文昌B凹陷古近系低渗储层物性影响因素定量评价与应用

Quantitative Evaluation and Application of Factors Affecting the Properties of Low Permeability Reservoirs from the Paleogene in Wenchang B Sag

珠江口盆地文昌B凹陷的油气勘探已经进入古近系中深层领域,低渗储层是制约该领域油气勘探的关键。该区低渗储层物性影响因素的研究处于定性阶段,主控因素不明确是导致"甜点"储层难以预测的关键。针对这种现状和难点,在系统分析沉积、成岩和构造作用对储层物性影响的基础上,利用岩心实验分析和钻井统计数据,运用多元回归方法对储层物性影响因素进行了定量评价,确定了储层物性主控因素及权重,从而综合预测出有利储层的分布区。结果表明:珠海组储层物性主控因素为胶结和压实作用,恩平组储层物性主控因素为沉积作用,文昌组储层物性主控因素为沉积和压实作用。根据上述研究结果,在地质模式的指导下精准预测了重点层段恩平组的优质储层展布,并指出D9-9构造和D9-10构造发育"甜点"储层,具有较大的勘探潜力。该项研究成果对文昌B凹陷乃至整个珠江口盆地西部低渗储层领域的油气勘探具有重要指导意义。

The exploration of oil and gas has entered the middle and deep area of Paleogene in Wenchang B Sag, Pearl River Mouth Basin. The key to restrict exploration in this area is low permeability reservoir. The factors affecting the physical properties of low permeability reservoirs are qualitative stage in this area. Yet, it is difficulty to predicting the "sweet point" reservoirs for the main control factors uncertainty. Based on a comprehensive analysis of the effects of sedimentation, diagenesis and tectonism on reservoir properties and the data of core experiment analysis and drilling statistics, this paper uses multivariate regression to quantitatively evaluate the influencing factors of reservoir properties to understand the main controlling factors and weights of reservoir properties, so as to predict the distribution area of high quality reservoirs. The results show that the main controlling factors of reservoir property in Zhuhai Formation are cementation and compaction, and other factors are sedimentation in Enping Formation, and sedimentation and compaction in Wenchang Formation. The above results facilitate the prediction of high quality reservoirs in the Enping Formation, the "sweet point" reservoirs developed in the D9-9 and D9-10 structure, which have great potential for exploration. This research has important guiding significance for exploration in the middle and deep layers of the Wenchang B Sag and even in the western part of the Pearl River Mouth Basin.