Marine ladder-shaped cable earthquake receiving method

Abstract

The invention provides a marine ladder-shaped cable earthquake receiving method. The method comprises: a whole first cable is divided into a first part cable, a second part cable and a third part cable according to the depth of an offshore exploration target layer, wherein the first part cable, the second part cable and the third part cable are different in lengths; the first part cable, the second part cable and the third part cable are respectively immersed below the sea level in three different depths; and two adjacent cables of the first part cable, the second part cable and the third part cable are respectively connected through a second cable with the length of 300 meters. The immersing depth of the first part cable is larger than or equal to that of an earthquake focus array, the immersing depth of the second part cable is larger than that of the first part cable, and the immersing depth of the third part cable is larger than that of the second part cable. Earthquake receiving is conducted by the method, and original earthquake data which are sufficient in low frequency and wide in frequency band can be obtained under the condition that a simulation manner is fixed.

Description

technical field [0001] The invention relates to a seismic receiving method of a marine stepped cable. Background technique [0002] With the development of the global economy, the global demand for petroleum energy is becoming stronger and stronger, and China's economic development occupies an increasingly important position in the world's economic development. China is not only a country with large oil energy reserves, but also a big oil energy consumption country. With the continuous development of onshore oil fields, inland oil resources are becoming less and less. The development of offshore oil energy is still in its infancy, especially in the disputed areas of the South China Sea that need to be developed urgently. The country has invested a lot of manpower and financial resources in offshore exploration. Oil exploration targets are also becoming more and more complex. Offshore exploration is moving towards deep water, from shallow underground exploration to mid-dee...

AI Technical Summary

Problems solved by technology

When the cable is laid shallowly, the frequency band is relatively wide, but the energy at the low-frequency end is low, and the penetration ability of seismic waves is poor, which is not conducive to the exploration of middle and deep layers

When the cable sinking depth is deep, the frequency band is relatively narrow, but it lacks high-frequency components, which is not conducive to improving resolution in shallow layers

When the excitation method is fixed, it is difficult to obtain raw seismic data with sufficient low frequency and wide frequency band

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