方位各向异性裂缝检测技术在牛东潜山的应用

Application of Azimuth Anisotropic Fracture Detection Technology in Niudong Buried Hill Zone

王攀 张梦琳 王鑫 赵智鹏 刘杏

WANG Pan ZHANG Menglin WANG Xin ZHAO Zhipeng LIU Xing

中国石油华北油田公司勘探开发研究院, 河北 任丘 062552

Research Institute of Exploration and Development, Huabei Oilfield Company, PetroChina, Renqiu, Hebei 062552, China

牛东潜山带碳酸盐岩储层具有非均质性强、横向变化快的特征，该区碳酸盐岩地层以缝洞储层为主。受裂缝的影响，振幅、频率、速度等地震属性的衰减现象明显，常规地震属性分析方法对裂缝的预测精度较低。准确识别裂缝储层是该区油气勘探的关键，为此在该区开展方位各向异性裂缝预测工作。成像测井结果表明，该区主要发育高陡裂缝，符合HTI介质的特征。基于Ruger的HTI介质纵波反射系数公式进行正演模拟，确定偏移距范围并划分4个方位角范围，得到方位角道集数据体。利用该数据体提取纵波的方位地震属性，求取裂缝方位和裂缝密度，并结合裂缝密度圈定了裂缝发育带，确定研究区裂缝的主方位为北东向。利用实际钻井的成像测井资料对预测结果进行验证，得到较好的匹配，证实AVAz技术对碳酸盐岩储层高陡裂缝的储层预测具有较好的实际应用价值。

The carbonate reservoir in the Niudong buried hill are mainly fracture-cave reservoirs, with strong heterogeneity and rapid lateral change. The prediction accuracy of cracks by conventional seismic attribute analysis methods is low due to the obvious attenuation of amplitude, frequency and velocity affected by the cracks. As a result, fracture prediction of azimuthal anisotropy is carried out in this area as the accurate identification of fracture reservoirs is the key to the hydrocarbon exploration. The results of imaging logging show that steep fractures are mainly developed in the study area, which has the characteristics of HTI medium. The azimuth angle dataset is obtained by determining the offset range and dividing the four azimuth ranges, which based on the forward modeling carrying out on the longitudinal wave reflection coefficient formula. The main direction of the fracture in the study area is determined to be NE by outlining the fracture development zone combined with the orientation and density of the features, which are calculated by azimuth seismic attributes of longitudinal wave extracted by the data volume. It is proved that AVAz technology has a good practical application value for reservoir prediction of high and steep fractures in carbonate reservoir by the use of imaging logging data in actual drilling, which verified the prediction results, and obtained a good match.

10.11885/j.issn.1674-5086.2019.03.18.01