Assessment of NPV Uncertainty on Heterogeneous Reservoirs during Polymer Flood

2013 ◽  
Vol 448-453 ◽  
pp. 4033-4037 ◽  
Author(s):  
Kyung Wan Yu ◽  
Byung In Choi ◽  
Kun Sang Lee
Keyword(s):  
Net Present Value ◽  
Water Saturation ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Low Permeability ◽  
Oil Viscosity ◽  
Permeability Model ◽  
Heterogeneous Reservoirs ◽  
Polymer Flood ◽  
Porosity And Permeability

This study shows net present value (NPV) distribution by considering uncertainties in porosity, oil viscosity, water saturation, and permeability for polymer flood with Monte Carlo simulation. For high and low average permeability conditions, differences of NPV between polymer flooding and water flooding have been investigated. According to results both average NPV and range of NPV distribution tend to increase with porosity and permeability in all cases. Although water saturation and oil viscosity affect NPV, they are not important parameters that conclude uncertainty of NPV under the conditions considered in this study. For high permeability model which has Dykstra-Parsons coefficient (DP) as 0.72 and porosity as 0.3088, Monte Carol simulations for polymer flood show that 50th percentile (P50) of NPV is 352.81 M$. If porosity is decreased from 0.3088 to 0.1912, the P50 is also decreased 63.8 %. The reduction of NPV during polymer flooding in low permeability reservoirs are almost 40 % higher than that of water flood. These differences come from polymer adsorption and permeability reduction that easily occurs in low permeability zone. The procedure has proven to be useful tool to generate probability distribution of NPV when polymer flood is selected as a tertiary flood process.

An Easy Calculation Method on Sweep Efficiency of Chemical Flooding

2013 ◽  
Vol 275-277 ◽  
pp. 496-501
Author(s):  
Fu Qing Yuan ◽  
Zhen Quan Li
Keyword(s):  
Oil Recovery ◽  
Orthogonal Design ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Solution Viscosity ◽  
Chemical Flooding ◽  
Oil Viscosity ◽  
Sweep Efficiency ◽  
Easy Calculation ◽  
Polymer Compound

According to the geological parameters of Shengli Oilfield, sweep efficiency of chemical flooding was analyzed according to injection volume, injection-production parameters of polymer flooding or surfactant-polymer compound flooding. The orthogonal design method was employed to select the important factors influencing on expanding sweep efficiency by chemical flooding. Numerical simulation method was utilized to analyze oil recovery and sweep efficiency of different flooding methods, such as water flooding, polymer flooding and surfactant-polymer compound flooding. Finally, two easy calculation models were established to calculate the expanding degree of sweep efficiency by polymer flooding or SP compound flooding than water flooding. The models were presented as the relationships between geological parameters, such as effective thickness, oil viscosity, porosity and permeability, and fluid parameters, such as polymer-solution viscosity and oil-water interfacial tension. The precision of the two models was high enough to predict sweep efficiency of polymer flooding or SP compound flooding.

scholarly journals Enhanced oil recovery ability of branched preformed particle gel in heterogeneous reservoirs

2018 ◽  
Vol 73 ◽  
pp. 65 ◽  
Author(s):  
Long Yu ◽  
Qian Sang ◽  
Mingzhe Dong
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Water Flooding ◽  
Low Permeability ◽  
High Permeability ◽  
Sweep Efficiency ◽  
Reservoir Heterogeneity ◽  
Heterogeneous Reservoirs ◽  
Preformed Particle Gel ◽  
Profile Control

Reservoir heterogeneity is the main cause of high water production and low oil recovery in oilfields. Extreme heterogeneity results in a serious fingering phenomenon of the displacing fluid in high permeability channels. To enhance total oil recovery, the selective plugging of high permeability zones and the resulting improvement of sweep efficiency of the displacing fluids in low permeability areas are important. Recently, a Branched Preformed Particle Gel (B-PPG) was developed to improve reservoir heterogeneity and enhance oil recovery. In this work, conformance control performance and Enhanced Oil Recovery (EOR) ability of B-PPG in heterogeneous reservoirs were systematically investigated, using heterogeneous dual sandpack flooding experiments. The results show that B-PPG can effectively plug the high permeability sandpacks and cause displacing fluid to divert to the low permeability sandpacks. The water injection profile could be significantly improved by B-PPG treatment. B-PPG exhibits good performance in profile control when the high/low permeability ratio of the heterogeneous dual sandpacks is less than 7 and the injected B-PPG slug size is between 0.25 and 1.0 PV. The oil recovery increment enhanced by B-PPG after initial water flooding increases with the increase in temperature, sandpack heterogeneity and injected B-PPG slug size, and it decreases slightly with the increase of simulated formation brine salinity. Choosing an appropriate B-PPG concentration is important for B-PPG treatments in oilfield applications. B-PPG is an efficient flow diversion agent, it can significantly increase sweep efficiency of displacing fluid in low permeability areas, which is beneficial to enhanced oil recovery in heterogeneous reservoirs.

Semi-Analytical Proxy for Vapex Process Modeling in Heterogeneous Reservoirs

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Jindong Shi ◽  
Juliana Y. Leung
Keyword(s):  
Steam Injection ◽  
Compositional Simulation ◽  
Vapor Extraction ◽  
Oil Viscosity ◽  
Field Development ◽  
Heterogeneous Reservoirs ◽  
Drainage Rate ◽  
Porosity And Permeability ◽  
Efficient Alternative ◽  
Data Driven Modeling

Vapex (vapor extraction) is a nonthermal process that has significant potential in providing a more environmentally friendly and energy-efficient alternative to steam injection. Vaporized solvent injected in-situ dissolves into the oil and reduces oil viscosity, allowing the oil to flow to a horizontal production well via gravitational forces. While compositional simulators are available for assessing the Vapex performance, the simulation process may become difficult when taking into account the uncertainty due to reservoir heterogeneity. A semi-analytical proxy is proposed to model the process, in a way analogous to the steam-assisted gravity drainage (SAGD) model described by Butler, who demonstrated the similarity between two processes with a series of Hele-Shaw experiments and derived an analytical steady-state flow rate relationship that is comparable with the SAGD case. Solvent concentration and intrinsic diffusivity are introduced in this model instead of temperature and thermal diffusivity in SAGD. In this paper, analytical solutions and implementation details for the Vapex proxy are presented. The proposed approach is then applied to various reservoirs discretized with spatially varying rock porosity and permeability values; bitumen drainage rate and solvent penetration are calculated sequentially at grid blocks along the solvent–bitumen interface over incremental time steps. Results from this model are compared against experimental data available in the literature as well as detailed compositional simulation studies. Computational requirement of the proxy in comparison with numerical simulations is also emphasized. An important contribution from this work is that process physics are built directly into this proxy, giving it an advantage over other data-driven modeling approaches (e.g., regression). It can be used as an efficient alternative to expensive detailed flow simulations. It presents an important potential for assessing the uncertainty due to multiscale heterogeneity on effective mass transfer and the resulting recovery performance, as well as assisting decisions-making for future pilot and field development.

scholarly journals Experimental investigation on reservoir damage caused by clay minerals after water injection in low permeability sandstone reservoirs

2021 ◽  
Author(s):  
Yazhou Zhou ◽  
Wenbin Yang ◽  
Daiyin Yin
Keyword(s):  
Clay Mineral ◽  
Mineral Content ◽  
Water Injection ◽  
Damage Mechanism ◽  
Water Flooding ◽  
Formation Damage ◽  
Low Permeability ◽  
Sem Images ◽  
Porosity And Permeability ◽  
Sandstone Reservoirs

AbstractWater injection is an effective method for developing low permeability sandstone reservoirs. In the process of water flooding, reservoir damage can occur due to clay mineral content changes and it will significantly affect oil production. There are few investigations on the changes in clay mineral content and the degree of reservoir damage after injecting the water into low permeability sandstone reservoirs with different permeabilities and lithologies. In this study, low permeability natural cores from different lithological strata were collected from 4 wells in the Daqing sandstone reservoir, and clay mineral components and contents were measured through X-ray diffraction. Changes in the clay mineral content were determined after water injection. The reservoir damage mechanism by clay mineral migration was determined by analyzing scanning electron microscopy (SEM) images after water injection. Meanwhile, the porosity and permeability of the cores were tested after water injection, and the degree of reservoir damage in different lithological strata was determined. The clay mineral content ranges from 6.78 to 14.14% in low permeability sandstone cores and declines by 49.73% after water flooding. Illite, chlorite and illite/smectite mostly decrease, and kaolinite decreases the least. Due to the large particle size of kaolinite, kaolinite migration will block the pore-throats and cause formation damage after water flooding. In argillaceous siltstone and siltstone, kaolinite particles blocking pore-throats are very serious, and the permeability decreases greatly by 21.87–36.89% after water injection. With increasing permeability, the permeability decreases greatly after water injection. The findings of this study can help to better understand the mechanisms of formation damage after injecting water into low permeability sandstone reservoirs.

Study the Displacement Characteristics of Foam Flooding after Polymer Flooding on NMR

2011 ◽  
Vol 361-363 ◽  
pp. 493-498
Author(s):  
Jin Sheng Zhao ◽  
Tian Tai Li ◽  
Ming Zhang ◽  
Zhao Min Li
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Fluid Distribution ◽  
Distribution Area ◽  
Low Permeability ◽  
High Permeability ◽  
Polymer Foam ◽  
Foam Flooding

Through parallel cores with different permeability contrast, the displacement process of foam flooding after polymer flooding is experimental studied. Using the experiment technology of nuclear magnetic resonance, the fluid distribution in cores with different diameter was studied. The distribution area of bore diameter in which oil is sweepouted of water flooding, polymer flooding and foam flooding under different processes and various heterogeneity conditions. The results show, against water flooding and polymer flooding, the distribution area of bore diameter in which oil is sweepouted is broadened. Foam can plugging the wide aperture in which water and polyer channeling，and foam can sweep the bore diameter which can’t be swept by water and polymer. Foam can not only advance the recovery of low permeability core but also sweep the oil in microbore of high permeability core.

Research the Degree Damage of Reverse Imbibitions to Low Permeability Water Flooding Gas Reservoir

2012 ◽  
Vol 524-527 ◽  
pp. 1203-1208
Author(s):  
Xiao Liang Huang ◽  
Zhi Lin Qi ◽  
Deng Sheng Lei ◽  
Zhi Jun Li
Keyword(s):  
Gas Phase ◽  
Water Saturation ◽  
Water Flooding ◽  
Pore Channel ◽  
Low Permeability ◽  
Gas Reservoir ◽  
Damage Degree ◽  
Productivity Decline ◽  
Core Permeability ◽  
Experiment Analysis

Abstract. Low permeability water-flooding gas reservoir easy to cause the well bottom effusion in the middle of development,Effusion was often can't take out.Then with the function of capillary forces，the effusion will be absorbed in pore of rocks around the bottom well,and the Porous Medium part was block, The gas phase circulation pore canal becomes small,finally gas-phase effective permeability will be influence in the rocks,reduced pore channel permeability,made the productivity decline。The paper,the base of special experiment,analysis relation between the rate of damage about core permeability and imbibitions water saturation,and Introducing the correlation coefficient to the capacity formula of reverse imbibitions gas reservoir ,then get the capacity formula of the water flooding gas reservoir for realize the similar gas reservoir reverse imbibitions damage degree provides the basis.

A New Methodology of Production Performance Prediction for Strong Edge-Water Reservoir

2020 ◽  
Vol 143 (8) ◽  
Author(s):  
Angang Zhang ◽  
Zifei Fan ◽  
Lun Zhao ◽  
Jincai Wang ◽  
Heng Song
Keyword(s):  
Performance Prediction ◽  
Water Saturation ◽  
Water Injection ◽  
Material Balance ◽  
Water Reservoir ◽  
Production Performance ◽  
Water Flooding ◽  
Gas Oil ◽  
Permeability Model ◽  
Water Influx

Abstract Material balance is a basic principle in reservoir engineering, which is still used as a quick and easy analytical tool for reservoir evaluation. In this article, a new methodology of production performance prediction for water-flooding reservoir was proposed based on the material balance principle, which considers the water saturation change caused by water injection and natural water influx, and its effect on transient gas–oil ratio. Among them, the cumulative water production was calculated based on Tong’s water-driver performance curve; the cumulative water influx was obtained by the Fetkovitch method; the transient gas–oil ratio can be acquired by Darcy’s law and Baker’s relative permeability model. Comparisons have been made between the new methodology and commercial reservoir simulator for two different reservoirs. The results show that there is good similarity between these two tools, which verifies the correctness of the new methodology.

Characteristics and Influence Factors for Oil Displacement Efficiency by the Micro-Model Water Flooding Experiment in Low Permeability Reservoir

2015 ◽  
Vol 1092-1093 ◽  
pp. 1371-1374
Author(s):  
Xiang Chun Zhang ◽  
Wei Sun ◽  
Tian Li Rao ◽  
Hai Zeng Jing ◽  
Yong Jing ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Influence Factors ◽  
Water Flooding ◽  
Low Permeability ◽  
Micro Model ◽  
Displacement Efficiency ◽  
Oil Viscosity ◽  
Oil Displacement ◽  
Piston Displacement ◽  
Oil Displacement Efficiency

Through the displacement experiment of low permeability sandstone micro model of water Erdos basin, summing up the water displacing oil characteristics, and to explore the influencing factors of micro water oil displacement efficiency. The study found that, the water flooding characteristic main performance for: flooding mode mainly by non piston displacement; heterogeneity is strong, the oil displacement efficiency is low; the crude oil viscosity is low, the oil displacement efficiency is high; the main influencing factors are: physical; heterogeneity; displacement ratio. Therefore, for low permeability sandstone reservoir development, process parameters should be selected reasonably, in order to ensure the good development effect.

scholarly journals Effect of initial water flooding on the performance of polymer flooding for heavy oil production

2020 ◽  
Vol 75 ◽  
pp. 19 ◽  
Author(s):  
Clement Fabbri ◽  
Romain de-Loubens ◽  
Arne Skauge ◽  
Gerald Hamon ◽  
Marcel Bourgeois
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
History Matching ◽  
Oil Production ◽  
Water Flooding ◽  
Relative Permeabilities ◽  
Oil Viscosity ◽  
Initial Water ◽  
Polymer Injection ◽  
Polymer Flood

In the domain of heavy to extra heavy oil production, viscous polymer may be injected after water injection (tertiary mode), or as an alternative (secondary mode) to improve the sweep efficiency and increase oil recovery. To prepare field implementation, nine polymer injection experiments in heavy oil have been performed at core scale, to assess key modelling parameters in both situations. Among this consistent set of experiments, two have been performed on reconstituted cylindrical sandpacks in field-like conditions, and seven on consolidated Bentheimer sandstone in laboratory conditions. All experiments target the same oil viscosity, between 2000 cP and 7000 cP, and the viscosity of Partially Hydrolyzed Polyacrylamide solutions (HPAM 3630) ranges from 60 cP to 80 cP. Water and polymer front propagation are studied using X-ray and tracer measurements. The new experimental results presented here for water flood and polymer flood experiments are compared with experiments described in previous papers. The effects of geometry, viscosity ratio, injection sequence on recoveries, and history match parameters are investigated. Relative permeabilities of the water flood experiment are in line with previous experiments in linear geometry. Initial water floods led to recoveries of 15–30% after one Pore Volume Injected (PVI), a variation influenced by boundary conditions, viscosity, and velocities. The secondary polymer flood in consolidated sandstone confirms less stable displacement than tertiary floods in same conditions. Comparison of secondary and tertiary polymer floods history matching parameters suggests two mechanisms. First, hysteresis effect during oil bank mobilization stabilizes the tertiary polymer front; secondly, the propagation of polymer at higher oil saturation leads to lower adsorption during secondary experiment, generating a lower Residual Resistance Factor (RRF), close to unity. Finally, this paper discusses the use of the relative permeabilities and polymer properties estimated using Darcy equation for field simulation, depending on water distribution at polymer injection start-up.

Can 25-cp Polymer Solution Efficiently Displace 1,600-cp Oil During Polymer Flooding?

SPE Journal ◽  
2018 ◽  
Vol 23 (06) ◽  
pp. 2260-2278 ◽  
Author(s):  
R. S. Seright ◽  
Dongmei Wang ◽  
Nolan Lerner ◽  
Anh Nguyen ◽  
Jason Sabid ◽  
...  
Keyword(s):  
Crude Oil ◽  
Polymer Solution ◽  
Relative Permeability ◽  
Oil Recovery ◽  
Polymer Solutions ◽  
Water Saturation ◽  
Field Application ◽  
Polymer Flooding ◽  
Solution Viscosity ◽  
Polymer Flood

Summary This paper examines oil displacement as a function of polymer-solution viscosity during laboratory studies in support of a polymer flood in Canada's Cactus Lake Reservoir. When displacing 1,610-cp crude oil from field cores (at 27°C and 1 ft/D), oil-recovery efficiency increased with polymer-solution viscosity up to 25 cp (7.3 seconds−1). No significant benefit was noted from injecting polymer solutions more viscous than 25 cp. Much of this paper explores why this result occurred. Floods in field cores examined relative permeability for different saturation histories, including native state, cleaned/water-saturated first, and cleaned/oil-saturated first. In addition to the field cores and crude oil, studies were performed using hydrophobic (oil-wet) polyethylene cores and refined oils with viscosities ranging from 2.9 to 1,000 cp. In field cores, relative permeability to water (krw) remained low, less than 0.03 for most corefloods. After extended polymer flooding to water saturations up to 0.865, krw values were less than 0.04 for six of seven corefloods. Relative permeability to oil remained reasonably high (greater than 0.05) for most of the flooding process. These observations help explain why 25-cp polymer solutions were effective in recovering 1,610-cp oil. The low relative permeability to water allowed a 25-cp polymer solution to provide a nearly favorable mobility ratio. At a given water saturation, krw values for 1,000-cp crude oil were approximately 10 times lower than for 1,000-cp refined oil. In contrast to results found for the Daqing polymer flood (Wang et al. 2000, 2011), no evidence was found in our application that high-molecular-weight (MW) hydrolyzed polyacrylamide (HPAM) solutions mobilized trapped residual oil. The results are discussed in light of ideas expressed in recent publications. The relevance of the results to field applications is also examined. Although 25-cp polymer solutions were effective in displacing oil during our corefloods, the choice of polymer viscosity for a field application must consider reservoir heterogeneity and the risk of channeling in a reservoir.

Sign in / Sign up

Export Citation Format

Share Document