松辽盆地双城断陷白垩系营城组四段致密油成藏主控因素及模式  

Hydrocarbon accumulation model and main controlling factors of tight oil of the fourth member of Cretaceous Yingcheng Formation in Shuangcheng fault depression,Songliao Basin

作　　者：杨为华 YANG Weihua(No.5 Oil Production Plant,PetroChina Daqing Oilfield Company,Daqing 163712,Heilongjiang,China)

机构地区：[1]中国石油大庆油田公司采油五厂,黑龙江大庆163712

出　　处：《岩性油气藏》2024年第4期25-34,共10页Lithologic Reservoirs

基　　金：国家科技重大专项“岩性地层油气藏成藏规律、关键技术及目标评价”(编号:2016ZX05001)资助。

摘　　要：综合利用地震资料和岩心分析测试资料如包裹体均一温度、岩石热解和储层物性等,对松辽盆地双城断陷白垩系营城组四段(营四段)致密油藏类型、分布特征、成藏期次进行了分析,并从烃源岩评价、储层特征、构造活动和输导体系4个方面对致密油成藏的主控因素进行了研究。研究结果表明:(1)松辽盆地双城断陷营四段致密油藏的类型及分布规律为,自中部洼槽向两侧斜坡依次发育源内岩性油藏、近源断层-岩性、地层油藏和远源构造油藏,油藏为一期成藏,主成藏期为晚白垩世姚家组沉积末期—嫩江组沉积初期(80~78 Ma)。(2)研究区营四下亚段发育的湖相泥岩、油页岩的生烃潜力较大,中部洼槽为生、排烃中心,生、排烃强度均较高,分别为(20~300)×10^(4)t/km^(2)和(5~53)×10^(4)t/km^(2);营四上亚段发育的扇三角洲相含砾砂岩储层厚度大、连续性好,前缘砂体延伸入湖,平均孔隙度为11.4%,平均渗透率为0.95 mD,其中孔隙度大于8.0%、渗透率高于0.85 mD的相对优质储层是致密油富集的有利目标;深层各类圈闭在早白垩世泉头组沉积末期即已形成,而主成藏期时研究区构造活动较弱,有利于油藏的形成和保存;由断裂、不整合和连通砂体组成的多类型立体输导体系是油气运移主要通道,促进油气向两侧斜坡汇聚。(3)研究区致密油成藏受“源-扇-体”耦合控制,围绕生烃洼槽呈环带状分布,具有大面积分布、局部富集的特点,中部洼槽为源内“源-储叠置、网毯连接、扇体聚集”成藏模式,东部斜坡为近源“源-储紧邻、断-砂匹配、阶梯运移”成藏模式,西部陡坡为远源“源-储分离、‘Y’型运聚、高点富集”成藏模式。被泥岩包裹或与泥岩互层式接触的扇体、油源断裂附近的断层-岩性圈闭和地层圈闭、靠近油源断裂的背斜和断背斜圈闭分别是中部洼槽、东部斜坡和西部斜坡的有利�By comprehensively utilizing seismic data and core analysis testing data such as inclusion homogenization temperature,rock pyrolysis,and reservoir properties,the types,distribution characteristics,and accumulation stages of tight oil reservoirs of the fourth member of Cretaceous Yingcheng Formation(Ying-4 member)in Shuangcheng fault depression of Songliao Basin were analyzed,and the main controlling factors for tight oil accumulation were studied from four aspects:source rock evaluation,reservoir characteristics,tectonic activities,and transport system.The results show that:(1)The distribution pattern of tight oil reservoirs of Ying-4 member in Shuangcheng fault depression of Songliao Basin is as follows:from the central trough to the slopes on both sides,there are lithologic reservoirs within the source,near source fault-lithologic reservoirs,strati‐graphic reservoirs,and far source structural reservoirs.The reservoir is one-stage hydrocarbon accumulation,and the main accumulation satge is from the late sedimentary period of Yaojia Formation in Late Cretaceous to the early sedimentary period of Nenjiang Formation(80-78 Ma).(2)The lacustrine mudstone and oil shale developed in the lower submember of Ying-4 member(K1yc4)in the study area have great potential for oil and gas generation.The central depression is the center of hydrocarbon generation and expulsion,with high hydrocar‐bon generation and expulsion intensities of(20-300)×10^(4) t/km^(2) and(5-53)×10^(4) t/km^(2),respectively.The fan delta conglomerate sandstone reservoirs developed in the upper K1yc4 has a large thickness and good continuity.The front sand bodies extend into the lake,with an average porosity of 11.4%and an average permeability of 0.95 mD.Among them,relatively high-quality reservoirs with porosity greater than 8.0%and permeability higher than 0.85 mD are favorable targets for tight oil enrichment.Deep traps of various types formed at the end of Quantou Formation in Early Cretaceous,structure during the main accumulation stage was wea

关 键 词：深层致密油 断陷盆地 源内自生自储 近源岩性地层油藏 远源构造油藏 输导体系 营城组四段 白垩系 双城断陷 松辽盆地 

分 类 号：TE121.1[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]