Iranian Journal of Oil and Gas Science and Technology

Abstract Knowing the characteristics of suitable environments for the precipitation of oil-prone source rocks facilitates oil explorations and leads to the development of oil fields. The current study investigates the properties of organic matter and sedimentary environment conditions of the Garau formation in various outcrop sections in Lurestan province from southwest of Iran (High Zagros) using elemental analysis, visual kerogen analysis, and Rock–Eval pyrolysis data. The geochemistry parameters indicate that the Garau formation is an excellent oil-prone source rock composed of kerogen types I and II. The oxygen index (OI) is minimal, revealing that organic matter is deposited in an anoxic sedimentary environment, suitable for preserving organic matter and hydrocarbon generation. The visual analysis of isolated kerogens from source rock samples indicates the abundance of dark amorphous organic matter (AOM) with low amounts of phytoclasts and pyrite without any palynomorph. Sedimentation appears to have occurred in deep and reduced parts of a carbonate basin during a rapid transgression. In addition, due to the effect of thermal maturation, the color of amorphous organic matter has darkened. The elemental analysis and van Krevelen diagram are employed to show the type of organic matter and reveal that the thermal maturity is related to the oil window. Elemental analysis reveals the high content of organic sulfur in the structure of kerogen. Moreover, the content of pyritic sulfur (Sp) and organic sulfur (So) is calculated.

Abstract The oil industry is looking for a way to develop reservoir management and optimal production of hydrocarbon reservoirs. The use of advanced technologies in the extraction of oil and gas reserves is essential in advancing the short-term and long-term goals of this industry, both in terms of product type and process. A technology road map is a plan that implements short-term and long-term goals using technology solutions to help achieve the goals. The technology road map for enhanced oil recovery (EOR)/improved oil recovery (IOR) of oil fields has been developed based on the emphasized fields and areas of the target technology. It has been expressed in 10 years according to the existing challenges and preventive measures, and all research and executive activities will be carried out with a focus on the road map. In this research, using the case study research method, by studying nine cases of research conducted in the research and technology of the National Iranian Oil Company, a map of executive achievements and technological solutions in each of the target technology areas, namely reservoir, well, and the facilities, are identified and presented based on the challenges and implementation stages. The results of this study show that in this road map, the issue of creating, developing, and equipping specialized centers for EOR; raising skills, expertise, and knowledge; and transferring technology as sustainability achievements are critical. In addition to other achievements, outputs and results of each stage and technological solutions to challenges are highly emphasized and essential.

Abstract The effect of using Conocarpus extract as a green inhibitor on the corrosion behavior of mild steel in a 1 M HCL environment is investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The impedance tests show that the polarization resistance increases from 29 for the blank solution to 299 for the solution containing 2500 ppm of Conocarpus extract. The polarization test results show that at room temperature, the corrosion current density for the blank solution decreases from 3.5 × 10^–4 to 2.6× 10^–5 for the solution containing 2500 ppm of Conocarpus extract, and the potential is shifted to negative values. The polarization test is performed at three temperatures of 25, 55, and 85 °C. The results show that the efficiency of 1925 ppm decreases from 93% at room temperature to 86% at 85 °C. The high-temperature efficiency does not decline significantly, indicating the effectiveness of Conocarpus extract at high temperatures. The FTIR tests also prove that the corrosion inhibitory effect of Conocarpus extract is due to the presence of heteroatoms such as N, S, and O. The adsorption isotherm results show that the adsorption of the extract as a single layer on the surface is consistent with the Langmuir isotherm.

Abstract Oil-well cementing is a multi-purpose operation in which cement slurries are prepared by mixing water, cement, and various additives and pumped into the well to isolate productive zones, protect the casing pipe, perform remedial operations, control drilling fluid lost, or abandon the well. Various additives are used to improve the mechanical properties of the slurry, like cement retarders and accelerators, which increase and decrease the thickening time of the cement slurry, respectively. Weight-enhancing additives are materials with a specific gravity higher than cement, which can weigh up the slurry to overcome the hydrostatic pressure of mud and perform an excellent cementing job. Improving the mechanical properties of these cement slurries has always been an essential issue in the discussion of oil well cementing. In this study, the effects of nanozeolite on heavy-weight oil-well cement slurry are investigated in the laboratory to improve the rheological and mechanical properties of the cement. In the designed experiments, nano-zeolite is added to the slurry with 1, 2, and 3% by weight of cement (BWOC). The results show that nanozeolite is an additive to reduce the thickening time, increase the plastic viscosity, and reduce the slurry’s yield point. Thus, it should be noted that the pumping time of the cement slurry can be adjusted using other additives based on the required cementing job timing schedule. The experiments also show that adding nano-zeolite to the cement slurry from 1 to 3% BWOC increases the free fluid of the cement slurry but does not show any effect on controlling the fluid loss. Finally, by adding 2% BWOC of nanozeolite, the compressive strength of the cement stone increases, and the initial setting time of the cement slurry decreases.

Abstract The increasing demand for hydrocarbons has prompted new recovery strategies by applying nanoparticle–surfactant flooding in chemical-enhanced oil recovery (CEOR). Some mechanisms that improve oil mobility are rock wettability alteration and reduced interfacial tension between the oil and water. In this work, silica (SiO₂) nanoparticles (NPs) were synthesized and characterized, and their effect on wettability alteration and interfacial tension (IFT) between the oil and SiO₂ nanoparticles (NPs) dispersed in sodium dodecyl sulfate (SDS) solutions was determined. Experiments on oil displacement by flooding with brine and NPs dispersed in an SDS solution were investigated in a micro glass model. X-ray diffraction (XRD) pattern and scanning electron microscopy (SEM) confirmed the mineral structure and platy polycrystalline morphologies that gave an estimated particle size of 88 nm using Scherrer’s formula. Fourier transform infrared spectroscopy (FTIR) showed characteristic symmetric and asymmetric stretching vibrations. The measured wettability alteration and IFT showed changes in wettability from water-wet toward a more water-wet condition and decreased IFT, respectively, as the SDS concentration increased. The optimum oil recovery of 67.45% was obtained at 2.08 mM SDS when SDS concentrations were varied (2.08, 6.25, 8.33, 10.42, and 14.58 mM) at a constant concentration of SiO₂ NPs (0.1 wt %). Having obtained the optimum oil volume from OOIP at 2.08 mM SDS, SiO₂ NPs concentration varied (0.05, 0.1, 0.15, 0.2, and 0.25 wt %) at a constant SDS concentration (2.08 mM). This optimized approach gave an excellent total oil recovery of 78.36% at 0.2 wt % SiO₂ NPs. Therefore, 0.2 wt % SiO2 NPs with 2.08 mM SDS should be applied in oil recovery.

Abstract Asphaltene-induced formation damage is one of the complicated processes of permeability damage in porous media, particularly in the near-wellbore area. Asphaltene particles precipitate out of the bulk fluid phase during production due to pressure drop, which may reduce permeability owing to the deposition of asphaltene nanoparticles on porous media surfaces and the plugging of pore throats by larger asphaltene agglomerates. Asphaltene precipitation and deposition in production tubes and surface facilities are well-documented concerns, and many solutions for managing them are available. However, the effects of asphaltene in the reservoir, particularly in the near-wellbore zone, are little known. In this study, using an artificial porous medium, experimental data on pressure drop due to changes in parameters such as the flow rate, the type of precipitant n-alkane solvent (n-heptane alkane solvent and n-decane), and the percentage of precipitant are obtained. Next, the permeability reduction from asphaltene deposition in a porous medium is calculated. Experimental data are fitted with the proposed quasi-experimental models at different time intervals to identify the dominant mechanism in reducing clogging. One of the study’s accomplishments is determining the principal mechanism of permeability reduction (in vitro) using a reasonably basic model with the least dependent parameters and a decent approximation. According to the findings, pore throat plugging becomes the dominant mechanism of permeability reduction although filtration cake formation and surface deposition may exist during the tests.