Influence of asphaltene inhibitors on asphaltene deposition in the porous media

This article deals with organic asphaltene deposition in the reservoir rock, for crude oil having high asphaltene content and high apparent viscosity. The crude oil is characterized using thermal analysis through the thermogravimetric method. Crude oil is blended with heptane and flooded through the formation core at 55°C and 200-1200 psi pressure. With the rise in flow pressure, asphaltene precipitation became more significant with about four hundred times fall in the initial flow rate (flow rate at 200 psi) of crude oil at 1200 psi pressure. Phthalic acid and turpentine oil are used as asphaltene inhibitors for this crude oil. These asphaltene inhibitors are easy to procure, required less dosage for asphaltene dissolution and are relatively less toxic as compared to the other organic solvents used frequently as asphaltene inhibitor in oil industries. The asphaltene inhibitors are injected into the crude oil and flowed through the pores of the core. It is found that the crude oil treated with phthalic acid resulted in 88.23% increment its flow rate as compared to the turpentine oil, suggesting significant organic asphaltene dissolution in the formation rock

Influence of asphaltene inhibitors on asphaltene deposition in the porous media

351-355This article deals with organic asphaltene deposition in the reservoir rock, for crude oil having high asphaltene content and high apparent viscosity. The crude oil is characterized using thermal analysis through the thermogravimetric method. Crude oil is blended with heptane and flooded through the formation core at 55°C and 200-1200 psi pressure. With the rise in flow pressure, asphaltene precipitation became more significant with about four hundred times fall in the initial flow rate (flow rate at 200 psi) of crude oil at 1200 psi pressure. Phthalic acid and turpentine oil are used as asphaltene inhibitors for this crude oil. These asphaltene inhibitors are easy to procure, required less dosage for asphaltene dissolution and are relatively less toxic as compared to the other organic solvents used frequently as asphaltene inhibitor in oil industries. The asphaltene inhibitors are injected into the crude oil and flowed through the pores of the core. It is found that the crude oil treated with phthalic acid resulted in 88.23% increment its flow rate as compared to the turpentine oil, suggesting significant organic asphaltene dissolution in the formation rock

Emulsification of Indian heavy crude oil using a novel surfactant for pipeline transportation

Abstract The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant. In this research, a novel surfactant, tri-triethanolamine monosunflower ester, was synthesized in the laboratory by extracting fatty acids present in sunflower (Helianthus annuus) oil. Synthesized surfactant was used to prepare oil-in-water emulsions of a heavy crude oil from the western oil field of India. After emulsification, a dramatic decrease in pour point as well as viscosity was observed. All the prepared emulsions were found to be flowing even at 1 °C. The emulsion developed with 60% oil content and 2wt% surfactant showed a decrease in viscosity of 96%. The stability of the emulsion was investigated at different temperatures, and it was found to be highly stable. The effectiveness of surfactant in emulsifying the heavy oil in water was investigated by measuring the equilibrium interfacial tension (IFT) between the crude oil (diluted) and the aqueous phase along with zeta potential of emulsions. 2wt% surfactant decreased IFT by almost nine times that of no surfactant. These results suggested that the synthesized surfactant may be used to prepare a stable oil-in-water emulsion for its transportation through offshore pipelines efficiently

Synthesis, characterization and evaluation of polyacrylamide graft starch/clay nanocomposite hydrogel system for enhanced oil recovery

Abstract In this paper the suitability of a graft polymer nanocomposite hydrogel system for enhanced oil recovery was examined using polyacrylamide graft starch/clay nanocomposite (a laboratory synthesized product) and chromium (III) acetate (crosslinker). X-ray diffraction analysis, Fourier transform infrared spectrometry analysis, field-emission scanning electron microscopy and transmission electron microscopy were carried out to reveal the laboratory synthesized product as a nanocomposite. The effects of various parameters like salt concentration, pH, temperature, polymer concentration and crosslinker concentration on the properties of the developed gel system were systematically evaluated. The thermal stability of the nanocomposite gel and the conventional gel system were also determined by thermogravimetric analysis. The graft polymer nanocomposite gel system exhibited acceptable gel strength, gelation time and gel stability compared with the conventional gel system. The nanocomposite gels prepared using a low crosslinker concentration showed higher gel strength and required longer gelation time than the conventional gel which is more desirable properties for the effective placement of gel during enhanced oil recovery operations. In addition, sand pack flooding experiments show that the graft polymer nanocomposite gels had better plugging capacity than the conventional gel systems under reservoir conditions. Hence, this gel system may be suitable in the water shutoff treatments required for enhanced oil recovery from oilfields

Temperature Augmented Visual Method for Initial Screening of Hydrate Inhibitors

The formation of gas hydrates in oil & gas pipelines and drilling fluid flow lines is a major issue in the petroleum industry. Gas hydrate inhibitors are normally used to inhibit the formation of gas hydrates in the pipelines/flowlines. Initial screening of hydrate inhibitors and AntiAgglomerants (AA) requires a safe and economical experimental setup/method. Conventional visual method was used for initial screening of hydrate inhibitors in many researches. Some researchers also suggested modified visual methods, but all of them lacks accurate measurement of induction time and found to be inappropriate for experimental solutions like drilling mud, etc. In this work, a temperature augmented visual method was presented which can be used in academic research laboratories for study and initial screening of hydrate inhibitors. This method is capable of parallel screening of inhibitors and determines hydrate induction time precisely. Experiments were conducted to determine the hydrate induction time of different inhibitors using augmented method and compared with conventional visual method. The developed method found to be more precise in determining the induction time of hydrates in all types of experimental solutions

Temperature Augmented Visual Method for Initial Screening of Hydrate Inhibitors

The formation of gas hydrates in oil & gas pipelines and drilling fluid flow lines is a major issue in the petroleum industry. Gas hydrate inhibitors are normally used to inhibit the formation of gas hydrates in the pipelines/flowlines. Initial screening of hydrate inhibitors and AntiAgglomerants (AA) requires a safe and economical experimental setup/method. Conventional visual method was used for initial screening of hydrate inhibitors in many researches. Some researchers also suggested modified visual methods, but all of them lacks accurate measurement of induction time and found to be inappropriate for experimental solutions like drilling mud, etc. In this work, a temperature augmented visual method was presented which can be used in academic research laboratories for study and initial screening of hydrate inhibitors. This method is capable of parallel screening of inhibitors and determines hydrate induction time precisely. Experiments were conducted to determine the hydrate induction time of different inhibitors using augmented method and compared with conventional visual method. The developed method found to be more precise in determining the induction time of hydrates in all types of experimental solutions

Modeling of Partially Hydrolyzed Polyacrylamide-Hexamine-Hydroquinone Gel System Used for Profile Modification Jobs in the Oil Field

The cross-linked polymer gel systems are being used increasingly to redirect or modify reservoir fluid movement in the vicinity of injection wells for the purpose of permeability/profile modification job in the oil field due to their high temperature stability and capability to provide rigid gel having high mechanical strength. In this study, a partially hydrolyzed polyacrylamide-hexamine-hydroquinonegel is used for the development of polymer gel system. The experimental investigation demonstrates that the gelation time varies with polymer and crosslinker concentration and the temperature. The mathematical model is developed with the help of gelation kinetics of polymer gel and using Arrhenius equation, which relates the gelation time with polymer, crosslinker concentrations, and temperature. The developed model is solved with the help of multivariate regression method. It is observed in this study that the theoretical values of gelation time have good agreement with the experimental values

Study the effect of synthesized graft copolymer on the inhibitive water based drilling fluid system

This research paper consists of the synthesis of carboxymethyl-graft-polyacrylamide copolymer by free radical polymerization technique and its characterization using Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FESEM) and thermogravimetric analysis. This graft copolymer was used as a drilling fluid additive and its effect on the Indian reactive shale sample was analyzed. The characterization of the shale sample used in this study was done by X-ray diffraction technique (XRD), FTIR, FESEM, and energy-dispersive X-ray spectroscopy (EDX) to determine the presence of various clay minerals. Experimental investigations revealed that the synthesized graft copolymer has a significant effect on the rheological and filtration properties of the inhibitive drilling fluid system and has high shale recovery performance. Hence, inhibitive drilling fluid system using synthesized graft copolymer may be used for the drilling of water sensitive shale formations

Development of fly ash reinforced nanocomposite preformed particle gel for the control of excessive water production in the mature oil fields

One of the appropriate methods to minimize water production and increase sweep efficiency is the utilization of Preformed Particle Gel (PPG) in the mature oil fields. In this paper, a new fly ash reinforced nanocomposite PPG was developed by the reaction of acrylamide as monomer, N,N′-Methylenebis (acrylamide) as crosslinker and nano fly ash in presence of Potassium Persulfate as initiator and it was compared with a conventional PPG which was designed without nano fly ash. On the incorporation of nano fly ash, swelling performance and thermal stability of PPG had increased significantly. Rheological data revealed that dynamic moduli (G′ and G″) of fly ash reinforced nanocomposite PPG has improved viscoelastic properties with a higher value of critical shear stress as compared to conventional PPG. The single sandpack flow experiment has shown the injectivity of nanocomposite PPG into the sandpack with a maximum resistance factor of 60.57. However, parallel-sandpack flow experiment showed that the newly developed nano fly ash reinforced nanocomposite PPG has a profile improvement rate of 92.98% and 97.83% for the permeability contrast of 2.16 and 4.14 respectively and hence it may be a promising agent in reducing excessive water production in mature oil fields