PETROLEUM RESEARCH
Year:2019 | Volume:29 | Issue:105 |Papers Count:14

Intelligent oilfield technology is one of the newest technologies in the oil/gas industry, which is increasingly regarded by international oil companies as a highly competitive advantage in production. The intelligent oilfield has various dimensions and components such as human resources, processes and equipment, but the cornerstone of intelligent oilfield is the effective use and management of field’ s big data in order to make strategic and timely decisions on production. In order to achieve the goal of optimal management and utilization of oilfield’ s data, in this study, by using PPDM standard and Azadegan oilfield as a case study, the oilfield’ s data model is designed in seven specialized subject areas, 70 tables and 2700 columns. Then, the field’ s data warehouse model is developed based on Kimball’ s methodology. In the next step, both data and data warehouse models were validated by experts. Consequently, in order to facilitate strategic and timely decisions on production, based on the designed data and data warehouse models in the previous stage, about 40 “ key performance indicators” were obtained and validated by the experts of oil and gas industry in three intervals of short, medium and long term, and the importance of each in the decision-making about the field’ s production was determined. The “ equipment type” , “ gas to oil ratio” and “ real production amount” indicators were evaluated with the highest weight and therefore the highest importance in the field’ s strategic decisions. At the end, in order to facilitate the production of real-time managerial reports about oilfield’ s production, the Azadegan oilfield’ s management dashboard is designed and presented.

The extraction of aromatics from aliphatics mixtures when they create an azeotropic media is a challenge for refinery and petrochemical industries. In this study, we have used liquid – liquid equilibria have been used to extract benzene or thiophene from n-hexane by N-formyl morpholine, and its deep eutectic solvents (DESs) with choline chloride at T = (298. 15 to 318. 15) K and atmospheric pressure have been investigated. The effects of temperature and mixing ration of aromatic / aliphatic/ NFM or DES on the distribution coefficients (β ) and selectivity (S) factors have been studied. The NRTL and UNIQUAC thermodynamic models have been used to correlate experimental LLE data. The obtained interaction parameters have been used to plot the phase equilibria of the studied systems. The obtained results show the potential of studied DESs for usage in ambient conditions and below than their pure consistent melting points. Finally, the LLE results indicate that in the extraction with NFM, some solvent impurities are entered into the hydrocarbon phase which in the case of its DESs form, this problem is removed.

By continuous production of a hydrocarbon reservoir, the reservoir pressure and production rate decreases. If the gas oil ratio, flowing bottomhole pressure and reservoir fluid properties are appropriate, the production rate will increase with the use of the artificial gas lift. Gas lift operation must be monitored and injection conditions have to be updated with respect to the condition variation in order to obtain the optimum production rate and predict the performance of a hydrocarbon field. One of the problems which occurs in gas lift operations is the instability phenomenon. This phenomenon reduces oil production and damages facilities. Also, because of available lift gas limitation, the injection gas must be allocated among producing wells in a way to produce in an optimum condition and prevent instability. In the current study, Eclipse was used to simulate reservoir. Then, wells and surface flow pipeline network were modeled using Prosper. Eventually, MATLAB was used for connecting reservoir, wells and flow pipeline network to create an integrated model and allocate optimized lift gas rate between wells, by genetic algorithm. Injection gas was allocated among wells according to different scenarios. Moreover, oil production and cashflow from each scenario were compared. According to the results, using the integrated production model with the optimal control system in an artificial gas lift process improves cashflow by 224. 86% over natural production condition in a hydrocarbon reservoir. Finally, although considering instability as a constraint in an optimal control system of integrated production model reduces cashflow by 2. 93%, it will reduce the damage to the downstream facility in the long-term.

In the current study, prepared PES nanofiltration membranes with phase inversion method were modified by the novel composite chitosan/GO (graphene oxide) nano-sheets coating process and the effect of coating on performance and membrane antifouling properties was investigated. The results revealed that the salt rejection strongly improved, and their hydrophilicity enhanced rather than PES. The rejection increased from 68% for PES to 94% due to pore size reduction and improvement in adsorption. But permeability flux was decreased by increasing skin layer after coating. In addition, contact angle was decreased because of chitosan and GO nano-sheets hydrophilic nature. The surface morphology was changed from rough surface to smoother one by coating. Finally, flux recovery ratio and total fouling ratio were in good agreement with contact angle results and roughness parameters. Moreover, an increase in flux recovery ratio and reduction of total fouling ratio indicated successfully enhancement of antifouling properties of membrane by coating of chitosan/GO nan-osheets.

Cross flows and molecular diffusion are of high importance in recovery of bypassed oil. Thus, reinforcing viscous cross flow as a driving force in order to increase the oil recovery is proposed. In order to strengthen viscous cross flow, injection of a viscose fluid such as foam in fractured micromodels was applied, and bypassed oil was recovered. Based on the results, effective mechanisms of bypassed oil displacement were viscous cross flow and emulsion. Moreover, two distinct region were observed in displacement front: a dynamic region in which the saturation of foam is low and participation of surfactant saturation is higher than gas phase, and a static region that foam saturation is high and fluids’ mobility are lower than dynamic region. In dynamic region, some oil was recovered by emulsion. The oil droplets flew through arc-like aqueous phase and accumulated near the downstream. As oil saturation decreases in fracture, an area that is known as mixing zone is observed in middle parts of matrix-fracture interaction. Moreover, pressure drop in the main stream is the driving force for moving these oil droplets through arc-like front. This pressure drop is constant in a steady state foam injection in porous media. Hence, the driving force is constant and strengthens the fluid flow up to a certain level in dynamic region. Therefore, each pressure drop in the mainstream corresponds with particular foam invasion depth and is proportional to an individual recovery factor.

In this research, the effect of electrolyte concentration and pH effects on transfer properties of mixed matrix cation exchange membranes filled with activated carbon nanoparticles modified by chitosan was studied. Moreover, the scanning optical microscopy images showed uniform particles dispersion and uniform surface for the membranes. The membrane water content and ion exchange capacity of nanocomposite membranes were improved. The membrane potential, selectivity and areal electrical resistance were enhanced initially and then decreased. Also, the selectivity of mixed matrix membrane was increased initially by increase in electrolyte concentration and then showed decreasing behaviour by more increase in electrolyte concentration. Moreover, obtained results exhibited more selectivity for the membranes at neutral condition in comparison with acidic or base regions. The areal electrical resistance of membranes was also decreased by increase in electrolyte concentration. Moreover, an increase in electrolyte pH initially caused that membrane areal electrical resistance enhanced however areal electrical resistance declined again at higher pH values. The ionic flux of prepared membrane showed an alternative trend when additive ratios were increased. Finally, the transfer properties of membranes showed that the modified membranes in this study were comparable with that of commercial ones.

The present paper is an attempt to characterize the reservoir properties and calculate geomechanical parameters using dipole sonic log of the Asmari Formation, Ramshir oil field, SW Iran, as well as predict bit selection. The Asmari Formation is divided to 8 zones based on reservoir parameters. Moreover, zones 1, 2, and 3 (individual zone 2) are in production stage. To understand lithological changes of the reservoir, 300 thin sections were studied. It was defined 8 lithological facies including dolostone, clayey limestone, wackestone/packstone, grainstone, anhydrite, sandstone, shale/marl, and pyritic shale. These variations indicated that sedimentary environment changes from shallow marine, tidal flat, to lagoon. Dolomitization, recrystallization, micritization, pyritization and solution are dominant diagenetic processes. The variation of geomechanical parameters, which is proportional to lithofacies changes, can be considered as a key to determine possible reservoir properties changes and drilling potential as well. These parameters are coincided, indicating that the presence of heterogeneity and reservoir potential of upper part is higher than lower part of the Asmari Formation.

In this study, a series of laboratory tests using a hydraulic fracturing system were conducted to examine the behavior of an induced hydraulic fracture as it approached a cemented natural fracture. To achieve this, sheet-like test specimens were cast with natural fractures of varied mechanical properties, thickness, and relative position to a fluid injection port. A tendency for the induced hydraulic fracture was shown to cross thick natural fractures filled with softer materials than the host rock and to be diverted by thick natural fractures with harder filling materials. The induced hydraulic fracture also tends to cross hard natural fractures when the natural fractures are relatively thin. In addition, the induced hydraulic fracture from the injection port was shown to be diverted by a thin, hard natural fracture that was placed relatively close to the injection port but crosses the same natural fracture when placed farther away from the injection port. Finally, the results provide a novel evidence of the impact of natural fracture filling materials on the outcome of hydraulic fracture propagation at its interaction with natural fractures.

The Gas-Liquid Cylindrical Cyclone (GLCC) separators have proven themselves in laboratory and field, as a well alternative to the conventional gravity-based gas/liquid separator. This study presents investigation of the effect of changes in physical aspects on GLCC performance. These changes are including increases in outlet length and reduction in gas body column length, inlet, body column, liquid and gas outlet diameter. In addition, results show that reduction of inlet diameter enhances the GLCC performance but any reduction in diameter of body column and liquid outlet has negative effect on that. Also, changes in gas outlet diameter does not have any effects on the GLCC flowrates domain. Finally, any increase in length of outlets rises the friction force and diminishes the performance of separator.

Gravity survey has a lot of applications in identifying geological structures which can form and store hydrocarbons. Also, this method helps the salt dome and dome-shaped uplift masses to be identified. In this paper, the nonlinear inverse modeling approach of gravity data is used to determine the geometry of the basement. In the process of modeling gravity data, a grid is generally approximated by a series of coordinating prisms, and then their thickness is calculated. In order to demonstrate the efficiency of the method, understanding how the method works and its details, the modeling noiseless and noisy gravity data was first performed. At the end, modeling real gravity measurements was performed using data from the South of Netherlands. Finally, the obtained results are in good agreement with the results obtained in the Mirzai thesis. Moreover, all the programs used in this article are provided by the authors in the MATLAB software environment.

Nowadays, biosurfactants are widely used in various industries due to their wide range of applications. In this paper, the production of rhamnolipid biosurfactant from Pseudomonas aeruginosa PTCC 1340 as one of the most important biosurfactants was investigated using a sunflower oil carbon source. For this purpose, soil samples were contaminated by crude oil with API 33 artificially. In this study, the production of biosurfactant in the removal of crude oil was investigated. Moreover, the results of this study showed that the maximum amount of rhamnolipid production was 4. 3 g/L. Rhamnolipid structure was examined and verified by TLC and FTIR analyzes. The study of the properties of the produced rhamnolipid showed that these substances had a high potential in reduction of surface tension, as the produced rhamnolipid reduced the surface tension of water from 69 mN/m to 26. 8 mN/m. It also showed that a considerable stability in mixing with NaCl salt up to a concentration of 15%. Finally, the results showed that Rhamnolipid supernatant eliminated 75. 17% of the crude oil in the soil, while the highest removal efficiency of the crude oil from the soil was 76. 92% by SDS surfactant. According to the successfull results, it can be suggested that the produced rhamnolipid biosurfactant can be used as an alternative to chemical surfactants in various industries.

The asphaltene molecules play a very important role in the crude oil for the exteraction of oil from oil reservoirs. Therefore, in this study, the aggregation and deposition of asphaltene N6 in aromatic solvents such as cyclohexane, benzene, toluene, chlorobenzene and bromobenzene were investigated by using molecular dynamics simulation at room temperature and pressure. In addition, physical properties such as density and solubility parameter for N6 asphaltene and pure solvents were calculated and compared with experimental data. There is a good agreement between the simulation results and experimental data. In addition, the behavior of asphaltene molecules was studied for pure and soluble in aromatic solvents conditions. The results show that the asphaltene molecules aggregate due to π-π bonds between the aromatic rings in the structure of them. Finally, the simulation results indicate that the asphaltene molecules are soluble in chlorobenzene better than other solvents, and also it is better than toluene solvent.