pp. 58
Author(s):  
Weitao Li ◽  
Kai Wang ◽  
Wenkuan Zheng
Keyword(s):  
High Temperature ◽  
Surfactant Concentration ◽  
Foam Stability ◽  
Mobility Control ◽  
Core Flooding ◽  
Sweep Efficiency ◽  
Film Drainage ◽  
Drainage Rate ◽  
Temperature And Pressure ◽  
The Stability

Aiming at improving the stability of Supercritical CO2 (SC-CO2) foam in high temperature and salinity reservoirs, a kind of betaine surfactant, Hexadecyl Hydroxypropyl Sulfo Betaine (HHSB), was screened to stabilize SC-CO2 foam. The properties of SC-CO2 foam were improved at elevated temperature and pressure. The effects of surfactant concentration, temperature, pressure and salinity on film drainage rate were measured to explore the stability of SC-CO2 foam. The results showed that an increase of surfactant concentration, pressure and salinity can decrease film drainage rate and enhance the foam stability, which was attributed to the increase of surfactant adsorption at the gas–liquid interface. The performance of SC-CO2 foam formed by HHSB was improved and the tolerant temperature was up to 100 °C. 1-D core flooding experiments indicated that compared with Coinjection of Surfactant and Gas (CSG) method the SC-CO2 foam generated through Surfactant-Alternative-Gas (SAG) method had lower foam strength but better in-depth migration capacity. The high temperature and pressure 3-D sand showed that in Water-Alternative-Gas (WAG) case CO2 broke early through the high permeability layers. In SAG case, SC-CO2 foam can improve the macroscopic sweep efficiency by reducing the CO2 mobility.

Polidocanol foam stability in terms of its association with glycerin

2013 ◽  
Vol 29 (5) ◽  
pp. 304-309 ◽  
Author(s):  
R Rial ◽  
L S Hervas ◽  
G Monux ◽  
A Galindo ◽  
A Martin ◽  
...  
Keyword(s):  
Surface Tension ◽  
Foam Stability ◽  
Control Group ◽  
Foam Sclerotherapy ◽  
Time Control ◽  
Group 3 ◽  
Group 2 ◽  
The Stability ◽  
Microscopic Measurement ◽  
Group 1

Objectives: Foam sclerotherapy effectiveness mainly depends on the concentration of the sclerosing agent and foam stability. The objective of this study was to determine if the addition of glycerol at different concentrations contributes to the stability of polidocanol foam. Materials and methods: Control Group: 3% polidocanol. Group 1: polidocanol 3% + glycerin 1.66%. Group 2: polidocanol 3% + glycerin 3.3%. Group 3: polidocanol 3% + Glycerin 5%. Tessari standard method. Five recordings were made for each mixture. Early visual liquefaction time and half liquid time decay were recorded in seconds. Microscopic measurement of the foams. Mixtures surface tension measurement (N/m). Results: Early visual liquefaction: Control Group: 27 (± 3.11); Group 1: 67.8 (± 6.49); Group 2:48.6 (± 8.2); and Group 3: 35.8 (± 4.49). Half-liquid time: Control: 129.2 (± 11.00); Group 1: 260.4 (±18.99); Group 2: 224.6 (±13.03); and Group 3: 189.2 (±8.52). Bubbles/mm2–diameter–wall thickness: Control: 68–98 μm-7 μm; Group 1: 189–60 μm-9 μm; Group 2: 76–92 μm-12 μm; and Group 3: 49–112 μm-20 μm. Surface tension: Control = 5.54 N/m; Group 1 = 5.45 N/m; Group 2 = 5.35 N/m; and Group 3 = 5.21 N/m. Conclusions: Small amounts of glycerin highly increase the stability and quality of polidocanol foam. This simple chemical method is easily reproducible and applicable.

Assessment of Foamed Fluids Based on Surfactants and Nanoparticles for Fracturing and Acidizing Applications

2021 ◽  
Author(s):  
Abeer Alarawi ◽  
Abdullah Al Moajil ◽  
Abdullah Alrustum ◽  
Waddah AlMahri
Keyword(s):  
Half Life ◽  
Foam Stability ◽  
Foam Height ◽  
Spherical Shape ◽  
Stability Index ◽  
Life Time ◽  
High Viscosity ◽  
Optical Microscope ◽  
Low Viscosity ◽  
Average Size

Abstract Foamed fluids are commonly used in acidizing and fracturing applications to minimize formation damage, improve fluid recovery, and as diverting-agents. However, significant concerns with foamed fluids are poor stability and low viscosity. The study objectives include evaluating the commercially available surfactants’ foamability and stability when mixed with and without nanoparticles. The prepared foamed fluid characteristics such as rheology, morphology, stability, and proppant suspension were evaluated. Foam loop rheometer experiments were conducted at 1500 psi and 70% N2 quality to assess foam-stability and rheological properties. Foam decaying time was detected by half-life-time measurements (measuring foam-height as a function of time). Turbiscan was used to study the proppant settling using backscattering light. A high-resolution optical microscope was used to observe foam morphology and stability. The surfactant C-nanoparticles-based foamed fluid demonstrated stable foam with a high viscosity value that reached &gt;110 cP at 100 S-1 77 °F and 70% N2 quality. Compared to the surfactant-based foamed fluid, combining the surfactant with nanoparticles as a foam-stabilizer increased the foam-half-life-time by nearly 35-75%. Foam bubbles size of surfactants A and B (with/without NPs) were large with an irregular shape and tended to rupture intermittently within 50 and 8 minutes, respectively. Bubbles average size of surfactant C (with/without NPs) based foams was small, and the count was higher than the foams of surfactants A and B. surfactant C (with/without NPs) based foams demonstrated bubbles with a spherical shape. Turbiscan stability index values of several surfactants-nanoparticles-based foamed fluids were almost comparable at 77 and 122 °F. Lastly, the foam fluids’ proppant settling velocity prepared with nanoparticles was lower than pure surfactant-based foams.

Studies on Foam Decay Trend and Influence of Temperature Jump on Foam Stability in Sclerotherapy

2017 ◽  
Vol 52 (2) ◽  
pp. 98-106 ◽  
Author(s):  
Taoping Bai ◽  
Yu Chen ◽  
Wentao Jiang ◽  
Fei Yan ◽  
Yubo Fan
Keyword(s):  
Half Life ◽  
Temperature Jump ◽  
Foam Stability ◽  
Time Range ◽  
Control Group ◽  
Influence Of Temperature ◽  
Drainage Time ◽  
Drainage Rate ◽  
C 23 ◽  
Gas Ratio

Objectives: This study investigated the influence of temperature jump and liquid–gas ratio on foam stability to derive the foam-decay law. Methods: The experimental group conditions were as follows: mutation temperatures (10°C, 16°C, 20°C, 23°C, 25°C, and 27°C to >37°C) and liquid–gas ratios (1:1, 1:2, 1:3, and 1:4). The control group conditions were as follows: temperatures (10°C, 16°C, 20°C, 23°C, 25°C and 27°C) and liquid–gas ratios (1:1, 1:2, 1:3, and 1:4). A homemade device manufactured using the Tessari DSS method was used to prepare the foam. The decay process was videotape recorded. In the drainage rate curve, the temperature rose, and the liquid–gas ratio varied from 1:1 to 1:4, causing faster decay. Results: In the entire process, the foam volume decreased with increasing drainage rate. The relationships were almost linear. Comparison of the experimental and control groups shows that the temperature jump results in a drainage time range of 1 to 15 seconds. The half-life ranges from 10 to 30 seconds. The maximum rate is 18.85%. Changes in the preparation temperature yields a drainage time range of 3 to 30 seconds. The half-life varies from 20 to 60 seconds. Conclusion: Decreasing the temperature jump range and liquid–gas ratio gradually enhances the foam stability. The foam decay time and drainage rate exhibit an exponential function distribution.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

Covalent Complexes Between Low Molecular Weight Heparin Fragments and Antithrombin III – Inhibition Kinetics and Turnover Parameters

1983 ◽  
Vol 49 (02) ◽  
pp. 109-115 ◽  
Author(s):  
M Hoylaerts ◽  
E Holmer ◽  
M de Mol ◽  
D Collen
Keyword(s):  
Molecular Weight ◽  
Half Life ◽  
Low Molecular Weight Heparin ◽  
Antithrombin Iii ◽  
Factor Xa ◽  
Life Time ◽  
Low Molecular Weight ◽  
High Affinity ◽  
Plasma Half Life ◽  
Covalent Complex

SummaryTwo high affinity heparin fragments (A/r 4,300 and M, 3,200) were covalently coupled to antithrombin III (J. Biol. Chem. 1982; 257: 3401-3408) with an apparent 1:1 stoichiometry and a 30-35% yield.The purified covalent complexes inhibited factor Xa with second order rate constants very similar to those obtained for antithrombin III saturated with these heparin fragments and to that obtained for the covalent complex between antithrombin III and native high affinity heparin.The disappearance rates from plasma in rabbits of both low molecular weight heparin fragments and their complexes could adequately be represented by two-compartment mammillary models. The plasma half-life (t'/j) of both low Afr-heparin fragments was approximately 2.4 hr. Covalent coupling of the fragments to antithrombin III increased this half-life about 3.5 fold (t1/2 ≃ 7.7 hr), approaching that of free antithrombin III (t1/2 ≃ 11 ± 0.4 hr) and resulting in a 30fold longer life time of factor Xa inhibitory activity in plasma as compared to that of free intact heparin (t1/2 ≃ 0.25 ± 0.04 hr).

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