Propagation of Regular HCl Acids in Carbonate Rocks: The Impact of an In Situ Gelled Acid Stage

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Ahmed M. Gomaa ◽  
Hisham A. Nasr-El-Din
Keyword(s):  
Material Balance ◽  
Chemical Species ◽  
Field Studies ◽  
Injection Rate ◽  
The Core ◽  
The Impact ◽  
First Time ◽  
Recent Laboratory ◽  
Injection Rates

Recent laboratory and field studies indicated that polymer-based in situ gelled acids can cause formation damage. Coreflood experiments using single-stage and multistage acids were conducted at 250 °F. 15 wt. % regular HCl and 5 wt. % in situ gelled acid-based on Fe(III) as a crosslinker were the acids that were used in this study. Propagation of acids and crosslinker inside 20 in. long cores was examined for the first time in detail. Stage volume and injection rate, which were the parameters that affect the propagating of various chemical species, were examined. Samples of the core effluent were collected and the concentrations of calcium, crosslinker, and acid were measured. Material balance was conducted to determine the amount of cross-liker that retained in the core. The results show that in situ gelled acid should be pumped at low injection rates. In situ gelled acid at low injection rate instantaneously plugged the tip of the wormhole and did not create additional wormholes inside the core. Therefore, when the final regular acid stage bypassed the gel, it started to propagate from nearly the last point that the first stage ended. In site gelled acid stage volume should not exceed 0.5 PV. No benefits were gained by increasing the volume of in situ gelled acids. Retention of total iron in the core increased in multistage acid treatments, especially at low acid injection rates.

Acid Stimulation Used in In-Situ Leaching Uranium

2010 ◽  
Author(s):  
Wen-sheng Liao ◽  
Li-min Wang ◽  
Yi-xuan Yao ◽  
Guo-ping Jiang ◽  
Hai-jun Zhao ◽  
...  
Keyword(s):  
Formic Acid ◽  
Injection Rate ◽  
Low Permeability ◽  
Reaction Products ◽  
Treatment Results ◽  
The Core ◽  
Fluid Systems ◽  
Core Permeability ◽  
Significant Production

Acidization was studied on a uranium sandstone deposit in Inner Mongolia with low–permeability and heavy calcium cementation. Acid dissolving test indicates that hydrochloric acid, formic acid and mud acid can easily dissolve formation minerals. With proper volumes and concentrations of acids used, the risk of precipitation of reaction products could be minimized. Core flow acidizing trial shows that the acidic fluid systems of hydrochloride acid, formic acid or acetic acid can significantly improve the core permeability. The average permeability has increased by 763 percent for the above three systems. But mud acid didn’t increase the core permeability; on the contrary, it caused formation damage, and led to lowering permeability. In the pilot test, the injection rate has improved by 118 percent for 6 wells. The acid treatment results indicate that a significant production enhancement of wellfields can be achieved by acid stimulation.

Synthesis Technology of Silica Aerogels/Polystyrene Core-Shell Composite Materials

2010 ◽  
Vol 168-170 ◽  
pp. 1833-1836
Author(s):  
Gang Qiang Geng ◽  
Jing Tao Guo ◽  
Jun Jun Zou ◽  
Gong Xun Bian
Keyword(s):  
Composite Materials ◽  
Polymerization Process ◽  
System Component ◽  
Core Shell ◽  
Ultrasound Technique ◽  
The Core ◽  
Optimum Reaction ◽  
The Impact ◽  
Shell Composite

In order to obtain super aerogels heat insulating composite materials with silane coupling agent on the in-situ surface treatment. The core-shell structure composite materials have been prepared by dispersion polymerization process of polystyrene grafted on the SiO2 particles. By TEM on these samples the impact of the system components initiator polymerization parameters and dispersion process was discussed. The results showed that the system component of the greatest impact on conversion rate is the ratio of aerogels /St ,the optimum reaction temperature is 75 °C.With organic initiator KPS as initiator after a unique ultrasound technique to obtain the core-shell composite materials structure which coating is 70%.

scholarly journals Analysis Of Methods And Means Of Bump Hazard Prediction

2021 ◽  
Vol 03 (04) ◽  
pp. 47-54
Author(s):  
Sayyidkosimov ` S.S. ◽  
◽  
Kazakov. A.N ◽  
Khakberdiev M.R. ◽  
Tursunbayev D.A. ◽  
...  
Keyword(s):  
Rock Mass ◽  
Underground Mining ◽  
A Priori ◽  
Field Studies ◽  
Gold Deposits ◽  
The Finite Element Method ◽  
The Core ◽  
Core Disking ◽  
The Impact ◽  
Element Method

The article analyzes the methods and tools for predicting the impact hazard in the conditions of underground mining of gold deposits. To assess the stress state of a rock mass, the core disking method is proposed as a basic method. The degree and categories of impact hazard of sections of the rock mass are estimated. Due to the impossibility of solving many problems by geomechanical only field studies. The reliable efficiency of the use of the finite element method and the boundary element method in predicting the impact hazard of the field sites a priori is shown.

scholarly journals Novel Bionanocellulose/κ-Carrageenan Composites for Tissue Engineering

2018 ◽  
Vol 8 (8) ◽  
pp. 1352 ◽  
Author(s):  
Izabela Cielecka ◽  
Marcin Szustak ◽  
Edyta Gendaszewska-Darmach ◽  
Halina Kalinowska ◽  
Małgorzata Ryngajłło ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Chondrogenic Differentiation ◽  
Expression Patterns ◽  
Swelling Properties ◽  
In Situ Method ◽  
Chondrogenic Phenotype ◽  
The Impact ◽  
First Time ◽  
Water Holding

In this work, novel bacterial cellulose/κ-carrageenan (BNC/κ-Car) composites, being potential scaffolds for tissue engineering (TE), and outperforming the two polymers when used as scaffolds separately, were for the first time obtained using an in situ method, based on the stationary culture of bacteria Komagateibacter xylinus E25. The composites were compared with native BNC in terms of the morphology of fibers, chemical composition, crystallinity, tensile and compression strength, water holding capacity, water retention ratio and swelling properties. Murine chondrogenic ATDC5 cells were applied to assess the utility of the BNC/κ-Car composites as potential scaffolds. The impact of the composites on the cells viability, chondrogenic differentiation, and expression patterns of Col1α1, Col2α1, Runx2, and Sox9, which are indicative of ATDC5 chondrogenic differentiation, was determined. None of the composites obtained in this study caused the chondrocyte hypertrophy. All of them supported the differentiation of ATDC5 cells to more chondrogenic phenotype.

Analysis of the impact of biomass burning emissions on global ozone production in the upper troposphere with MOCAGE CTM and IAGOS airborne data.

2020 ◽  
Author(s):  
Martin Cussac ◽  
Virginie Marécal ◽  
Valérie Thouret ◽  
Béatrice Josse
Keyword(s):  
Significant Role ◽  
Biomass Burning ◽  
Transport Model ◽  
Chemical Species ◽  
Ozone Production ◽  
In Situ Observation ◽  
Transport Pathway ◽  
Upper Troposphere ◽  
The Impact

<p>The UTLS (Upper Troposphere/Lower Stratosphere) is a key layer of the atmosphere as its chemical composition impacts both the troposphere and the stratosphere, and therefore plays a significant role in the climate system. Ozone at this altitude for instance plays a great role on surface temperature. Unlike in the stratosphere; it can be produced from the photolysis of precursors originating in the troposphere; mainly nitrous oxides (NO<sub>x</sub>) and carbon monoxide (CO) at this pressure range. Biomass burning emissions in particular are likely to play a significant role in the quantities of these species in the upper troposphere and thus impacting ozone balance. This effect is investigated thanks to the global chemistry transport model MOCAGE. Because of the strong vertical gradients in this layer of the atmosphere, well resolved in-situ observation dataset are valuable for model evaluation. As of measurements used to validate MOCAGE results, IAGOS in-situ measurements from equipped commercial aircraft were chosen for their fine vertical resolution as well as their wide geographical coverage. Using both of these tools, upper tropospheric air composition is studied, with a focus on ozone precursors and production linked to biomass burning emissions.</p><p>Firstly is investigated the direct impact of biomass burning emissions on CO concentration in the upper troposphere, as it is both a good tracer of wildfire plumes in the atmosphere and it plays a role in the upper troposphere chemical balance. For this purpose MOCAGE simulations spaning over the year of 2013 where biomass burning emissions were turned on and off are compared to estimate a contribution to upper tropospheric CO. These simulations were validated using all the available data from the IAGOS database. It was found that biomass burning impacted CO levels globally, with the strongest enhancement happening above the most emitting areas (equatorial Africa and the Boreal forests). The importance of a fast vertical transport pathway above the fires was also highlighted with the possible occurrence of pyroconvection in addition to deep convection. Secondly, other chemical species related to ozone production were looked upon. Peroxyacetyl Nitrates (PAN) for instance were found to be impacted by biomass burning as it is a product of NOx oxidation as well as the main "reservoir" specie for NOx in the upper troposphere. Ultimately, ozone production resulting from biomass burning emissions is investigated, both in biomass burning plumes encountered by IAGOS aircraft, and on a more global scale using the MOCAGE simulations.</p>

Optimum Injection Rate of A New Chelate That Can Be Used To Stimulate Carbonate Reservoirs

SPE Journal ◽  
2011 ◽  
Vol 16 (04) ◽  
pp. 968-980 ◽  
Author(s):  
M.A.. A. Mahmoud ◽  
H.A.. A. Nasr-El-Din ◽  
C.A.. A. De Wolf ◽  
J.N.. N. LePage
Keyword(s):  
Acetic Acid ◽  
Ethylenediaminetetraacetic Acid ◽  
Injection Rate ◽  
Carbonate Reservoirs ◽  
Damkohler Number ◽  
Optimum Conditions ◽  
The Core ◽  
Damköhler Number ◽  
Optimum Injection Rate ◽  
Injection Rates

Summary Different chelating agents were used as alternatives for hydrochloric acid (HCl) in matrix acidizing to create wormholes in carbonate formations. Previous studies demonstrated the use of ethylenediaminetetraacetic acid (EDTA), hydroxy ethylenediaminetriacetic (HEDTA), and glutamic acid-N,N-diacetic acid (GLDA) as standalone stimulation fluids to stimulate carbonate reservoirs. The main problem of using EDTA and HEDTA is their low bio-degradability. GLDA was introduced as a standalone stimulation fluid for deep carbonate reservoirs where HCl can cause corrosion and face dissolution problems. In this study, calcite cores 1.5 in. in diameter and 6 or 20 in. in length were used to determine the optimum conditions where the GLDA can break through the core and form wormholes. GLDA solutions with pH values of 1.7, 3, and 3.8 were used. The optimum conditions of injection rate and pH were determined using coreflood experiments. Damköhler number was determined using the wormhole length and diameter from the CT scan 3D and 2D images. GLDA was compared with chelates that are used in the oil industry such as EDTA and HEDTA. GLDA also was used to stimulate parallel cores with different permeability ratios (up to 6.25). GLDA was found to be very effective in creating wormholes at pH = 1.7, 3, and 3.8; at different injection rates; and at temperatures up to 300°F. Increasing the temperature increased the reaction rate and less volume of GLDA was required to break through the core and form wormholes. Unlike HCl, in GLDA there was no face dissolution or washout in the cores even at low injection rates (0.5 cm3/min). An optimum injection rate and Damköhler number were found at which the pore volume (PV) required to create wormholes was the minimum. GLDA at pH 1.7 and 3 created wormholes with a small number of PV (at 1 cm3/min, GLDA at pH 1.7 required 1.5 PV at 300°F, and at pH 3 it required 1.8 PV). Compared with acetic acid, the volume of GLDA at pH 3 required to create wormholes was less than that required with acetic acid at the same conditions. GLDA was found to be effective in stimulating parallel cores up to 6.25 permeability contrast (final permeability/initial permeability).

scholarly journals 2.1.2 Preliminary Results of the Micrometeoroid Experiment on Board Helios A

1976 ◽  
Vol 31 ◽  
pp. 159-163
Author(s):  
E. Grün ◽  
J. Kissel ◽  
H. Fechtig ◽  
P. Gammelin ◽  
H.-J. Hoffmann
Keyword(s):  
Interplanetary Dust ◽  
Strong Increase ◽  
The Sun ◽  
Impact Rate ◽  
M 10 ◽  
Large Particles ◽  
The Impact ◽  
First Time ◽  
Measured Particle

AbstractFor the first time in situ measurements of interplanetary dust have been performed between 0.3 AU and 1 AU from the sun by the micrometeoroid experiment on board Helios A. The measured particle masses are between 10−15 g and 10−8 g and their measured speeds are between 2 km/sec and 20 km/sec. Particle impacts are identified by the time-of-flight spectra of the ions released upon impact. 15 large particles (m ≥ 10−12 g) were detected from Dec. 15, 1974 to Sept. 5, 1975. They show a strong increase of the impact rate (appr. a factor of 10) between 1 AU and 0.3 AU. The directions from which they impacted the sensor are concentrated between the solar direction and the apex direction of the Helios spacecraft.

Impact of traffic lights on car accidents at intersections

2018 ◽  
Vol 29 (12) ◽  
pp. 1850121
Author(s):  
R. Marzoug ◽  
N. Lakouari ◽  
O. Oubram ◽  
H. Ez-Zahraouy ◽  
A. Khallouk ◽  
...  
Keyword(s):  
Cellular Automata ◽  
Green Light ◽  
Critical Time ◽  
Injection Rate ◽  
Traffic Lights ◽  
High Injection ◽  
Car Accidents ◽  
Simulation Results ◽  
The Impact ◽  
Injection Rates

Using the cellular automata Nagel–Schreckenberg (NaSch) model, we numerically study the impact of traffic lights on the probability of car accidents ([Formula: see text]) at the intersection of two roads. It is found that, the probability [Formula: see text] is more stable with variation of the green light ([Formula: see text]) when the symmetric lights are adopted. Moreover, simulation results show the existence of a critical time [Formula: see text], below which ([Formula: see text]) [Formula: see text] increases as the injection rate ([Formula: see text]) increases, however, above which ([Formula: see text]) the growing of [Formula: see text] has for effect the decrease of [Formula: see text]. Furthermore, the decrease of [Formula: see text] is almost always accompanied by a loss of the flux, especially with asymmetrical lights. To overcome this problem, we proposed a strategy that can greatly increase the flux and keep the probability [Formula: see text] as small as possible, especially for the low and high injection rates.

Bioremediation of a Cyanide-Contaminated Site Using EH-/PH-Controlled Conditions (ENA)

2009 ◽  
Vol 71-73 ◽  
pp. 717-720
Author(s):  
P. Harborth ◽  
M. Thieme ◽  
K. Fricke
Keyword(s):  
Field Studies ◽  
Contaminated Site ◽  
H2o2 Treatment ◽  
Iron Cyanide ◽  
Controlled Conditions ◽  
In Situ Conditions ◽  
Cyanide Complexes ◽  
First Time ◽  
Ph Controlled

In the course of remedial investigations for a former gasworks site, high cyanide pollution of the soil (74.6 - 101.7 mg/kgDS total cyanide) and of the groundwater (3,840 µg/l total cyanide /approx. 300 µg/l free cyanides) were particularly problematic. Extensive investigations in the laboratory as well as in field studies finally resulted in a 2-step oxic/anoxic concept. Both the free cyanides as well as the complex bound cyanides could be biodegraded at more than 90% through a combination of H2O2-treatment (ISCO) and denitrification by in situ conditions. Furthermore a destruction of the iron cyanide complexes under fermentative conditions could be observed for the first time.

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