渤东低凸起南段中生界火山岩潜山优质储层形成控制因素及综合预测

Controlling factors and comprehensive prediction for the formation of Mesozoic high quality volcanic buried hill reservoirs in the southern part of Bodong low uplift

为厘清低勘探程度区火山岩潜山优质储层的分布特征,借鉴陆上成熟探区火山岩储层发育模式,综合分析了火山岩储层控制因素,探索了一套“岩相-裂缝-溶蚀孔缝”三因素火山岩储层预测方法。利用该方法对渤东低凸起南段火山岩潜山优质储层进行了预测,结果表明:研究区发育裂隙式和中心式两种火山喷发模式,火山口主要位于研究区西侧,向东逐渐由近火山口相转变为远火山口相,火山岩原生孔、缝主要分布于研究区西侧;构造裂缝的分布则表现出较强的非均质性,靠近大断层位置裂缝密度较大;风化淋滤作用则表现为西强东弱的特点,研究区西侧次生溶蚀孔缝更为发育。“岩相-裂缝-溶蚀孔缝”三因素地质预测结果与地球物理属性预测结果一致,火山岩优质储层主要分布在研究区西侧。这种地质与地球物理综合预测方法为低勘探程度区火山岩优质储层预测提供了参考。

In order to clarify the distribution characteristics of high quality volcanic buried hill reservoirs in areas with low exploration degree,referring to the development pattern of volcanic reservoirs in onshore mature exploration areas,the controlling factors of volcanic reservoirs are comprehensively analyzed,and a three-factor volcanic reservoir prediction method of“lithofacies-fractures-eroded pores and fractures”is proposed.Application of this method in the study area shows that:There are two types of volcanic eruption modes(i.e.,fissure type and central type)in the study area.The craters are mainly located in the west,and gradually transform from near crater facies to far crater facies eastward.The primary pores and fractures of volcanic rocks are mainly distributed in the west of the study area.The distribution of structural fractures shows strong heterogeneity,with dense fractures located near major faults.The weathering and leaching process is strong in the west and weak in the east,resulting in richer developed secondary eroded pores and fractures in the western region.According to the three-factor prediction results of“lithofacies-fractures-eroded pores and fractures”,the high quality volcanic reservoirs are mainly distributed in the west of the study area,which is consistent with the prediction result of geophysical properties.Both of them confirm each other,and provide a reference for the prediction of high-quality volcanic reservoirs in areas with low exploration degree.