【摘要】：以鄂爾多斯盆地志丹油田煙霧峁區(qū)塊延長組長4+5,長6儲層為例,基于巖心滲流實驗的歸一化處理、考慮啟動壓力梯度、引入有效驅動系數(shù)及油水粘度比,將滲流理論與室內實驗及生產實踐密切結合,綜合分析特低~超低滲透儲層油水滲流效應,探討其注水開發(fā)啟示。結果表明,特低~超低滲透儲層滲流特征受啟動壓力影響,啟動壓力將導致油井提前見水;當含水飽和度大于某一臨界值后,油層含水變化率逐漸減小,無因次采液指數(shù)與采油指數(shù)之間的分化逐漸加劇,其相對穩(wěn)定的變化區(qū)間則是油層提液增產及調整挖潛的重要機遇期。依據(jù)無因次采液、采油指數(shù)變化規(guī)律及其相應的含水率變化區(qū)間,可將特低~超低滲透油層開采過程劃分為初產、穩(wěn)產、有效提液、低效循環(huán)等4個階段;在中高含水期,較高的有效驅動系數(shù)有利于油層提液增產;在特高含水后期,較小的有效驅動系數(shù)及油水粘度比則有利于油層提高低效循環(huán)階段的最終采收率。流體飽和度不僅對特低~超低滲透油層含水率及采液采油指數(shù)等變化具有重要的控制和影響,而且也是導致區(qū)塊生產差異的主要因素。對于那些飽和度分布不同、平面及層間生產差異比較突出的井區(qū),應依據(jù)其所處開采階段分別采取不同的對策參數(shù),以改善油田整體開發(fā)效果。
[Abstract]:Taking Yanchang formation 45 and Chang 6 reservoirs in Yanchang Block, Zhidan Oilfield, Ordos Basin as an example, based on normalized treatment of core percolation experiment, starting pressure gradient is considered, effective driving coefficient and oil-water viscosity ratio are introduced. By combining seepage theory with laboratory experiment and production practice, the oil and water seepage effect of ultra-low permeability reservoir is comprehensively analyzed, and the enlightenment of water injection development is discussed. The results show that the percolation characteristics of ultra-low to ultra-low permeability reservoirs are affected by start-up pressure, and the starting pressure will lead to early water breakthrough in oil wells, and when the saturation of water is greater than a certain critical value, the rate of change of water cut in reservoir decreases gradually. The differentiation between dimensionless fluid recovery index and oil recovery index is gradually aggravated, and its relatively stable range is an important opportunity period for increasing oil production and adjusting potential. According to the variation law of dimensionless fluid recovery, oil recovery index and its corresponding water cut change interval, the production process of ultra-low to ultra-low permeability reservoir can be divided into four stages: initial production, stable production, effective extraction, low efficiency circulation, and in the middle and high water cut period, the oil recovery process can be divided into four stages: initial production, stable production, effective extraction and low efficiency circulation. The higher effective driving coefficient is conducive to increasing oil production, and the smaller effective driving coefficient and oil-water viscosity ratio are beneficial to increase the final oil recovery in the low efficiency cycle stage in the late stage of extra high water cut. Fluid saturation not only has an important control and influence on the changes of water cut and oil recovery index of ultra-low to ultra-low permeability reservoirs, but also is the main factor leading to the difference of block production. For those wells whose saturation distribution is different and the production difference between plane and layer is obvious, different countermeasures should be taken according to the stage of production in order to improve the overall development effect of oil field.
【作者單位】： 西安石油大學地球科學與工程學院;
【基金】：陜西省自然科學基金(2013JM5006) 西安石油大學青年科技創(chuàng)新項目(2012BS010)
【分類號】：TE312

【參考文獻】

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