| 用双椭圆方法确定反射点位置 |
| |
| 引用本文： | 李启成,苑树鹏,郑新娟,席桂梅,贺翔,吴奎,徐伊豪.用双椭圆方法确定反射点位置[J].地质论评,2021,67(2):67030011-67030011. |
| |
| 作者姓名： | 李启成 苑树鹏 郑新娟 席桂梅 贺翔 吴奎 徐伊豪 |
| |
| 作者单位： | 辽宁工程技术大学矿业学院，辽宁阜新，123000;朝阳工程技术学校，辽宁朝阳，122000;朝阳师范专科学校，辽宁朝阳，122000 |
| |
| 基金项目： | 本文为国家自然科学基金资助项目“汶川地震前后的应力场时空演化”（编号： 41674055）的成果 |
| |
| 摘 要： | 在反射波地震勘探中使用动校正确定反射点位置用到很多假设，如勘探深度要远远大于炮检距；假定倾斜反射界面的反射点与水平反射界面反射点都位于炮检距的中点；近似认为倾斜反射界面的动校正量等于水平反射界面的动校正量；假定反射面倾角固定且较小等，上述假设一定会造成勘探误差。由于反射点位置和反射面倾角未知，所以理论上无法唯一地确定反射点位置。如果反射波传播的介质的波速一定，从炮点发出的地震波，经反射点后，在接收点被接收，其可能的反射点是椭圆的一部分，但还不能唯一确定反射点；再取炮点和另外一个接收点，其可能的反射点是另外一个椭圆的一部分。如果假定反射面是平面，可以是水平面，也可以是有固定倾角的倾斜平面，该平面在地震波射线平面内是一条直线，该直线一定是两椭圆的公切线。把两椭圆方程和切线方程联立，就可以求解出公切点位置，公切点位置就是反射点位置，这就是用双椭圆确定反射点位置的方法。通过建立模型对勘探方法进行了检验，证实了用双椭圆方法确定反射点位置的有效性。双椭圆方法有一个重要的副产品，就是在确定反射面位置的同时计算出反射面的视倾角。
|
| 关 键 词： | 反射点 动校正 地震勘探 双椭圆法 |
| 收稿时间： | 2020/9/25 0:00:00 |
| 修稿时间： | 2021/3/17 0:00:00 |
Determining the positions of reflection point by double elliptic method |
| |
| LI Qicheng,YUAN Shupeng,ZHENG Xinjuan,XI Guimei,HE Xiang,WU Kui,XU Yihao.Determining the positions of reflection point by double elliptic method[J].Geological Review,2021,67(2):67030011-67030011. |
| |
| Authors: | LI Qicheng YUAN Shupeng ZHENG Xinjuan XI Guimei HE Xiang WU Kui XU Yihao |
| |
| Institution: | Mining College Liaoning Technical University,Fuxin,Liaoning,123000;Chaoyang Technical School,Chaoyang,Liaoning,122000;Chaoyang Normal School,Chaoyang,Liaoning,122000 |
| |
| Abstract: | The normal moveout correction is widely used in reflection seismic exploration,and there are many assumptions in the normal moveout correction to determine the reflection point.For example,the exploration depth must be much larger than the offset;the reflection points both the inclined reflector and the horizontal reflector are located at the midpoint of offset;amounts of the normal moveout correction at the inclined reflector are considered to be equal to that at the horizontal reflector;the inclination angle of the reflector is assumed small,etc.The above assumptions will definitely cause exploration errors,so a double elliptic method will be proposed to more accurately determine the reflection point Methods:Since the inclination angle of the reflector is unknown,it is theoretically impossible to uniquely determine the position of the reflection point.The seismic wave emitted from the shot point will be received at the receiver point after passing through the reflection point.If the seismic wave speed in the medium is constant,the possible reflection point is part of the ellipse,but the reflection point cannot be uniquely determined.if the shot point and another receiver point are chosen,the possible reflection point is part of another ellipse.If the reflector is assumed to be a plane,it can be a horizontal plane or an inclined plane with a fixed inclination.The plane is shown a straight line in the plane of the seismic wave ray,and the straight line must be the common tangent of the two ellipses.Combining the two elliptic equations with the tangent equation can determine the positions of tangent points,the positions of the tangent points are the positions of reflection points.This is the method to determine the positions of reflection point by double ellipse.Results: We establish a theoretical model and explore the model with the double elliptic method,and the exploration results agree well with the theoretical model.Conclusions: The double elliptic method was tested by a theoretical model,which proved the validity that double elliptic method determines the positions of the reflection point.An important by-product of the double elliptic method is while the positions of the reflector.are calculated, the apparent inclination angle of the reflector is determined. |
| |
| Keywords: | reflection point normal moveout correction seismic exploration double elliptic method |
|
| 点击此处可从《地质论评》浏览原始摘要信息 |
| 点击此处可从《地质论评》下载免费的PDF全文 |
|
