【作者】 孙志伦；

【导师】 印兴耀；

【作者基本信息】 中国石油大学 ， 地球探测与信息技术， 2008， 硕士

【摘要】 由于廊固凹陷主体构造带的三维地震资料采集时间较早,限于当时勘探装备及技术水平,地震资料的品质较差,严重制约了该凹陷精细勘探的进程。根据对廊固凹陷进行“整体研究、整体部署、整体评价”的勘探部署要求,为实现后续的廊固凹陷三维地震数据的整体连片,保证地震资料的精度,确保精细落实该凹陷的勘探目标,要通过精细的地质论证确定在中岔口南地区实施二次三维地震采集。本文认真分析了廊固凹陷研究区域的概况,包括区域地表概况,地表地震地质条件、干扰波及表层吸收衰减、深层地震地质条件等。收集了研究区域内及周边的相关资料并对其进行了详细的分析、研究和评价,认为以往一次采集方法的缺陷主要是面元较大、覆盖次数较低、激发和接收参数不合适、仪器性能较低等。通过对研究区内以往的单炮记录进行定性和定量分析认为,原始单炮记录的信噪比较低,规则干扰和随机干扰相对严重,深层反射能量弱。此外,还对邻区近几年的采集效果进行了分析。综合起来,认为针对研究区地震地质条件复杂、原始资料频率低、障碍物及干扰多、表层条件复杂等施工难点,我们应该认真分析以往的采集方法及资料品质,采取减小采集面元,提高覆盖次数,进行激发因素试验,了解表层结构等措施提高资料的信噪比和分辨率;针对接收条件差,干扰严重等施工难点,我们应借鉴以往的施工经验,选择合理的接收参数,并保障施工安全。接下来,本文进行了地震采集方法的研究。通过建立地球物理模型,选择合理的观测方向、面元大小、覆盖次数、最大炮检距、接收线距、最大非纵距等采集参数,根据设计要求及地震地质条件确定了激发和接收参数以及静校正的方法。为了论证采集参数的合理性,对其进行优化,提高资料的品质,对设计的观测系统进行了点试验和二维线试验。再结合本次三维勘探的技术要求及以往的地震资料特点,确定了基本观测系统参数、激发参数、接收参数以及仪器参数。最后对采集效果进行了分析,认为全工区资料品质相对平稳,能量足,具有较高的信噪比和分辨率,为落实本区的潜山及潜山内幕各类圈闭,以及发现和落实周边深、小潜山圈闭奠定了非常好的资料基础。更多还原

【Abstract】 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.更多还原