【作者】 程明华；

【导师】 杜启振； 王贵重；

【作者基本信息】 中国石油大学 ， 地质工程， 2009， 硕士

【摘要】 库车坳陷克拉苏构造带是塔里木盆地天然气勘探的重点区带,由于地表地下地质结构复杂,合理构造建模和准确的速度建场难,是制约该区圈闭落实和油气发现的主要因素。围绕该区的构造建模和速度建场等两个关键技术问题,本文在技术路线和实际应用上采取了针对性措施,具体开展以下研究:克拉苏构造带为山前冲断带,逆掩推覆剧烈,地震资料性噪比低,总体资料品质较差,很难客观真实的刻画地下地质构造特征。地震地质综合标定是构造建模的基础,在此基础上,本文应用地质剖面和遥感影像技术,精细标定表层构造,为地下地质构造的合理建模提供参考依据。克拉苏构造带发育的构造与盐岩发育密切相关,通过研究精细解释盐岩发育状况,结合断层相关褶皱理论,分区段建立了克拉苏构造带五个区段的构造解释模型。在构造建模过程中,运用了地震非地震联合解释、模型正演、数值模拟、处理解释一体化和平衡剖面等技术手段,确保构造建模的合理可靠。速度建场的主要目标是进行准确的变速成图。层速度充填法速度建场是山前冲断带的一套建场方法,核心是准确求取层速度。在进一步完善建场方法的同时,本文主要对如何准确求取层速度进行深入分析研究,对钻井速度进行统计分析,并结合地震速度,采用模型迭代、正演分析、循环进行分析得到层速度在不同构造部位的变化梯度。在构造建模基础上,分块建立速度场,进行变速成图。通过研究,建立了克拉苏构造带各区段的构造模式,深化了对克拉苏构造带的地质认识。在速度研究基础上,发现并落实了一批圈闭,综合评价后,提出了有利目标和井位建议。目前通过钻探,已经发现了大北3、克深2两个千亿方大气田,大北气田的评价勘探也取得良好效果。通过在克拉苏构造带的应用,山前复杂区构造建模和速度建场技术得到了发展和完善。更多还原

【Abstract】 Kelasu tectonic belt in Kuqa Depression is a major zone of natural gas exploration in Tarim basin. Due to its complicated subsurface geological structure, it is very difficult to build reasonable structure model and correct velocity field. Moreover, the above two factors restrict the discovery of the traps and reservoirs further. Aiming to the reasonable structure model building and correct velocity field construction, this paper adopt corresponding methods in the application and the implement means in Kelasu tectonic belt .Kelasu tectonic belt is a foothill thrust belt, which has strong overthrust nappe. For its low signal to noise ratio and general data of low quality, it is difficult to describe the complicated subsurface geological structure. Seismic-geologic comprehensive calibration is the basement of building a structure model, as a good reference for seismic-geologic comprehensive calibration of the subsurface geological structure, surficial structure of Kelasu tectonic belt have been finely calibrated by the using of geological profiles and remote sensing images. The structure of Kelasu tectonic belt and salt rock are closely related, through fine description of the salt rock’s development, together with the analysis of fault-related fold theoretic, a five sectional structure model of Kelasu tectonic belt has been built. In order to make sure the structure model is reasonable and reliable, a series of technical means have been used during the procedure of structure modeling, such as joint interpretation of seismic and non-seismic, forward modeling, numerical simulation, integration of processing and interpretation, balanced section technique, and so on.Correct variable velocity mapping is the main target of building a velocity field construction. Interval velocity filling method velocity-field-built is very useful for foothill thrust belt, whose core is to acquire interval velocity correctly. Aiming to the correct change gradient of interval velocity in different parts of the structure, drilling velocity and seismic velocity have been analyzed by iteration model, forward analysis and cycle analysis. On the basement of the structure model, together with the correct interval velocity, a proper velocity field has been constructed, and the variable velocity mapping has been completed reasonably and correctly further.Through the study of this subject, Kelasu tectonic belt’s sectional structure model has been set up; the understanding of Kelasu tectonic belt has been deepen; a series of traps has been discovered and implemented; a number of favorable targets and well locations have been suggested by through comprehensive evaluation; Dabei3 and Keshen2 gas fields have been discovered, and each one’s reserve is above one hundred billion cubic meters; and Dabei gas field has received good exploration assessment. At the same time, the technic of the build of reasonable structure model and correct velocity field in complex foothill area have been developed and refined practically.更多还原