Single-Phase Retarded Inorganic Acid Optimizes Remediation of Drilling Formation Damage in High-Temperature Openhole Horizontal Carbonate Producer

In high-temperature carbonate producers, conventional hydrochloric (HCl) acid systems have been ineffective at delivering sustainable production improvement due to their kinetics. Retarded acids are deemed necessary to control the reaction and create effective wormholes. This scenario is even more critical in wells completed across long openhole horizontal intervals due to reservoir heterogeneity, changing downhole dynamics, and uniform acid placement goals. Out of the different retarded acid options, emulsified acid is one of the preferred choices by Middle East operators because of its excellent corrosion inhibition and deep wormhole penetration properties. However, it also brings other operational complexities, such as higher friction pressures, reduced pump rates, and more elaborate mixing procedures, which in some cases restrict its applicability. The recent introduction of a single-phase retarded inorganic acid system (SPRIAS) has enabled stimulation with the same benefits as emulsified acids while eliminating its drawbacks, allowing friction pressures like that of straight HCl and wormholing performance equivalent to that of emulsified acid. A newly drilled oil producer in one of the largest carbonate fields in onshore Middle East was selected by the operator for pilot implementation of the SPRIAS as an alternative to emulsified acid. The candidate well featured significant damage associated with drilling, severely affecting its productivity. The well was completed across 3,067 ft of 6-in. openhole horizontal section, with a bottomhole temperature of 285°F, permeability range of 0.5 to 1.0 md, and an average porosity of 15%. Coiled tubing (CT) equipped with fiber optics was selected as the fluid conveyance method due to its capacity to enable visualization of the original fluid coverage through distributed temperature sensing (DTS), thus allowing informed adjustment of the stimulation schedule as well as identification of chemical diversion and complementary fluid placement requirements. Likewise, lower CT friction pressures from SPRIAS enabled the utilization of high-pressure jetting nozzle for enhanced acid placement, which was nearly impossible with emulsified acid. Following the acidizing treatment, post-stimulation DTS showed a more uniform intake profile across the uncased section; during well testing operations, the oil production doubled, exceeding the initial expectations. The SPRIAS allowed a 40% reduction in CT friction pressures compared to emulsified acid, 20% optimization in stimulation fluids volume, and reduced mixing time by 18 hours. The experience gained with this pilot well confirmed the SPRIAS as a reliable option to replace emulsified acids in the region. In addition to production enhancement, this novel fluid simplified logistics by eliminating diesel transportation, thus reducing equipment and environmental footprints. It also reduces friction, thus enabling high-pressure jetting via CT, leading to more efficient stimulation with lower volumes.

Prediction of phenolic compounds and glucose content from dilute inorganic acid pretreatment of lignocellulosic biomass using artificial neural network modeling

Dilute inorganic acids hydrolysis is one of the most promising pretreatment strategies with high recovery of fermentable sugars and low cost for sustainable production of biofuels and chemicals from lignocellulosic biomass. The diverse phenolics derived from lignin degradation during pretreatment are the main inhibitors for enzymatic hydrolysis and fermentation. However, the content features of derived phenolics and produced glucose under different conditions are still unclear due to the highly non-linear characteristic of biomass pretreatment. Here, an artificial neural network (ANN) model was developed for simultaneous prediction of the derived phenolic contents (CPhe) and glucose yield (CGlc) in corn stover hydrolysate before microbial fermentation by integrating dilute acid pretreatment and enzymatic hydrolysis. Six processing parameters including inorganic acid concentration (CIA), pretreatment temperature (T), residence time (t), solid-to-liquid ratio (RSL), kinds of inorganic acids (kIA), and enzyme loading dosage (E) were used as input variables. The CPhe and CGlc were set as the two output variables. An optimized topology structure of 6–12-2 in the ANN model was determined by comparing root means square errors, which has a better prediction efficiency for CPhe (R2 = 0.904) and CGlc (R2 = 0.906). Additionally, the relative importance of six input variables on CPhe and CGlc was firstly calculated by the Garson equation with net weight matrixes. The results indicated that CIA had strong effects (22%-23%) on CPhe or CGlc, then followed by E and T. In conclusion, the findings provide new insights into the sustainable development and inverse optimization of biorefinery process from ANN modeling perspectives. Graphical Abstract

Effects of organic acid on the physicochemical properties of gelatine extracted from Fringescale sardinella (Sardinella fimbriata) bones

Gelatine from marine sources especially from the fish becomes a popular alternative to replace the commercial gelatines from bovine and porcine. Fringescale sardinella (Sardinella fimbriata) is commonly used in the fish processing industry and has a high potential to produce gelatine from its by-products. The extraction of gelatine is one of the most important steps that influence its functional properties. Inorganic acid was commonly used in the extraction, however, nowadays it faces some issues due to health safety and its effect on the environment. The aim of this study was to assess the effects of organic acid (fruit vinegar) as a replacement for inorganic acid (hydrochloric acid) during extraction on the physicochemical properties of S. fimbriata gelatine. The extracted gelatines were characterized in terms of their physico-chemical properties such as the yield percentage, gel strength, melting point, molecular weight, structural composition, and amino acid analyses. Results showed that gelatine extracted with organic acid demonstrated low yield percentage (2.9±0.01%) and poor gel strength (75.9±1.06 g) and melting point (22.0±1.00°C) values compared to the standard. This gelatine also demonstrated a low amount of proline and hydroxyproline contents, which were 43.77±8.21 g/mg and 34.99±6.50 g/mg, respectively. Overall findings have suggested that different types of acid used in the extraction resulted in different physico-chemical properties of the gelatine. Such findings suggested that S. fimbriata bone hold the potential to be an alternative source for vast applications in industries. Further studies may focus on different concentrations of acid used in the extraction process. Such findings will help to improve S. fimbriata bone gelatine properties for extended uses in various industries.

Effect of Crystallization Additives on Durability of Cement Composites in Aggressive Environments

This article analyses the effect of crystallization additives on the long-term durability of self-compacting concretes (SCCs) in relation to specific types of chemically aggressive environments. The effect of both an inorganic acid solution and the aggressive solutions produced during plant ensilage were tested, while the effect of diesel on these modified concretes was also investigated. Attention was given to the effect of crystallization additives on the characteristically capillary porous structures of self-compacting concrete, specifically in terms of the long-term durability of SCCs in relation to the above-stated chemically aggressive solutions. The effect of aggressive environments was evaluated through a set of physical-mechanical trials and physical-chemical analyses.

Laboratory studies of the oil-displacing capacity of multifunctional chemical composition based on surfactants

The development of deposits of hard-to-recover reserves, including heavy and high-viscosity oil, dictates the need to search for new and improve existing enhanced oil recovery methods. One of the well-known methods of increasing oil recovery is the use of reservoir treatments with chemical compositions containing surfactants. A new multifunctional chemical oil-displacing composition (MFC) capable of operating in a wide temperature range has been created at the Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences. The oil-displacing composition of MFC based on a surfactant, an adduct of inorganic acid, polyol, ammonium and aluminum salts, and urea is designed to increase the oil recovery of fields at both early and late stages of development.The article presents the results of laboratory tests of the developed MFC for enhanced oil recovery. Experiments were carried out on the setup to study the filtration characteristics of models of heterogeneous formation.As a result of experiments, it was found that the use of the MFC composition leads to a significant increase in the oil displacement coefficient at both low and high temperatures. The high oil-displacing capacity of MFC at low temperature is caused by the interaction of inorganic acid and polyol, which are part of the composition, with the formation of a strong acid that reacts with the carbonate rock of the reservoir. At high temperature, due to the processes of hydrolysis of urea and aluminum salt, MFC evolves into an alkaline composition with the formation of an alkaline buffer system (pH = 9), which is optimal for oil displacement purposes.

Investigation of Dc-Conductivity and Morphology of PMMA/PANI Composite

Various inorganic acid doped PMMA/PANI composite are prepared by in-situ polymerization technique. Morphology, room temperature (RT) conductivity and DC-conductivity with temperature variation (77-300 K) are analyzed by scanning electron microscopy (SEM) and linear four probe technique, respectively. Fibril structures with different diameter are observed in doped PMMA/PANI composite, whereas smooth texture is found in PMMA polymer film. Room temperature DC conductivity is found 0.1497 × 10-2 S/cm for H2SO4-and 0.309 × 10-3 S/cm for H3PO4-, 0.244 × 10-3S/cm for HCl-doped conductive composite, respectively. Temperature dependent DC Conductivity is measured and it behaves like semiconductor.