柴达木盆地红柳泉地区地震资料岩性处理及储层横向预测

SEISMIC LITHOLOGIC PROCESSING AND LATERAL PREDICTION FOR RESERVOIRS IN HONGLIUQUAN REGION OF QAIDAM BASIN

经过三十多年的勘探,证实柴达木盆地红柳泉地区存在构造—岩性复合油气藏。但因油藏主要受控于河道砂体,储集砂层薄、岩性岩相横向变化快,所以,单纯用钻井资料难以确定油藏范围。为此,近年来在本区开展了高分辨牢地震、垂直地震剖面勘探和储层研究。我们首先对地震资料进行精细处理和特殊处理,以提取储油层段的反射特征、振幅和虚速度等异常信息,再结合钻井、油气测试等资料作综合分析,对含油气范围和地质储量作出预测。预测结果表明,本区原已探明的两个孤立的油气井应属于连片的含油区块,连片后的含油面积和油气储量将增加两倍。 预测结论已成为我们建议的探井所证实。通过预测,本区扩大了含油面积,增加了地质储量提高了勘探成功率,取得了明显的经济效益。

More than 30 years' surveys in the HLQ region of Qaidam Basin have shown that there exist structurally lithologically complex reservoirs in this area. They arc however under the control of channel sandstones. Since the reservoir beds are thin and the lithology and lithofacies laterally vary fast there, it is difficult to delineate the reservoir limits by drilling data alone. To this end, high-resolution seismic surveys, VSP surveys and reservoir studies have been carried out in recent years in the area. Special processes have been taken in order to extract the anomalous information associated with the reflecting attribute, amplitude and pseudo-velocity of the reservoir bed. The prediction on the reservoir limits and its geologic reserve are consequently made on the basis of the integrated analysis in combination with the data from drilling, oil / gas testing and so on. The results indicate that the two oil-producting wells previously affirmed to be isolate should be in the same oil-bearing block, and the potential oil-bearing area and the geologic reserve will be as much again as those previously proved. The above prediction has been confirmed by the drilling by us proposed and led to the extension of the oil-bearing area and the increase of the geologic reserve. The techniques suggested here are helpful to offer much probability for seismic surveys to meet with success and to yield distinct economic effects.