基于交会图决策树的缝洞体类型常规测井识别方法——以塔河油田奥陶系为例

发布时间：2018-05-14 04:14

本文选题：交会图 + 决策树　；参考：《石油与天然气地质》2017年04期

【摘要】：塔河油田奥陶系具有丰富的油气资源,受岩溶作用影响发育洞穴、孔洞和裂缝等多种储集空间,洞穴中充填不同物质。多种储集空间和充填物组合形成多种缝洞体类型,导致常规测井响应特征复杂,识别类型难度大。依据露头、岩心和井壁成像测井等信息,确定了6种缝洞体类型,分别为未充填洞穴型、砂泥充填洞穴型、角砾充填洞穴型、方解石充填洞穴型、缝洞型和裂缝型。结合不同类型缝洞体之间岩性和物性差异,对比分析不同类型缝洞体的双侧向、自然伽马、声波、中子、密度测井响应特征及分布规律。将测井响应两两组合建立交会图,优选出9个识别缝洞体类型敏感的测井响应交会图版,结合决策树方法,形成逐级识别缝洞体类型方法。应用该方法对塔河油田实际井资料进行处理解释,识别结果与岩心和录井对比,符合率均大于85%。该识别方法减少不同类型缝洞体常规测井响应之间相互混淆的影响,有助于发挥每个常规测井响应的作用,提高识别符合率。
[Abstract]:The Ordovician in Tahe Oilfield is rich in oil and gas resources, which is influenced by karstification to develop caves, caverns and fractures, and different materials are filled in the caves. Many types of fractures and cavities are formed by the combination of various reservoir spaces and fillers, which leads to the complexity of the response characteristics of conventional logging and the difficulty of identifying the types. According to the information of outcrop, core and wellbore imaging logging, six types of fracture and cavity body are determined, which are unfilled cave type, sand mud filling cave type, breccia filling cave type, calcite filling cave type, fracture cavity type and so on. Combined with the difference of lithology and physical properties among different types of fracture and cavity bodies, the response characteristics and distribution of dual lateral, natural gamma, acoustic, neutron and density logging of different types of fracture and cavity bodies are analyzed. In this paper, the cross graph of logging response is established, and nine log response cross charts which are sensitive to the type of fracture and cavity body are selected, and the method of identifying fracture and cavity body type step by step is formed by combining the decision tree method. The method is used to process and interpret the actual well data in Tahe Oilfield. The identification results are compared with the core and mud logging, and the coincidence rate is higher than 85%. This method reduces the influence of confusion between the conventional logging responses of different types of fracture-cavity bodies, and helps to play the role of each conventional logging response and improve the recognition coincidence rate.
【作者单位】：中国石化石油勘探开发研究院;
【基金】：国家科技重大专项(2016ZX05014-002-001,2017ZX05005-005-005) 中科院先导专项(XDA14010204)
【分类号】：P618.13;P631.81

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