摘要
鄂尔多斯盆地下古生界碳酸盐岩中裂缝普遍发育,裂缝是天然气高产富集的关键因素之一。为了精细预测不同尺度裂缝平面展布规律,为勘探选区和开发井位部署提供指导依据,以该盆地大牛地气田奥陶系马家沟组为研究对象,利用岩心、成像测井等资料分析其裂缝发育特征,基于地震资料品质及正演模拟分析裂缝带地震响应特征,优选出裂缝预测敏感地震属性,形成了一套基于地震叠后属性的多尺度裂缝预测方法。研究结果表明:①研究区裂缝发育段测井特征表现为高声波时差、低电阻率、低补偿密度、低波阻抗,地震响应特征不明显,仅表现为波组连续性变差、差异扭动;②利用倾角和相干属性可以实现大尺度裂缝带的边界刻画,利用高精度Likelihood融合属性可以预测小尺度裂缝的分布特征和发育带强度,相干属性、倾角属性、最大似然属性3种方法预测的裂缝成果相互印证,并且刻画精度逐渐提高;③裂缝预测结果符合实际地质情况,与钻井漏失点吻合较好,研究成果可用于研究区下一步勘探选区和开发井位部署。结论认为,大牛地气田的裂缝综合预测方法对于同类地质情况和地震资料基础的区块具有指导意义。
There often exist well-developed fractures in Lower Paleozoic carbonate rocks,Ordos Basin,which function as one of the key factors affecting high yield and enrichment of natural gas.In order to precisely predict plane distribution laws of fractures with different sizes as well as provide reference for selecting exploration areas and deploying development wells,the Ordovician in Daniudi gasfield of Ordos Basin was taken as an objective to analyze development characteristics of the fractures in the Ordovician Majiagou Formation by using core and imaging logging data.Then,seismic response characteristics were analyzed for fracture zones and seismic attributes sensitive to fracture prediction were chosen dependant on quality analysis on seismic data and forward modeling.In addition,one method was established to predict multi-scale fractures based on seismic poststack attributes.Results show that(1)for developed fractures in the study area,their logging characteristics are featured by high interval transit time,low resistivity,compensation density and wave impedance,while implicit in seismic response characteristics only emerging as worsening continuity and differential torsion of waves;(2)the boundary of great fractures can be depicted by using dip angle and coherence,and the distribution of small fractures and the intensity in a certain zone with these small ones can be predicted by using high-accuracy Likelihood fusion attributes.Results predicted from those three sorts of fractures can prove each other,and the depicted accuracy is improved a lot;and(3)these results are in line with actual geological situations and better accordant with lost-circulation points.They are conducive to selecting areas and deploying development wells.In summary,the comprehensive fracture prediction method used in Daniudi gasfield is of guiding significance to other blocks with similar geological situations and seismic data.
作者
孙涵静
SUN Hanjing(Exploration and Development Research Institute,Sinopec North China Company,Zhengzhou,Henan 450006,China)
出处
《天然气技术与经济》
2023年第1期29-36,共8页
Natural Gas Technology and Economy
基金
中国石化科技部项目“鄂尔多斯盆地元古—下古生界三维地震成像及目标处理解释技术”(编号:P20043-3)。
关键词
鄂尔多斯盆地
大牛地气田
马家沟组
多尺度裂缝
综合预测
Ordos Basin
Daniudi gasfield
Majiagou Formation
Multi-scale fracture
Comprehensive prediction
