مجله پژوهش نفت
پیاپی 129 (خرداد و تیر 1402)

PPG with mesh size 40-50 in 100-time diluted sea water, showed the maximum swelling capacity. Presence of 0.8 wt% nno silica in the geAInjection of preformed particle gels (PPG) into fractured reservoirs is one of the most effective methods in reducing unwanted water production and increasing oil recovery. In this research, a sample of PPG has been synthesized by free radical polymerization method, and its performance for the conformance control has been evaluated. The swelling capacity of the synthesized gel has good stability against the desired conditions of temperature, salinity, pH and the presence of carbon dioxide. Also, due to the presence of hydrophilic organic groups, the interactions of oil and formation water lead to an increase in the swelling ratio of gel particles. The plugging performance of synthesized PPG samples in fractures was also investigated by the Hele-Shaw Cell system. The gel network placed in the fracture create a new porous media with far less permeability than the initial fracture. The ability of the gel to maintain the permeability of this formed porous medium depends on the flow rate and salinity of the secondary water injection, as well as the size of the gel particles. Secondary water injection into the fracture after gel placement, forms wormhole-like paths for flow of water through the gel network, and the higher the injected flow rate results in the lower resistance of the gel network against water flow. Gel particles with a matching size ratio (the ratio of the diameter of the swollen gel particles to the width of the fracture) less than 2.9, increase resistance to the water flow with increasing in their size, but the particles with a matching size ratio of 2.9 or higher, reduce the resistance to water flow due to network breakdown. Comparing this value with some of the previously published data, it seems that the critical matching size ratio is independent on gel properties and injection conditions. Finally, the effect of gel treatment in reducing water production and increasing oil recovery has been investigated in the fractured micromodel. The gel particles plugged the fracture and the secondary injected brine was sufficiently diverted towards matrix, so the oil recovery factor from matrix in subsequent water flooding increased by 65%.structure enhanced the stability of the synthesized PPG samples, in the high salinity brines and in the presence of the CO2. Presence of water-soluble fractions of oil, leads to 6 unit increase in the swelling ratio of gel particles due to the hydrophilic nature of these organic groups. The gel network placed in the fracture create a new porous media with far less permeability than the initial fracture. The ability of the gel to maintain the permeability of the formed porous medium depends on the flow rate of the secondary water injection, salinity and the size of the gel particles. Secondary water injection into the fracture after gel placement, opens wormhole-like paths for moving through the gel network, and the higher the injected flow rate, the lower the resistance of the gel network against water flow. Gel particles with a matching size ratio (the ratio of the diameter of the swollen gel particles to the width of the fracture) less than 2.9, increase resistance to the water flow with increasing in their size, but the particles with a matching size ratio of 2.9 or higher, reduce the resistance to water flow due to particle breakdown. This critical matching size ratio is independent of gel properties and injection conditions. The gel network swollen in more salinity has a higher resistance to water flow, while the secondary low salinity water injection, although it reduces the gel strength, but leads to an increase in the resistance of the gels to water flow. In the fractured micromodel test, the oil recovery factor from matrix increased from 29% in the primary fooding to 94% at the end of the secondary flooding.

Rain Optimization Algorithm (ROA) is a population-based algorithm that finds the optimal solution for complex optimization problems by simulating the movement of raindrops. By moving the raindrops towards the minimum points according to the diameter of the raindrops, this algorithm is able to find the minimum or maximum points of a function or optimization problem with acceptable speed and accuracy. In order to improve the search and discovery capabilities of this algorithm, a random search was added before starting to solve the problem by this algorithm, which is inspired by cluster bombs. Thus, before starting to optimize by ROA, random points around this raindrop are first selected and the search starts from a point that has a smaller value. For this reason, the name of the new algorithm was changed to the improved IROA rain optimization algorithm. The effectiveness of the proposed optimizer was tested through the optimization of a simulation problem in mining engineering (simulation of the movement of cement slurry in matrix and fractures) and its performance was compared with several well-known meta-heuristic algorithms. The results show that IROA is able to achieve more accurate solutions in complex optimization problems by providing faster and more efficient convergence speed compared to other successful optimizers.

This study investigates and evaluates the effects of heating type using microwaves and conventional heating on the yield and quality of oil-shale produced from the Qalikuh reservoir with total organic carbon TOC between 3.83 and 26.4% by the weight and average  16.5% by weight. With microwaves heating, Maximum oil produced is %5.9 by weight and  Based on the analysis of SARA shale oil compounds, asphaltene compounds decrease (24% by weight), saturated compounds increase (on average 40% by weight), and resinous and aromatic compounds also have fluctuating behavior. In conventional heating, Maximum oil Produced is 4.5% by weight, and  the amounts of saturated compounds (about 23% by weight) and asphaltic compounds (on average 14% by weight) in shale oil decrease, but resinous compounds (about 28% by weight) decrease and compounds Aromatic values also fluctuate. The highest desulfurization in shale oil produced using microwaves was observed, The amount of nitrogen in the shale oil also decreases with the heating by microwaves finally reaches to 8% by weight. In shale oil produced by normal heating, finally sulfur decreases by 31%, nitrogen increases by 21%, and oxygen increases by 60%.

Shidvar wetland is located in the Persian Gulf Based on importance of coral islands as the fourth international wetland of Hormozgan province. The current research was conducted with the aim of investigating the amount of total petroleum hydrocarbons (TPHs) pollution in the sediments around the coral ecosystems of Wetland during Khordad 1401. Sediment samples were randomly collected from the depth of 0-5 cm of the seabed and the coasts of island and transferred to the laboratory according to the MOOPAM method, the concentration of TPHs was determined by UVF device in terms of micrograms per gram of sediment dry weight. The results obtained from the sediment texture analysis showed that in sea sediments, the highest to lowest percentage of silt and clay particles were observed in the third > second > first stations and in the first > third > second coastal sediments. The range of changes of sand particles in marine sediments varies from 51.57% to 52.07% and in coastal sediments from 56.76%to 68.15%. The results show that the concentration of TPHs is lower than the background value of environmental risk (4 μg/g). Generally, the reason for the presence of punctate compounds in this wetland can be considered as the 1.5km proximity of this natural ecosystem to Lavan Island, which is one of the four important areas of oil operations in the Persian Gulf and is connected with huge facilities for refining, transporting, loading and exporting crude oil. The findings of the environmental risk showed that sediments of the study area fortunately do not have any adverse biological effects on the life of aquatic organisms in this area.

South Pars gas field is one of the fields in southwestern Iran in the Zagros sedimentary basin and includes two reservoirs, Kangan and Dalan. Kangan and Dalan formations that belong to Dahram group and are considered as the most important gas reservoirs in the Persian Gulf region. The use of well drilling logs in uncored wells to identify rock-related features has always been discussed by geologists.  In this study, based on wavelet analysis of gamma-neutron and sonic logs, stratal surfaces including sequence boundary and maximum flooding surface were identified.  In this study, using wavelet analysis of well log data such as GR, NPHI, RHOB, DT and also combining them with Cyclolog data, a suitable and low error method for automatic determination of these boundaries was presented. Also in this study, sequence stratigraphy was investigated by INPEFA method of Cyclolog software to determine sequence boundaries (SB) and maximum flooding surface (MFS) with positive inflection points and negative inflection points of available INPEFA log curves , respectively. In addition, the highstand system tract (HST) was identified by the negative trend of the INPEFA curve and the transgressive system tract (TST) was determined by the positive trend of this curve. Accordingly, sequence stratigraphy study of Dalan and Kangan formations was performed by INPEFA method in 4 wells of South Pars gas field.  Finally, the agreement between the automatic sequence boundaries obtained from the wavelet transform method and INPEFA and its comparison with the core information in four wells from the study field, shows satisfactory results.

In this research, the nanofibrous polystyrene /titanium dioxide nanotube (PS/TiO2 nanotubes) membrane was prepared by electrospinning method. In order to synthesize titanium dioxide nanotubes, the anodizing method was used. Then, the effect of different weight percentages of titanium dioxide nanotubes on the performance of the resulting membranes was investigated. The nanoparticles and nanocomposites prepared in this research were analyzed using several analyses, including fourier transform infrared spectroscopy (FT-IR) and field emission scanning electron microscopy (FE-SEM), along with X-ray energy diffraction spectroscopy (EDS). The thermal behavior and crystal structure of prepared nanocomposite membranes were investigated using (TGA) analysis and X-ray diffraction (XRD), respectively. Afterward, in order to investigate the prepared structures, analyses such as porosity measurment, water contact angle, swelling and water flux of the membranes were performed. The photocatalytic property of the prepared membranes toward decomposition of methylene blue was investigated by two methods. The obtained results demonstrated that the dye removal was accomplished in the best way in the static method (using the membrane as an absorbent) for 48 hours. The prepared nanocomposite membranes were also used in the dye filtration removal process and the best result was obtained by using the membrane containing titanium dioxide nanotubes with the concentration, 0.05 g/(V(50).

dioxide has been considered by the process of cyclic surface adsorption using calcium-based adsorbents. Despite a proper performance, the reduction of adsorption capacity due to the sintering of Ca-based adsorbents with increasing number of cycles is still a big challenge. In this study, the performance of two Ca-based adsorbents prepared from lime ore (limestone) and eggshell sources in terms of adsorption capacity during 20 consecutive carbonation and calcination cycles was investigated. Then, in order to overcome the sintering problem, both limestone and eggshell adsorbents were treated with acetic acid at a concentration of 10% by volume. The results showed that the presence of acetic acid in both types of adsorbents led to an increase in the effective conversion at the end of 20th cycle, so that the values of 0.38 and 0.33 were obtained for limestone and eggshell with 10% v/v acetic acid, respectively, which was comparable to the corresponding values for raw limestone and eggshell (in the absence of acetic acid), that is 0.24 and 0.20. The reason for the increase in the conversion by treating with acetic acid can be attributed to the formation of calcium acetate, which has led to the formation of more porous and stable structures. By comparing the two calcium sources used in this study, it was found that limestone has a better performance than eggshell in terms of CO2 adsorption capacity, so that the conversion rate of raw limestone was 1.2 times higher than raw eggshell, which could be related to its high purity as well as its larger crystal size compared to eggshell.