scholarly journals Viscosity Measurements of Different Fluids Used for Mobility Control in Mature Reservoirs

2017 ◽  
Vol 19 (2) ◽  
pp. 141
Author(s):  
Mahmoud Elsharafi ◽  
Denzel Kinyua ◽  
Cody Chancellor
Keyword(s):  
Oil Recovery ◽  
Oil Production ◽  
Oil Industry ◽  
Mobility Control ◽  
Rock Surface ◽  
Viscosity Measurements ◽  
Different Temperatures ◽  
Carbonate Formations ◽  
Enhance Oil Recovery ◽  
The Impact

In the oil industry, it is important to increase the mobility of hydrocarbon fluids (oil and/or gas) and decrease the mobility of water. Doing so results in an increase in oil production and a decrease in unwanted water production. Polymers have been widely used to increase water viscosity, causing a decrease in water mobility. Surfactants have been used to change reservoir wettability and to clean the rock surface. The use of surfactants changes the formation wettability from oil wet to water wet. This results in an increase in oil production from various water wet sandstone and carbonate formations. Low water salinity has also been used to enhance oil recovery. The mobility of the oil should be more than the mobility of the water to ensure maximum extraction efficiency. As a result, viscosity measurements are very important in determining the impact of a viscous fluid in enhanced oil recovery (EOR). We measured the viscosity of mixed fluids used in the oil industry such as brines of varying concentration (Sodium Chloride and Calcium Chloride solutions) and various polymer solutions at different temperatures.

Viscosity Measurements for Various Mixed Fluids Used to Enhance Oil Recovery

2017 ◽  
Author(s):  
Mahmoud O. Elsharafi ◽  
Cody Chancellor ◽  
Denzel Kinyua ◽  
Reuben Denwe
Keyword(s):  
Oil Recovery ◽  
Oil Fields ◽  
Effect Of Temperature ◽  
Fluid Viscosity ◽  
Water Mobility ◽  
Reservoir Rocks ◽  
Viscosity Measurements ◽  
Different Types ◽  
Enhance Oil Recovery ◽  
The Impact

In mature reservoirs, the goal is to increase oil mobility and decrease water mobility. As a result, oil production will be increased and unwanted water production will be decreased. Surfactant and alkaline are widely used to change the wettability of reservoir rocks from oil wet to water wet. Viscosity measurements are important in finding out the impact viscous fluids on enhanced oil recovery (EOR). This project focuses on the viscosity measurements of various mixed fluids used in oil-fields to enhance oil recovery. Two types of surfactants (A and B) and one type of alkaline were utilized throughout the work. In addition, different types of oil obtained from different areas were implemented. The viscosity of these mixed fluids was measured while observing the implications of using varying surfactant and alkaline concentrations. Lastly, the effect of temperature on fluid viscosity was monitored.

Waterflooding in Carbonate Reservoirs: Does the Salinity Matter?

2014 ◽  
Vol 17 (03) ◽  
pp. 304-313 ◽  
Author(s):  
A.M.. M. Shehata ◽  
M.B.. B. Alotaibi ◽  
H.A.. A. Nasr-El-Din
Keyword(s):  
Oil Recovery ◽  
Sudden Change ◽  
Oil Production ◽  
Deionized Water ◽  
Production Performance ◽  
Shallow Aquifer ◽  
Secondary Recovery ◽  
Tertiary Recovery ◽  
The Impact ◽  
Indiana Limestone

Summary Waterflooding has been used for decades as a secondary oil-recovery mode to support oil-reservoir pressure and to drive oil into producing wells. Recently, the tuning of the salinity of the injected water in sandstone reservoirs was used to enhance oil recovery at different injection modes. Several possible low-salinity-waterflooding mechanisms in sandstone formations were studied. Also, modified seawater was tested in chalk reservoirs as a tertiary recovery mode and consequently reduced the residual oil saturation (ROS). In carbonate formations, the effect of the ionic strength of the injected brine on oil recovery has remained questionable. In this paper, coreflood studies were conducted on Indiana limestone rock samples at 195°F. The main objective of this study was to investigate the impact of the salinity of the injected brine on the oil recovery during secondary and tertiary recovery modes. Various brines were tested including deionized water, shallow-aquifer water, seawater, and as diluted seawater. Also, ions (Na+, Ca2+, Mg2+, and SO42−) were particularly excluded from seawater to determine their individual impact on fluid/rock interactions and hence on oil recovery. Oil recovery, pressure drop across the core, and core-effluent samples were analyzed for each coreflood experiment. The oil recovery using seawater, as in the secondary recovery mode, was, on the average, 50% of original oil in place (OOIP). A sudden change in the salinity of the injected brine from seawater in the secondary recovery mode to deionized water in the tertiary mode or vice versa had a significant effect on the oil-production performance. A solution of 20% diluted seawater did not reduce the ROS in the tertiary recovery mode after the injection of seawater as a secondary recovery mode for the Indiana limestone reservoir. On the other hand, 50% diluted seawater showed a slight change in the oil production after the injection of seawater and deionized water slugs. The Ca2+, Mg2+, and SO42− ions play a key role in oil mobilization in limestone rocks. Changing the ion composition of the injected brine between the different slugs of secondary and tertiary recovery modes showed a measurable increase in the oil production.

scholarly journals A New Method of Plugging the Fracture to Enhance Oil Production for Fractured Oil Reservoir using Gel Particles and the HPAM/Cr3+ System

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 446 ◽  
Author(s):  
Lei Zhang ◽  
Nasir Khan ◽  
Chunsheng Pu
Keyword(s):  
Oil Recovery ◽  
Oil Production ◽  
Oil Reservoirs ◽  
New Method ◽  
Water Flooding ◽  
Whole Process ◽  
Gel Particles ◽  
The Matrix ◽  
Water Cut ◽  
Enhance Oil Recovery

Due to the strong heterogeneity between the fracture and the matrix in fractured oil reservoirs, injected water is mainly moved forward along the fracture, which results in poor water flooding. Therefore, it is necessary to reduce the water cut and increase oil production by using the conformance control technology. So far, gel particles and partially hydrolyzed polyacrylamide (HPAM)/Cr3+ gel are the most common applications due to their better suitability and low price. However, either of the two alone can only reduce the conductivity of the fracture to a certain extent, which leads to a poor effect. Therefore, to efficiently plug the fracture to enhance oil recovery, a combination of gel particles and the HPAM/Cr3+ system is used by laboratory tests according to their respective advantages. The first step is that the gel particles can compactly and uniformly cover the entire fracture and then the fracture channel is transformed into the gel particles media. This process can enhance the oil recovery to 18.5%. The second step is that a suitable HPAM/Cr3+ system based on the permeability of the gel particles media is injected in the fractured core. Thus, the fracture can be completely plugged and the oil in the matrix of the fractured core can be displaced by water flooding. This process can enhance oil recovery to 10.5%. During the whole process, the oil recovery is increased to 29% by this method. The results show that this principle can provide a new method for the sustainable and efficient development of fractured oil reservoirs.

scholarly journals A Laboratory Approach on the Hybrid-Enhanced Oil Recovery Techniques with Different Saline Brines in Sandstone Reservoirs

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1051 ◽  
Author(s):  
Yisheng Hu ◽  
Qiurong Cheng ◽  
Jinping Yang ◽  
Lifeng Zhang ◽  
Afshin Davarpanah
Keyword(s):  
Oil Recovery ◽  
Foam Stability ◽  
Oil Production ◽  
Mobility Control ◽  
Recovery Factor ◽  
Wettability Alteration ◽  
Bulk Solution ◽  
Formation Water ◽  
Sandstone Reservoirs ◽  
Brine Injection

As foams are not thermodynamically stable and might be collapsed, foam stability is defined by interfacial properties and bulk solution. In this paper, we investigated foam injection and different salinity brines such as NaCl, CaCl2, KCl, and MgCl2 to measure cumulative oil production. According to the results of this experiment, it is concluded that sequential low-salinity water injections with KCl and foam flooding have provided the highest cumulative oil production in sandstone reservoirs. This issue is related to high wettability changes that had been caused by the KCl. As K+ is a monovalent cation, KCl has the highest wettability changes compared to other saline brines and formation water at 1000 ppm, which is due to the higher wettability changes of potassium (K+) over other saline ions. The interfacial tension for KCl at the lowest value is 1000 ppm and, for MgCl2, has the highest value in this concentration. Moreover, the formation brine, regarding its high value of salty components, had provided lower cumulative oil production before and after foam injection as it had mobilized more in the high permeable zones and, therefore, large volumes of oil would be trapped in the small permeable zones. This was caused by the low wettability alteration of the formation brine. Thereby, formation water flowed in large pores and the oil phase remained in small pores and channels. On the other hand, as foams played a significant role in the mobility control and sweep efficiency, at 2 pore volume, foam increased the pressure drop dramatically after brine injection. Consequently, foam injection after KCl brine injection had the maximum oil recovery factor of 63.14%. MgCl2 and formation brine had 41.21% and 36.51% oil recovery factor.

scholarly journals On the Improvement of the State Tax Policy in the Oil Sector in the Period of the New Coronavirus Infection (COVID-19) Spread

JURIST ◽  
2021 ◽  
Vol 2 ◽  
pp. 2-9
Author(s):  
Elena N. Gorbunova ◽  
Keyword(s):  
Tax Policy ◽  
Oil Prices ◽  
Oil Production ◽  
Oil Industry ◽  
State Tax ◽  
Coronavirus Infection ◽  
The Russian Federation ◽  
Oil Sector ◽  
The Impact ◽  
Financial Result

In the article, the author analyzed the situation in the oil industry in the conditions of low oil prices and the pandemic. COVID-19. The impact of the COVID-19 pandemic on the oil industry has been identified. The author developed a tax bill on financial results in oil production, as one of the ways to overcome the consequences of low oil prices and the pandemic of COVID-19. All the basic elements of tax on the financial result are discussed in detail. The author proposes ways to improve the state’s tax policy in the context of the spread of a new coronavirus infection (COVID-19), by introducing a bill in the form of a separate chapter of the Tax Code of the Russian Federation “Tax system in the form of a tax on financial result in oil production”.

scholarly journals Half a century of continuous oil production by in-situ combustion in Romania – case study Suplacu de Barcau field

2021 ◽  
Vol 343 ◽  
pp. 09009
Author(s):  
Gheorghe Branoiu ◽  
Florinel Dinu ◽  
Maria Stoicescu ◽  
Iuliana Ghetiu ◽  
Doru Stoianovici
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Oil Production ◽  
Oil Field ◽  
Oil Reservoir ◽  
In Situ Combustion ◽  
Cyclic Steam Stimulation ◽  
The Impact ◽  
Steam Stimulation

Thermal oil recovery is a special technique belonging to Enhanced Oil Recovery (EOR) methods and includes steam flooding, cyclic steam stimulation, and in-situ combustion (fire flooding) applied especially in the heavy oil reservoirs. Starting 1970 in-situ combustion (ISC) process has been successfully applied continuously in the Suplacu de Barcau oil field, currently this one representing the most important reservoir operated by ISC in the world. Suplacu de Barcau field is a shallow clastic Pliocene, heavy oil reservoir, located in the North-Western Romania and geologically belonging to Eastern Pannonian Basin. The ISC process are operated using a linear combustion front propagated downstructure. The maximum oil production was recorded in 1985 when the total air injection rate has reached maximum values. Cyclic steam stimulation has been continuously applied as support for the ISC process and it had a significant contribution in the oil production rates. Nowadays the oil recovery factor it’s over 55 percent but significant potential has left. In the paper are presented the important moments in the life-time production of the oil field, such as production history, monitoring of the combustion process, technical challenges and their solving solutions, and scientific achievements revealed by many studies performed on the impact of the ISC process in the oil reservoir.

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.

A Novel Method to Enhance Oil Recovery by Inter-fracture Injection and Production through the Same Multi-fractured Horizontal Well

2021 ◽  
pp. 1-19
Author(s):  
Youwei He ◽  
Yu Qiao ◽  
Jiazheng Qin ◽  
Yong Tang ◽  
Yong Wang ◽  
...  
Keyword(s):  
Water Resources ◽  
Oil Recovery ◽  
Horizontal Well ◽  
Oil Production ◽  
Oil Reservoirs ◽  
Hydraulic Fractures ◽  
Discrete Fracture Model ◽  
Unconventional Oil ◽  
Fractured Horizontal Well ◽  
Enhance Oil Recovery

Abstract Conventional enhanced oil recovery (EOR) approaches are inefficient in the unconventional reservoirs. This paper provides a novel approach to enhance oil recovery from unconventional oil reservoirs through synchronous inter-fracture injection and production (SiFIP) and asynchronous inter-fracture injection and production (AiFIP). The compartmental embedded discrete fracture model (cEDFM) is introduced to simulate complex fracture geometries to quantitatively evaluate the performance of SiFIP and AiFIP. EOR performances using multiple producing methods are investigated (i.e., depletion, fluid flood, fluid Huff and Puff, SiFIP, AiFIP. Higher cumulative oil production rates can be achieved by AiFIP and SiFIP. AiFIP yields the highest oil recovery factor, two times higher than depletion. Compared with SiFIP, AiFIP may be a preferred method when CO2/water resources are short. The impacts of fracture and injection parameters on oil production are discussed. The feasible well completions for AiFIP and SiFIP are provided. AiFIP (CO2) achieves the best EOR performance among different producing methods. This paper demonstrates the feasibility of SiFIP and AiFIP to improve oil recovery. The proposed methods improve flooding performance by transforming fluid injection among wells to among hydraulic fractures from the same Multi-fractured horizontal well (MFHW), which is a promising EOR approach in unconventional oil reservoirs. The proposed EOR method (AiFIP-CO2) can improve the oil recovery, and mitigate the emission of CO2 as well as reduce the waste of water resources.

Improving Oil Recovery Through Fracture Injection and Production of Multiple Fractured Horizontal Wells

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Youwei He ◽  
Shiqing Cheng ◽  
Zhe Sun ◽  
Zhi Chai ◽  
Zhenhua Rui
Keyword(s):  
Oil Recovery ◽  
Oil Production ◽  
Horizontal Wells ◽  
Co2 Injection ◽  
Production Rates ◽  
Well Production ◽  
Well Completion ◽  
Tight Formations ◽  
Fractured Horizontal Wells ◽  
The Impact

Abstract Well production rates decline quickly in the tight reservoirs, and enhanced oil recovery (EOR) is needed to increase productivity. Conventional flooding from adjacent wells is inefficient in the tight formations, and Huff-n-Puff also fails to achieve the expected productivity. This paper investigates the feasibility of the inter-fracture injection and production (IFIP) method to increase oil production rates of horizontal wells. Three multi-fractured horizontal wells (MFHWs) are included in a cluster well. The fractures with even and odd indexes are assigned to be injection fractures (IFs) and recovery fractures (RFs). The injection/production schedule includes synchronous inter-fracture injection and production (s-IFIP) and asynchronous inter-fracture injection and production (a-IFIP). The production performances of three MFHWs are compared by using four different recovery approaches based on numerical simulation. Although the number of RFs is reduced by about 50% for s-IFIP and a-IFIP, they achieve much higher oil rates than depletion and CO2 Huff-n-Puff. The sensitivity analysis is performed to investigate the impact of parameters on IFIP. The spacing between IFs and RFs, CO2 injection rates, and connectivity of fracture networks affect oil production significantly, followed by the length of RFs, well spacing among MFHWs, and the length of IFs. The suggested well completion scheme for the IFIP methods is presented. This work discusses the ability of the IFIP method in enhancing the oil production of MFHWs.

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