致密油储层甜点地震预测

致密油储层物性差,非均质性强,甜点储层与围岩波阻抗差异较小,常规储层反演方法预测难度较大。笔者从致密油储层成因的角度出发,以柴西红柳泉地区为例,针对薄层致密泥灰岩储层,形成了一套有效的甜点储层地震预测系列技术。通过岩石物理分析,建立致密储层岩性识别图版;在此基础上,结合实钻井的正演模拟分析,明确致密储层甜点在目的层段呈现中振幅、中频率的地震响应特征;进而采用分频成像、90°相位旋转、分频属性优化等技术,对该区致密油甜点储层分布进行了有效预测,认为红34井区为主要的致密油产油区,红22井区西北部及红38井区南部可以作为下步勘探的有利目标区。预测结果与实钻井吻合度高,证实了该方法的可行性。

Seismic Prediction for Sweet Spot Reservoir of Tight Oil

As tight oil reservoir has the characters of poor physical property,strong heterogeneity, smaller difference of wave-impedance between and surrounding rock, the conventional reservoir inversion method is difficult to predict.From the perspective of reservoir genesis,the authors take the Hongliuquan area of Qaidam basin as an example,aims at thin layers of tight marlite reservoir,explores a set of effective technology series to predict sweet spot distribution.Through rock physics analysis,we establish a lithology identification chart,on this basis,combine forward simulation of drilling wells, clear that the sweet spot reservoir has the respose characters of medium amplitude and frequency values in objective intervals, and use frequency division imaging, 90°phase rotation, spectral attribute-optimization technology,predict the sweet spot distribution of tight oil effectively,confirm that the Hong 34 well block is the main of the tight oil producting zone,and the northwest Hong 22,the southern Hong38 well block can be used as the favorable targets for further exploration.The prediction result has a high agreement with the real drillings,confirms the feasibility of this method.