火山岩岩相测井识别机理与方法——以兴城地区火山岩为例

Mechanism and Method of the Volcanic Lithofacies Identification By Taking the Volcanic Rocks of Xingcheng

火山岩岩相控制着储层的储集类型,在徐家围子断陷兴城地区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,岩相识别精度低,导致储层预测准确率不高,严重制约勘探开发的进程。测井资料具有精度高、信息丰富的特点,但还没有成型的火山岩岩相测井识别方法。为此,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27口取心井验证,岩相识别符合率为85.6%,亚相为77.9%,解释精度提高了20%,满足了火山岩精细勘探开发的需求。

The reservoir space types of reservoir are controlled by volcanic lithofacies through deep volcanic exploration and development in Xingcheng area. The identification precision of lithofacies is one of the key factors determining the success or failure of volcanic rock reservoir prediction, the low recognition accuracy of the lithofacies leads to low prediction accuracy of reservoir prediction, which severely restricts the process of exploration and development. The precision is low using cuttings and seismic data to identify volcanic lithofacies, it is difficult to satisfy the demand of precise exploration in Xujiaweizi area now. Although well logging data has the characteristics of rich information and high resolution, there is no method to use well logging data to identify volcanic lithofacies. According to the characteristics of volcanic rock in xujiaweizi area, 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 which are used to identify volcanic lithofacies. Then selecting sensitive logging information, the classifications are determined by using 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 using the method, it has been verified by 26 coring wells, the coincidence rate of lithofacies and sub-lithofacies is 85.6% and 77.9% respectively, and the demand for fine exploration and development is satisfied by using the method to identify lithofacies.