Displacement behavior and mechanism of long-term water flooding in sandstone oil reservoirs

2021 ◽  
Vol 28 (3) ◽  
pp. 834-847
Author(s):  
Ren-yi Cao ◽  
Zong Dai ◽  
Zhi-kai Wang ◽  
Ya-hui Wang ◽  
Jun Jiang ◽  
...  
2020 ◽  
Vol 213 ◽  
pp. 02020
Author(s):  
Fachao Shan ◽  
Lun Zhao ◽  
Anzhu Xu ◽  
Bing Bo ◽  
Gang Ma ◽  
...  

Generally the dynamic methods are used to calculate the oil increase after flooding control in the oilfield, but the evaluation results of different methods are quite different, and the evaluation results are uncertain. Therefore, for flooding control well groups in heavy oil reservoirs, the water flooding characteristic curve method, decline method and net oil increase method are used to calculate the oil increase, and the influence of the method parameter values on the results are analyzed, and the parameter value limits and calculation errors of each method are determined. Based on this, the adaptability of each method is proposed. The results show that the effect evaluation of the whole region flooding control is suitable to use the water flooding characteristic curve method or the decline method, the effect evaluation of the single well group flooding control is more suitable to use the decline method, the net oil increase method is not recommended. The application range and parameter value limit of the effect evaluation method of flooding control are put forward, which can guide the actual production effect evaluation in the oilfield.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Huang Zhiyu ◽  
Lu Hongsheng ◽  
Zhang Tailiang

Abstract In order to enhance oil recovery in high-temperature and high-salinity oil reservoirs, the copolymeric microspheres containing acrylamide (AM), acrylonitrile (AN) and AMPS was synthesized by inverse suspension polymerization. The copolymeric microsphere was very uniform and the size could be changed according to the condition of polymerization. The lab-scale studies showed that the copolymeric microsphere exhibit good salt-tolerance and thermal-stability when immersed in 20×105 mg/L NaCl(or KCl) solution, 7500 mg/L CaCl2 (or MgCl2) solution or 2000 mg/L FeCl3 solution, respectively. The copolymeric microsphere showed satisfactory absorbency rates. The sand-pipes experiments confirmed that the average toughness index was 1.059. It could enhance the oil recovery by about 3% compared with the corresponding irregular copolymeric particle.


2021 ◽  
Author(s):  
Suria Amalia Suut ◽  
Mahmood Khamis Al Kalbani ◽  
Issa Quseimi ◽  
Abdullah Gahaffi ◽  
Arjen Wielaard ◽  
...  

Abstract This paper summarises a ONE development success story of reviving a mature brownfield in South of Oman, Field β, just within ONE year through collaboration between different disciplines, comprehensive data analysis, optimising and recompletion of existing wells. Field β, comprised of multi-stacked clastic reservoirs, was put on stream in 1980s and peaked in early 1990s. Pilot water injection started in 1993 and full field water flooding continued in 1997. After more than 35 years since start of production, one can say the field was already in the tail end of its life. It had been stabilizing at low rate after 25 years and starting to decline further and at some point was one of the potential candidates to be decommissioned. A new FDP (FDP18) for part of the field was delivered in 2018 with the first well drilled at the end of that year. In 2019, despite drilling further wells on the FDP18, production was declining and was at 2018 rate towards the year end. Intensive data analysis and integrated reservoir reviews per reservoir layers were actively performed and new opportunities and data gathering were identified. FDP18 wells from 2019 onwards were then deepened to also acquire log data over deeper than the target reservoirs. Further synergy between asset and exploration teams also instigated in new discoveries including oil in shallower carbonate reservoirs, which were logged and sampled when drilling the FDP18 wells. Declining production, low oil price and COVID-19 crisis that hit 2020 challenged the team to be more resilient and with ONE development mindset between development and WRFM team, also between asset and exploration team, existing long-term closed in and very low productivity wells were utilised to tap these new opportunities. As a result, the field production has been increased by more than double, highest since 10 years ago, with a potential of triple its production rate, all achieved through optimizing and recompletion of existing wells within 1 year, at a very attractive low UTC.


Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 446 ◽  
Author(s):  
Lei Zhang ◽  
Nasir Khan ◽  
Chunsheng Pu

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.


Fuel ◽  
2015 ◽  
Vol 153 ◽  
pp. 559-568 ◽  
Author(s):  
David W. Zhao ◽  
Ian D. Gates

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