scholarly journals New Waterflooding Characteristic Curves Based on Cumulative Water Injection

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Zhiwang Yuan ◽  
Zhiping Li ◽  
Li Yang ◽  
Yingchun Zhang

When a conventional waterflooding characteristic curve (WFCC) is used to predict cumulative oil production at a certain stage, the curve depends on the predicted water cut at the predicted cutoff point, but forecasting the water cut is very difficult. For the reservoirs whose pressure is maintained by water injection, based on the water-oil phase seepage theory and the principle of material balance, the equations relating the cumulative oil production and cumulative water injection at the moderately high water cut stage and the ultrahigh water cut stage are derived and termed the Yuan-A and Yuan-B curves, respectively. And then, we theoretically analyze the causes of the prediction errors of cumulative oil production by the Yuan-A curve and give suggestions. In addition, at the ultrahigh water cut stage, the Yuan-B water cut prediction formula is established, which can predict the water cut according to the cumulative water injection and solve the difficult problem of water cut prediction. The application results show Yuan-A and Yuan-B curves are applied to forecast oil production based on cumulative water injection data obtained by the balance of injection and production, avoiding reliance on the water cut forecast and solving the problems of predicting the cumulative oil production of producers or reservoirs that have not yet shown the decline rule. Furthermore, the formulas are simple and convenient, providing certain guiding significance for the prediction of cumulative oil production and water cut for the same reservoir types.

2013 ◽  
Vol 274 ◽  
pp. 675-678
Author(s):  
Cheng Fu ◽  
Bin Huang

The remaining oil distribution is very complex and the difficulty in tapping measures is more and more big when the west block of South-eight area has gone into the ultra-high water cut stage. So the remaining oil distribution in 109 units has been comprehensively studied on the condition that the composite water cut reaches 9.06% by establishing reservoir geologic model and proceeding reservoir numerical simulation according to recent tapping measures and remaining oil analysis experience in the process of adjusting scheme. And combined with some reservoir engineering methods such as: waterflooding characteristic curve and material balance method, obvious effects has been obtained in this research.


2013 ◽  
Vol 868 ◽  
pp. 645-650
Author(s):  
Lin Li

The parameters of reservoir impact all the sectors of oilfield developing after flood development, so methods of separate stratum injection allocation are researched for forecasting the petroleum reservoir performance accurately. The methods of separate stratum injection allocation are significative for remaining oil distribution, injection allocation of interval and the level of exploitation and administration in high water cut stage. First, we should derive injection-withdrawal ratio (IWR), gradient of pressure and water cut by material balance equation.The injection allocation of single well,injection wells and property of interval are determined by the research of split coefficient.We find the reservoir small error, lower water cut, high degree of reservoir recovery by anaysising the results of separate stratum injection allocation.The results show that separate stratum injection allocation is scientific and reasonable, simple and applied for the oil field in high water cut stage.


Author(s):  
Yanlai Li ◽  
Jie Tan ◽  
Songru Mou ◽  
Chunyan Liu ◽  
Dongdong Yang

AbstractFor offshore reservoirs with a big bottom water range, the water cut rises quickly and soon enters the ultra-high water cut stage. After entering the ultra-high water cut stage, due to the influence of offshore production facilities, there are few potential tapping measures, so it is urgent to explore the feasibility study of artificial water injection development. The quasi-three-dimensional and two-dimensional displacement experiments are designed using the experimental similarity criteria according to the actual reservoir parameters. Several experimental schemes are designed, fluid physical properties, interlayer distribution, and development mode according to the actual reservoir physical properties. Through the visualization of experimental equipment, the bottom water reservoir is visually stimulated. The displacement and sweep law of natural water drive and artificial water injection in bottom water reservoir with or without an interlayer, different viscosity, and different well spacing is analyzed. The following conclusions are obtained: (1) For reservoirs with a viscosity of 150 cp. The recovery factor after water injection is slightly higher than before water injection. However, the recovery factor is lower than that without injection production. The reason is that the increment of injection conversion is limited to reduce one production well after injection conversion. (2) For reservoirs with a viscosity of 30 cp. The recovery factor after injection is 39.8%, which is slightly higher than 38.9% without injection. (3) For reservoirs with a viscosity of 150 cp. In the case of the interlayer. The recovery factor after injection is 30.7%, which is significantly higher than 24.8% without injection. (4) After the well spacing of the low-viscosity reservoir is reduced, the recovery factor reaches 46.1%, which is higher than 38.9% of the non-infill scheme. After the infill well in a low-viscosity reservoir is transferred to injection, the recovery factor is 45.6%, which has little change compared with non-injection, and most of the cumulative production fluid is water. The feasibility and effect of water flooding in a strong bottom water reservoir are demonstrated. This study provides the basis for the proposal of production well injection conversion and the adjustment of production parameters in the highest water cut stage of a big bottom water reservoir.


2019 ◽  
Vol 64 (26) ◽  
pp. 2751-2760 ◽  
Author(s):  
Jun Yao ◽  
Lei Zhang ◽  
Hai Sun ◽  
Tao Huang ◽  
Yongfei Yang ◽  
...  

Author(s):  
Kuiqian Ma ◽  
Ao Li ◽  
Shuhao Guo ◽  
Jieqiong Pang ◽  
Yongchao Xue ◽  
...  

The multi-layer co-exploitation method is often used in offshore oilfields because of the large spacing between the injection and production wells. As oilfields gradually enter the high water-cut stage, the contradiction between the horizontal and vertical directions becomes more prominent, and the distribution of the remaining oil is more complex. Oilfields are facing unprecedented challenges in further enhancing oil recovery. Using oilfield A, which is in the high water-cut stage, as the research object, we compiled a detailed description of the remaining oil during the high water-cut stage using the information collected during the comprehensive adjustment and infilling of the oilfield. In addition various techniques for tapping the potential reservoir, stabilizing the oil, and controlling the water were investigated. A set of key techniques for the continuous improvement of the efficiency of water injection after comprehensive adjustment of high water-cut fields was generated. Based on the determined configuration of the offshore deltaic reservoir, a set of detailed descriptive methods and tapping technology for extracting the remaining oil in the offshore high water-cut oilfield after comprehensive adjustment was established. By considering the equilibrium displacement and using a new quantitative characterization method that includes displacement, a new technique for determining the quantity of water that needs to be injected into a stratified injection well during the high water-cut stage was established. Based on the principle of flow field intensity reconfiguration, a linear, variable-intensity, alternating injection and withdrawal technique was proposed. With the application of this series of techniques, the increase in the water content was controlled to within 1%, the natural reduction rate was controlled to within 9%, and the production increased by 1.060 × 107 m3.


2014 ◽  
Vol 900 ◽  
pp. 677-680
Author(s):  
Chun Hong Nie

This paper has discussed the characteristics, roles, feasibility and obvious effects of the technology by applying electric field to enhance oil recovery when the oil field is in high water cut stage and super high water cut stage. In view that most oil wells in old oil field have entered into the super high water cut production, the remaining oil in the main reservoir is in fragmented distribution with poor results of water injection and new reserves of oil mostly have a low penetration rate and are thin layers of poor physical properties, the use of the direct current field in period of high water cut is the best policy to achieve high and stable yield and is fairly promising.


2010 ◽  
Vol 44-47 ◽  
pp. 1476-1481 ◽  
Author(s):  
De Li Jia ◽  
Chang Jiang Zhao ◽  
Shu Jin Zhang ◽  
Ming Xin Zhao ◽  
De Kui Xu

To solve the problem that the conventional layered water injection technology has too long test and adjustment period and strong interference among layers at the ultra-high water cut stage, a novel digital synchronous dynamic test and adjustment technology is proposed and developed in this paper. Many advanced technologies, including digital multi-information test and adjustment, bidirectional transmission of remote wireless signals and non-contact electric energy transformation, are adopted to combine multi-information test and flow control to be a whole thrown into the well. This technology can automatically monitor each water injection layer and adjust water flow in user-defined period without any intervention; it can synchronously and dynamically adjust flow of each layer; and it also can monitor and adjust flow data by the redisplay of computer. The experimental results show that this technology not only reduces the field workload and improves water injection effect, but also provides the basis of data analysis for implementation and adjustment of meticulous oil development plan.


2021 ◽  
Author(s):  
Kuiqian Ma ◽  
Cunliang Chen ◽  
Wei Zhang ◽  
Bin Liu ◽  
Xiaodong Han

Abstract Performance prediction is one of the important contents of oilfield development. It is also an important content affecting investment decision-making, especially for offshore oilfields with large investment. At present, most oilfields in China have entered high water cut stage or even extra high water cut stage, which requires higher prediction accuracy. Water drive curve is an important method for predicting performance. Traditional methods are based on exponential formulas, but these methods have poor adaptability in high water cut period. Because traditional methods deviate from straight line in high water cut period. In this paper, a robust method for predicting performance of offshore oilfield in high water cut period based on big data and artificial intelligence is proposed. Firstly, the reasons for the "upward warping" phenomenon of traditional methods deviating from the straight line are analyzed. It is found that the main reason for the deviation is that the relationship between the relative permeability ratio of oil to water and the water saturation curve no longer conforms to the exponential relationship. So a new percolation characteristic characterization equation with stronger adaptability is proposed, which focuses on the limit of high water flooding development. On this basis, the equation of the new water drive characteristic curve is deduced theoretically, and the dynamic prediction method is established. What's more, the solution of the method is based on large data and AI algorithm. This method has been applied to many high water flooding phase permeability curves, and the coincidence rate is more than 95.6%. The new water drive characteristic curve can better reflect the percolation characteristics of high water cut reservoirs. At the same time, the performance of adjustment wells and measures on the curve of development dynamic image is analyzed. Curve warping indicates that adjustment wells or measures are effective. Field application shows that the prediction error of the new method is less than 6%, which is more in line with the needs of oilfield development. Because of the application of artificial intelligence algorithm, the application is more convenient and saves a lot of time and money. This is a process of self-learning and self-improvement. As the oil field continues over time, each actual data will be recalculated into the database. Then the fitting and correction are carried out, and then the solution is learned again. This method has been applied to several oil fields in Bohai. And the effect is remarkable, which provides a good reference for the development of other oil fields.


2014 ◽  
Vol 703 ◽  
pp. 308-311
Author(s):  
Kao Ping Song ◽  
Cheng Cheng Wang ◽  
Cheng Fu ◽  
Xiao Hui Wu

D aqing o ilfield is in high water cut stage and always appears two phenomenon called "two speeds" and "two low". Based on the geological characteristics of the block, the current exploration wells arrangement and producing dynamics, two sets programs of water injection intensity and water injection timing were designed. Through the numerical simulation prediction of the two sets of 16 programs, the optimization results are 9 injection intensity and 93% of water cut. The cumulative oil producing capacity is 1402.41×104t and the cumulative increasing oil capacity is 6.26×104t and the increasing value of the recovery efficiency in Secondary oil layer is 1.33% when the water cut is 98%.


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