Pore structure evolution characteristics of sandstone …
acid in the uranium sandstone during the acid-leaching process, producing precipitation when it reached certain critical conditions. The precipitation may have attached to the particle surface of the
New Acid Combination for a Successful Sandstone Acidizing …
To enhance the acid performance and to minimize formation damage, a systematic investigation to the interactions between the fines control acid and clay minerals in sandstone reservoirs has been ...
Experimental study on deformation and failure …
During the water-rock interaction process, the dissolution of primary minerals in sandstone when exposed to water, coupled with chemical reactions between minerals and …
Study on the Performance Degradation of Sandstone …
Results show that in this study area, the most obvious e ect was seen ff with the use of dibasic acids (hydrochloric acid + acetic acid), which e ectively reduced the ff sample quality, uniaxial …
Abstract and Figures
The acid dissolution of detrital grains is generally consid- ... [33], and the Chang7 sandstone did not subject to strong . dissolution, so the contribution of dissolution pores to perme-
Sandstone Diagenesis: The Evolution of Sand to Stone
The importance of sandstone diagenesis as a subject is evidenced by the explosive growth of both pure and applied research in this subject through the 1980s and 1990s. ... These pore waters are dominated by aqueous Na+ and HCO−3 and are slightly to moderately acidic owing to the presence of decaying organic material. 3 Marine environments ...
Effect of wetting–drying cycles on mode I and mode II …
Semantic Scholar extracted view of "Effect of wetting–drying cycles on mode I and mode II fracture toughness of sandstone in natural (pH = 7) and acidic (pH = 3) environments" by A. Dehestani et al.
Sandstone damage mechanism: a sulfuric acid dissolution, …
The dynamic peak stress of sandstone is greatly affected by the acid dry-wet cycle, and as the pH of the acidic solution decreases, the elastic modulus and dynamic peak stress both decrease while ...
Chemical thermodynamics and chemical kinetics analysis …
The results show that the deterioration of sandstone shear strength is most se-vere in an acid environment, followed by that in an alkaline environment and that in neutral environment. In …
Chapter 6: Weathering and Soil Practice Flashcards
Study with Quizlet and memorize flashcards containing terms like Which of the following is/are most susceptible to chemical weathering by dissolution? A) quartz B) clay minerals C) iron oxides D) calcite, What two factors speed up rates of chemical reaction and weathering in rocks and soils? A) low temperatures; very dry B) low temperatures; very moist C) high temperatures; …
Deterioration of sandstones: Insights from experimental …
The susceptibility of sandstones to deteriorative factors when used for construction requires detailed experimental evaluation. This study investigated the (bio)weathering behaviour of Lower ...
Dissolution versus cementation and its role in determining …
Secondary porosity generation by acid dissolution is suggested by laboratory simulations, theoretical calculations, and field observations (e.g., etched texture in bleached red sandstones) [5, 7 ...
XRD and EDS observation of sandstone: (a) XRD spectrum …
The degradation of shear mechanical properties of rock fracture surfaces was determined after applying multiple dry-wet cycles. Artificially fractured feldspathic sandstone specimens were soaked ...
The Rock
Calcite cemented sandstone is subject to acidic dissolution and is more easily eroded. Clay and gypsum cements, which are soft minerals, tend to produce much softer sandstone and the sand can sometimes be rubbed off in a person's hands. The cementing agents also affect the porosity of a sandstone. When the initial sand is first deposited there ...
GEOL 1000
Study with Quizlet and memorize flashcards containing terms like The chemical process _____ weathers limestone and often is responsible for creating caves and sinkholes beneath the Earth's surface. a. oxidation b. dissolution c. exfoliation, _____ is a mechanical weathering process by which rocks can be broken down by water repeatedly freezing and thawing. a. Sheet jointing b. …
Study on Deterioration of Strength Parameters of Sandstone …
In addition, acid rain, mineral dissolution, acid deposition, and other factors make groundwater acidic. This caused the underground structure to erode and has also threatened its safety and ...
Sandstone FAQs: Your Ultimate Guide | Bhandari …
Calcite cemented sandstone is subject to acidic dissolution and is more easily eroded. Clay and gypsum cement, which are soft minerals, tend to produce much softer sandstone and the sand can sometimes be rubbed off in …
(PDF) Acidizing of conventional and tight sandstone formation …
Dissolution of the wellbore damage is the main target of sandstone acidizing. The presence of minerals like clays, feldspar, zeolites, and alumino-silicates makes acidizing a challenging task ...
Experimental Study on Physicomechanical Properties of Deep Sandstone …
In addition, acid rain, mineral dissolution, acid deposition, and other factors make groundwater acidic. This caused the underground structure to erode and has also threatened its safety and ...
(PDF) Dissolution of Apatite in North Sea Jurassic …
Minerals that are susceptible to acid dissolution, ... Apatite is a subject of intense chemical weathering ... history of a sandstone by heavy-mineral dissolution patterns.442D.J.M This and the ...
Effect of the surface-area-to-volume ratio on dissolution and
The degradation of mechanical properties in sandstone exposed to acidic environments is a result of internal mineral dissolution and microstructure damage.
A NOVEL IN-SITU GENERATED ACID SYSTEM ON …
The new insitu-generated acid treatment was applied to stimulate two types of sandstone cores (Grey Berea and Bandera). X-Ray Diffraction (XRD) was performed on the sandstone cores to analyze their carbonate and clay content. Coreflood studies were conducted to investigate the impact of the treatment fluid on the permeability of outcrop
(PDF) The Physicomechanical Deterioration Characteristics and
The physicomechanical deterioration characteristics of sandstone subjected to H2SO4, HCl, and H2O solutions of different pH values are studied by the method of long-term accelerated immersion.
Chemical thermodynamics and chemical kinetics analysis of …
The aim of this paper is to study the mechanism of strength deterioration of sandstone under the action of dry–wet cycles in acid and alkaline environments based on the …
INVESTIGATING THE USE OF CHELATING AGENTS FOR …
cost of citric acid makes it a financially unfavorable formulation, especially since regular 9:1 mud acid performed almost as well as 9:1 mud acid with 1 wt% citric acid added to it. Also, the newly developed Na-GLDA is compatible with HF at certain concentrations of both. The optimum acid mixture formulation was found to be 20 wt% Na-GLDA + 1
Effect of the surface-area-to-volume ratio on dissolution …
This study investigates the impact of hydro-chemical action on the deterioration of physical and mechanical properties of rock, with a specific focus on sandstone subjected to HCl, and H 2 SO 4 solutions with pH values of 2 and 5. The research explores the role of the surface-area-to-volume (SATV) ratios of 0.65 and 0.70 in influencing the dissolution and deterioration …
Study on the Effect of Dry–Wet Cycles on Dynamic
The influence of water–rock interaction in the process of coal mine construction cannot be ignored, especially when the groundwater quality is complex and contains acidic substances. In this paper, considering the influence of mining, blasting, and earthquake, the dynamic mechanical properties and fractal characteristics of sandstone under acid dry–wet …
Chemical thermodynamics and chemical kinetics analysis of sandstone …
By analyzing the main minerals contained in sandstone, the chemical equations of the mineral dissolution in acid and alkaline environment are obtained. Based on the theory of chemical thermodynamics and chemical kinetics, the shear strength deterioration mechanism of the sandstone under the action of chemical solutions and dry–wet cycles is ...
Characteristics and main controlling factors of the …
Acidic dissolution is the main dissolution process, but it is relatively weak. The pore-throat system exhibits poor and concentrated sorting, with nanometer-sized pores being predominant. ... the samples were subject to a 3-h long vacuum pre-treatment at a high temperature of 300 °C to remove residual bound water and capillary water and reduce ...
Selective Dissolution of Clay Minerals in Tight Sandstone by …
(2) To reveal the dissolution reaction mechanism between organic acid fluids and tight sandstone, providing a theoretical basis for improving the prediction ability of relatively high-quality reservoirs under tight backgrounds.