鄂尔多斯盆地陇东地区太原组铝土岩储层地震预测技术与勘探效果  

Seismic prediction technology and exploration results of the Taiyuan Formation bauxite reservoir,Longdong area,Ordos Basin

作　　者：朱望明 郭亚斌 雷宇 杨丹 张敏[1] 王世成 刘鹏飞[3] 刘燕 ZHU Wangming;GUO Yabin;LEI Yu;YANG Dan;ZHANG Min;WANG Shicheng;LIU Pengfei;LIU Yan(Changqing Branch,Geophysical Research Institute,BGP,CNPC,Xi'an 710021,China;Exploration Division of PetroChina Changqing Oilfield Company,Xi'an 710018,China;The Second Oil Production Plant of PetroChina Changqing Oilfield Company,Qingyang 745100,China)

机构地区：[1]中国石油东方地球物理勘探有限责任公司研究院长庆分院,陕西西安710021 [2]中国石油长庆油田分公司勘探事业部,陕西西安710018 [3]中国石油长庆油田分公司第二采油厂,甘肃庆阳745100

出　　处：《天然气地球科学》2024年第8期1421-1431,共11页Natural Gas Geoscience

基　　金：中国石油长庆油田分公司重大科技专项“鄂尔多斯盆地地震格架大剖面综合解释与基础地质研究”(编号:2023DZZ02)资助.

摘　　要：前人利用岩心和测、录井资料分析鄂尔多斯盆地陇东地区太原组铝土岩成因机理,认为古地貌控制铝土岩富集,沟槽区铝土岩发育。以往研究针对铝土岩储层的地震预测方法还不够系统,如何应用三维地震资料刻画古地貌和预测铝土岩储层发育区域成为迫切需要。针对这些问题,通过地震模型正演分析,结合已有地质认识,探索陇东地区太原组铝土岩地震预测与有利区优选的方法。研究获得如下认识:①石千峰组底—太原组底厚度与太原组厚度相关性好,可用于预测宏观古地貌。在宏观古地貌预测的基础上,通过“趋势面法”对微古地貌进行恢复,在各自单元内进一步划分出主沟槽、次沟槽、潜坑及浅洼等“负向地貌”单元,细化了微观古地貌形态。②在压制煤层强反射干扰的前提下,采用叠后地质统计学反演获得的纵波阻抗体能很好地预测陇东地区铝土岩空间展布特征。③通过综合古地貌、岩性、断裂及构造等因素对陇东地区太原组铝土岩储层开展地震预测,形成了“一低一弱,一高两带”的井位优选模式,该模式在铝土岩高效井位部署中发挥了积极作用。L47井太原组铝土岩试气获高产气流,标志着盆地铝土岩新领域获得重大突破,目前已落实有利勘探面积近8000 km^(2),勘探前景广阔。Previous researches analyzed the genesis mechanism of bauxite in the Taiyuan Formation in Longdong area of Ordos Basin by using core and logging data,and believed that karstification controlled bauxite enrichment,and bauxite developed in gully areas.Previous research on seismic prediction methods for bauxite reservoirs has not been systematic enough.It is urgent to apply three-dimensional seismic data to characterize ancient landforms and predict the development areas of bauxite reservoirs.Aiming at these issues,this paper analyzed seismic forward modeling and combined existing geological understandings to explore the seismic prediction method of Taiyuan Formation bauxite and favorable zones selection in Longdong area.The study obtained the following understandings:(1)The thickness between the bottom of Shihezi Formation and the bottom of Taiyuan Formation correlates well with the thickness of Taiyuan Formation,which can be used to predict macro paleo-geomorphology.Based on the prediction of macro paleo-geomorphology,the micro paleo-geomorphology was restored through“trend surface method”,and further divided into main gullies,minor gullies,hidden pits and other“negative landforms”within each unit,refining the micro paleo-geomorphology.(2)Under the premise of suppressing strong reflections from coal seams,the P-wave impedance obtained through inversion of post-stack geological statistics can well predict the spatial distribution of bauxite in Longdong area.(3)Comprehensively predicting the Taiyuan Formation bauxite reservoirs in Longdong area using factors like paleo-geomorphology,lithology,faults and structures formed a“one low,one weak,one high and two zones”well location selection mode,which played a positive role in efficient deployment of bauxite wells.The high-yield gas flow obtained from the gas testing of the Taiyuan Formation bauxite rock in Well L47 marks a significant breakthrough in the new field of bauxite rock in the basin.Currently,a favorable exploration area of nearly 8000 square kilom

关 键 词：鄂尔多斯盆地 岩溶古地貌 铝土岩 地震预测 综合评价 

分 类 号：TE132.1[石油与天然气工程—油气勘探]