Built-up area exciting and receiving method of earthquake data in low-signal-to-noise-ratio region

Abstract

The invention provides a built-up area exciting and receiving method of earthquake data in a low-signal-to-noise-ratio region, which is used for solving the problem of poor quality of earthquake acquisition data of the low-signal-to-noise-ratio region. The method comprises the following steps of: acquiring a near-surface speed structural model through micro VSP (Vertical Seismic Profile) and micro logging information; determining an earthquake exciting depth and a wall rock speed; and determining exciting and receiving parameters by taking a built-up exciting area, a built-up receiving area and a multi-line receiving mode as core concepts and taking suppressing of external interference as a target. Compared with the conventional technology of the same type, the method has the advantages of high capabilities of suppressing noise and external interference.

Description

technical field [0001] The patent of the invention belongs to the field of seismic exploration of oil and gas, and relates to a combination area excitation and receiving method of seismic data in areas with low signal-to-noise ratio, which is effective for seismic exploration of oil and natural gas in all areas. technical background [0002] At present, the area of ​​oil and gas exploration in my country has begun to shift from searching for structural oil and gas reservoirs to searching for various hidden and complex oil and gas reservoirs, and from simple areas to complex areas. In recent years, in the seismic exploration of various complex surfaces such as deserts, mountains, and loess plateaus, it has been found that the surface structure in these areas is complex, and the excitation and reception conditions vary greatly, making the quality of seismic data in this area unable to meet the requirements for processing and interpretation. , thus restricting the further impro...

AI Technical Summary

Problems solved by technology

③ The thickness of loess changes drastically, and the topography fluctuates abruptly, which makes the surface investigation extremely difficult, and the error of small refraction data is relatively large

④Complicated and changeable surface structure, weak reflection energy and low signal-to-noise ratio in the middle and deep layers in the original records

⑤Complicated terrain, vertical and horizontal gullies, severe topography fluctuations and serious differences in loess thickness, resulting in difficulties in obtaining surface static correction data

The content of these studies and the shortcomings of the receiving technology are as follows: ① Large-area combination of geophones is used to improve the signal-to-noise ratio of the data, but the large-combination receiving technology cannot suppress lateral interference and is limited by the combined height difference

② In order to overcome the special terrain and interference in the loess area, a special asymmetric shooting and unequal channel receiving 3D observation system is adopted, but this system has shortcomings such as too many observation system parameters that need to be demonstrated, low work efficiency, and not suitable for promotion.

However, the embedment of the geophone is affected by the surface conditions and is not easy to change

It can be seen from the above that these methods only start from improving one factor in the seismic acquisition of the loess plateau, or the exploration area is single, and it is difficult to extend to other areas. Geophone combination method, this combination method is mainly to suppress the original regular interference and random interference propagating along the survey line direction, but for the vertical survey line direction, the strong secondary interference cannot effectively suppress, and this kind of Secondary interference is also difficult to deal with indoors

Images