The gas reservoir of Ciying Formation in Qujing basin is a typical lithologic gas reservoir with super-shallow burial depth of 300 - 450 m. The major reservoir has high porosity and moderate permeability, and its lithology is medium-fine sandstone in point bar of delta plain facies and shows very rapid lateral change. As no specific seismic reservoir prediction technologies are available before, success rate of exploration and development was low. Based on analyses of reservoir physical properties and wave impedance characteristics, forward modeling and seismic response, we established a reservoir prediction model, I.e. , mound or lenticular low frequency strong wave trough impedance and low impedance. It was successfully used to predict the distribution of favorable sedimentary facies through analyses of seismic facies and seismic attribute. The interpretation traps of mudstone and coal seam were effectively eliminated. By AVO analyses and multi-wavelet decomposition, a gas reservoir identification model, I. E. , type-IE AVO, strong low frequency and weak high-frequency was built and applied to predict the distribution of gas reservoirs. The reservoir and gas potential prediction results are integrated to comprehensively evaluate lithologic traps. Several favorable lithologic traps are discovered and successfully verified by drilling, significantly improving exploration success rate. The Neogene basins are widely distributed in Yunnan Province and have great exploration potentials, but are still underexplored by now. The technique of seismic reservoir prediction can be applied for exploration and development of similar gas reservoirs.%云南曲靖盆地茨营组气藏埋深300～450 m,属超浅埋深岩性气藏.主力储层属高孔中渗储层,为三角洲平原相河道边滩沉积的中细砂岩,横向变化极快.因前期尚未形成具有较强针对性的地震储层预测技术系列,导致勘探开发成功率低.通过储层物性及波阻抗特征分析、地震模型正演与储层地震响应特征分析,建立了“丘型或透镜状、低频强波谷振幅、低阻抗”有利储层预测模式.利用地震相及地震属性分析技术手段,预测出有利沉积相带分布,有效排除了泥岩及煤层陷阱.通过AVO特征分析,应用多子波分解技术,建立了“Ⅲ类AVO、低频强/高频弱”含气储层识别模式,预测了含气储层分布.综合储层预测与含气性预测成果,对岩性圈闭进行了综合评价,发现多个有利岩性圈闭,预测结果被实钻验证,勘探成功率明显提高.云南新近系盆地分布广、数量大,勘探潜力大,本次所形成的地震储层预测技术系列可望为该类气藏勘探开发提供借鉴.
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