塔北隆起玉东地区盐下薄砂岩高分辨地震预测

High resolution seismic prediction of thin sandstone under gypsum-salt in the Yudong area of the uplift in the north of the Tarim basin

古近系薄砂岩是塔里木盆地玉东地区盐下主力产气储层段,薄砂岩储层的准确预测是玉东地区勘探成功的关键.本文通过岩心、测井、地震等资料综合研究及储层岩石物理分析建立了薄砂岩正演地质模型,正演模拟与地震响应特征分析发现玉东三维8种敏感地震属性与薄砂岩厚度呈4类(线性正相关、线性负相关、指数负相关、对数正相关)强相关,其中交流分量、道积分与薄层指示因子等敏感属性经RGB-HIS信息融合具有最佳的薄砂岩分辨能力.经地震属性信息融合、地质统计学高分辨反演和地震沉积学预测,古近系薄砂岩储层砂体主要分布于玉东北部的YT5井至YD1井、YD4井一带,薄砂岩发育三期透镜状水下分流河道和砂坝叠加砂体,砂体相互叠置连通.研究形成了一套薄砂岩储层预测新方法,为塔里木盆地古近系盐下薄砂岩储层预测和岩性圈闭勘探提供技术指导.

Paleogene thin sandstone in the Tarim Basin Yudong area under the salt is the main production gas reservoir section. The accurate prediction of thin sandstone reservoir is the key to successful exploration in Yudong area. In this paper,the forward geological model of thin sandstone is established by comprehensive study of core,logging and seismic data and physical analysis of reservoir rocks. Model for forward modeling and analysis of seismic response characteristics find that there are eight kinds of sensitive seismic attributes of Yudong three dimensions are strongly correlated with the thickness of thin sandstone in four categories（ linear positive correlation,linear negative correlation,exponential negative correlation,logarithmic positive correlation）. Among them, the sensitive components such as AC component,channel integral and thin layer indicator are the best thin sandstone resolution by RGBHIS information fusion. After seismic attribute information fusion,geostatistics high resolution inversion and seismic sedimentology prediction. The Paleogene thin sandstone reservoir sand bodies are mainly distributed in the area of YT5 well to YD1 well and YD4 well. Thin sandstone development of three lenticular underwater diversion channel and sand bar stack sand body, sand bodies overlap each other. The study finally formed a new method for predicting thin sandstone reservoirs and provide technical guidance for prediction of Paleogene under gypsum-salt sandstone reservoirs and exploration of lithologic traps in Tarim Basin.