井打在溶洞外的缝洞型油藏数值试井模型  

A numerical well test model for wells drilled out of big-size cavity of fractured carbonate reservoirs

作　　者：陈方方[1] 张福祥[1] 邓兴梁[1] 朱永峰[1] 袁玉春[1] 马小平[1] 

机构地区：[1]中国石油天然气股份有限公司塔里木油田分公司勘探开发研究院,库尔勒841000

出　　处：《科技导报》2015年第9期46-49,共4页Science & Technology Review

基　　金：国家重大科技专项(2011ZX05004-004)

摘　　要：缝洞型碳酸盐岩油藏多发育大尺度的溶洞和裂缝,非均质性极强。这类油藏不能使用常规的连续介质理论描述。根据缝洞型碳酸盐岩油藏的特征,结合地震、地质等资料,建立了井未钻遇溶洞的缝洞型碳酸盐岩油藏数值试井物理数学模型。利用有限元方法对模型进行求解并绘制了试井样版曲线,对影响井底压力动态的主要因素进行了分析。研究表明:当井打在洞外时,由于洞内的渗透性远优于洞外地层,压力导数曲线后期出现明显下掉,溶洞的尺寸主要影响压力导数曲线的下掉幅度。模型解释结果与实测数据对比分析表明,该试井模型具有较高的预测精度,能够为碳酸盐岩油藏的试井分析提供理论指导。Conventional continuous multiple medium theories are not suitable for describing the fractured-cavernous carbonate reservoir with big-size fractures and caves. An interpretation model for well test of naturally fractured vuggy reservoir has been developed with consideration of wells drilled outside a big cavity. The model equations are solved with the finite-element method. The analysis of the affecting factors of dynamic pressure at well bottom indicates that the pressure derivative curve of the late stage will go down and form a concave because of the high permeability of the cave. The scale and permeability of the cave mainly affect the amplitude of the pressure derivative reduction. The predicted model has a good agreement with the field test. This can provide a theoretical basis and guidance for well test interpretation of carbonate reservoir.

关 键 词：缝洞型油藏 碳酸盐岩 大尺度溶洞 数值试井 

分 类 号：P618.13[天文地球—矿床学]