南海东部某油田地震成像畸变下的构造恢复

Structural reconstruction of an oil field in the east of South China Sea under seismic imaging distortion

海上油气田开发到中后期,构造研究的精细程度直接影响到油藏的开发效果。针对南海东部油田开发中低幅度构造的地震成像畸变问题开展了研究。首先,为了消除断层阴影对于构造的影响,通过对断层附近成像畸变分析,根据层位和断层控制建立速度模型,准确恢复断层附近的速度场,有效消除断层阴影影响,精细恢复断层阴影带内的低幅度构造特征;然后通过高分辨率反演刻画浅层异常体分布,进行速度校正,以消除浅层异常体对构造影响。在地震成像畸变的情况下,将测井数据和地震数据相融合,并结合地震速度和地质规律分析相互验证校正构造解释,取得了较好的应用效果,为油田地质和油藏研究提供了准确的基础数据。

In the middle and late stage of offshore oil and gas field development, the fineness of structural research directly affects the development effect of oil reservoir. In this paper, the seismic imaging distortion of low amplitude structures in the development of oil fields in the east of the South China Sea is studied. Firstly, in order to eliminate the influence of fault shadow on the structure, through the analysis of imaging distortion near the fault, a velocity model is established according to the horizon and fault control, so as to accurately restore the velocity field near the fault, effectively eliminate the influence of fault shadow, and finely restore the low amplitude structural characteristics in the fault shadow zone;Then, the distribution of shallow abnormal bodies is characterized by high-resolution inversion and velocity correction to eliminate the influence of shallow abnormal bodies on the structure. In the case of seismic imaging distortion, the combination of logging data and seismic data, combined with seismic velocity and geological law analysis, mutually verified and corrected structural interpretation,achieved good application results, and provided accurate basic data for oilfield geology and reservoir research.