مجله پژوهش نفت
پیاپی 131 (مهر و آبان 1402)

In recent years, petroleum engineers have focused on smart water injection as an economical and environmental consideration method to increase oil recovery. On the other hand, the phenomena of migration and swelling of clays in the reservoir rock due to the decrease in salinity and the change in the ionic ambiance cause significant changes in the permeability of the sandstone/carbonate reservoirs, which is the cause of damage to the formation. This study performed static tests to determine the amount and type of clay using XRD and SEM tests on the rock core sample. Then, the injection water salinity was designed according to the results of swelling gauge tests to study the effect of different liquids on the swelling of identified clays (kaolinite and smectite) from the static results. In the continuation of the new micromodel dynamic tests and flooding by making a porous clay environment according to the specifications of the real reservoir rock was designed. In this study, the formation damage index to express the simultaneous or separate effect of swelling and migration of swelling and non-swelling clays according to the observational evidence of permeability changes in the micro model along with the interpretation and comparison of quantitative calculations of flooding experiments in salt water/clay interactions are presented. The common result of these experiments shows two suitable patterns of smart water injection, the gradual reduction of formation water salinity with the priority of injection of swelling control fluid and the removal of a migration control fluid, as well as the combination of one percent of zirconium oxychloride in 20 times diluted seawater as a suitable injection fluid for swelling control. With this achievement, in the scenario of smart water injection as a method of EOR which is interested in the oil industry, by removing or controlling formation damage due to fluid incompatible with the reservoir rock, the maximum production recovery will be achieved.

The Spheripol process is one of the most widely used technologies in the world for the production of polypropylene (PP). The geometry of the reactor is such that the use of ideal reactors alone causes an error in the simulation results. Therefore, in this research, we have tried to combine the ideal reactors modules in Aspen Plus. v11 to get the most accurate results. In order to calculate the volume of the ideal reactor, we used the concept of «required length for fully developed flow» and considered the inlets, outlet, and pump of the reactor as a continuously stirred tank reactor (CSTR) while the other part of the reactor considered as plug flow reactor (PFR). We also used three different kinetic constants reported by three different research groups and compared the result with the production plant data. Due to the importance of the thermodynamic model for the prediction of phase behavior, we used the Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state that was used by previous authors. The results are validated with the production plant data and previous articles. Also, the effect of methanol as a catalyst poison is investigated.

Plate and frame heat exchangers are widely used in the industry due to their high heat transfer coefficient. In this research, experimental studies was carried out on corrugated plates, because the corrugations result in reducing the liquid turbulence to the counter current liquid flow and increasing heat transfer efficiency.  Dendritic nanofins were synthesized on copper plates in a heat exchanger microchannel and the effect of the heat transfer coefficient behavior was investigated. Synthesis of dendritic nanofins performed by a standard two-electrode glass cell with a graphite electrode as a reference electrode on six corrugated copper plates with dimensions of 4.6 cm ×4.6 cm in a plate heat exchanger microchannel by electrodeposition method. The dendritic copper nanofin array grew on the copper plates from electrolyte solution consisting of CuSO4 (0.6M), H2SO4 (0.4M) and an increasing current starting from 1.2 to 4.8 A/cm2 in 300 seconds. Characterization of the coated surface was performed by FESEM method, and the adhesion of this coating to the surface was investigated by AAS method. The microchannel designed with two hot and cold inlet fluids and it was installed in a system with the ability to check the improvement of the heat transfer coefficient by applying copper nanofins coatings. In this system, water was selected as a circulating fluid with two hot and cold inlets and two hot and cold outlets in the microchannel. The cold water inlet temperature was 7°C and the hot water inlet temperature was set at 45, 50 and 55°C in separate experiments. The heat transfer coefficient was measured in two stages before coating with copper nanofins and after coating. The measured increase in heat transfer coefficient between 40% and 62% as a result.

In this study, surface tension modeling is developed using intermolecular thermodynamic potential function including the two-parameter Lennard-Jones model in a semi-analytical form and the three-parameter well-square model in a full-analytical form in a wide range of temperatures in the bulk scale. The comparison of the results for hydrocarbon fluids (light to heavy) and non-hydrocarbon fluids shows that the prediction of surface tension through the square-well model, due to its high flexibility and mathematical simplicity compared to the Lennard-Jones model, provides significant agreement with experimental data.

Kangan Formation with Triassic age, it has the largest gas reserves in the Middle East and the world. This formation is in Salman field (Including 187 meters of thickness in the 2SK-1 well and 189 meters of thickness in the 2SKD-1 well) And in Lavan field (including 186 meters of thickness in LN-3 well), and with the sequence of carbonate, limestone, Dolomite limestone, Dolomite with anhydrite Layer, Marl and shale (on the Kangan Formation). According to microscopic studies in the mentioned wells, 15 faces were identified which belong to four facies belts: Sabkha, Tidal flat, Lagoon and Shoal. Based on the identified microfacies, a homoclinal carbonate ramp can be introduced. The known diagenesis processes in the Kangan Formation, which are effective on the reservoir quality are: mechanical and chemical compaction, anhydrite and calcite cement as a reservoir quality reducer and dissolution, dolomitization and fracturing can be mentioned as increasing reservoir quality. The types of porosity observed are: Intragranular porosity, Moldic, Fenestral, vuggy, Intraparticle, and fracture. The vertical changes of the facies indicate three third-order depositional sequences and five fourth-order depositional sequences in Salman and Lavan fields. Each sequence consists of two system tracts, TST (including intertidal, lagoon, back shoal) and HST (including intertidal and shoal) in reservoir units K1 and K2. Reservoir quality study also according to distribution and separation of samples of Grain supported and Mud supported facies, sedimentary environment and the size of dolomite crystals, compared to the available porosities and permeability, indicates class 1 and 2 of Lucia.

In this study, the significant diagenetic processes in the Sarvak reservoir of an oil field located in the Dezful Embayment were studied from petrographic and petrophysical point of view. Therefore, after studying the thin sections provided by cores and cutting and preparing related diagenetic logs, it was determined that the main diagenetic processes affecting the reservoir quality include cementation, dissolution, dolomitization, and compaction. In addition, petrophysical logs were studied, and then porous zones were distinguished from other parts using VDL, SPI, and dolomite volume logs. Some input logs including secondary porosity, effective porosity, dolomite mineral volume, and VDL logs were used to determine diagenetic electrofacies. Accordingly, eight diagenetic facies codes were identified using the MRGC clustering method. This study indicates that dolomitization had both constructive (Facies 1) and destructive (Facies 2) effects on reservoir quality in different zones. Moreover, secondary porosity causes the development of high reservoir quality facies (Facies 6). Some facies (Facies 3, Facies 4, and Facies 5) have low reservoir quality due to a lack of developing dissolution and dolomitization. In addition, low porosity intervals include high compaction features (solution seam and stylolite). Based on this study, it is possible to construct diagenetic electrofacies indicating the different diagenetic processes and dividing rocks to related rock types.

In this study, CFD simulation of low-pressure flare (LP) of the gas refinery has been investigated to evaluate the effects of geometric parameters of flare tip, especially the effect of steam injection on the combustion characteristics of flame, as well as no flame backflow. The computational model was developed by considering related transport phenomena (momentum, heat, mass, radiation, turbulence and chemical reactions). In order to create the suitable computational mesh, finer meshes were selected around the steam injection nozzles and internal parts of the flare. The results of the developed computational model include temperature and velocity profiles (shape and appearance of the flame), profiles of the gas species, tracking of the injected steam, as well as profiles of the combustion products. The results of the CFD simulation showed that due to the injection of steam from the nozzles in the center of the flare tip and its very high speed, a complex hydrodynamics is created in the opening of the flare tip, which leads to the formation of vortices. Due to the formation of a vortex at the flare tip, some of the surrounding air is drawn into the flare tip, which is in the form of a flame in the gas seal to the perforated plate of the flare tip. For this reason, the body temperature of the flare tip increases up to 2200K in some parts of the perforated plate and gas seal plates. The results of the simulation regarding the return of the flame into the flare tip are consistent with the observations in the industrial unit. The internal body of the LP flare tip in the industrial unit due to the flame being drawn into the flare tip faced with thermal stresses, and as a result causes its rapid destruction.

The adsorption properties of uniform nano-plate cobalt based metal-organic framework of [Co6(oba)6(CH3O)4(O)2]n·3DMF (TMU-11NP) for removal of dibenzothiophene (DBT) has been investigated. TMU-11NP can be obtained quickly and easily via sonochemical method. The effect of particle size reduction and enhancement of surface area from 630 to 838 m2/g and changing the morphology from the agglomeration of particles to regular nanoplates has increased the absorption capacity of DBT from 825 to 1666.6 mg/g. The selectivity test of DBT over naphthalene (NA) clearly shows that π-π interactions between organic linkers of TMU-11 and the aromatic ring of DBT are not responsible for the adsorption desulfurization (ADS) process. The synergistic effects of reducing the particle size and subsequently, increasing the surface area and increasing the accessibility of inactive unsaturated coordination sites around one of the cobalt centers, as well as the uniform morphology of the plates, have led to the observation of such results. Also, nano particles of Co3O4, obtained from calcination of TMU-11NP, show higher DBT removal performance (300 mg/g) compared to its commercial counterpart (83 mg/g). The adsorption mechanism of DBT in the presence of TMU-11NP adsorbent was investigated and it was found to follow the Langmuir model. Our findings may offer a new approach to producing adsorbents with preferable performance in practical applications.

Conditional optimization is one of the best methods to increase production from hydrocarbon reservoirs. Integrated production modeling can optimize and manage production from reservoirs. In this research, a new method for optimizing integrated production systems is presented. The components of the integrated model are the reservoir, well, surface choke, pipeline, and separator models. The effect of separator inlet flow regimes and surface separator operation conditions on the efficiency of separator operation and oil production systems in this model cannot be neglected. This model includes the separator pressure controller and the objective function is to maximize the oil in the storage tank. The limitation of optimization is the non-formation of clotted flow at the inlet of the separator. The optimization model has excellent performance for optimizing integrated systems in stable, transient, and quasi-stable reservoirs. The optimization model can perform well in situations where the choke changes from critical to subcritical or vice versa. The amount of accumulated oil in the storage tank for the integrated model with clotted flow control is equal to BBL820, and for the integrated model without clotted flow control is equal to BBL 934.3 and for Olga software is equal to BBL 741.5. Using the optimal integrated model with clotted flow control, in addition to increasing oil production in the storage tank, also prevents the formation of slug flow.

By increasing the extraction from the hydrocarbon reservoirs, the investment risks in the hydrocarbon field development projects reduces. Experimental analysis, generalization of their results, modeling and design the reservoir are used because of the uncertainty in geological issues during the preparation of dynamic and static models of the fields and the high cost of auditing these projects. Engineered water injection improves oil recovery, but the mechanism of its effect is not completely clear. According to the researches, one of the effective mechanisms of engineered water is the change of electric charge on the surface of oil and as a result, change of wettability. The effect of electric charge on the wetting behavior of carbonate rock which leads to harvest increase, has been investigated in this study. The existing surface complex models were reconstructed for the pure calcite rock model and the ionic composition used in this work. Models has been examined from the electric potential and surface absorption points of views and the best model was considered to predict zeta potential. Based on the obtained contact angles, 40 times diluted seawater increases the hydrophilicity by 30.79% compared to concentrated seawater. The results also showed that 40 times diluted seawater leads to a decrease in the zeta potential of pure calcite/brine from -2.9 to -5.4 mV and a decrease in the zeta potential of crude oil/brine from -6.2 to -18.3 mV. Based on the results, the electric charge of these two surfaces becomes more negative as the water salinity decreases and consequently the repulsive force between these two interfaces and the thickness of the blue film between these two interfaces increases. These changes lead to increase the water-friendliness of the rock, the greater tendency of oil for separating from the reservoir rock and ultimately lead to an increase in harvest.