耦合双重分形蚓孔的表皮因子计算模型

发布时间：2018-03-29 11:43

本文选题：碳酸盐岩　切入点：酸化　出处：《石油学报》2017年06期

【摘要】：基质酸化是碳酸盐岩油气藏最经济有效的增产方式之一,表皮因子是此类油藏酸化设计中的关键因素。鉴于酸岩反应影响因素多,酸蚀蚓孔生长随机性强,且呈分支型体积展布,以往的表皮因子计算模型通常只将其简化为一等效半径,计算结果可靠性较低。为此,引入了以不规则几何形态为研究对象的分形几何学方法,验证了室内实验得到的单蚓孔平面分布的分形性,得到了其分形维数及单蚓孔长度扩展模型。结合Golfier模型,对多蚓孔同时扩展模拟结果进行了分析,建立了描述多蚓孔间竞争分布的双重分形数学模型。在此基础上,按照酸蚀蚓孔长度与污染半径间对比关系,将表皮因子计算模型改进为两区模型、三区模型和交叉分布模型3种模式。结合现场实际数据,对计算结果进行了参数敏感性分析。根据表皮因子随用酸量、施工排量的变化趋势可以优选施工参数,渗透率差异系数代表储层污染程度,也是影响表皮因子和增产效果的重要因素和选井选层的重要依据。对比表明,通过常规等效半径模型得到的表皮因子小于双重分形模型下的计算值,这也解释了碳酸盐岩储层在负表皮因子下,经过酸化后仍能增产的原因。
[Abstract]:Matrix acidification is one of the most economical and effective ways to increase production in carbonate reservoir. Epidermal factor is the key factor in acidizing design of this kind of reservoir. The former epidermal factor calculation model only simplifies it to an equivalent radius, and the reliability of the calculation results is low. Therefore, a fractal geometry method with irregular geometry as the object of study is introduced. The fractal properties of the plane distribution of the single wormhole are verified, and the fractal dimension and the length expansion model of the single wormhole are obtained. Combined with the Golfier model, the simulation results of the simultaneous expansion of the wormhole are analyzed. A double fractal mathematical model is established to describe the distribution of competition between the vermis holes. Based on the comparison between the length of the wormhole and the pollution radius, the calculation model of the epidermis factor is improved to a two-zone model. The three models of three-zone model and cross-distribution model are used to analyze the sensitivity of the calculation results. According to the change trend of the construction displacement, the construction parameters can be selected according to the epidermal factor with the amount of acid used. Permeability difference coefficient represents the degree of reservoir pollution, is also an important factor affecting skin factor and stimulation effect and an important basis for selecting wells and layers. The epidermal factor obtained by the conventional equivalent radius model is less than the calculated value under the double fractal model, which also explains the reason why carbonate reservoir can still increase production after acidification under the negative epidermal factor.
【作者单位】：中国石油勘探开发研究院;中国矿业大学地球科学与测绘工程学院;中国石油塔里木油田公司;
【基金】：国家重大科技专项(2011ZX05059,2017ZX05030-005)资助
【分类号】：TE357.2

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