scholarly journals CAUSES AND ANALYSIS OF WATER ENCROACHMENT OF SOME OFFSHORE FIELDS PRODUCTS OF AZERBAIJAN

2021 ◽  
Vol 447 (3) ◽  
pp. 112-117
Author(s):  
Novruzova Sudaba ◽  
Gadashova Elmira ◽  
Fariz Ahmed
Keyword(s):  
Fluid Flow ◽  
Oil Recovery ◽  
Oil Production ◽  
Heterogeneous Structure ◽  
New Production ◽  
Injection Wells ◽  
Field Methods ◽  
Stage Of Development ◽  
Production Wells ◽  
The Republic

The results of researches of the water encroachment of some offshore fields (Neft Dashlary, Guneshli, Pirallahi, Darwin Banka, Apsheron Banka, Western Apsheron, etc.) of the Republic of Azerbaijan, most of which are at a late stage of development, have been presented. These fields are represented by weakly cemented and loose reservoirs of heterogeneous structure, in which there is an uneven fluid flow. Water breakthrough occurs through high-permeability layers, and layers with low permeability are involved in development to a less extent. Subsequent attempts to involve them in the development process cause an irrational increase in the volume of injected water, which leads to product encroachment. The type of reservoir, characterized by the presence of fracture zones, contributing to the flow of water from the aquifers to the producing wells, as well as improving their hydrodynamic connection with the injection wells, also contributes to the growth of the rate of watering. The geological and technological reasons for the water encroachment have been determined. The heterogeneity of the above mentioned deposits has been proven. It is indicated that an additional reason for the early water encroachment of production wells is the violation of the annulus tightness. Maintaining high rates of oil production is achieved by bringing in new production wells, while most of the watered wells are retired from operation without having exhausted their potential. It is proposed to carry out the measures that will ensure isolation of the most washed out zones and depleted areas of the main productive layer of the field. Methods of selective water isolation and flow diversion technologies should be carried out, first of all, in wells with an increased density of current reserves in order to obtain additional oil production and increase the oil recovery factor, as well as in wells with a high fluid flow rate.

Mechanism Analysis of Indigenous Microbial Enhancement for Residue Oil Recovery

2011 ◽  
Vol 365 ◽  
pp. 305-311
Author(s):  
Fu Chang Shu ◽  
Yue Hui She ◽  
Zheng Liang Wang ◽  
Shu Qiong Kong
Keyword(s):  
Oil Recovery ◽  
Mechanism Analysis ◽  
Sweep Efficiency ◽  
Injection Wells ◽  
The North ◽  
Physico Chemical ◽  
Production Wells ◽  
Microbial Enhancement ◽  
Filtration Properties ◽  
Technological Treatment

Biotechnological nutrient flooding was applied to the North block of the Kongdian Oilfield during 2001-2005. The biotechnology involved the injection of a water-air mixture made up of mineral nitrogen and phosphorous salts with the intent of stimulating the growth of indigenous microorganisms. During monitoring of the physico-chemical, microbiological and production characteristics of the North block of the Kongdian bed, it was revealed significant changes took place in the ecosystem as a result of the technological treatment. The microbial oil transformation was accompanied by an accumulation of carbonates, lower fatty acids and biosurfactants in water formations, which is of value to enhanced oil recovery. The microbial metabolites changed the composition of the water formation, favored the diversion of the injected fluid from closed, high permeability zones to upswept zones and improved the sweep efficiency. The results of the studies demonstrated strong hydrodynamic links between the injection wells and production wells. Microbiological monitoring of the deep subsurface ecosystems and the filtration properties of the fluids are well modified, producing 40000 additional tons of oil in the test areas.

A Decline Curve Analysis Model Based on Fluid Flow Mechanisms

2005 ◽  
Vol 8 (03) ◽  
pp. 197-204 ◽  
Author(s):  
Kewen Li ◽  
Roland N. Horne
Keyword(s):  
Fluid Flow ◽  
Linear Relationship ◽  
Relative Permeability ◽  
Oil Recovery ◽  
Single Phase ◽  
Oil Production ◽  
Curve Analysis ◽  
Production Data ◽  
Decline Curve Analysis ◽  
Decline Curve

Summary Decline-curve-analysis models are used frequently but still have many limitations. Approaches of decline-curve analysis used for naturally fractured reservoirs developed by waterflooding have been few. To this end, a decline-analysis model derived on the basis of fluid-flow mechanisms was proposed and used to analyze the oil-production data from naturally fractured reservoirs developed by waterflooding. Relative permeability and capillary pressure were included in this model. The model reveals a linear relationship between the oil-production rate and the reciprocal of the oil recovery or the accumulated oil production. We applied the model to the oil-production data from different types of reservoirs and found a linear relationship between the production rate and the reciprocal of the oil recovery as foreseen by the model, especially at the late period of production. The values of maximum oil recovery for the example reservoirs were evaluated with the parameters determined from the linear relationship. An analytical oil-recovery model was also proposed. The results showed that the analytical model could match the oil-production data satisfactorily. We also demonstrated that the frequently used nonlinear type curves could be transformed to linear relationships in a log-log plot. This may facilitate the production-decline analysis. Finally, the analytical model was compared with conventional models. Introduction Estimating reserves and predicting production in reservoirs has been a challenge for many years. Many methods have been developed in the last several decades. One frequently used technique is the decline-curve-analysis approach. There have been a great number of papers on this subject. Most of the existing decline-curve-analysis techniques are based on the empirical Arps equations: exponential, hyperbolic, and harmonic. It is difficult to foresee which equation the reservoir will follow. On the other hand, each approach has some disadvantages. For example, the exponential decline curve tends to underestimate reserves and production rates; the harmonic decline curve has a tendency to overpredict the reservoir performance. In some cases, production-decline data do not follow any model but cross over the entire set of curves. Fetkovich combined the transient rate and the pseudosteady-state decline curves in a single graph. He also related the empirical equations of Arps to the single-phase-flow solutions and attempted to provide a theoretical basis for the Arps equations. This was realized by developing the connection between the material balance and the flow-rate equations on the basis of his previous papers. Many derivations were based on the assumption of single-phase oil flow in closed-boundary systems. These solutions were suitable only for undersaturated(single-phase) oil flow. However, many oil fields are developed by waterflooding. Therefore, two-phase fluid flow (rather than single-phase flow)occurs. In this case, Lefkovits and Matthews derived the exponential decline form for gravity-drainage reservoirs with a free surface by neglecting capillary pressure. Fetkovich et al. included gas/oil relative permeability effects on oil production for solution-gas drive through the pressure-ratio term. This assumes that the oil relative permeability is a function of pressure. It is known that gas/oil relative permeability is a function of fluid saturation, which depends on fluid/rock properties.

scholarly journals THE USE OF OIL-SOLUBLE POLYMERS TO ENHANCE OIL RECOVERY IN HARD TO RECOVER HYDROCARBONS RESERVES

2021 ◽  
Author(s):  
Sudad H Al-Obaidi ◽  
Patkin AA ◽  
Chang WJ
Keyword(s):  
Oil Recovery ◽  
Early Stage ◽  
New Technology ◽  
Salt Content ◽  
Water Soluble ◽  
Heterogeneous Structure ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Stage Of Development ◽  
Effective Development

Currently, the share of new fields in many places over the world, which are at the initial stage of development, is constantly growing.Fields often have a complex heterogeneous structure with hard-to-recover reserves, therefore, for their effective development, it is necessary to use completely new approaches, including improving existing methodsof enhanced oil recovery.In this work, experimental verification of a new technology using oil-soluble polymers and comparing it with technology based on the use of water-soluble polymers has been performed. In laboratory conditions, a newtechnology for polymer flooding at an early stage of development using oil-soluble polymers was developed and experimentally confirmed. The new technology has made it possible to increase the degree of reservesrecovery by an average of 30% compared to existing methods of enhanced oil recovery and to solve a number of problems arising from the use of water-soluble polymers. Such problems are the freezing of aqueouspolymer solutions in winter and the poor solubility of polymers in formation waters with a high salt content. The use of new technology can also reduce energy costs by 25%.

Field Realization of Adaptive Reservoir Simulation for Steam Injection Forecasting

2021 ◽  
Author(s):  
Stanislav Ursegov ◽  
Evgenii Taraskin ◽  
Armen Zakharian
Keyword(s):  
Oil Recovery ◽  
Oil Production ◽  
Steam Injection ◽  
Carbonate Reservoirs ◽  
Base Case ◽  
Simple Liquid ◽  
Limited Information ◽  
Viscous Oil ◽  
Production Wells ◽  
Liquid Displacement

Abstract Globally, steam injection for heavy and high-viscous oil recovery is increasing, including carbonate reservoirs. Lack of full understanding such reservoir heating and limited information about production and injection rates of individual wells require to forecast steam injection not only deterministic and simple liquid displacement characteristic modeling types, but also the data-driven one, which covers the adaptive modeling. The implementation and validation of the adaptive system is presented in this paper by one of the world's largest carbonate reservoirs with heavy and high-viscous oil of the Usinsk field. Steam injection forecasting in such reservoirs is complicated by the unstable well interactions and relatively low additional oil production. In the adaptive geological model, vertical dimensions of cells are similar to gross thicknesses of stratigraphic layers. Geological parameters of cells with drilled wells do not necessarily match actual parameters of those wells since the cells include information of neighboring wells. During the adaptive hydrodynamic modeling, a reservoir pressure is reproduced by cumulative production and injection allocation among the 3D grid cells. Steam injection forecasting is firstly based on the liquid displacement characteristics, which are later modified considering well interactions. To estimate actual oil production of steamflooding using the reservoir adaptive geological and hydrodynamic models, dimensionless interaction coefficients of injection and production wells were first calculated. Then, fuzzy logic functions were created to evaluate the base oil production of reacting wells. For most of those wells, actual oil production was 25 – 30 % higher than the base case. Oil production of steamflooding for the next three-year period was carried out by modeling two options of the reservoir further development - with and without steam injection. Generally, forecasted oil production of the option with steam injection was about 5 % higher. The forecasting effectiveness of cyclic steam stimulations of production wells was done using the cross-section method, when the test sample was divided into two groups - the best and the worst, for which the average forecasted oil rates after the stimulations were respectively higher or lower than the average actual oil rate after the stimulations for the entire sample. The difference between the average actual oil rates after the stimulations of the best and the worst groups was 32 %, i.e. this is in how much the actual oil production could have increased if only the best group of the sample had been treated.

scholarly journals Compositions and Co-occurrence Patterns of Bacterial Communities Associated With Polymer- and ASP-Flooded Petroleum Reservoir Blocks

2020 ◽  
Vol 11 ◽  
Author(s):  
Guoling Ren ◽  
Jinlong Wang ◽  
Lina Qu ◽  
Wei Li ◽  
Min Hu ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Bacterial Communities ◽  
Chemical Properties ◽  
Oil Production ◽  
Chemical Flooding ◽  
Petroleum Reservoir ◽  
Promising Alternative ◽  
Asp Flooding ◽  
Production Wells ◽  
Occurrence Patterns

Polymer flooding technology and alkaline-surfactant-polymer (ASP) flooding technology have been widely used in some oil reservoirs. About 50% of remaining oil is trapped, however, in polymer-flooded and ASP-flooded reservoirs. How to further improve oil recovery of these reservoirs after chemical flooding is technically challenging. Microbial enhanced oil recovery (MEOR) technology is a promising alternative technology. However, the bacterial communities in the polymer-flooded and ASP-flooded reservoirs have rarely been investigated. We investigated the distribution and co-occurrence patterns of bacterial communities in ASP-flooded and polymer-flooded oil production wells. We found that Arcobacter and Pseudomonas were dominant both in the polymer-flooded and ASP-flooded production wells. Halomonas accounted for a large amount of the bacterial communities inhabiting in the ASP-flooded blocks, whereas they were hardly detected in the polymer-flooded blocks, and the trends for Acetomicrobium were the opposite. RDA analysis indicated that bacterial communities in ASP-flooded and polymer-flooded oil production wells are closely related to the physical and chemical properties, such as high salinity and strong alkaline, which together accounted for 56.91% of total variance. Co-occurrence network analysis revealed non-random combination patterns of bacterial composition from production wells of ASP-flooded and polymer-flooded blocks, and the ASP-flooded treatment decreased bacterial network complexity, suggesting that the application of ASP flooding technology reduced the tightness of bacterial interactions.

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 New information about the mechanism of oil displacement from productive reservoirs using flow control technologies

2020 ◽  
Vol 177 ◽  
pp. 01012
Author(s):  
Rustam Mukhametshin ◽  
Gulnara Kvon
Keyword(s):  
Oil Recovery ◽  
Experimental Studies ◽  
High Water ◽  
High Viscosity ◽  
Oil Displacement ◽  
Low Viscosity ◽  
Stage Of Development ◽  
Wide Range ◽  
Production Wells ◽  
Control Technologies

The article is devoted to improving the efficiency of methods application to increase oil recovery of deposits that are at the final stage of development. This stage is characterized by a high degree of waterlogging of reservoirs and extracted products. From a wide range of chemical methods for increasing oil recovery in Russian oil deposits, flow-regulating (flow-deflecting) technologies have become widespread. The article analyzes the results of purposeful use of thickened water for the completion of reserves of already flooded sandstone layers. Experimental studies were performed on two specially created five-point elements in the experimental sections of the Romashkinskoye deposit. To monitor the process of low-viscosity and high-viscosity oil displacement the following methods were used: a) intake, monitoring and production wells, in which the interval of productive horizons are lined with fiberglass pipes; b) method of high-frequency resistivity (technology of "VNIIneftepromgeophysics" Institute). The studies performed in the monitoring mode showed that, along with the increase in reservoir coverage by flooding at the macro level, there is also a displacement of part of the capillary-trapped oil in the already flooded layers’ intervals, that is, at the level of micro-uniformity of the porous medium. The paper concludes on the effectiveness of using flow-regulating technologies in conditions of high water availability of development objects.

scholarly journals CHRONOLOGY OF DEVELOPMENT AND APPLICATION OF ENHANCED OIL RECOVERY METHODS ON EXAMPLE OF DEPOSITS OF REPUBLIC OF BASHKORTOSTAN

2018 ◽  
Vol 59 (4) ◽  
pp. 88
Author(s):  
Albina S. Belyaeva ◽  
Anna A. Nikitina ◽  
Raiykhana V. Kunakova ◽  
Eldar M. Movsum-zade
Keyword(s):  
Enhanced Oil Recovery ◽  
Russian Federation ◽  
Oil Recovery ◽  
Technology Development ◽  
Oil Production ◽  
Stages Of Development ◽  
Republic Of Bashkortostan ◽  
The Russian Federation ◽  
The Republic ◽  
Recovery Methods

In this paper the evolution of the methods of oil production intensification and enhanced oil recovery (EOR) in the USSR and the Russian Federation is considered. By authors were identified and described the historical stages of development of the secondary and tertiary EOR fields on the example of the Republic of Bashkortostan with the indication of major events that have had a significant impact on the technology development of deposits in the country.

scholarly journals Increase in recoverable oil reserves based on system treatments of injection wells

2021 ◽  
Vol 6 (3) ◽  
pp. 121-129
Author(s):  
Artem V. Fomkin ◽  
Andrey M. Petrakov ◽  
Stanislav A. Zhdanov ◽  
Robert R. Rayanov ◽  
Elena N. Baykova ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Oil Production ◽  
Production Potential ◽  
Injection Wells ◽  
Oil Reserves ◽  
Recoverable Reserves ◽  
Technological Efficiency ◽  
Khanty Mansi Autonomous

Background. The article considers and justifies the need to take into account the indicators that characterize the amount of balance reserves involved in the development, as well as the increase in recoverable oil reserves due to EOR, when evaluating the technological efficiency of the treatment of the alignment of the pick-up profile (RUNWAY). Aim. If the increase in recoverable reserves is significantly less than production, this will lead to a loss of oil production potential. This fact is of particular importance in the conditions of the arrangement of the old squares and the presence of a developed infrastructure on them. Materials and methods. Materials were used to assess the dynamics and degree of development of oil reserves, calculations of the increase in recoverable reserves. Results. The article presents the results of the accumulated technological efficiency of work to improve oil recovery using various technologies for leveling the intake profile (runway) and non-stationary flooding at the facilities of Subsurface user in Khanty-Mansi Autonomous Area – Yugra on the basis of system-targeted impact on the reservoir. The article also presents materials on the assessment of the dynamics and degree of development of oil reserves, as well as calculations of the increase in recoverable reserves. Conclusions. Calculations based on the assessment of the increase in initial and residual recoverable oil reserves from the implementation of annual EOR programs carried out in accordance with the methodology of PJSC Gazpromneft indicate that the implementation of these programs contributes to additional involvement in the active development of previously poorly drained or non-drained oil reserves.

scholarly journals Status Quo of a CO2-Assisted Steam-Flooding Pilot Test in China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Zongyao Qi ◽  
Tong Liu ◽  
Changfeng Xi ◽  
Yunjun Zhang ◽  
Dehuang Shen ◽  
...  
Keyword(s):  
Field Test ◽  
Oil Recovery ◽  
Heavy Oil ◽  
Oil Production ◽  
Oil Field ◽  
Drainage Pattern ◽  
Steam Flooding ◽  
Production Wells ◽  
Water Cut ◽  
Production Dynamics

It is challenging to enhance heavy oil recovery in the late stages of steam flooding. This challenge is due to reduced residual oil saturation, high steam-oil ratio, and lower profitability. A field test of the CO2-assisted steam flooding technique was carried out in the steam-flooded heavy oil reservoir in the J6 block of the Xinjiang oil field (China). In the field test, a positive response to the CO2-assisted steam flooding treatment was observed, including a gradually increasing heavy oil production, an increase in the formation pressure, and a decrease in the water cut. The production wells in the test area mainly exhibited four types of production dynamics, and some of the production wells exhibited production dynamics that were completely different from those during steam flooding. After being flooded via CO2-assisted steam flooding, these wells exhibited a gravity drainage pattern without steam channeling issues, and hence, they yielded stable oil production. In addition, emulsified oil and CO2 foam were produced from the production well, which agreed well with the results of laboratory-scale tests. The reservoir-simulation-based prediction for the test reservoir shows that the CO2-assisted steam flooding technique can reduce the steam-oil ratio from 12 m3 (CWE)/t to 6 m3 (CWE)/t and can yield a final recovery factor of 70%.

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