Wettability alteration of oil-wet dolomite using nanosolution in cationic surfactant for enhanced oil recovery

Reservoir wettability is depending firmly on the existence of polar components (acids or bases) which are soluble in crude oil and their interaction on the solid surfaces. Wettability alteration by chemical agents such as surfactant and nanoparticles is seen to be one of the realistic methods to modify the wettability of carbonate rock from oil-wet to water-wet conditions. An experimental study of wettability changes upon exposure to cetyltrimethyl ammonium bromide (CTAB) surfactant and nanoparticles dispersed in CTAB has been conducted. Besides that, the stability of the nanoparticles colloidal was also determined by sedimentation and transport test. In addition to that, interfacial tension (IFT) before and after addition of nanoparticles into the system was also determined. Finally, core displacement test was accomplished to determine the effectiveness of nanoparticles in displacing the remaining oil trapped in the reservoir. It was found that CTAB could alter the wettability of oil-wet dolomite to water-wet and addition of nanoparticles has enhanced the contact angle reduction. Al2O3 nano solution was more stable than ZrO2 and about 55% of Al2O3 and 52.5% of ZrO2 could be recovered from the transport test. The IFT of the system was 0.077 mN/m and has reduced after addition of nanoparticles into the system. The reduction of IFT due to Al2O3 was greater as compared to ZrO2. Oil recovery by water flooding was 55%, 62.7% and 56% for sand packs 1, 2, and 3 respectively. However, after injection of two pore volumes of Al2O3, ZrO2 nano solutions, and CTAB surfactant additional 20%, 16.7% and 14.1% of oil were recovered from sand packs 1, 2 and 3, respectively due to wettability alteration. As the conclusion, favourable wettability must be obtained in order to produce more oil especially in carbonate and mature reservoirs

Fabrication of polycarbonate-based polymer optical fiber cladding: effect of different solvents

Normally, the cladding layer is fabricated by using heat through continuous extrusion, melt spinning, batch extrusion, and heat drawing technique. These techniques require high temperature precision in order to obtain the desired morphology of the cladding without compromising the quality of the polymer. Hence, in this study dip-coating method was utilized to coat the polycarbonate (PC) core with poly (methyl methacrylate) (PMMA) as a cladding part. The PC core was dipped into different cladding solutions using three types of organic solvent (i.e. Tetrahydrofuran (THF), N-Methyl-2-pyrrolidone (NMP), and Dimethylacetamide (DMAc) and subjected to post-treatment process. The thickness of fabricated cladding layer was ~10–15 μm for all coating solutions. The cladding prepared by THF exhibits transparent layer wrapping the core. However, the cladding layers for PMMA dissolved in NMP and DMAc showed translucent appearance. The THF/PMMA solvent displayed ~98 % transmittance at visible region which was higher than NMP/PMMA and DMAc/PMMA. The failure strain (3.6 %) and tensile strain (88.98 MPa) of THF/PMMA sample were higher compared to other solutions. Young’s modulus which measures the stiffness and represents the breakability of a solid material was lower for THF/PMMA. Therefore, the THF is the most appropriate solution for fabrication of PC-based POF cladding layer

Applications of aluminium oxide and zirconium oxide nanoparticles in altering dolomite rock wettability using different dispersing medium

Application of nanotechnology in oil and gas industry has received great attention from many researchers. This is due to two features of nanoparticles that make them unique which are their size and the ability to adjust their behaviour. Nanoparticles are very active and energetic materials with a high tendency to form nano textured surfaces in combination with surfactants, and causing a major change in the system's interfacial properties. Surface energy of surfactants can be significantly increased by the interaction of nanoparticle and surfactant and more adsorption on the rock surface occurs with higher surface energy. The objective of this study is to investigate the effectiveness of Al2O3 and ZrO2 nanoparticles to alter oil-wet dolomite rock to more water wet condition. In this study, nanoparticle was dispersed in three different surfactants namely cetyltrimethylammonium bromide, CTAB (cationic), sodium dodecyl sulphate, SDS (anionic) and TX-100 (nonionic). Critical micelle concentration of the surfactant was determined by measuring its surface tension (SF). The CMC value of the surfactant was established at the inflection point of the curve. The IFT was determined after the addition of nanoparticles. The results revealed that there is significant reduction of IFT after addition of nanoparticles. Reduction of IFT indicates the ability of the solution to decrease capillary forces and increase mobility of the oil in pore throat. Initial wettability of the dolomite substrate was determined and then was submerged in different nanofluids at different concentration. Contact angle of the rock surface was measured as quantitative method to determine the wettability of the system. The experiment was further investigated by evaluating adsorption of the surfactant on the rock surface. Isotherm adsorption of the surfactant was studied and the result revealed that ionic surfactant has higher adsorption capacity. This is mainly because the charged group on solid surface strongly influences the adsorption of surfactant at solid-liquid interface

A Review on Hydrogen Separation through Inorganic Membrane

The process of membrane separation is indicated as attractive choices than mature technologies for example cryogenic distillation as well as pressure swing adsorption. Hydrogen (H2) of high purity can be acquired via membranes of dense metallic and mainly palladium as well as its alloys with highly selective properties to H2. Composite membranes improvement via deposition of thin metallic layer on inorganic or porous polymeric supports is deemed as an effective technique in improving gas permeation of dense metallic membranes. Membranes of inorganic materials demonstrated excellent separation performance in purifying H2. In addition, these membranes are appropriate for high temperature separation application, which is preferable through high-temperature WGS reaction as well as pre-combustion CO2 capture. This paper presented mini review on hydrogen separation via inorganic membranes, taken into account both porous and nonporous type membrane to make known of recent investigation and for further optimization

Tubular carbon membrane prepared from pi/ncc: effects of pyrolysis atmosphere

The performance of Tubular Carbon Membrane (TCMs) due to pyrolysis conditions was studied. Dip-coating technique was used to synthesize the P84 co-polyimide/Nanocrystalline cellulose-based TCM, and pure gas O2 and N2 were used to determine the permeation properties of the TCMs. Different atmosphere i.e Argon, Nitrogen and Helium were introduced during the heat treatment processes at a flow rate of 200 mL/min to enhance the membrane’s performance. The pyrolysis temperature and heating rate were set at 800 °C and 3°C/min. It was found that the best pyrolysis condition for the preparation of PI/NCC-based TCMs was conducted in Argon atmosphere with the permeance of 3.22 ± 3.21 and 29.90 ± 2.98 GPU for N2, and O2 gas. The membrane also demonstrated that the highest O2/N2 selectivity of 9.29 ± 2.54. In comparisons to all other carbonization atmosphere, preparation of TCMs in Ar atmosphere showed the lowest weight loss and revealed the highest N2 selectivity in this study

Real-time fluid flow movement identification in porous media for reservoir monitoring application using polycarbonate optical fibre Bragg grating sensor

Fibre optic sensing technology has recently been hailed as a viable alternative for a real-time reservoir monitoring method. The aim of this study is to develop a robust and high-sensitivity polycarbonate optical fibre (PCPOF) sensor that can detect oil movement in porous media. To enhance the sensing capability of the Bragg sensor, partial removal of the cladding and deposition of APTES treated TiO2 on the sensing region was conducted. The cladding layer was removed using the chemical etching and the etching time was varied from 5 to 11 min. The best etching time was 9 min with a cladding thickness of ∼1.47 µm and increasing the etching time may result in damage to the fibre core. The nanoparticles were coated evenly to the sensing areas through a double dip-coating technique to ensure uniform distribution of TiO2. Sensor sensitivity was tested at 60 °C, 90 °C, and 120 °C. The sensitivity of the sensor was found to be more than 100 nm/RIU on average in different temperatures and the sensor was also capable to work at a temperature of 120 °C. Thus, the fabricated fibre optic sensor offers huge potential for real-time monitoring of reservoirs in oil and gas fields, which should be a very useful tool for engineers

Fabrication of polycarbonate polymer optical fibre core via extrusion method: the role of temperature gradient and collector speed on its characteristics

Fabrication of polycarbonate polymer optical fibre core using various extrusion temperatures and drawing speeds was experimentally demonstrated. Extrusion temperature had a significant effect on fibre performance. The optimum temperature in which fibre exhibited the best thermal and optical properties was 290 °C, however, at higher temperature due to degradation of the polymer the fibre lost its quality for light propagating. The mechanical properties of the fibre were influenced by its diameter. Increasing the drawing speed to 20 rpm reduced the diameter of the fibre to ~341 μm and Young's modulus and tensile strength increased to 2.12 and 119.06 MPa, respectively. Our comprehensive investigation of polycarbonate polymer core features may propose a novel method for precise fabrication of polymer optical fibre suitable in optical industries

A new potential polymeric cladding material for polycarbonate fibre optic core for high temperature use

The selection of a suitable cladding material for a fibre optic is crucial, and the application of polymeric material in high temperature conditions is garnering much attention from many researchers. However, polymer suffers from a weak thermal resistance, limiting its use in high temperature conditions. Therefore, this study aims to develop a new potential cladding material that has a good balance between optical and thermal properties. Two sets of cladding materials are proposed, namely the blend of polycarbonate/polymethyl methacrylate (PC/PMMA) and polymethylpentene (PMP). The cladding materials were dissolved in different solvents, followed by the casting on a glass plate to form a flat sheet cladding layer. PC/PMMA blend showed a miscible blending with a single Tg value and physical blending. Both PC/PMMA blend and PMP claddings demonstrated more than 90% of luminous transparency. The materials also showed high thermal stability with the onset degradation temperature of ∼ 300 °C. The optimum ratio for PC/PMMA was 80/20. Next, the cladding layer was fabricated by coating the core in 80/20 PC/PMMA and PMP. The scanning electron microscopy (SEM) image reveals that core–clad ratio for the PC fibre is 1.02 for both materials. The maximum tensile strength for the PC with PMP cladding was higher than that of the PC with PC/PMMA cladding. PMP-clad fibre has higher power output, which was a 60% increment from bare PC fibre output compared to PC/PMMA-clad fibre, with only 28.8% power output increment. Though both materials have huge potential to be used as the cladding for PC core, PMP cladding showed superior performance compared to PC/PMMA cladding

Effect of heating rates on the microstructure and gas permeation properties of carbon membranes

High performance tubular carbon membrane (TCM’s) for CO2 separation were prepared by controlling the carbonization heating rates in range of 1-7 o C/min carbonized at 800 o C under Argon environment. A single permeation apparatus was used to determine the gas permeation properties of the membrane at room temperature. Fine turning of the carbonization condition was necessary to obtain the desired permeation properties. The preparation of PI/NCC-based TCM at low heating rate caused the gas permeance for the examined gas N2 and CO2 decreased whereas the selectivity of CO2/N2 increased. It was also identified that the gas permeation properties of the resultant TCM and its structure was highly affected by the heating rate. The best carbonization heating rate was found at 3o C/min for the fabrication of TCM derived via polymer blending of PI/NCC for CO2/N2 separation

Effect of heating rates on the microstructure and gas permeation properties of carbon membranes

High performance tubular carbon membrane (TCM’s) for CO2 separation were prepared by controlling the carbonization heating rates in range of 1-7 oC/min carbonized at 800 oC under Argon environment. A single permeation apparatus was used to determine the gas permeation properties of the membrane at room temperature. Fine turning of the carbonization condition was necessary to obtain the desired permeation properties. The preparation of PI/NCC-based TCM at low heating rate caused the gas permeance for the examined gas N2 and CO2 decreased whereas the selectivity of CO2/N2 increased. It was also identified that the gas permeation properties of the resultant TCM and its structure was highly affected by the heating rate. The best carbonization heating rate was found at 3oC/min for the fabrication of TCM derived via polymer blending of PI/NCC for CO2/N2 separation