西湖凹陷W构造钻井非均质储层识别可行性分析

Identification of the Heterogeneous Reservoirs in Structure W in Xihu Sag

西湖凹陷W构造的主要目的层花港组砂体横向变化快,埋藏深,属于低孔低渗储层。通过对构造区内已钻井的岩石物理分析确定:低纵横波速度比可以指示砂岩储层;低纵横波速度比、高泊松阻尼因子可以指示高含气储层。通过构造区已钻井测井数据的AVO正反演研究可知:纵横波速度比、泊松阻尼因子双参数分析可以有效区分低孔低渗储层和特低孔低渗储层;且子波频率越高,准确度越高。

The sandstone reservoir of Huagang Formation in Structure W in Xihu Sag is characterized by deep burial depth, lateral alteration in lithology, and classified as the low porosity and low permeability reservoir. The analysis of the petrophysieal properties in the wells drilled in this area shows that low P-S wave velocity ratio indicates the existence of sandstone reservoirs, low P-S wave velocity ratio and high Poisson dampening factor may indicate high possibility of gas bearing reservoir. Based on the study of AVO modeling and inversion on logging data, it can be concluded that the comprehensive analysis of P-S wave velocity ratio and Poisson damping factor can be used to effectively distinguish low porosity-low permeability reservoir and ultra-low porosity-low permeabil- ity reservoir. In addition, the higher accuracy can be expected with the increase of the wavelet frequency.