A Fuzzy Method to Evaluate Remaining Oil Potentiality of PI Group

2013 ◽  
Vol 734-737 ◽  
pp. 1131-1134
Author(s):  
Jian Zhong Liu ◽  
Jin Cheng Xu

The remaining oil distribution and its potential evaluation are the keys to the well network adjustments and comprehensive potential exploration on the later stage production. In view of the vagueness of the influence factors of remaining oil potentiality, a set of quantitative evaluate method about how to suit remaining oil potentiality of heavy oil reservoir at high water-cut stage is established. Six factors are taken into consideration, including oil saturation, reservoir thickness, permeability, porosity, water injection distance and sedimentary facies. First, make sure the evaluate criterion and the influence weight of a single effect factor. And then, use the fuzzy theory to calculate the latent capacity of the block, comprehending many factors. In the end, certain the foundation of remaining oil potentialities according to the value of the latent capacity. Using this method, remaining oil potentiality of the east of Beierxi is calculated at high water cut period. This provides a theoretical guide to formulation and implementation of the in-situ potential measurement.

2014 ◽  
Vol 628 ◽  
pp. 348-353
Author(s):  
Tao Li ◽  
Zian Li ◽  
Jiang Wang

Sanan oilfield has entered late stage of high water cut development. It urgently needs accurate prediction of remaining oil distribution. But previous studies on 3D structure were far could not meet the requirements of fine reservoir description. This paper applied RMS, a piece of excellent geological modeling software establishing the 3D fine structural model of typical block in Sanan oilfield on the bases of 3D fine seismic structural interpretation data. It included the 28 faults’ model, 11 horizons’ model and the structural model. And then measured and analyzed the faults elements data. Based on abundant geologic data, well data and seismic data of the block, this structural model reproduced the fine seismic interpretation results accurately. It was really fine enough to meet the requirements of the fine reservoir description. This research solved the problem that traditional modeling techniques could not handle complex cutting relationship of faults’ model. It laid a solid foundation for reservoir numerical simulation and remaining oil distribution prediction.


2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Yongfei Yang ◽  
Haiyuan Yang ◽  
Liu Tao ◽  
Jun Yao ◽  
Wendong Wang ◽  
...  

To investigate the characteristics of oil distribution in porous media systems during a high water cut stage, sandstones with different permeability scales of 53.63 × 10−3 μm2 and 108.11 × 10−3 μm2 were imaged under a resolution of 4.12 μm during a water flooding process using X-ray tomography. Based on the cluster-size distribution of oil segmented from the tomography images and through classification using the shape factor and Euler number, the transformation of the oil distribution pattern in different injection stages was studied for samples with different pore structures. In general, the distribution patterns of an oil cluster continuously change during water injection. Large connected oil clusters break off into smaller segments. The sandstone with a higher permeability (108.11 × 10−3 μm2) shows the larger change in distribution pattern, and the remaining oil is trapped in the pores with a radius of approximately 7–12 μm. Meanwhile, some disconnected clusters merge together and lead to a re-connection during the high water cut period. However, the pore structure becomes compact and complex, the residual nonwetting phase becomes static and is difficult to move; and thus, all distribution patterns coexist during the entire displacement process and mainly distribute in pores with a radius of 8–12 μm. For the pore-scale entrapment characteristics of the oil phase during a high water cut period, different enhance oil recovery (EOR) methods should be considered in sandstones correspondent to each permeability scale.


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 522-524 ◽  
pp. 1262-1265
Author(s):  
Qi Xu

Effective comprehensive logging, seismic fine prediction of structure and sand body, analysis of remaining oil controlling factors and distribution, is the precondition for remaining oil development in high water cut oilfield during the middle and later periods of the development. Based on combination of fine well and seismic fine structure and sand body prediction research, this article analyzes main control factors and distribution regularity of remaining oil in the block. Through the analysis, the structure and reservoir heterogeneity affected the distribution of remaining oil in the Fuyu oil layer in the Chao 64 block, the distribution of remaining oil in the plane, interlayer and layer showed different distribution characteristic. The remaining oil mainly distributed in the reverse faulting footwall high structure position, injection production faultiness part, and micro range structural high position, inter well isolated sand body development area.


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.


2014 ◽  
Vol 1073-1076 ◽  
pp. 2201-2204
Author(s):  
Sui Ting Zhao ◽  
Qi Li ◽  
Xiao Ru He ◽  
Kao Ping Song ◽  
Ji Cheng Zhang

In this paper, the indexes have been determined for identifying ineffective injection-production circulation and corresponding mathematical model was constructed with fuzzy theory. Application examples show that this method is simple, fast and accurate. For high and extra-high water cut oilfields, because of the long-term erosion of injected water, there are some high penetrative channels between the injection and production wells, resulting in most injected water along the channel to cause the invalid injection and production, for which it is hard to increase water flooding swept volume, causing flooding and high water cut well and reducing oil production. To improve the effectiveness of water injection to achieve stable yields, it is important to take the measures of ineffective injection-production wells profile control, plugging and so on for fast and accurate identifying ineffective injection-production wells. To that end, this paper applied fuzzy theory to establishing the mathematical model for identifying ineffective injection-production wells.


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