徐家围子地区火山岩岩相识别机理与方法

Mechanism and Method of the Volcanic Lithofacies Identification in Xujiaweizi Area

徐家围子断陷深层火山岩勘探开发中,岩相的识别精度是决定火山岩储层预测成败的关键因素之一。测井资料具有精度高、信息丰富的特点,但没有成型的火山岩岩相测井识别方法。利用大量钻井取心、薄片分析、常规及电成像测井资料,以地质理论为指导,通过自然伽马、密度及电成像测井识别岩相的机理研究,选取敏感测井信息,确定火山岩岩相测井分类标志,建立了火山岩岩相测井识别方法。结果表明,应用该方法能识别出5大相、11亚相,经24口取心井验证,岩相识别符合率为84.6%,亚相为77.2%,解释精度提高了20%,满足火山岩精细勘探开发的需求。

In the exploration and development of deep volcanic rocks in Xujiaweizi fault depression,the recognition accuracy of lithofacies is one of the key factors that determine the success or failure of volcanic reservoir prediction.Although well logging data has rich information and high resolution,there is no method to identify volcanic lithofacies with well logging data.According to the characteristics of volcanic rock in Xujiaweizi area and based on geological theory,a lot of cores,wafer analysis,conventional and image logging data are used to study the mechanism of natural gamma,density,neutron and image logging and volcanic lithofacies identification.Then with sensitive logging information,the classifications are determined by logging data to identify volcanic lithofacies.Well logging identification method of volcanic lithofacies is established.5 lithofacies and 11 sub-lithofacies can be identified by this method,it has been verified by 24 coring wells,the coincidence rate of lithofacies and sub-lithofacies is84.6% and 77.2%respectively,and the method is good to identify lithofacies.