Initial Oil Research Articles

Influence of In Situ Formed Nickel- and Cobalt-Containing Catalysts on the Mechanism of Conversion of Heavy Oil Asphaltenes

The influence of the amount of precursors of cobalt and nickel oxides on the composition and structure of catalytic cracking products of heavy oil from the Zyuzeevskoye field was studied. It was found that an increase in the amount of a loaded precursor led to the destruction of a larger amount of resin–asphaltene components and the yield of an IBP–360°C fraction. It was established that nickel-containing catalysts facilitated the destruction of 66% high-molecular-weight components, and cobalt-containing catalysts contributed to a low yield of by-products. The structural group analysis of initial oil asphaltenes and those formed after thermal and catalytic cracking was studied. A possible mechanism of the reactions was presented based on the experimental data.

Transformation of Heavy Oil Components in the Process of Initiated Cracking

In this work, the effect of butyl bromide on the thermal transformations of heavy oil from the Karmalskoye field (Republic of Tatarstan) in the presence of an initiating additive, n-butyl bromide, was studied. It was shown that the addition of butyl bromide increased the yield of gasoline and diesel fractions due to the destruction of high-molecular-weight components. It was established that almost all bromine from butyl bromide entered the compaction products upon the cracking of heavy oil, and butyl radicals entered the composition of gaseous products. It was noted that the direction of thermal transformations of hydrocarbons changed in the presence of butyl bromide. As compared to the initial oil, the amount of low-molecular-weight alkanes and isoprenoids increased significantly, the concentration of cyclohexanes and cyclopentanes decreased, and tri-, tetra- and pentacyclic saturated hydrocarbons were completely destroyed.

3D Geological Model for Zubair Reservoir in Abu-Amood Oil Field

The Zubair reservoir in the Abu-Amood field is considered a shaly sand reservoir in the south of Iraq. The geological model is created for identifying the facies, distributing the petrophysical properties and estimating the volume of hydrocarbon in place. When the data processing by Interactive Petrophysics (IP) software is completed and estimated the permeability reservoir by using the hydraulic unit method then, three main steps are applied to build the geological model, begins with creating a structural, facies and property models. five zones the reservoirs were divided (three reservoir units and two cap rocks) depending on the variation of petrophysical properties (porosity and permeability) that results from IP software interpretation. Five wells that penetrate the lower Cretaceous Formation (Zubair reservoir) are used to construct the geological model. ZUB-1 unit considered as the most important zone which have a good petrophysical parameters about 24% for porosity, 800 md permeability, 38% water saturation and 85% net to gross. The initial oil in place is estimated to be about 1.7898*109 STB. Finally, 3D geological model support in improving and estimates the hydrocarbon potentialities in oil field and enhances the production of the field.

Removal of cutting oil from wastewater by utilization of novel adsorbent developed from teak leaf (Tectona grandis): equilibrium, kinetic, and thermodynamic studies

The disposal of oily wastewater is a severe environmental problem faced by the metalworking and automobile industries. When released into the environment, oil-contained wastewater severely threatens plant, animal, and human life. Adsorption has emerged as a unique technique, and using natural adsorbents makes it further cheap and more eco-friendly. Removal of both free and emulsified oil from wastewater by using biosorbents was looked upon as an alternative. The present research aims to develop a novel biosorbent from teak (Tectona grandis) leaves suitable for removing oil from wastewater. Batch Sorption studies were carried out by varying pH, sorbent dosage, contact period, mixing speed, and initial oil concentration. The optimum conditions for maximum adsorption efficiency were determined. The results showed that the adsorption of oil onto teak leaf (Tectona grandis) adsorbent follows Freundlich isotherm with a maximum sorption capacity of 10.115 mg/g and a pseudo-second-order kinetic model. The thermodynamic parameter (ΔH = 5033.75 KJ/mol) suggested oil adsorption’s spontaneous and endothermic nature onto the teak leaf (Tectona grandis) adsorbent. The best regeneration efficiency was achieved with 0.01 M HCl.

An application of advanced oxidation process on industrial crude oily wastewater treatment

Advanced oxidation process, via photo-catalytic oxidation process was demonstrated in this study as one of the promising techniques of simulated oily wastewater treatment. Several effective factors such as initial oil concentration, catalyst dose, stirring speed (rpm), pH value and hydrogen peroxide (H2O2) dose influencing on the photo-catalytic degradation rate of oily wastewater were investigated. The catalyst used in this work was titanium dioxide (TiO2). The solubility of oil in water was increased using emulsifier. Results indicated that the photo-catalytic oxidation process has a good removal percentage of oil from oily wastewater reached to 98.43% at optimum operating parameters of 1 g/L initial oil concentration, 850 rpm, 8 pH, 3 mL H2O2 and 1.5 g/L of TiO2 after 40 min of irradiation time. The degradation reaction follows a first order kinetics with a correlation coefficient (R2) of 93.7%. Ultimately, the application of photo-catalytic oxidation processes at these optimum operating parameters on an industrial oily wastewater collected from an effluent stream of Ras Shukair at Red See supplied by Asuit Petrochemical Company was done in Egypt. The results showed that the best oil removal (99%) was achieved after adding 3 mL of H2O2 in a reaction time of 40 min compared to without adding H2O2.

In Situ Combustion of Heavy Oil within a Vuggy Carbonate Reservoir: Part I—Feasibility Study

Worldwide, the known recoverable heavy oil and bitumen reserves make up more than 64% of the total reserves, of which more than 60% are trapped in carbonates. Air injection has immense potential for hydrocarbon recovery from various reservoirs. While most of the successful air-based techniques are performed within carbonate reservoirs containing light oil, theoretically, in situ combustion (ISC) has also shown great potential for recovering heavy oil and bitumen. Carbonates are complex in terms of geology and are often associated with fractures and vugs that affect the fluid flow, pressure propagation and progression of the ISC reactions. This paper describes the first experiment in which the triple-porosity concept was applied to simulate heterogeneity through artificially induced vugs, core matrix and fractures. This approach was used to study the feasibility of the ISC recovery technique for heavy oil (14° API) within a dolomite reservoir using a combustion tube (CT) in an experiment performed at 1740 psig. The combustion front advanced through 78% of the core length prior to the termination of air injection, producing 80% of the initial oil. To differentiate between the various sources of the CO2 gas (a product of carbonate decomposition vs. the combustion reaction) the atomic ratios of (CO2 + CO)/CO = 6 and (CO2 + CO)/N2 = 0.21 were applied. Additionally, partial upgrading of the produced heavy oil was observed.

Effect of wettability on oil and water distribution and production performance in a tight sandstone reservoir

Wettability is an important factor that dominates the micro-distribution of initial oil and water, residual oil, and subsequent oil recovery in a tight oil reservoir. In this paper, integrated experimental techniques have been developed to examine the effect of wettability on oil and water micro-distribution together with production performance in a tight reservoir. Wettability alteration indicated by contact angles during the aging process was firstly monitored and measured continuously. Then, nuclear magnetic resonance (NMR) measurements were integrated with rate-controlled mercury injection (RMI) tests to determine pore and throat size distribution. Subsequently, NMR measurements were performed to not only characterize the oil and water distribution in the process of wettability change, but also evaluate the production performance and recovery potential. Furthermore, displacement experiments were carried out to visually observe the microscopic distribution of residual oil under different wettability conditions. For a strong water-wetting rock, oil is separated from the surface of a pore/throat on which a thin water film is adsorbed, and then fills the center of the pore in the form of oil droplets. The displacement experiments show that water saturation of a two-phase flow zone on relative permeability curves ranges from 22.5% to 55.1% and that water saturation at the isotonic point is 43.6% with its waterflooding oil recovery of 42.1%. For a weak oil-wetting rock, oil is mainly distributed in porous media in the form of an oil film. The water saturation of a two-phase flow zone ranges from 22.3% to 48.1%, while that of the isotonic point is 38.1% with waterflooding oil recovery of 33.2%. With wettability altering from strong water-wetting to weak oil-wetting, oil either is adsorbed on the pore and throat surface or migrates from the center of a larger pore to a smaller pore and/or throat. It is more unfavorable to the seepage of oil due to the fact that the two-phase flow zone is narrowed and a decrease in water saturation at the isotonic point, leading to a lower waterflooding oil recovery. After waterflooding, oil droplets caused by the Jamin effect, oil clusters resulted from heterogeneity, and small oil droplets dispersed at the corner of a pore are visually observed in cores with strong water-wetting. Within weak oil-wetting cores, residual oil is mainly distributed in a membrane-like form due to adsorption and oil clusters resulted from heterogeneity.

Influence of FeP and Al(H2PO4)3 Nanocatalysts on the Thermolysis of Heavy Oil in N2 Medium

The high viscosity of heavy oil is the main challenge hindering its production. Catalytic thermolysis can be an effective solution for the upgrading of heavy oil in reservoir conditions that leads to the viscosity reduction of native oil and increases the yield of light fractions. In this study, the thermolysis of heavy oil produced from Ashalchinskoye field was carried out in the presence of FeP and Al(H2PO4) nanocatalysts at a temperature of 250 °C in N2 gas environment. It was shown that Al(H2PO4)3 and FeP catalysts at a concentration of 0.5% significantly promoted the efficiency of the heavy oil thermolysis and are key controlling factors contributing to the acceleration of chemical reactions. The Al(H2PO4)3 + NiCO3 nanoparticles were active in accelerating the main chemical reactions during upgrading of heavy oil: desulfurization, removal of the side alkyl chains from polyaromatic hydrocarbons, the isomerization of the molecular chain, hydrogenation and ring opening, which led to the viscosity reduction in heavy oil by 42%wt. Moreover, the selectivity of the Al(H2PO4)3 + NiCO3 catalyst relative to the light distillates increased up to 33.56%wt., which is more than two times in contrast to the light distillates of initial crude oil. The content of resins and asphaltenes in the presence of the given catalytic complex was reduced from 34.4%wt. to 14.7%wt. However, FeP + NiCO3 nanoparticles contributed to the stabilization of gasoline fractions obtained after upgraded oil distillation. Based on the results, it is possible to conclude that the thermolysis of heavy oil in the presence of FeP and Al(H2PO4)3 is a promising method for upgrading heavy oil and reducing its viscosity.

Flow pattern analysis of the oil-water batch transportation using a wheel flow loop

Oil-water batch transportation is a new method to reduce pipeline corrosion based on the concept of flow management. Its good corrosion inhibition performance has been preliminarily verified in the previous study. But the previous research is only limited to a certain length of horizontal pipe and only two basic flow patterns are discussed, including stratified flow and dispersed flow. To further expand the batch transportation concept on reducing corrosion in oil-water pipe flows, the evolution of the oil-water interface in the marine riser pipe was evaluated by using a wheel flow loop and was investigated via the CFD simulation. The results show that the water-driving-oil interface kept more stable than the oil-driving-water interface and the oil film could attach longer to the pipe surface compared with water. Four types of flow patterns can be identified in the batch transportation mode, i.e., annular flow, stratified flow, dispersed flow, and transition flow between annular flow and dispersed flow. The result of parameter analysis suggests that the initial oil volume fraction and flow rate are the key factors governing the total length of the oil-continuous section Lo, which determines the corrosion mitigation efficiency of the batch transportation mode in vertical pipe flow.

Catalytic Low-Temperature Thermolysis of Heavy Oil in the Presence of Fullerene C60 Nanoparticles in Aquatic and N2 Medium

Catalytic thermolysis is considered to be an effective process for viscosity reduction, the conversion of high-molecular components of oil (resins and asphaltenes) into light hydrocarbons, and the desulfurization of hydrocarbons. In this paper, we conducted non-catalytic and catalytic thermolysis of a heavy oil sample isolated from the Ashalcha oil field (Tatarstan, Russia) at a temperature of 250 °C. Fullerene C60 nanoparticles were applied to promote selective low-temperature thermolytic reactions in the heavy oil, which increase the depth of heavy oil upgrading and enhance the flow behavior of viscous crude oil. In addition, the influence of water content on the performance of heavy oil thermolysis was evaluated. It was found that water contributes to the cracking of high-molecular components such as resins and asphaltenes. The destruction products lead to the improvement of group and fractional components of crude oil. The results of the experiments showed that the content of asphaltenes after the aquatic thermolysis of the heavy oil sample in the presence of fullerene C60 was reduced by 35% in contrast to the initial crude oil sample. The destructive hydrogenation processes resulted in the irreversible viscosity reduction of the heavy oil sample from 3110 mPa.s to 2081 mPa.s measured at a temperature of 20 °C. Thus, the feasibility of using fullerene C60 as an additive in order to increase the yield of light fractions and reduce viscosity is confirmed.

Generation of condensate bubble aphrons (CBA) by partially vaporized condensate to enhance oil removal from produced water

This paper demonstrates flotation separation for dispersed oil droplets and dissolved organics by preparing condensate bubble aphrons (CBA) by partially vaporizing condensate. The results show that the new CBA consists of a condensate membrane and a gas core, with a three-phase contact angle above 140° from the oil surface due to excellent wettability. At different temperatures and condensate compositions, bubbles are about 25–100 µm in size. The half-life time (140–230 s) of CBA and gas hold-up (10–25%) is much higher than nitrogen bubbles. It shows that the CBA has good stability and dispersibility. The flotation experiment of CBA found that the condensate group distribution ratio was optimally adapted to the temperature, and the optimum oil removal efficiency of up to 87% was obtained when the operating temperature was higher than the bubble point of 25–35 °C. The experimental experiment shown the recommended initial oil concentration (400 mg/L) and the mixing ratio of condensate and water (1.0%). Otherwise, CBA flotation efficiency was 10% higher than dissolved gas flotation. With the addition of flocculant, the CBA flotation efficiency can reach 97% of oil droplets and can achieve 50% removal of Acetic acid (HAc).

A semi-analytical rate-transient analysis model for light oil reservoirs exhibiting reservoir heterogeneity and multiphase flow

Rate-transient analysis (RTA) has been widely applied to extract estimates of reservoir/hydraulic fracture properties. However, the majority of RTA techniques can lead to misdiagnosis of reservoir/fracture information when the reservoir exhibits reservoir heterogeneity and multiphase flow simultaneously. This work proposes a practical-yet-rigorous method to decouple the effects of reservoir heterogeneity and multiphase flow during TLF, and improve the evaluation of reservoir/fracture properties. A new, general, semi-analytical model is proposed that explicitly accounts for multiphase flow, fractal-based reservoir heterogeneity, anomalous diffusion, and pressure-dependent fluid properties. This is achieved by introducing a new Boltzmann-type transformation, the exponent of which includes reservoir heterogeneity and anomalous diffusion. In order to decouple the effects of reservoir heterogeneity and multiphase flow during TLF, the modified Boltzmann variable allows the conversion of three partial differential equations (PDE's) (i.e., oil, gas and water diffusion equations) into ordinary differential equations (ODE's) that are easily solved using the Runge-Kutta (RK) method. A modified time-power-law plot is also proposed to estimate the reservoir and fracture properties, recognizing that the classical square-root-of-time-plot is no longer valid when various reservoir complexities are exhibited simultaneously. Using the slope of the straight line on the modified time-power-law plot, the linear flow parameter can be estimated with more confidence. Moreover, because of the new Boltzmann-type transformation, reservoir and fracture properties can be derived more efficiently without the need for defining complex pseudo-variable transformations. Using the new semi-analytical model, the effects of multiphase flow, reservoir heterogeneity and anomalous diffusion on rate-decline behavior are evaluated. For the case of approximately constant flowing pressure, multiphase flow impacts initial oil rate, which is a function of oil relative permeability and well flowing pressure. However, multiphase flow has a minor effect on the oil production decline exponent. Reservoir heterogeneity/anomalous diffusion affect both the initial oil production rate and production decline exponent. The production decline exponent constant is a function of reservoir heterogeneity/anomalous diffusion only. The practical significance of this work is the advancement of RTA techniques to allow for more complex reservoir scenarios, leading to more accurate production forecasting and better-informed capital planning.

Geological Model for Jeribe/Euphrates Formation, Tertiary Reservoir in Qaiyarah Oil Field, North of Iraq

Visualization of subsurface geology is mainly considered as the framework of the required structure to provide distribution of petrophysical properties. The geological model helps to understand the behavior of the fluid flow in the porous media that is affected by heterogeneity of the reservoir and helps in calculating the initial oil in place as well as selecting accurate new well location. In this study, a geological model is built for Qaiyarah field, tertiary reservoir, relying on well data from 48 wells, including the location of wells, formation tops and contour map. The structural model is constructed for the tertiary reservoir, which is an asymmetrical anticline consisting of two domes separated by a saddle. It is found that the three formations in the tertiary reservoir is composed of limestone and dolomitic limestone with very thin shale rims introduced only in the Dhiban Formation, which have the minimum thickness compared to the main other two formations those considered the main reservoir units. Upscaling from the software has been used to distribute and correlate between the logs and core data, which came very acceptable results to be used for distribution to the entire field. Both log analysis and core data have showed that the reservoir is clean formation, no volume of shale has considered in the STIIOP calculations with average water saturation calculated to be 31.5% and average porosity of approximately 22% with temperature gradient of 1.2 °F/100 ft. This comes up with Stock Tank Initial Oil in Place calculated to be 6.519*109.

A Comparison of The Performances of Conventional and Low Salinity Water Alternating Gas Injection for Displacement of Oil

This study focuses on identifying the crucial physical and chemical factors, such as gravity, initial oil phase, injection depth, vertical to horizontal permeability contrast, and salinity of injected water for improving oil recovery factor during water alternating gas (WAG) injection. The conventional WAG injection attracts interest from oil and gas industry and hence, has become one of the most reliable enhanced oil recoveries (EOR) techniques. During WAG injection, due to gravity effect, water subsides below oil layer while gas overflow above the oil layer. In fact, water sweeps bottom zones of the reservoir and gas sweep the attic oil at the upper zones of the reservoir. Although the conventional WAG does improve oil recovery factor, there still remains a substantial amount of oil in reservoir pores due to rock-fluid and fluid-fluid interfacial tensions (IFT) that leads to the capillary forces impeding the microscopic displacement efficiency. The low salinity waterflooding (LSWF) was therefore proposed to break the IFT between rock clay and fluids, and further increase oil recovery factor. Recent researches revealed that LSWF alters oil-wet reservoir to water-wet behavior. This wettability alteration is believed to be the main mechanism of LSWF to improve oil recovery. Other mechanisms of LSWF include multi-ion exchange (MIE) between rock clay minerals and injected salt water, pH increase, and fines migration. In this study, the CMG GEM simulator was used to simulate conventional WAG injection and LSWAG injection. The simulation results showed that there is an increase of oil recovery factor of about 6% for WAG injection with low salinity water of 1027ppm to sea water of 51,346 ppm. The simulations have also showed that the physical factors namely, gravity, initial oil phase, injection depth, vertical to horizontal permeability contrast are influential on the displacement efficiency and must be studied thoroughly in the design of LSWAG operations besides the salinity and chemical composition of the injection water.

Understanding Imbibition Mechanisms of Catanionic Surfactant–Stabilized Nanoemulsion for Enhanced Oil Recovery in Tight Sandstone Reservoirs: Experimental and Numerical Assessment

Summary Surfactant-induced imbibition is considered a promising method for increasing oil recovery from tight oil reservoirs beyond primary production. Nanoemulsion (nE) offers a great potential for this application owing to its unique physicochemical properties, such as kinetic stability, large surface area, and low oil-aqueous interfacial tension (IFT). Herein, we designed and prepared a series of surfactant-stabilized oil-in-water (O/W) nE using efficient catanionic surfactants by a low-energy method. The physicochemical properties of the nE samples were comprehensively characterized to better perform experimental and numerical simulations and constrain the modeling. We conducted imbibition tests on Chang 7 tight cores using nE and brine and also assessed the imbibition dynamics. Results indicated that nE was successfully synthesized at a surfactant concentration ranging from 0.4 to 1.0 wt%. The oil droplets in nE had a mean size of 10 nm. All the nE samples were able to lower the oil-aqueous IFT to an ultralow level of 10–3 mN/m. In addition, nE demonstrated superior capacities in wettability alteration, and oil solubilization and emulsification, which were all integrated into numerical modeling. The imbibition oil recovery was increased by 18.8% of the initial oil in place when nE1 (0.4 wt%) was used compared to that of brine. Because of the interactions among oil, nE, and rock surface, nE required a longer time to reach imbibition equilibrium than brine. The simulation results, for the first time, suggested that the dominant imbibition mechanisms of nE varied with time, during which IFT reduction and wettability alteration played the leading roles in the first 50 hours. The reactions of oil solubilization and emulsification became significant after 50 hours and then contributed equally to the oil recovery with IFT reduction and wettability alteration. The diffusion of nanosized oil droplets increased the equilibrium time of imbibition, thereby promoting the ultimate oil recovery.

Using magnesium oxide nanoparticles in a magnetic field to enhance oil production from oil-wet carbonate reservoirs

Enhanced oil production can maximise yield from depleted reservoirs, and in the face of dwindling global oil reserves can reduce the need for exploratory drilling during the transition away from fossil fuels. A hybrid technique, merging a magnetic field (MF) and magnesium oxide (MgO) nanoparticles (NPs), was investigated as a potential method of enhancing oil production from oil-wet carbonate reservoirs. The impact of this hybrid technique on rock wettability, zeta potential, and interfacial tension was also investigated. Displacement experiments were carried out on oil-wet Austin chalk – a laboratory carbonate rock analogue – using MgO NPs in deionized water (DW) and salt water (SW), in the presence of an MF up to 6000 G in strength. It was found that the addition of MgO NPs to DW before the spontaneous imbibition of the solution into initially oil-wet rock samples increased the recovery factor (RF, defined as the volume of oil recovered divided by the initial oil in place). For 0.005 wt% and 0.0025 wt% MgO NPs mixed in DW, the RF was 12.5% and 15.9% respectively. When DW was replaced with SW as the imbibing fluid, the RF increased by a further 0.7% of initial oil in place for the 0.0025 wt% MgO NPs. This additional increase in oil recovery was attributed to the presence of potential determining ions, which made the rock more water-wet. To avoid pore-clogging and thus the limited ingress of the solution into the rock, the NPs’ concentration was kept low. This hybrid technique is a cleaner alternative to conventional enhanced oil recovery techniques and will enable oil industries to produce oil more efficiently from existing reservoirs: when used in conjunction with Carbon Capture and Storage (CCS), this provides a useful short to medium-term option to support energy production during the transition to net zero.

Processes for the Clarification of the Crude Oil of Baobab Seeds Extracted by Pressing on Activated Carbon Elaborated from the Capsules of the Fruit (<i>Adansonia digitata</i> L.)

The baobab, Adansonia digitata L. plays an important role in the economy of local populations. The oil from the seeds of the baobab fruit is nowadays highly prized because of its numerous cosmetic and therapeutic applications and its composition of unsaturated fatty acids, sterols and tocopherols. However, unlike refined oils, locally extracted baobab oil has not undergone purification operations to ensure its quality. Only a filtration on special cloths is carried out after decantation. Indeed, the oil obtained after pressing is cloudy because of the presence of various impurities. It therefore requires treatment operations to make it more attractive and of higher quality. Therefore, in order to provide innovative solutions to local companies to improve the quality of vegetable oils, a study of clarification (treatment) of crude oil is necessary. An experimental device has been developed in the laboratory. It includes a glass column and a filter bed of dune sand and activated carbon. This study has shown the efficiency of the experimental device. Indeed, the activated carbon, thanks to its adsorbing power, has allowed a significant decrease in turbidity at the 5% threshold, from 14.61 NTU for the raw oil to 0.08 NTU for the oil filtered on 3% carbon and 0.033 NTU for the oil filtered on 5% carbon. That is to say an abatement higher than 95%. This decrease in turbidity could be correlated with the decrease in brown index from 187.39a for the initial crude oil to 128.53d for the oil treated with 3% activated carbon versus 187.59a for the oil filtered on cloths. The lowest brown index was observed with the filtration using 5% activated carbon (35.99b). Thus, for the yellowness index, only the filtration on 5% charcoal allowed to obtain a significant decrease in yellowness. The yellowing index of the oil with 5% was 44.67b against 79.04a for the oil filtered with 3% activated carbon, 86.33a for the crude oil and 86.46a for the oil filtered on cloths. Finally, the oil sample treated with 5% activated carbon had the clearest clarity than the other samples with a clarity (L) equal to 97.98c against 95.63d for the oil treated with 3% carbon and 94.99b for the oil filtered on filter cloths. According to the results obtained, the experimental device made it possible to obtain a clearer baobab oil with a low brown index, thus improving the sensory quality of the oil.

Analysis of the degree of influence of geological and technological factors on the initial flow rates of wells commissioned after their downtime

The results of statistical processing of data from 97 wells put into re-operation, after their long downtime due to flooding, are presented. In which, depending on the geological and physical conditions and the state of development of oil deposits, different results are obtained. With an average initial oil flow rate of 1.12 tons/day in reservoir-vaulted deposits with low-viscosity oil in the Fergana oil and gas region - 0.5 tons/day, in reservoir-arch deposits with high-viscosity oil in the Surkhandarya oil and gas region - 0.97 tons/day, in sub-gas deposits of the Bukhara-Khiva region - 2.5 tons/day. By assessing the informativeness of geological, physical and technological factors using the Kulbak method, the degree of their influence on the initial oil flow rate of wells after their re-commissioning was established. Taking into account the degree of influence of the factors considered, it is recommended to put into re-operation wells located in the arched part of the reservoir, having the highest effective oil-saturated thicknesses, in areas with a low oil recovery factor and a lower degree of reduction in initial reservoir pressure, as well as watered in a short period of operation.

A feasibility study for recycling biodegradable adsorbent in the oil spill clean-up from seawater

In the present work, the efficiency of Conocarpus leaves to remove oil from seawater was estimated. Conocarpus leaves were characterized by Brunauer–Emmett–Teller, scanning electron microscopy, Fourier-transform infrared spectroscopy and contact angle. The sorption parameters (sorption time, pH, oil ratio, biomass dose, initial oil concentration and temperature were investigated. The change in the pH of the oil/seawater system does not influence the oil sorption. Maximum oil sorption percent reached 88% at 2 min, 0.35 g at room temperature. The kinetic studies show rapid sorption and the pseudo-second-order kinetic governed the oil sorption. The isotherm modeling displayed that the oil uptake was fitted by the Langmuir isotherm. The outcomes of this work indicated a good sorption capacity (1.76 g/g) of Conocarpus leaves. In addition, Conocarpus leaves can be recycled for 4 cycles until the performance decays under 40%.

Hollow polyester/kapok/hollow polyester fiber-based needle punched nonwoven composite materials for rapid and efficient oil sorption.

Nowadays oil pollution poses a serious threat to the environment and people's daily life. As reusable and environmentally friendly materials, fiber-based oil sorption materials can effectively alleviate this phenomenon. However, maintaining a high sorption rate along with improved mechanical properties remains a challenge for oil sorption materials. Herein, we report a novel hollow PET/kapok/hollow PET nonwoven with high porosity and oil retention, outstanding cyclic oil sorption rate and improved mechanical performance using kapok as the oil preserver and hollow PET as the conductor and structure enhancer. Benefiting from the three-layer composite structure fabricated by carding and needle punching reinforcement, the resulting oil sorption materials, with kapok proportion more than or equal to 60%, exhibited high oil sorption rate and oil sorption speed. The materials of 20HP/60K/20HP component content present a high initial oil sorption rate of 28.22 g g-1, a maximum oil sorption rate of 31.17 g g-1 and a sorption rate constant of the Quasi second-order kinetic equation of 0.067 in plant oil. On the other hand, when the proportion of kapok fiber in the material was below 60%, due to the introduction of hollow PET, the mechanical properties were significantly boosted, and its oil retention and reusability were distinguished, with a reuse rate stabilizing at a relatively high level (>93%) in plant oil after undergoing three oil sorption cycles. The successful fabrication of hollow PET/kapok/hollow PET nonwovens could provide a new approach for the design and development of oil sorption materials.