绕射波成像技术在河道砂体储层预测中的应用

Application of diffracted wave imaging technology in channel sand reservoir prediction

河道砂体是东部油田主要油气储集体类型。提高河道、岩性尖灭体等小尺度储集体的预测与识别精度,是东部油田进一步挖掘潜在储量的关键所在。地震勘探中接收到的记录中除了反射波还蕴含小尺度不连续地质体产生的丰富的绕射波信息,通过对绕射波进行分离和成像,能提高地下小尺度不连续地质体的地震识别能力。通过应用平面波域反射波与绕射波波场分离技术,从地震记录中将绕射波分离出来,再通过基于共散射点道集的等效偏移距叠前时间偏移完成绕射波成像。该技术在胜利油田的实际应用,显著提高了河道砂体的识别精度和浅层河道含气检测能力。

Channel sands are main types of oil and gas reservoir in the eastern oil field,and the improvement of identification accuracy of small-scale reservoir such as channel and thinning out plays an important role in the further excavation of the potential oil reserves in the eastern oil field. Records of seismic exploration include not only reflected wave information,but also abundant diffracted wave information generated by small-scale discontinuity geological bodies. By separating and imaging diffraction wave,the identification ability of underground small-scale geologic bodies can be improved.The diffraction wave field separation technique was used in plane wave domain to separate diffraction wave,and then diffracted wave imaging was completed by equivalent offset prestack time migration based on common diffration point gathers.Practical application in Shengli Oilfield showed that this technology can significantly improve the identification accuracy of channel sand and enhance capability of gas detection of shallow channel.