Langgu Hollowly SouthZhongchakou Area Secondary 3D Seismic Exploration Acquisition Method Research

It was very early when the 3D seismic data acquisition in the major structural zone of LangGu hollow was conducted. At that time, the exploration equipments and technologies were limited, the seismic data quality was very poor, so the exploration progress was seriously restricted. Based on the exploration requirement of"integral research, integral layout, integral evaluation", to carry through 3D seismic data integation of LangGu hollow, ensure the precision of seismic data and find out the detail of exploration targets, we have to carry out secondary 3D seismic acquisition based on careful geologic argumentation.In this paper, we analyse carefully the general situation of the hollow, including seismic and geological conditions of the surface and deeper strata, disturbing waves, absorption and attenuation in the surface and so on. Then carefully collect, analyse, research and evaluate the correlative data of the study area and surrounding areas. Conclude the disadvantages of the first acuqistion include: big binning, insufficient coverage folds, unappropriate shooting and receiving parameters, low-performance equipments and so on. Do qualitative and quantitative analysis to the previous single shot records, we find that the S/N is very low, deep energy is very weak and there are too many regular and random disturbances. In addition, we analyse the previous acquisition results of the surrounding areas. In conclusion, to deal with the technical difficulties, including complicated seismic geologic conditions, low frequency of raw data, abundant obstructions, abundant disturbances and complicated surfaces, we should analyse the previous acquisition methods and data quality carefully, improve the S/N and resolution of the data by minishing binning, increasing coverage folds, doing shooting factor stimulation, surveying the surface structures and so on. To deal with the field construction difficulties, including poor receiving conditions and serious disturbance, we should choose the appropriate receiving parameters and insure the field security by taking experiences into consideration.After that, we study the seismic acquisition technologies. First, build geophysical model, choose the appropriate surveying direction, binning size, maximum offset, and receiving line-spacing, maximum off-line spacing and so on. Then determine the shooting parameters, receiving parameters and static correction methods based on design requirements and experiences.To demonstrate the rationality of the acquisition parameters, do optimization and improve the data quality, we conduct point and 2D-line experiments. Combined with present 3D exploration technologies and previous experiences, we determine parameters of fundamental geometry, shooting, receiving and equipments. Finally, we analyse the acquisition result, conclude that the record all over the area is of great balance, sufficient energy, high S/N and resolution. This is a good beginning for finding out the buried hills and theirs structures, also for discovering deep and small buried hill traps.