密井网区井震结合储层描述方法

RESERVOIR DESCRIBING TECHNIQUE BY THE WELL-SEISMIC COMBINATION FOR THE DENSE WELL PATTERNS

为进一步提高密井网区砂体刻画精度,采用井震结合地震趋势引导、曲线定相、厚度参考和模式预测4个关键步骤,从砂体展布趋势与沉积期次、微相边界位置、井间连通状况和砂体展布规模4个方面对研究区不同类型砂体进行精细刻画,并从储层空间结构演变与地震反射效果的对应关系角度评价技术的适用性。结果表明:宏观砂体分布的变化集中出现在废弃河道、河间砂体、河道边界、窄小河道走向、不同期次河道叠加演化5种情况;存在5类储层结构形成有效地震反射,分别是最大水退期、上部层位快速水退、水进阶段较大水退期、水进阶段稳定期和水退阶段较大水进期,而水进水退的过渡位置受临层厚砂体影响地震反射效果不好,该对应关系的提出,有利于推动技术有形化,加深地质认识程度。

In order to further enhance the sandbody characterized precision in the dense well pattern area,with the help of the seismic well combination,through the following four key steps: seismic trend guideline,curve phase determination,thickness reference and model prediction,and moreover from the following four aspects: sandbody distribution trend and depositional period-times,microfacies boundary position and well connectivity state,the fine characterizations were conducted for different types of the sandbody,and furthermore the technical adaptability was evaluated from the viewpoints of the corresponding relationships between the reservoir special structure evolution and seismic reflection effects. The achievements showed that the changes of the macro-sandbody distribution are focused in the following aspects: the abandoned channels,inter-channel / branch sandbodies,river boundaries,narrow channel directions and evolutions of different-period / time river superposition; the effective seismic reflections resulted from the existed five reservoir structures: the largest period of the water retreat,the rapid water retreat in theupper layer,the much bigger water retreat in the stage of the water transgression / advance,the stable stage of the water advance and the much larger encroachment of the water retreat; while influenced by the nearby thick sandbodies in the transitional position of the water advance and retreat,the effects of the seismic reflection are not so good. The presented corresponding relationships are conducive to the progress of the technical realization / materialization and further understand of the geological knowledges.