scholarly journals A comprehensive review of the chemical-based conformance control methods in oil reservoirs

2021 ◽  
Vol 11 (5) ◽  
pp. 2233-2257
Author(s):  
Perekaboere Ivy Sagbana ◽  
Ahmad Sami Abushaikha

AbstractThe production of excess water during oil recovery creates not only a major technical problem but also an environmental and cost impact. This increasing problem has forced oil companies to reconsider methods that promote an increase in oil recovery and a decrease in water production. Many techniques have been applied over the years to reduce water cut, with the application of chemicals being one of them. Chemicals such as polymer gels have been widely and successfully implemented in several oil fields for conformance control. In recent years, the application of foam and emulsions for enhanced oil recovery projects has been investigated and implemented in oil fields, but studies have shown that they can equally act as conformance control agents with very promising results. In this paper, we present a comprehensive review of the application of polymer gel, foam and emulsion for conformance control. Various aspects of these chemical-based conformance control methods such as the mechanisms, properties, applications, experimental and numerical studies and the parameters that affect the successful field application of these methods have been discussed in this paper. Including the recent advances in chemical-based conformance control agents has also been highlighted in this paper.

2018 ◽  
Vol 9 (3) ◽  
pp. 542
Author(s):  
Abdeli D. ZHUMADILULI ◽  
Irina V. PANFILOV ◽  
Jamilyam A. ISMAILOVA

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.


2012 ◽  
Vol 518-523 ◽  
pp. 102-107 ◽  
Author(s):  
Ping Quan Wang ◽  
Xun Yong Nie ◽  
Xin Min Zhang ◽  
Ping Ya Luo ◽  
Yang Bai

Vicious or severe loss mainly refers to total or complete lost circulation which occurs in fractured or cavity formation and requires repeated particulate materials or cementing slurry sealing,which is a major technical problem accompanied by drilling engineering. The special gel is an association polymer with good rheology property designed to cure severe lost circulation, which can form a type of reversible supramolecular structure(dynamic physical molecular network, rather than chemical cross-linking) by the intermolecular force of supramolecular. The gel has good shear-thinning property which can provide the gel be pumped and flow in pipes easily and flow with high viscosity and resistance in the zone porous. And the gel has visible viscoelasticity that the gel have high displacement efficiency to cut off the connection between the formation fluid and the drilling fluid in borehole. And the gel is hard to be diluted by formation fluids for its apparent viscosity and strong cohesive force. Therefore, the gel is potential to control severe lost circulation accompanying with water zones or overflow and loss coexist. In field application, the gel was successful to deal with several severe loss complexities in Sichuan and Changqin oil fields in China.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Imran Akbar ◽  
Hongtao Zhou ◽  
Wei Liu ◽  
Muhammad Usman Tahir ◽  
Asadullah Memon ◽  
...  

In the petroleum industry, the researchers have developed a new technique called enhanced oil recovery to recover the remaining oil in reservoirs. Some reservoirs are very complex and require advanced enhanced oil recovery (EOR) techniques containing new materials and additives in order to produce maximum oil in economic and environmental friendly manners. In this work, the effects of nanosuspensions (KY-200) and polymer gel HPAM (854) on oil recovery and water cut were studied in the view of EOR techniques and their results were compared. The mechanism of nanosuspensions transportation through the sand pack was also discussed. The adopted methodology involved the preparation of gel, viscosity test, and core flooding experiments. The optimum concentration of nanosuspensions after viscosity tests was used for displacement experiments and 3 wt % concentration of nanosuspensions amplified the oil recovery. In addition, high concentration leads to more agglomeration; thus, high core plugging takes place and diverts the fluid flow towards unswept zones to push more oil to produce and decrease the water cut. Experimental results indicate that nanosuspensions have the ability to plug the thief zones of water channeling and can divert the fluid flow towards unswept zones to recover the remaining oil from the reservoir excessively rather than the normal polymer gel flooding. The injection pressure was observed higher during nanosuspension injection than polymer gel injection. The oil recovery was achieved by about 41.04% from nanosuspensions, that is, 14.09% higher than polymer gel. Further investigations are required in the field of nanoparticles applications in enhanced oil recovery to meet the world's energy demands.


2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Lei Zhang ◽  
Cheng Jing ◽  
Jing Liu ◽  
Khan Nasir

Due to the limited temperature resistance, the deep conformance control technology of using the conventional hydrolyzed polyacrylamide (HPAM) gel failed to enhance oil recovery in high-temperature heterogeneous oil reservoirs. Therefore, it is necessary to develop a gelant with high temperature resistance to meet the demands of increasing oil production and decreasing water cut in high-temperature heterogeneous oil reservoirs. In this paper, a copolymer is first synthesized by the method of inverse emulsion polymerization using 2-acrylamide-2-tetradecyl ethyl sulfonic acid (AMC16S), acrylamide (AM), and acrylic acid (AA). The developed copolymer has a highly branching skeleton and can resist temperature up to 100 °C. And then, a gelant with high temperature resistance and good shear resistance can be formed by mixing a certain proportion of the developed copolymer and polyethyleneimine (PEI). After the controllable gelation, a copolymer gel is formed and the formed gel can maintain the stable performance for a long time in the high-temperature environment. Experimental results show that the developed gelant can be applied in the conformance control of high-temperature heterogeneous oil reservoir.


Geosciences ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 470
Author(s):  
Josipa Hranić ◽  
Sara Raos ◽  
Eric Leoutre ◽  
Ivan Rajšl

There are numerous oil fields that are approaching the end of their lifetime and that have great geothermal potential considering temperature and water cut. On the other hand, the oil industry is facing challenges due to increasingly stringent environmental regulations. An example of this is the case of France where oil extraction will be forbidden starting from the year 2035. Therefore, some oil companies are considering switching from the oil business to investing in geothermal projects conducted on existing oil wells. The proposed methodology and developed conversions present the evaluation of existing geothermal potentials for each oil field in terms of water temperature and flow rate. An additional important aspect is also the spatial distribution of existing oil wells related to the specific oil field. This paper proposes a two-stage clustering approach for grouping similar wells in terms of their temperature properties. Once grouped on a temperature basis, these clusters should be clustered once more with respect to their spatial arrangement in order to optimize the location of production facilities. The outputs regarding production quantities and economic and environmental aspects will provide insight into the optimal scenario for oil-to-water conversion. The scenarios differ in terms of produced energy and technology used. A case study has been developed where the comparison of overall fields and clustered fields is shown, together with the formed scenarios that can further determine the possible conversion of petroleum assets to a geothermal assets.


2020 ◽  
Vol 143 (8) ◽  
Author(s):  
Munqith Aldhaheri ◽  
Mingzhen Wei ◽  
Ali Alhuraishawy ◽  
Baojun Bai

Abstract Polymer bulk gels have been widely applied to mitigate excessive water production from mature oil fields by correcting the reservoir permeability heterogeneity. This paper reviews water responses, effective times, and economic assessments of injection-well gel treatments based on 61 field projects. Eight parameters were evaluated per the reservoir type using the descriptive analysis, stacked histograms, and scatterplots. Results show that water production generally continues to increase after the treatment for undeveloped conformance problems. Contrarily, it typically decreases after the reactive gel treatments target developed conformance issues. For the developed problems, gel treatments do not always mitigate the water production where the water cut may stabilize or increase by 17% in 22% of instances. In addition, they often do reduce water production but not dramatically to really low levels where the water cut stays above 70% and reduces by only 10% in most cases. Gel treatments are economically appraised based only on the oil production response, and both water responses (injection and production) are not considered in the evaluation. They have a typical payout time of 9.2 months, cost of incremental oil barrel of 2 $/barrel, and effective time of 1.9 years. In addition, they have better water responses and economics in carbonates than in sandstones and in unconsolidated and naturally fractured reservoirs than in matrix-rock formations. The current review strongly warns reservoir engineers that gel treatments are not superior in alleviating the water production and candidates should be nominated based on this fact to achieve favorable economics and avoid treatment failures.


SPE Journal ◽  
2021 ◽  
pp. 1-14
Author(s):  
Zheyu Liu ◽  
Yiqiang Li ◽  
Xin Chen ◽  
Yukun Chen ◽  
Jianrong Lyu ◽  
...  

Summary Surfactant-polymer (SP) flooding has been regarded as an efficient technique for enhanced oil recovery in the development of mature oil fields, especially for those with heterogeneous conglomerate reservoirs. However, people are still unclear about the optimal SP flooding initiation timing (OSPT) that is expected to contribute to the maximum ultimate recovery factor in the case with a limited amount of SP solution injection. Accordingly, this study aims to investigate OSPT through conducting a series of experiments, including nuclear magnetic resonance (NMR) online monitoring, full-diameter coreflooding, and microfluidic study. The fractional-flow curve is used to identify OSPT, of which the effect on the oil recovery is analyzed. OSPT is demonstrated to be dependent on the amount of injected SP solution. An earlier-started SP flooding is favorable for achieving higher oil recovery factors under the premise of sufficiently high SP solution injection [more than 1.5 pore volume (PV)]. With the commonly used 0.65 PV of SP solution in the reservoir scale, OSPT is suggested to be at the moment when a water cut of 80 to 90% is reached. The formation of dense emulsions in the early-started SP flooding affects the performance of the post-waterflooding, which eventually decreases the ultimate oil recoveries because of inadequacy of SP solution. An earlier-started SP flooding contributes to a larger swept volume, but the initial efficiency of the SP flooding is lower than that of the waterflooding when the injection pressure is constant. OSPT is proposed through analyzing the fractional-flow curve in the case of 0.65 PV of SP injection, and the determined OSPT is validated by coreflooding experiments and field data. Moreover, OSPT for the conglomerate reservoir is suggested to be earlier than that for the relatively homogenous sandstone reservoir.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yanxia Zhou ◽  
Xiangguo Lu ◽  
Bao Cao ◽  
Yigang Liu ◽  
Yunbao Zhang ◽  
...  

NB35-2 oilfield is a typical offshore sandstone reservoir with viscous crude oil and high permeability. Due to the inherent severe heterogeneity, the efficiency of conventional water flooding is pretty low and usually accompanied with early water breakthrough. In order to recover the residual oil and better realize its potential, applications of enhanced oil recovery (EOR) technology are necessary. However, the selection of EOR method and related parameters may directly impact the final results and can be noticeably different for different reservoirs; therefore, to optimize the oil production rate and final oil recovery, systematical optimization of every detail based on the condition of a specific reservoir is of key importance. In this paper, physical simulations were first conducted to select the best recovery methods for the target area based on the static geophysical model under the guidance of reservoir engineering theory. Then, detailed development variants for each method were determined by numerical simulation with the support of data obtained from previous pilot tests (polymer gel flooding and thermal fluid huff and puff) conducted in this area. Three exploitation methods were developed for the target well group, including polymer gel flooding (conformance control, Pattern 1), steam huff and puff (thermal recovery method, Pattern 2), and a combination of polymer gel flooding and steam huff and puff (conformance control and thermal recovery, Pattern 3). The numerical simulation result also showed that Pattern 3 yielded the highest oil recovery. Moreover, the amount of additional oil being recovered by applying Pattern 3 was even higher than the total additional oil being extracted by Patterns 1 and 2. In addition, sensitivity analysis was conducted to rank the most important parameters based on the three Patterns. At last, it is thought that the synergistic effect between conformance control and thermal recovery made more oil recovered, which was intuitively clarified in the mechanism analysis.


2021 ◽  
pp. 61-72
Author(s):  
I. G. Sabanina ◽  
T. V. Semenova ◽  
Yu. Ya. Bolshakov ◽  
S. V. Vorobjeva

Currently, most of the oil fields in the West Siberian oil and gas province are in the final stage of development. There is water-cut in production, a decrease in oil production, and the structure of residual reserves deteriorates. The search and application of the most successful scientific methods and technologies for improving oil recovery in the development of fields is quite an urgent task.It should be taken into account that hydrophobic reservoirs are common in the oil fields of Western Siberia, and when applying the method of reservoir flooding, this fact should be taken into account and a more detailed approach should be taken to the study of capillary forces to prevent flooding of productive objects. Despite the good knowledge of the West Siberian megabasin, some fundamental issues of its structure and oil and gas potential remain debatable.The article proposes methods for improving oil recovery of the BS10 formation of the Ust-Balykskoye oil field based on the study of capillary pressures in productive reservoir formations, and provides recommendations for the placement of injection wells. The study of the capillary properties of reservoir rocks will significantly improve the efficiency of exploration and field operations in oil fields.


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