Mechanistic Simulation of Polymer Injectivity in Field Tests

SPE Journal ◽  
2016 ◽  
Vol 21 (04) ◽  
pp. 1178-1191 ◽  
Author(s):  
Mohammad Lotfollahi ◽  
Rouhi Farajzadeh ◽  
Mojdeh Delshad ◽  
Al-Khalil Al-Abri ◽  
Bart M. Wassing ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Pressure Rise ◽  
Shear Thickening ◽  
Injection Rate ◽  
Field Application ◽  
Polymer Flooding ◽  
Velocity Shear ◽  
Polymer Rheology ◽  
Deep Bed Filtration ◽  
The Impact

Summary Polymer flooding is one of the most widely used chemical enhanced-oil-recovery (EOR) methods because of its simplicity and low cost. To achieve high oil recoveries, large quantities of polymer solution are often injected through a small wellbore. Sometimes, the economic success of the project is only feasible when injection rate is high for high-viscosity solution. However, injection of viscous polymer solutions has been a concern for the field application of polymer flooding. The pressure increase in polymer injectors can be attributed to (1) formation of an oil bank, (2) polymer rheology (shear-thickening behavior near wellbore), and (3) plugging of the reservoir pores by insoluble polymer molecules or suspended particles in the water. In this paper, a new model to history match field injection-rate/pressure data is proposed. The pertinent equations for deep-bed filtration and external-cake buildup in radial coordinates were coupled to the viscoelastic polymer rheology to capture important mechanisms. Radial coordinates were selected to minimize the velocity/shear-rate errors caused by gridblock size in the Cartesian coordinates. The filtration theory was used and the field data history matched successfully. Systematic simulations were performed, and the impact of adsorption (retention), shear thickening, deep-bed filtration, and external-cake formation was investigated to explain the well-injectivity behavior of polymer. The simulation results indicate that the gradual increase in bottomhole pressure (BHP) during early times is attributed to the shear-thickening rheology at high velocities experienced by viscoelastic hydrolyzed polyacrylamide (HPAM) polymers around the wellbore and the permeability reduction caused by polymer adsorption and internal filtration of undissolved polymer. However, the linear impedance during external-cake growth is responsible for the sharper increase in injection pressure at the later times. One can use the proposed model to calculate the injectivity of the polymer-injection wells, understand the contribution of different phenomena to the pressure rise in the wells, locate the plugging or damage that may be caused by polymer, and accordingly design the chemical stimulation if necessary.

scholarly journals Polymer Optimisation- Shear Thinning or Thickening?

2019 ◽  
Vol 7 (4) ◽  
Author(s):  
Gloria Gyanfi ◽  
Wilberforce Nkrumah Aggrey ◽  
Ernest Ansah Owusu ◽  
Kofi Ohemeng Prempeh
Keyword(s):  
Shear Rate ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Shear Thickening ◽  
Shear Thinning ◽  
Injection Rate ◽  
Injection Well ◽  
Polymer Injection ◽  
Well Pattern ◽  
The Impact

With most polymers employed in polymer enhanced oil recovery exhibiting one or both non-Newtonian behaviours that is shear thickening and thinning at different shear rate, it is expedient to analyse the impact of these non-Newtonian behaviours in polymer optimisation. CMG simulation suite was employed to analyse the permeability pinch-out formation with a five (5) spot injection well pattern for a 360days simulation run using a 90days polymer injection well cycling. Shear thinning polymer was found not to be conducive for lower permeable formation as a high percentage of the polymer was retained. NPV was affected by polymer injection rate which controlled polymer optimisation

The Research on Effect Factors of the Polymer Flooding in Low Permeability Reservoir of Daqing Oilfield

2011 ◽  
Vol 383-390 ◽  
pp. 3809-3813
Author(s):  
Yong Li Wang ◽  
Tao Li ◽  
Zhi Guo Fu ◽  
Shu Xia Liu ◽  
Bai Lin Yu ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Injection Rate ◽  
Polymer Flooding ◽  
Low Permeability ◽  
Effect Factors ◽  
Field Development ◽  
Low Permeability Reservoir ◽  
Well Pattern ◽  
Simulation Results ◽  
Enhance Oil Recovery

The pilot block is a heterogeneous reservoir with low permeability which is only 100-200(mD). Polymer flooding will be used to enhance oil recovery (EOR). Therefore, some experiment will be carried out in this pilot block .According to the simulation results, we can infer the effect factors of the polymer flooding such as concentration, injection rate, slug amounts, and well pattern. It gives us effective information for the field development plan.

scholarly journals Laboratory Study on EOR in Offshore Oilfields by Variable Concentrations Polymer Flooding

2017 ◽  
Vol 10 (1) ◽  
pp. 94-107 ◽  
Author(s):  
Kaoping Song ◽  
Ning Sun ◽  
Yanfu Pi
Keyword(s):  
Oil Recovery ◽  
Field Application ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Displacement Efficiency ◽  
Constant Concentration ◽  
Sweep Efficiency ◽  
Displacement Effect ◽  
Fracture Pressure ◽  
Recovery Technique

Background: Polymer flooding is the most commonly applied chemical enhanced-oil-recovery technique in offshore oilfields. However, there are challenges and risks in applying the technology of polymer flooding to offshore heavy oil development. Objective: This paper compared the spread law and the displacement effect of different injection modes and validated the feasibility of enhancing oil recovery by variable concentrations polymer flooding. Method: Two types of laboratory experiments were designed by using micro etching glass models and heterogeneous artificial cores. Furthermore, in order to determine a better polymer flooding mode, the displacement results, displacement characteristic curves and oil saturation distribution of heterogeneous artificial cores were also compared, respectively. Results: The experimental results showed that the recovery of variable concentrations polymer flooding was higher than that of constant concentration polymer flooding, under conditions of same total amount of polymer and similar water flooding recovery. Its sweep efficiency and displacement efficiency were also significantly higher than those of constant concentration polymer flooding. Moreover, variable concentrations polymer flooding had lower peak pressure and was at lower risk for reaching the formation fracture pressure. Conclusion: As a consequence, variable concentrations polymer flooding has certain feasibility for heterogeneous reservoir in offshore oilfields, and can improve interlayer heterogeneity to further tapping remaining oil in medium and low permeability layer. Conclusions of this paper can provide reference for the field application of polymer flooding in offshore oilfields.

A Numerical Simulation Comparison of Five-Spot vs. Line Drive in Micellar/Polymer Flooding

1982 ◽  
Vol 22 (01) ◽  
pp. 69-78
Author(s):  
H. Kazemi ◽  
D.J. MacMillan
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Large Scale ◽  
Plug Flow ◽  
Recovery Process ◽  
Field Application ◽  
Polymer Flooding ◽  
Spot Pattern ◽  
Injection Wells ◽  
Production Wells

Abstract The work presented in this paper was undertaken to study the effect of pattern configuration on oil recovery by the Maraflood oil-recovery process. The patterns studied are the five-spot and the 4 × 1 line drive. These patterns are obtained by placing infill wells in an existing 10-acre (40 469-m2) waterflooded five-spot pattern to obtain the 2.5-acre (10 117-m2) patterns. The number of infill wells is the same for both the new five-spot and new line-drive configurations and is about three times the number of existing wells. Both patterns have been used successfully in field applications by Marathon before this study. For instance, a line-drive pattern was used in Project 119-R and a five-spot pattern was used in Project 219-R. This work shows that the line drive produces more tertiary oil than the five-spot under otherwise identical reservoir conditions. Breakthrough times and oil rates for line-drive production wells are nearly the same. Meanwhile, five-spot production wells have vastly differing oil breakthrough times and oil rates. Both of the latter effects result from a nonuniform distribution of waterflood residual oil saturation in the field. Our study also shows that if producing wells in each line-drive row are connected by a perfect vertical fracture and if the same is true of the injection wells, the line-drive efficiency will improve very little. Introduction The Maraflood oil-recovery process is a viable enhanced oil-recovery technique. An appraisal of this process and other surfactant-enhanced oil-recovery schemes was reported by Gogarty. Three significant field tests of the Maraflood process were reported by Earlougher et al. In addition, a large-scale field application of this process was presented recently by Howell et al. in field applications of the Maraflood process, both line-drive and five-spot configurations have been used. In our field experience, an existing five-spot waterflood pattern is convened to another five-spot or 4 × 1 line-drive configuration by adding infill wells. The new five-spot or line-drive pattern has an area-per-well spacing of one-fourth of the original waterflood spacing. In practice, the number of infill wells required for both cases is somewhat greater than three times the number of existing wells. As the total number of wells increases, this ratio approaches the theoretical limit of three. In addition to the preceding arrangements of infill wells, many others are possible. In some arrangements, fewer infill wells are required than in our five-spot and 4 × 1 line drive. In such cases, the area per well increases, which generally causes these problems:required injectivity per injection well increases and may not be attainable because of the high viscosity of the injected fluids andthe breakthrough time is delayed. As an example, consider the case where no infill wells are drilled. In addition to the two problems just listed, the micellar/polymer flooding scheme will sweep only those regions that already have been swept well by the waterflood. The regions left unswept by the waterflood also will be left essentially unswept by the micellar/polymer flood. This means that a substantial amount of oil is left in place. Therefore, these types of undesired patterns were not considered in this study. Patterns with more infill wells than those in this study were not considered because of current economic limitations. Because of the likelihood of economic and technical merits, we also considered the placement of long vertical fractures to connect existing waterflood wells in place of infill wells. The fractures were arranged to form a more effective line drive. We emphasize that the patterns studied in this paper are those usually used in micellar/polymer flooding applications. Muskat has reported breakthrough waterflood sweep efficiencies of 72% and 88% for five-spot and 4 × 1 line drive patterns when the mobility ratio is unity. Muskat's results are for ideal plug flow displacement of red water by blue water in a perfectly homogeneous reservoir. SPEJ P. 69^

scholarly journals Macroscopic visual displacement of a polymer solution for enhanced oil recovery: Hele-Shaw cell experiments and computational simulation

2020 ◽  
Vol 66 (3 May-Jun) ◽  
pp. 273
Author(s):  
S. De Santiago ◽  
O. Olivares-Xometl ◽  
N. V. Likhanova ◽  
I. V. Lijanova ◽  
P. Arellanes-Lozada
Keyword(s):  
Oil Recovery ◽  
Flow Direction ◽  
Computational Simulation ◽  
Homogeneous Medium ◽  
Oil Production ◽  
Field Application ◽  
Polymer Flooding ◽  
Water Flooding ◽  
The Matrix ◽  
The One

Numerous laboratory studies and field application tests have shown that polymer flooding is an effective method to improve the oil recovery by displacing residual oil after water flooding. In this work, a series of visual model displacement experiments was conducted in Hele-Shaw cells to determine the effectiveness of polymer flooding in homogeneous and fractured media with a fracture parallel or perpendicular to the flow direction. The matrix with parallel fracture to the flow direction presented a delay in the oil production process during water and polymer flooding with respect to the homogeneous medium and the one with perpendicular fracture, where the highest recovery numbers during waterflooding and polymer flooding were achieved for the medium with perpendicular fracture to the flow direction, reaching 56 % of cumulative oil recovery. The displacement results and multiphasic simulation show that the homogeneous medium is an attractive candidate for additional recovery application with polymer flooding after water flooding when the oil production reached almost zero, although the production rate is lower than the one obtained for a porous medium with a fracture perpendicular to the flow direction.

scholarly journals The impact of permeability heterogeneity on water-alternating-gas displacement in highly stratified heterogeneous reservoirs

2021 ◽  
Author(s):  
Mohammad Yunus Khan ◽  
Ajay Mandal
Keyword(s):  
Oil Recovery ◽  
Field Application ◽  
Carbonate Reservoir ◽  
High Permeability ◽  
Oil Saturation ◽  
Heterogeneous Reservoirs ◽  
Heterogeneous Reservoir ◽  
Low Viscosity ◽  
Water Alternating Gas ◽  
The Impact

AbstractAvailability of gases at the field level makes attractive to water-alternating-gas (WAG) process for low viscosity and light oils carbonate reservoir. However, impact of reservoir heterogeneity on WAG performance is crucial before field application. In general, ramp carbonates have heterogeneity due to variation of permeability and porosity. However, WAG performance significantly affected by permeability variations. This article investigates merits and demerits of WAG displacement due to permeability heterogeneities such as permeability anisotropy, high permeability streaks (HKS), matrix permeability, dolomite and thin dense stylolite layers. High-resolution compositional simulations with tuned equation of state (EoS) were carried out using 2D and 3D sector models. The study focuses on WAG performance in terms of oil recovery, vertical sweep, solvent utilization, gas oil ratio (GOR), water cut (WCT), WAG response time, gravity override, hysteresis, un-contacted oil saturation and economics. The results of simulation show that the heterogeneous reservoir provides initially faster WAG response, lower expected ultimate recovery (EUR), faster gas breakthrough, higher GOR and WCT production compared to homogeneous reservoir. The gas gravity override at smaller wells spacing is less in homogeneous reservoir as compared to heterogeneous reservoir, but it is reverse in case of larger well spacing. In heterogeneous reservoir, the HKS shows significant gas override resulting in poor vertical sweep due to capillary holding, and the high permeability dolomite layer shows early water breakthrough. This reservoir has higher solvent utilization in initial stage, and then, it becomes nearly equal to homogeneous reservoir. Simulation in both reservoirs overestimates incremental recovery of 2–3% OOIP at one pore volume injection because of not involving un-contacted oil saturation as predicted in core flood. The findings of this study will help to understand WAG performance and design in highly heterogeneous reservoirs for field applications. Graphical abstract

scholarly journals Study on the Impact of Polymer Retention in Porous Media on Further Surfactant-Polymer Flood

2015 ◽  
Vol 8 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Junjian Li ◽  
Hanqiao Jiang ◽  
Qun Yu ◽  
Fan Liu ◽  
Hongxia Liu
Keyword(s):  
Porous Media ◽  
Oil Recovery ◽  
Underground Water ◽  
Polymer Flooding ◽  
Polymer Flood ◽  
Good Potential ◽  
Enhance Oil Recovery ◽  
Polymer Application ◽  
The Impact ◽  
Polymer Retention

Polymer flood gains expansive popularity as a promising EOR method in various oilfields worldwide. However, there are still substantial amount of resources underground after polymer application. To further enhance oil recovery, secondary chemicals are sometimes utilized to sweep the remaining hydrocarbons to maintain the consistent development of oilfields. In this paper, a series of experiments are established and conducted to explore the feasibility of surfactant/ polymer flooding applied to a polymer flooded reservoir, and also the influence of polymer retention in porous media to enhance the oil recovery performance of subsequent chemical drive. The data of the experiments suggest that surfactant/polymer flooding owns a very good potential as a subsequent EOR technique, and that polymer retention in pores helps block underground water channels, improving greatly the sweeping efficiency of secondary chemical flood.

Mechanistic Understanding of the Impact of EOR Polymer on the Inhibition Mechanism and Performance of Phosphonate Scale Inhibitors

2021 ◽  
Author(s):  
Alan Beteta ◽  
Lorraine Boak ◽  
Katherine McIver ◽  
Myles Jordan ◽  
Robin Shields
Keyword(s):  
Oil Recovery ◽  
Positive Impact ◽  
Current Trend ◽  
Pressure Rise ◽  
Reservoir Rock ◽  
Water Volume ◽  
Inhibition Mechanism ◽  
Inhibition Performance ◽  
The Impact ◽  
Scale Management

Abstract With the current trend for application of Enhanced Oil Recovery (EOR) technologies, there has been much research into the possible upsets to production, from the nature of the produced fluids to changes in the scaling regime. The key question being addressed in this publication is the influence of EOR chemicals, such as hydrolyzed polyacrylamide (HPAM), on scale inhibitor (SI) squeeze lifetime for barium sulphate and calcium carbonate scale risk. Squeeze lifetime is defined as the duration of time (or produced water volume) before the minimum inhibitor concentration (MIC) is reached. This is controlled by the adsorption, and later release, of the inhibitor onto the reservoir rock and the MIC of the inhibitor selected for the produced brine. This paper builds on earlier published work investigating potential changes to inhibitor adsorption caused by polymer EOR produced and moves to the evaluation of the changes in MIC due to the presence of EOR chemical. In the static inhibitor performance bottle tests, the EOR polymer alone appeared to show some degree of inhibition performance against BaSO4, but below a level required for effective scale management. However, in combination with the inhibitor (DETPMP) at near MIC levels, the inhibition efficiency was negatively impacted by the presence of degraded HPAM EOR polymer. During dynamic tube blocking tests, the inclusion of even low levels of HPAM (2.5 ppm) were shown to reduce the differential pressure build up suggesting barite scale inhibition or reduced adhesion to the coil. Furthermore, the scale morphology produced in these tests, examined under a scanning electron microscope, was clearly impacted in the presence of HPAM. For the CaCO3 system there appears to be increasing positive impact from HPAM on CaCO3 morphology with HPAM concentration and, as observed for BaSO4, an improved performance in dynamic efficiency experiments. However, at higher HPAM concentrations (500 ppm) the precipitate was amorphous and only a minor pressure rise was observed during the tube blocking experiments. From these observations, it is clear that HPAM can impact the way both calcite and barite scale grow, especially at lower inhibitor concentrations (<MIC) and hence impacts the mechanism by which DETPMP can function to prevent scale nucleation and growth. This study represents a comprehensive review of both inhibition performance in the presence of an EOR polymer and with these findings the implication to field treatment lifetimes and associated costs of scale management via scale squeeze in a field under HPAM flooding.

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