Control of dominant seepage flow on high water cut reservoirs with vector well pattern

Author(s):  
Xiaocong Lyu ◽  
Huiqing Liu ◽  
Zhanxi Pang ◽  
Lizeng Xing ◽  
Yongping Jiang ◽  
...  
2021 ◽  
Author(s):  
Hongfu Shi ◽  
Yingxian Liu ◽  
Lifu Jiang ◽  
Jingding Zheng ◽  
Liqin Gan

Abstract Abundant faults, long oil-bearing intervals (up to 500m), and diverse fluids including conventional oil and heavy oil, result in P oilfield became one of the most complex oil fields in the Bohai Bay. The main characters ofinitial development plan are directional well with commingle production, open hole completion, large draw down, high oil production rate, and reverse nine-point well pattern. At present, the oilfield has entered a stage of high water cut, with average water cut more than 85%. What can we do next, decommissioning or rebirthing? An integrated solution was proposed to redevelop the oilfield which focus on the layers’ subdivision, the fine description of the sand body,a large number of horizontal wells on the top of the water-flooded layer are used to tap the potential, increase the water injector to transform the stream lines and rebuild the reservoir pressure, and search for potential sand bodies to increase reserves.


2020 ◽  
Vol 12 (1) ◽  
pp. 1736-1749
Author(s):  
Jincai Wang ◽  
Zifei Fan ◽  
Lun Zhao ◽  
Li Chen ◽  
Jun Ni ◽  
...  

Abstract After a sandstone oilfield enters the high water-cut period, the viscosity of crude oil has an important influence on remaining oil distribution and waterflooding characteristics under the same factors of, e.g., reservoir quality and development methods. Based on a comprehensive interpretation of the waterflooded layers in new oil wells, physical simulation experiments, and reservoir numerical simulations, we analyzed the waterflooding laws of a high water-cut sandstone reservoir with different oil viscosities in Kazakhstan under the same oil production speed, and we clarified the remaining oil potential of reservoirs with different viscosities and proposed corresponding development measures. The results show that low-viscosity oil reservoirs (1 mPa s) have uniform waterflooding, thick streamlines, small waterflooding areas, and low overall waterflooding degrees because of their homogeneous oil–water viscosities. However, within waterflooded areas, the reservoirs have high oil displacement efficiencies and high waterflooding degrees, and the remaining oil is mainly concentrated in the unwaterflooded areas; therefore, the initial production and water cut in new oil wells vary significantly. High-viscosity oil reservoirs (200 mPa s) have severe waterflooding fingering, large waterflooding areas, and high overall waterflooded degrees because of their high oil–water mobility ratios. However, within waterflooded areas, the reservoirs have low oil displacement efficiencies and low waterflooding degrees, and the remaining oil is mainly concentrated in both the waterflooded areas and the unwaterflooded areas; therefore, the differences in the initial production and water cut of new oil wells are small. Moderate-viscosity oil reservoirs (20 mPa s) are characterized by remaining oil distributions that are somewhere in between those of the former two reservoirs. Therefore, in the high water-cut period, as the viscosity of crude oil increases, the efficiency of waterflooding gradually deteriorates and the remaining oil potential increases. In the later development, it is suggested to implement the local well pattern thickening in the remaining oil enrichment area for reservoirs with low viscosity, whereas a gradual overall well pattern thickening strategy is recommended for whole reservoirs with moderate and high viscosity. The findings of this study can aid better understanding of waterflooding law and the remaining oil potential of reservoirs with different viscosities and proposed corresponding development measures. The research results have important guidance and reference significance for the secondary development of high water-cut sandstone oilfields.


2014 ◽  
Vol 1010-1012 ◽  
pp. 1654-1664
Author(s):  
Ji Cheng Zhang ◽  
You Lv ◽  
Qi Li ◽  
Xiao Yue Wang

In recent years, Xingnan development zone have totally gone into high water cut stages and high recovery degree reserves from the partial period, facing with a stern fact that it transitions from a basic injected and produced fluid balance to a serious imbalance. Therefore, it is of important practical significance for predicting the production of remaining oil and improving recovery efficiency that strengthen the research of diminishing prediction of each well pattern. In this paper, by using a series means of graphical method, try and error method, curvilinear dislocation, type curve matching method and binary regression analysis, we comprehensively judged the production decline types of different well patterns, and calculate the production decline rate of each set of well pattern..


2014 ◽  
Vol 522-524 ◽  
pp. 1346-1350
Author(s):  
Jian Huai Wang ◽  
Wei Nan Zhang

Taking M reservoir of D field as an example, analyzing the development feature of a thick sandstone reservoir in the high water cut stage which is driven by natural water, and studying the distribution law of remaining oil for this reservoir through 3 aspects: sweeping of the edge-bottom water, completeness of the well pattern and barrier of the partial interbed, and expounding the development method and effect of this thick sand reservoir in the high water cut stage through exploiting 3 kinds of remaining oil rich regions as fellows: the region which is not swept by the edge-bottom water; incomplete region of the well pattern and barrier region of the partial interbed.


2013 ◽  
Vol 868 ◽  
pp. 585-588
Author(s):  
Yi Kun Liu ◽  
Xue Ming Wang ◽  
Shi Yuan Shao ◽  
Ming Yang ◽  
Yong Ping Wang

East Xing Six District of Daqing oilfield development has 50 years of history, the block has entered high well density, high water cut stage. The apricot East Xing Six District demonstration zone development belongs to the continental sedimentary system, it has reservoir types and physical properties have large differences, It was long-term effected by injected water, after water flooding, water degree condition becomes very complex and unpredictable, so the washing condition analysis is an important guarantee for Daqing oilfield stable production. Using the oil field sealed coring well data, various types of reservoirs washing degree thickness change and growth are analyzed, We can know that with the further water flooding development and well pattern infilling, all kinds of oil reservoir production status; and then analyzes the potential distribution of the oilfields, and provides a basis for the development of the block and the adjustment of the next step of work, has an important guiding significance.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Gaocheng Feng ◽  
Yuhui Zhou ◽  
Weiying Yao ◽  
Lingtong Liu ◽  
Zhao Feng ◽  
...  

Most multilayer sandstone reservoirs in the Bohai Sea have already entered the middle or high water cut production stage with large amounts of remaining oil being scattered distributed. Therefore, there is an urgent need to find a suitable countermeasure to reduce water cut and increase oil recovery. In this study, taking the narrow-channel reservoirs in the M oilfield as an example, we qualitatively described the sand body scale and the contact relationships between different sand bodies, in addition to carefully analyzing the material base and remaining oil distribution characteristics. Accordingly, we proposed a countermeasure based on the injection-production structural adjustment to reduce water cut and increase oil recovery from high water cut, narrow-channel reservoirs. Herein, three optimization strategies were developed based on the proposed development mode: a seepage field optimization strategy was developed based on the quantified injection-production index; a well pattern optimization strategy for narrow-channel reservoirs was developed to overcome the production energy refueling problem; an injection-production measure optimization strategy was developed to tap the different types of remaining oil. Additionally, the well pattern optimization and injection-production optimization strategies were integrated to optimize and adjust the seepage field system. The findings reported herein this paper help understand the development of similar offshore oilfields with a high water cut.


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