冀中坳陷深潜山及其内幕地震勘探技术研究

冀中坳陷的勘探程度高,易于勘探的埋藏较浅的大型潜山几乎勘探殆尽,但深潜山的勘探程度相对较低,且具有很大的勘探潜力,是目前主要勘探领域。为了大幅度地提高深潜山地震资料品质及其成像精度,满足超深隐蔽型油气藏勘探的需求,针对深潜山及其内幕勘探目标埋藏深、隐蔽性强、地震波能量吸收衰减严重、地震波场非常复杂、资料的信噪比和分辨率低、成像困难、储层的非均质性强、潜山形态及内幕圈闭落实难度大等勘探难点,开展了大量的攻关研究,形成了宽方位高密度采集、基于目的层响应频率的低频采集处理、时间域融合地震勘探、碳酸盐岩储层非均质性定量预测等4项关键技术。通过应用,地震资料的能量和信噪比得到大幅度提高,而且低频信息丰富,成像效果好,深潜山及其内幕断层更为清楚,圈闭形态更落实,同时也取得了良好的勘探效果。

Study of Seismic Exploration Technology for Deep Buried Hills and Their Inner Curtains of Jizhong Depression

Exploration degree is high in Jizhong Depression. Nearly all large-scale buried hills suitable for exploration and with small buried depth have been brought under exploration. However, exploration degree is relatively low for deep buried hills, which have a great potential tbr exploration and become the main exploration field at the present time. To improve the quality of seismic data and imaging precision for deep buried hills and meet the demand for exploration of super-deep subtle oil and gas reservoirs, the study has been made in light of the characteristics of deep buried hills and their inner curtains, such as large buried depth, strong subtleness, serious attenuation of seismic wave energy absorption, complicated seismic wave field, 19w signal-noise ratio and resolution of data, difficulty of imaging, strong heterogeneity of reservoir, difficult identification of the shapes of buried hills and their inner curtain traps. The study led to development of four key technologies-wide-azimuth high-intensity acquisition technique, low-frequency acquisition and processing technique based on target formation response frequency, technique of combining time domain with seismic exploration, and technique of quantitatively predicting heterogeneity of carbonate rock reservoir. Those technologies significantly improved the energy of seismic data and signal-noise ratio with abundant low- frequency information and good imaging results. Deep buried hills and their inner curtain faults became clearer while the shapes of traps are easier to be identified. Good exploration results were achieved at the same time.