A Displacement Correction Method for Offshore Time-Lapse Seismic Receiving Points

Abstract

The invention relates to a seaborne time shifting earthquake receiving point displacement correction method. The method comprises the following steps of 1) selecting one gun line and calculating an average navigation speed of an acquisition boat when the acquisition boat collects each gun data; 2) selecting one gun point on the gun line and grouping earthquake data acquired through gun point excitation and collected by the acquisition boat according to acquisition cables; 3) selecting one acquisition cable, calculating an offset distance of a gun point to each receiving point on the acquisition cables, taking a minimum offset distance receiving point as an original point and calculating an arc length coordinate of each receiving point on the acquisition cables at a gun point excitation moment; 4) calculating the arc length coordinate of each receiving point on the acquisition cables at a t moment relative to the arc length coordinate original point at the gun point excitation moment; 5) taking the arc length coordinate and the earthquake data on the receiving point at the t moment as an original sample, wherein an earthquake wave field value on a spline interpolation is obtained and an interpolation result is the earthquake data after displacement correction at the t moment; 6) according to a record time interval, gradually changing the t value and repeatedly carrying out the step4 and the step5 till that record time is up so that displacement correction of each receiving point on the selected acquisition cable under the selected gun point is acquired.

Description

technical field [0001] The invention relates to a method for correcting the displacement of a sea time-lapse seismic receiving point, which belongs to the field of oil and gas seismic exploration. Background technique [0002] At present, in order to improve production efficiency, offshore oil and gas seismic exploration generally adopts streamer acquisition. This marine seismic data acquisition method generally consists of an acquisition ship towing two air gun sources and multiple acquisition cables to form an acquisition system (such as figure 1 As shown), the two air gun sources fired alternately at a certain time interval. When the source was excited, the receiving cable began to record the underground reflection signal, and the navigation and positioning system recorded the shooting time and the position information of the corresponding shot point and receiving point. In order to obtain ideal observation system parameters during the acquisition process, the acquisitio...

AI Technical Summary

Problems solved by technology

However, when matching the data collected twice before and after the time-lapse seismic data, the difference between the two data of the non-target layer is generally close to zero, and the difference is mainly concentrated in the oil-producing layer. At this time, the error caused by the displacement of the receiving point is relatively small. Subtle differences caused by reservoir changes become non-negligible

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