水下井口探测技术研究

在海上油田开发过程中,往往存在一些当时不具备开发条件的水下井口。这些井口一方面现阶段具有重新开发价值,另一方面也是海洋工程建设的障碍物。而水下井口尺度小,常用的调查手段较难探测到。文中介绍了浅地层剖面仪和磁力仪的原理,并开展了浅地层剖面仪和磁力仪综合探测水下井口的应用与分析。结果表明浅地层剖面仪和磁力仪均可探测到井口,在浅地层剖面图像上表现为垂向的声学空白带,为桩坑和井口的反射;磁异常平面等值线为等轴状,存在极大值和极小值,井口位于极大值和极小值之间。浅地层剖面仪和磁力仪探测的井口位置相差1m,与给定井口坐标偏差2m,满足工程需求。因此使用浅地层剖面仪和磁力仪综合探测水下井口在现阶段不失为一种可行的方法。

Research on Detection Technology of Subsea Well Mouth

There are usually some subsea wells which have no further developing conditions in the offshore oilfield development. These wells have, on the one hand, the value to be developed again at the present state, but on the other hand they become obstacles for marine engineering constructions. However, it is difficult to detect them by using common survey procedures because of their small mouth. For the purpose of detecting these wells, the principles of sub-bottom profiler and magnetometer and the comprehensive application of these two instruments in the detection of subsea well mouths are introduced. It is see that both sub-bottom profiler and magnetometer can be used for the detection of subsea well mouths. The vertical acoustic blanks occurring in the profiles of sub-bottom profiler indicate the presence of pile holes or subsea well mouths. The presence of an equated shape on the plane contour map of magnetic anomalies, together with the presence of magnetic anomaly maximum and minimum, may possibly indicate that the position of well mouth should be located between the maximum and the minimum of the magnetic anomalies. The deviation of the well mouth position detected by sub-bottom profiler and magnetometer is 1 m. Comparing the given coordinates of the well mouth, the deviation is 2 m, satisfying the requirements of engineering. It is, therefore, concluded that using sub-bottom profiler and magnetometer for synthetically detecting the subsea well mouths should be a reasonable method at the present stage.