scholarly journals Performance Mechanism of Hydrogel for Enhanced Oil Recovery: A Numerical Simulation Study Based on the Phase-Field Approach

2021 ◽  
Author(s):  
Seyed Hosein Hayatolgheibi ◽  
Forough Ameli ◽  
Mohammad Reza Moghbeli
Keyword(s):  
Oil Recovery ◽  
Phase Field ◽  
Excess Free Energy ◽  
Experimental Studies ◽  
Recovery Factor ◽  
Water Flooding ◽  
Effective Parameters ◽  
Field Approach ◽  
Controlled Flow ◽  
Good Agreement

Abstract Hydrogels are increasingly applied in oil recovery processes. This leads to more controlled flow of fluids in porous media. In this process, hydrogel is injected to the reservoir to block the high permeability areas. The trapped oil in low permeability regions, is then swept by water flooding. pH-sensitive hydrogel microspheres were synthesized in another work of the authors, which effectively increased the oil recovery factor in experimental studies. In this communication, phase-field approach was used to simulate this process and to obtain the tuning parameters of the model including thickness of the contact surface(є), phase transform parameter(M0), excess free energy(\(\wedge\)), and interfacial tension. Diffusion of hydrogels was studied by Cahn–Hilliard conservative approach and the breakage, deformation, and plugging mechanisms were analyzed, based on pressure drop variations in micromodel. Moreover, Effective parameters on oil recovery factor were analyzed. Results indicated a good agreement between experimental and modeling studies of oil recovery factor in water and hydrogel flooding with absolute errors of 2.29% and 4.06%, respectively. The recovery factor was calculated using a statistical method which was in good agreement with the modeling results. The tuned parameters of the model were reported as, є= 111.7µm, M0= 5*10-13m3/s, \(\wedge\)=-0.0003 J/m3, and δ = 2×10-5 Pa.s.

Improving Water Injectivity Through Lateral Radial Drilling into the Reservoir

2021 ◽  
Author(s):  
Effiong Essien ◽  
Uchenna Onyejiaka ◽  
Stanley Onwukwe ◽  
Nnaemeka Uwaezuoke
Keyword(s):  
Oil Recovery ◽  
Damage Zone ◽  
Water Injection ◽  
Progressive Increase ◽  
Recovery Factor ◽  
Water Flooding ◽  
Increase With Increase ◽  
Drilling Technology ◽  
Water Cut ◽  
Radial Drilling

Abstract Poor formation permeability and near well bore damage may limit water injectivity into the reservoir in a water injection project. This paper seeks to evaluate the effect of radial drilling technique on water injectivity and oil recovery in water flooding operation. Radial drilling technology utilizes hydraulic energy to create lateral perpendicular small holes through the casing into the reservoir. The holes may extend to 100 m (330 ft) into the reservoir to access fresh formations beyond the near wellbore, and damage zone. A black oil simulator (Eclipse 100) was used to modeling a lateral radial drill from the borehole into the reservoir, and that of a conventional perforation of the wellbore respectively. A simulation study was carried out using various presumed radial drill configurations in determining injectivity index, displacement efficiencies, recovery factor and water cut of the process. The determined results were further compared with that of the conventional perforation process case respectively. The results show a significant improvement in water injectivity in radial drill case with the increasing length and number of radials as compared to the conventional wellbore perforation case. The determined Recovery factor shows a progressive increase with increase in the numbers of radials drilled, irrespective of the radial length. However, it was observed that, the more the number and length of the radials drilled in to the reservoir, the higher the water cut from producer wells. Radial Drilling Technology, therefore, has a promising potential to improving water injectivity into the reservoir and thereby optimizing oil recovery in a water flooding operation.

scholarly journals INCREASING OIL RECOVERY APPLYING ELECTRIC STIMULATION ON THE FORMATION

2021 ◽  
Author(s):  
Bahshillo Akramov ◽  
◽  
Sherali Umedov ◽  
Odiljon Khaitov ◽  
Jaloliddin Nuriddinov ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Surface Tension ◽  
Electric Field ◽  
Electric Fields ◽  
Oil Recovery ◽  
Experimental Studies ◽  
Surface Tension Coefficient ◽  
Recovery Factor ◽  
Water Interface ◽  
Oil Water

The work is devoted to increasing the degree of depletion of reserves of longterm exploited hydrocarbon deposits on the basis of the obtained results of theoretical and experimental studies of the application of electrodynamic technologies for stimulating the formation and bottomhole formation zone. The electrolysis of formation fluids, water, oil-bearing rocks, is accompanied by a mass transfer, primary and secondary chemical reactions, the formation of all kinds of salts, alkalis and acids, new organic substances and all kinds of surfactants. Not only the liquid is subjected to electrolysis, but also the oil and gas bearing rocks themselves (solid electrolyte). The magnetic and electrical forces arising during the electric treatment of reservoirs make it possible to effectively drain heterogeneous reservoirs and extract residual oil from non-working layers. The work also carried out experiments to study the effect of the electric field on the surface tension coefficient at the oil-water interface. The circumstance of an abrupt change in the surface tension coefficient at the oil-water interface makes it possible in principle to create conditions in the reservoir that make it possible to slow down the cusping processes by applying an electric field of various magnitudes or, in other words, by regulating the amount of mass transfer. In numerical terms, the oil recovery factor without electrophysical treatment was 52.94%. Under electrophysical impact, the oil recovery factor was 94.12%, i.e. equaled to almost complete extraction of oil from the sample. In the field, this figure, of course, will decrease by 2-3 times, but it remains quite high in comparison with other methods of increasing oil recovery. Thus, the studies performed on samples in laboratory conditions indicate the possibility of using constant electric fields to increase oil recovery from depleted watered formations. Electrochemical treatment of the formation can significantly increase the displacement of oil from the formation. The increase in oil displacement reaches 15-20% and more. With the help of water alone, 58% of the oil (of its total volume in the sand) was displaced from the sand, and under electric field with a voltage of 10 V and 20 V, the total amount of displaced oil, respectively, increased to 67 and 83%. Thus, the laboratory studies performed on the samples also indicate the possibility of using constant electric fields to increase oil recovery from depleted watered formations. The carried out theoretical and experimental studies show the possibility of using the technology of electrochemical and electrothermochemical leaching of oilsaturated rocks to intensify oil production. The effectiveness of the recommended technology is especially noticeable in fields that have entered the final stage of development with a high water cut.

Successful in the Lab, Not as Effective in the Field? Uncertainties in the Field Observations of Low Salinity Water Flooding in Sandstone and Carbonate Reservoirs-A Critical Analysis

2021 ◽  
Author(s):  
Navpreet Singh ◽  
Hemanta Kumar Sarma
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Experimental Studies ◽  
Carbonate Reservoirs ◽  
Water Flooding ◽  
Water Salinity ◽  
Field Scale ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Salinity Water

Abstract Low salinity waterflooding has been an area of great interest for researchers for almost over three decades for its perceived "simplicity," cost-effectiveness, and the potential benefits it offers over the other enhanced oil recovery (EOR) techniques. There have been numerous laboratory studies to study the effect of injection water salinity on oil recovery, but there are only a few cases reported worldwide where low salinity water flooding (LSW) has been implemented on a field scale. In this paper, we have summarized the results of our analyses for some of those successful field cases for both sandstone and carbonate reservoirs. Most field cases of LSW worldwide are in sandstone reservoirs. Although there have been a lot of experimental studies on the effect of water salinity on recovery in carbonate reservoirs, only a few cases of field-scale implementation have been reported for the LSW in carbonate reservoirs. The incremental improvement expected from the LSW depends on various factors like the brine composition (injection and formation water), oil composition, pressure, temperature, and rock mineralogy. Therefore, all these factors should be considered, together with some specially designed fit-for-purpose experimental studies need to be performed before implementing the LSW on a field scale. The evidence of the positive effect of LSW at the field scale has mostly been observed from near well-bore well tests and inter-well tests. However, there are a few cases such Powder River Basin in the USA and Bastrykskoye field in Russia, where the operators had unintentionally injected less saline water in the past and were pleasantly surprised when the analyses of the historical data seemed to attribute the enhanced oil recovery due to the lower salinity of the injected water. We have critically analyzed all the major field cases of LSW. Our paper highlights some of the key factors that worked well in the field, which showed a positive impact of LSW and a comparative assessment of the incremental recovery realized from the reservoir visa-a-vis the expectations generated from the laboratory-based experimental studies. It is envisaged that such a comparison could be more meaningful and reliable. Also, it identifies the likely uncertainties (and their sources) associated during the field implementation of LSW.

scholarly journals Effect of Emulsification on Enhanced Oil Recovery during Surfactant/Polymer Flooding in the Homogeneous and Heterogeneous Porous Media

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Xiaoyan Wang ◽  
Jie Zhang ◽  
Guangyu Yuan ◽  
Wei Wang ◽  
Yanbin Liang ◽  
...  
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
High Water ◽  
Heterogeneous Porous Media ◽  
Recovery Factor ◽  
Water Flooding ◽  
Core Flooding ◽  
Positive Role ◽  
High Water Cut ◽  
Water Cut

Surfactant polymer (SP) flooding has become an important enhanced oil recovery (EOR) technique for the high-water cut mature oilfield. Emulsification in the SP flooding process is regarded as a powerful mark for the successful application of SP flooding in the filed scale. People believe emulsification plays a positive role in EOR. This paper uses one-dimensional homogenous core flooding experiments and parallel core flooding experiments to examine the effect of emulsification on the oil recoveries in the SP flooding process. 0.3 pore volume (PV) of emulsions which are prepared using ultralow interface intension (IFT) SP solution and crude oil with stirring method was injected into core models to mimic the emulsification process in SP flooding, followed by 0.35 PV of SP flooding to flood emulsions and remaining oil. The other experiment was preformed 0.65 PV of SP flooding as a contrast. We found SP flooding can obviously enhance oil recovery factor by 25% after water flooding in both homogeneous and heterogeneous cores. Compared to SP flooding, emulsification can contribute an additional recovery factor of 3.8% in parallel core flooding experiments. But there is no difference on recoveries in homogenous core flooding experiments. It indicates that the role of emulsification during SP flooding will be more significant for oil recoveries in a heterogeneous reservoir rather than a homogeneous reservoir.

The Simulation and Pilot Application of Low Salinity Water Flooding for Offshore Low Permeability Reservoir

2021 ◽  
Author(s):  
Hongfu Shi ◽  
Yingxian Liu ◽  
Yifan He ◽  
Wankun Xu
Keyword(s):  
Oil Recovery ◽  
Production Performance ◽  
Recovery Factor ◽  
Water Flooding ◽  
Low Permeability ◽  
Throat Radius ◽  
Low Permeability Reservoir ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Salinity Water

Abstract The use of LSWF (Low Salinity Water Flooding) is becoming more prevalent in recent years which can both improve the recovery factor and reduce the cost compared to other EOR (enhanced oil recovery) technics. This is especially important for the offshore oilfield development at present. Moreover, good quality of injected water is more applicable to low permeability sand which is characterized as smaller pore-throat radius and is easier damaged. Therefore, LSWF technology is proposed to address the above production problem while reduce the investment of equipment upgrade. In this paper, we presented the optimization and implementation of LSWF for offshore low permeability reservoir. Firstly, we provided a critical review of LSWF included the main mechanisms, laboratory test and field effect. Secondly, we designed and conducted several laboratory core flood tests. Thirdly, a lot of synthetic models were established to simulate the effects of LSWF and to optimize the field program. Finally, the production performance of the pilot wells was discussed. After LSWF, the water injection well presents the phenomenon of "scissors" - the injection pressure drops significantly below the safety pressure while the injection volume increases. Moreover, the decline of pilot well groups decreased by 20% ~ 26% compared with non-water flooded. The estimated recovery factor increased by 12%, which is consistent with other field tests worldwide. In summary, LSWF is a feasible, neconomic and efficient method for offshore low permeability reservoir production.

scholarly journals An experimental study of alternative hot water alternating gas injection in a fractured model

2018 ◽  
Vol 37 (3) ◽  
pp. 945-959 ◽  
Author(s):  
Amirhossein Ebadati ◽  
Erfan Akbari ◽  
Afshin Davarpanah
Keyword(s):  
Oil Recovery ◽  
Gas Injection ◽  
Conventional Technique ◽  
Hot Water ◽  
Recovery Factor ◽  
Water Flooding ◽  
Fractured Reservoir ◽  
Carbon Dioxide Gas ◽  
Water Alternating Gas ◽  
Alternative Water

Alternative injection of gas as slugs with water slugs, or alternative water gas injection, is the conventional technique for improving the recovery factor due to its high potential for mobilizing the residual oil in place in the reservoirs and to control gas mobility. The water alternating gas methodology is a combination of two oil recovery procedures: gas injection and waterflooding. The principal parameters that must be evaluated in water alternating gas injection in laboratory scale are reservoir heterogeneity, rock type, and fluid properties. In the current investigation, a feasibility study has been performed to analyze the five various scenarios of enhanced oil recovery techniques and compare them experimentally. The laboratory experiments are done for one of the Iranian reservoirs which have been subjected to waterflooding for several years, and the amount of recovery factor for water flooding is about 42%. The results of this study illustrate that water alternating gas injection and hot water alternating gas injection exert a profound impact on the amount of recovery factor. Moreover, the primary purpose of this study is to assess the application of alternative hot water and hot carbon dioxide gas injections in the conventional and fractured reservoir model.

Experimental Study of Polymer Flooding in Fractured Systems Using Five-Spot Glass Micromodel: The Role of Fracture Geometrical Properties

2012 ◽  
Vol 30 (5) ◽  
pp. 689-705 ◽  
Author(s):  
Behbood Abedi ◽  
Mohammad Hossein Ghazanfari ◽  
Riyaz Kharrat
Keyword(s):  
Oil Recovery ◽  
Polymer Flooding ◽  
Recovery Factor ◽  
Reservoir Rock ◽  
Water Flooding ◽  
Recovery Method ◽  
Geometrical Properties ◽  
Fracture Orientation ◽  
Glass Micromodel

Water flooding is being widely used in the petroleum industry and has been considered as a simple inexpensive secondary recovery method. But in fractured formations, existence of fracture system in reservoir rock induces an adverse effect on oil recovery by water flooding. Polymer flooding has been successfully applied as an alternative enhanced oil recovery method in fractured formations. But, the role of fracture geometrical properties on macroscopic efficiency of polymer flooding is not yet well-understood, especially in fractured five-spot systems. In this work five-spot glass micromodel, because of micro-visibility, ease of multiple experimentations and also presence of the unexplored issues, was used to experimentally investigate the influence of fracture geometrical characteristics such as fracture orientation, fracture spacing, fracture overlap and etc on the macroscopic efficiency of polymer flooding. The tests were performed on the fractured models which are initially saturated with the crude oil at fixed flow rate conditions and in a horizontally mounting. The results revealed that the macroscopic efficiency of polymer flooding depends on fracture geometrical properties. Fracture orientation showed more imposing effect than other fracture geometrical properties, and fracture with 45 degree inclination to the mean flow direction, gives greatest oil recovery factor. Large spacing fractures give more recovery than small spacing ones and in case of overlapping, fractures with less overlapping help polymer to better propagate which could be related to their greater effective fracture length. This pre-called effect could be responsible to show how continuity and width to length ratio of fractures affect recovery factor, less fracture discontinuity as well as more length to width ratio of fracture give more swept zone. Also, increasing number of fractures decreases oil recovery factor. The results of this work can be helpful to better understanding the role of fracture geometrical properties on macroscopic efficiency of polymer flooding in five-spot fractured systems.

scholarly journals The Key Parameter Effect Analysis Of Polymer Flooding On Oil Recovery Using Reservoir Simulation

2019 ◽  
Vol 4 (1) ◽  
pp. 49
Author(s):  
Tomi Erfando ◽  
Novia Rita ◽  
Romal Ramadhan
Keyword(s):  
Oil Recovery ◽  
Reservoir Simulation ◽  
Polymer Concentration ◽  
Polymer Flooding ◽  
Recovery Factor ◽  
Water Flooding ◽  
Base Case ◽  
Driving Mechanism ◽  
Geological Condition ◽  
Recovery Method

As time goes by, there will be decreasing of production rates of a field along with decreasing pressure. This led to the necessity for further efforts to increase oil production. Therefore, pressure support is required to improve the recovery factor. Supportable pressure that can be used can be either water flooding and polymer flooding. This study aims to compare recovery factor to scenarios carried out, such as polymer flooding with different concentrations modeled in the same reservoir model to see the most favorable scenario. The method used in this research is reservoir simulation method with Computer Modeling Group (CMG) STARS simulator. The study was carried out by observing at the pressure, injection rate, and polymer concentration on increasing field recovery factor. This study used cartesian grid with the assumption of homogeneous reservoir, there are no faults or other geological condition in the reservoir, and driving mechanism is only solution gas drive. This reservoir, oil type is light oil with API gravity 40.3˚API and layer of conglomerate rock. The simulation result performed with various scenarios provides a good result. Where the conditions case base case field recovery factor of 6.7%, and after water flooding produced 25.5% of oil, whereas with tertiary recovery method is polymer flooding was carried out with four concentrations of 640 ppm, 1,500 ppm, 3,000 ppm, and 4,000 ppm obtained optimum values at 4,000 ppm polymer concentration with recovery factor 28.9%, SOR reduction final value 0,5255, polymer adsorption of 818,700 ppm, reservoir final pressure 1,707 psi, and an increase in water viscosity to 0.94 cP.

scholarly journals Investigation effect of wettability and heterogeneity in water flooding and on microscopic residual oil distribution in tight sandstone cores with NMR technique

Open Physics ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 544-550 ◽  
Author(s):  
Pufu Xiao ◽  
Xiaoyong Leng ◽  
Hanmin Xiao ◽  
Linghui Sun ◽  
Haiqin Zhang ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Physical Simulation ◽  
Spontaneous Imbibition ◽  
Recovery Factor ◽  
Water Flooding ◽  
Pore Throat ◽  
Tight Sandstone ◽  
Large Pore ◽  
Oil Distribution ◽  
The Difference

AbstractIn order to explore the effect of wettability and pore throat heterogeneity on oil recovery efficiency in porous media, physical simulation experiment and nuclear magnetic resonance (NMR) measurements were conducted to investigate how crude oil residing in different sized pores are recovered by water flooding. Experimental results indicate that the recovery factor of water flooding is governed by spontaneous imbibition and also pore throat heterogeneity. It is found that intermediate wetting cores lead to the highest final recovery factor in comparison with water wet cores and weak oil wet cores, and the recovery oil difference in clay micro pore is mainly because of the wettability, the difference in medium pore and large pore is affected by pore throat heterogeneity. Water wet core has a lower recovery factor in medium and large pore due to its poor heterogeneity, in spite of the spontaneous imbibition effect is very satisfying. Intermediate wetting cores has significant result in different sized pore and throat, the difference in medium pore and large pore is affected by pore throat heterogeneity.

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