scholarly journals Analytical Model of Waterflood Sweep Efficiency in Vertical Heterogeneous Reservoirs under Constant Pressure

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Lisha Zhao ◽  
Li Li ◽  
Zhongbao Wu ◽  
Chenshuo Zhang
Keyword(s):  
Analytical Model ◽  
Oil Recovery ◽  
Constant Pressure ◽  
Water Saturation ◽  
Water Injection ◽  
Single Layer ◽  
Sweep Efficiency ◽  
Heterogeneous Reservoirs ◽  
Water Cut ◽  
Swept Volume

An analytical model has been developed for quantitative evaluation of vertical sweep efficiency based on heterogeneous multilayer reservoirs. By applying the Buckley-Leverett displacement mechanism, a theoretical relationship is deduced to describe dynamic changes of the front of water injection, water saturation of producing well, and swept volume during waterflooding under the condition of constant pressure, which substitutes for the condition of constant rate in the traditional way. Then, this method of calculating sweep efficiency is applied from single layer to multilayers, which can be used to accurately calculate the sweep efficiency of heterogeneous reservoirs and evaluate the degree of waterflooding in multilayer reservoirs. In the case study, the water frontal position, water cut, volumetric sweep efficiency, and oil recovery are compared between commingled injection and zonal injection by applying the derived equations. The results are verified by numerical simulators, respectively. It is shown that zonal injection works better than commingled injection in respect of sweep efficiency and oil recovery and has a longer period of water free production.

Improvement of Uniform Oil Displacement Technology on the Example of Kazakhstani Fields

2018 ◽  
Vol 9 (3) ◽  
pp. 542
Author(s):  
Abdeli D. ZHUMADILULI ◽  
Irina V. PANFILOV ◽  
Jamilyam A. ISMAILOVA
Keyword(s):  
Oil Recovery ◽  
Research University ◽  
Water Injection ◽  
Oil Fields ◽  
Simulation Test ◽  
Sweep Efficiency ◽  
Oil Companies ◽  
Industrial Companies ◽  
Energy Current ◽  
Water Cut

Most of oil companies today are focused on increasing the recovery factor from their oil fields. New drilling and well technologies as well as last advances in reservoir management, monitoring and Enhanced Oil Recovery (EOR) methods are thought to play a major role to meet the future demand of energy. Current decline in discovery of new oilfields intensified by a decline in oil prices make industrial companies to work on development of new efficient and economic techniques that will allow better production at lower cost. One such technology developed at Kazakh National Research University is presented in this paper. The latter propose the use of specific perforated holes on tubing liners in order to control the rate of water injection into variably permeable layers and to prevent non-uniform displacement of oil. The study was initially conducted on experimental facility that proved a positive correlation between the perforation density and water flow rates. Then the simulation test was performed using the data from several Kazakhstani oil fields. The results show an increase of sweep efficiency as well as a decrease in water-cut compared to traditional well case.

scholarly journals Chemical Migration and Emulsification of Surfactant-Polymer Flooding

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jierui Li ◽  
Weidong Liu ◽  
Guangzhi Liao ◽  
Linghui Sun ◽  
Sunan Cong ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Sweep Efficiency ◽  
Equal Concentration ◽  
Multiple Sample ◽  
Water Cut ◽  
And Migration ◽  
Swept Volume ◽  
Chemical Migration

With a long sand-packed core with multiple sample points, a laboratory surfactant-polymer flooding experiment was performed to study the emulsification mechanism, chemical migration mechanism, and the chromatographic separation of surfactant-polymer flooding system. After water flooding, the surfactant-polymer flooding with an emulsified system enhances oil recovery by 17.88%. The water cut of produced fluid began to decrease at the injection of 0.4 pore volume (PV) surfactant-polymer slug and got the minimum at 1.2 PV. During the surfactant-polymer flooding process, the loss of polymer is smaller than that of surfactant, the dimensionless breakthrough time of polymer is 1.092 while that of surfactant is 1.308, and the dimensionless equal concentration distance of the chemical is 0.65. During surfactant-polymer flooding, the concentration of surfactant controls the formation of the emulsion. From 50 cm to 600 cm, as the migration distance increases, the concentration of surfactant decreases, and the emulsification strength and duration decrease gradually. With the formation of emulsion, the viscosity of the emulsion is relatively stable, which is beneficial to enhanced oil recovery. With the shear of reservoirs and migration of surfactant-polymer slug, the emulsion is formed to improve the swept volume and sweep efficiency and enhance oil recovery.

scholarly journals Improvement of oil field development using enhanced oil recovery methods

2021 ◽  
pp. 23-28
Author(s):  
G Moldabayeva ◽  
R Suleimenova ◽  
N Buktukov ◽  
M Mergenov
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Water Injection ◽  
Oil Field ◽  
Water Soluble ◽  
Sweep Efficiency ◽  
Conformance Control ◽  
Water Soluble Polymer ◽  
Field Development ◽  
Water Cut

Purpose. To develop a technology to increase the oil recovery of formations using injection of polymer compositions. Methodology. For this study, practical methods were used such as enhanced oil recovery using stimulating technologies, technology using polymer systems based on a water-soluble polymer acrylamide, and emulsion-polymer technology. To achieve the conformance control, which was a prerequisite for testing, a thorough selection of wells was carried out, as well as an analysis of their hydrodynamic connection. Findings. As a result of using the method for limiting water inflows in the development of oil-bearing formations, redistribution of filtration channels, and a decrease in the production of fossil water as well as stabilisation of water cut were achieved. Originality. The scientific novelty of the study is the withdrawal of wells that are able to redistribute the volume of water injection at perforation intervals. Increased sweep efficiency and pressure at the wellhead at the beginning and at the end of the conformance control indicate a decrease in the conductivity of high-permeability formation intervals. Practical value. Application of the proposed technology for limiting water inflows will make it possible to develop low-permeability interlayers with filtration flows. The wells brought to a stable production rate during the study will ensure a decrease in formation water production and the water cut of the produced products, as well as stabilisation of the water cut over a certain period.

scholarly journals A Tracer Streamline Practice for Re-Evaluation Waterflood Pattern to Introduce a Cyclic Water Injection Scheme

2021 ◽  
Vol 6 (3) ◽  
pp. 127-136
Author(s):  
Dike Fitriansyah Putra ◽  
Lazuardhy Vozika Futur ◽  
Mursyidah Umar
Keyword(s):  
Oil Recovery ◽  
Water Injection ◽  
Oil Field ◽  
Sweep Efficiency ◽  
Water Influx ◽  
Injection Scheme ◽  
Pressure Water ◽  
Water Cut ◽  
Cyclic Injection ◽  
Selection Of

Waterflood introduces in the oil field a couple of years ago. Several waterflood schemes have been implemented in the fields to get the best incremental oil, such as peripheral injection, pattern waterflood, and etcetera. Many waterflood schemes are not working properly to boost the oil recovery due to unpredicted and unexpected water tide array. Then, the tracer practice started to be used for getting a better picture of the transmissibility reservoir as well as the direction of water pathway. This practice honors the parameters, such pressure, water cut, GOR, and rates. The streamline modeling is used to map the tracer, and it concludes that the selection of location of the injector should be based on the highest oil recovery achieved. Subsequently, the cyclic water injection method is one alternative. Apparently, this approach yields a quantify incremental recovery.  This research utilizes the pressure different approach to figure out the route of water in the formation. The inter-well tracer technique in this modeling study is a tool to review communication between injectors and producers in the existing pattern. Many scenario should be tried to find the best options for the new pattern opportunities. In parallel, a innovative scheme of waterflood technique should be implemented too for escalating oil recovery. The stream pathway observes a new potential of the waterflood scheme. It is called "cyclic injection" scheme.  The novelty of this approach is the ability to solve the poor sweep efficiency due to improper pathway of water influx in the oil bearing".

scholarly journals Investigation on the effect of active-polymers with different functional groups for EOR

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 61-68
Author(s):  
Dong Zhang ◽  
Jian Guang Wei ◽  
Run Nan Zhou
Keyword(s):  
Functional Groups ◽  
Oil Recovery ◽  
Molecular Size ◽  
Type I ◽  
Cleaning Efficiency ◽  
Sweep Efficiency ◽  
Profile Control ◽  
Branched Chain ◽  
Swept Volume ◽  
Enhance Oil Recovery

AbstractActive-polymer attracted increasing interest as an enhancing oil recovery technology in oilfield development owing to the characteristics of polymer and surfactant. Different types of active functional groups, which grafted on the polymer branched chain, have different effects on the oil displacement performance of the active-polymers. In this article, the determination of molecular size and viscosity of active-polymers were characterized by Scatterer and Rheometer to detect the expanded swept volume ability. And the Leica microscope was used to evaluate the emulsifying property of the active-polymers, which confirmed the oil sweep efficiency. Results show that the Type I active-polymer have a greater molecular size and stronger viscosity, which is a profile control system for expanding the swept volume. The emulsification performance of Type III active-polymer is more stable, which is suitable for improving the oil cleaning efficiency. The results obtained in this paper reveal the application prospect of the active-polymer to enhance oil recovery in the development of oilfields.

Carbonated Water Injection for Recovery of Oil and Wettability Analysis

2014 ◽  
Vol 695 ◽  
pp. 499-502 ◽  
Author(s):  
Mohamad Faizul Mat Ali ◽  
Radzuan Junin ◽  
Nor Hidayah Md Aziz ◽  
Adibah Salleh
Keyword(s):  
Oil Recovery ◽  
Oil And Gas ◽  
Promising Result ◽  
Water Injection ◽  
High Mobility ◽  
Wettability Alteration ◽  
Sweep Efficiency ◽  
Gas Flooding ◽  
Carbonated Water Injection ◽  
Carbonated Water

Malaysia oilfield especially in Malay basin has currently show sign of maturity phase which involving high water-cut and also pressure declining. In recent event, Malaysia through Petroliam Nasional Berhad (PETRONAS) will be first implemented an enhanced oil recovery (EOR) project at the Tapis oilfield and is scheduled to start operations in 2014. In this project, techniques utilizing water-alternating-gas (WAG) injection which is a type of gas flooding method in EOR are expected to improve oil recovery to the field. However, application of gas flooding in EOR process has a few flaws which including poor sweep efficiency due to high mobility ratio of oil and gas that promotes an early breakthrough. Therefore, a concept of carbonated water injection (CWI) in which utilizing CO2, has ability to dissolve in water prior to injection was applied. This study is carried out to assess the suitability of CWI to be implemented in improving oil recovery in simulated sandstone reservoir. A series of displacement test to investigate the range of recovery improvement at different CO2 concentrations was carried out with different recovery mode stages. Wettability alteration properties of CWI also become one of the focuses of the study. The outcome of this study has shown a promising result in recovered residual oil by alternating the wettability characteristic of porous media becomes more water-wet.

Effect of pressure variation on polymer flooding

2021 ◽  
Author(s):  
Ahmad Ali Manzoor
Keyword(s):  
Polymer Solution ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Heavy Oil ◽  
Constant Pressure ◽  
Maximum Pressure ◽  
Core Flooding ◽  
Sweep Efficiency ◽  
Black Oil Model ◽  
Original Oil In Place

Chemical-based enhanced oil recovery (EOR) techniques utilize the injection of chemicals, such as solutions of polymers, alkali, and surfactants, into oil reservoirs for incremental recovery. The injection of a polymer increases the viscosity of the injected fluid and alters the water-to-oil mobility ratio which in turn improves the volumetric sweep efficiency. This research study aims to investigate strategies that would help intensify oil recovery with the polymer solution injection. For that purpose, we utilize a lab-scale, cylindrical heavy oil reservoir model. Furthermore, a dynamic mathematical black oil model is developed based on cylindrical physical model of homogeneous porous medium. The experiments are carried out by injecting classic and novel partially hydrolyzed polyacrylamide solutions (concentration: 0.1-0.5 wt %) with 1 wt % brine into the reservoir at pressures in the range, 1.03-3.44 MPa for enhanced oil recovery. The concentration of the polymer solution remains constant throughout the core flooding experiment and is varied for other subsequent experimental setup. Periodic pressure variations between 2.41 and 3.44 MPa during injection are found to increase the heavy oil recovery by 80% original-oil-in-place (OOIP). This improvement is approximately 100% more than that with constant pressure injection at the maximum pressure of 3.44 MPa. The experimental oil recoveries are in fair agreement with the model calculated oil production with a RMS% error in the range of 5-10% at a maximum constant pressure of 3.44 MPa.

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.

Fitting Foam-Simulation-Model Parameters to Data: II. Surfactant-Alternating-Gas Foam Applications

2014 ◽  
Vol 18 (02) ◽  
pp. 273-283 ◽  
Author(s):  
W. R. Rossen ◽  
C. S. Boeije
Keyword(s):  
Steady State ◽  
Capillary Pressure ◽  
Oil Recovery ◽  
Water Saturation ◽  
Field Application ◽  
Model Parameters ◽  
Fractional Flow ◽  
Sweep Efficiency ◽  
Water Fraction ◽  
Foam Model

Summary Foam improves sweep in miscible and immiscible gas-injection enhanced-oil-recovery processes. Surfactant-alternating-gas (SAG) foam processes offer many advantages over coinjection of foam for both operational and sweep-efficiency reasons. The success of a foam SAG process depends on foam behavior at very low injected-water fraction (high foam quality). This means that fitting data to a typical scan of foam behavior as a function of foam quality can miss conditions essential to the success of an SAG process. The result can be inaccurate scaleup of results to field application. We illustrate how to fit foam-model parameters to steady-state foam data for application to injection of a gas slug in an SAG foam process. Dynamic SAG corefloods can be unreliable for several reasons. These include failure to reach local steady state (because of slow foam generation), the increased effect of dispersion at the core scale, and the capillary end effect. For current foam models, the behavior of foam in SAG depends on three parameters: the mobility of full-strength foam, the capillary pressure or water saturation at which foam collapses, and the parameter governing the abruptness of this collapse. We illustrate the fitting of these model parameters to coreflood data, and the challenges that can arise in the fitting process, with the published foam data of Persoff et al. (1991) and Ma et al. (2013). For illustration, we use the foam model in the widely used STARS (Cheng et al. 2000) simulator. Accurate water-saturation data are essential to making a reliable fit to the data. Model fits to a given experiment may result in inaccurate extrapolation to mobility at the wellbore and, therefore, inaccurate predicted injectivity: for instance, a model fit in which foam does not collapse even at extremely large capillary pressure at the wellbore. We show how the insights of fractional-flow theory can guide the model-fitting process and give quick estimates of foam-propagation rate, mobility, and injectivity at the field scale.

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