油源断裂与区域性泥岩盖层配置渗漏时期预测方法及应用  

Prediction method and application of leakage period in oil source fracture-regional mudstone caprock configuration

作　　者：刘云鑫[1] 张金宝 于英华[1] LIU Yunxin;ZHANG Jinbao;YU Yinghua

机构地区：[1]东北石油大学 [2]中国石油大庆油田有限责任公司勘探事业部

出　　处：《海相油气地质》2023年第3期330-336,共7页Marine Origin Petroleum Geology

基　　金：国家自然科学基金项目“富泥三角洲特征及形成机理研究--以海拉尔盆地大磨拐河组三角洲为例”(编号:41572126);黑龙江省自然科学基金项目“页岩露头储层模型定量表征”(编号:LH2022D013)和“富泥三角洲沉积模拟研究”(编号:LH2023D005)联合资助

摘　　要：为了研究含油气盆地油源断裂与区域性泥岩盖层配置(断盖配置)之上的油气分布规律,在油气渗漏机制定性分析的基础上,建立了一套渗漏时期分布预测方法。首先,确定断盖配置油气渗漏部位,即断层上下盘盖层的断接厚度小于断裂分段生长连接所需的最小断接厚度(断接厚度下限)的部位;其次,确定断盖配置封闭性开始破坏时期,即观察点的断接厚度开始小于断接厚度下限的地质时期;然后,确定断层岩封闭的开始时期,即断层岩排替压力开始大于下伏储层岩石排替压力的地质时期;最后,将前三者结合可确定断盖配置油气渗漏的时空分布,渗漏时期即为断层封闭性开始破坏到断层岩封闭开始之间的时期。实例应用结果表明:对于渤海湾盆地黄骅坳陷歧口凹陷南大港断裂与沙河街组一段中亚段泥岩盖层的配置,向上覆东营组三段的油气渗漏主要分布在中东部,渗漏从馆陶组沉积中期持续至第四纪早期,持续时期相对较长,这对于下伏沙河街组三段烃源岩生成的油气在东三段聚集成藏十分有利。分析结果与目前南大港断裂处东三段油气显示主要位于中东部相吻合,证明此方法对断盖配置渗漏时期分布的预测是可行的。In order to study the distribution pattern of oil and gas above the oil source fault-regional mudstone caprock configuration(fault-caprock configuration)in petroliferous basins,a set of prediction methods for the distribution of leakage periods was established based on qualitative analysis of the leakage mechanism.Firstly,determine the location of oil and gas leakage in the fault-caprock configuration,that is,where the joint thickness of caprock between upper and lower walls of fault(Hf)is less than the minimum required for the fracture segment connection(Hf-l).Secondly,determine the beginning time of sealing failure,that is,according to a study spot in the fault,when its Hf is firstly less than the Hf-l.Then,determine the starting time of fault rock sealing,that is,when the displacement pressure of fault rock is firstly greater than that of the underlying reservoir rock.Finally,the combination of the three can determine the spatiotemporal distribution of oil and gas leakage in the fault-caprock configuration.The leakage period is between the beginning time of sealing failure and the beginning time of fault rock sealing.The application results of the example show that for the fault-caprock configuration of the Nandagang fault and the mudstone caprock in the middle section of the Shahejie Member 1 in the Qikou Sag,Huanghua Depression,Bohai Bay Basin,the oil and gas leakage to the overlying Dongying Member 3 is mainly distributed in the central and eastern parts,from the middle period of Guantao Formation to the early Quaternary with a relatively long duration.This is very favorable for the hydrocarbon’s accumulation in Dongying Member 3 generated by the source rocks of underlying Shahejie Member 3.The analysis results are consistent with the current oil and gas display in Dongying Member 3 at the Nandagang fault,proving that this method is feasible for predicting the distribution of leakage periods in fault-caprock configuration.

关 键 词：油源断裂 泥岩盖层 渗漏部位 渗漏时期 预测方法 南大港断裂 

分 类 号：TE122.1[石油与天然气工程—油气勘探]