松辽盆地南部大情字井向斜区葡萄花油层石油富集规律及成藏模式

针对松辽盆地南部大情字井向斜区葡萄花油层石油成藏及富集规律研究程度低的问题,从有效烃源岩、优质储层、油源断层及断裂密集带4个方面入手,深入开展石油富集规律及成藏模式研究。根据断裂发育特征及构造高程,将向斜区进一步划分为3个次级构造单元,并对不同构造单元油藏类型和石油分布特征进行剖析:向斜断裂深洼区以断层-岩性油藏为主;向斜过渡缓坡区以岩性油藏、断层-岩性油藏和构造-岩性油藏为主;向斜过渡陡坡区发育少量岩性油藏。平面上,受断裂密集带发育位置的影响,石油主要呈条带状富集于向斜断裂深洼区和过渡缓坡区;垂向上,受储层发育位置的影响,石油集中分布于葡萄花油层Ⅱ砂组。以此为基础分析向斜区石油富集规律,得出石油富集的4个主控因素:1有效烃源岩厚度控制石油富集;2油源断层组成垂向优势输导通道;3分流河道岔道口是石油富集的有利部位;4断裂密集带控制石油富集。最终建立了向斜区4种成藏模式:1向斜断裂深洼区黑157井以南,嫩一段烃源岩供烃,超压倒灌,油源断层沟通,反向构造控藏;2向斜断裂深洼区黑157井以北,青一段烃源岩供烃,油选择性充注分流河道成藏及断裂密集带内断层组合形成的局部构造控藏;3向斜过渡缓坡区,构造-岩性和岩性圈闭控藏模式;4向斜过渡陡坡区岩性圈闭控藏模式。

Oil Enrichment Regularity and Accumulation Modes of Putaohua Reservoir in Daqingzijing Syncline Area,Southern Songliao Basin

Considering the low research degree on oil accumulation and enrichment regularity of Putaohua reservoir in Daqingzijing syncline area of southern Songliao basin,combining various aspects such as effective source rock zone,effective sandstone reservoir,oil-source faults and intensively faulted zone,the hydrocarbon enrichment regularity and accumulation modes are analyzed.Based on the characteristics of the faults and tectonic evolution,Daqingzijing syncline area was subdivided into three sub-tectonic units,and we analyzed the reservoir type and the characteristics of oil-gas distribution respectively.Syncline fault deep depression area develops fault-lithological reservoir;Syncline transition ramp area mainly develops lithological reservoir,fault-lithological reservoir and structure-lithological reservoir;Syncline transition steep slope zone develops few lithological reservoir.Intensively faulted zone is the mainly area of oil enrichment in plane,while controlled by the difference of sandstone reservoir development,oil mainly enriches in PⅡ in the vertical.Four oil enrichment regularities are concluded as follows,① the distribution of effective hydrocarbon source rocks controls the oil enrichment;② oil-source faults act as preferential translocation channels in the vertical direction;③ distribution channel crotch is the favorable area for oil enrichment;④intensively faulted zone controls the enrichment of oil. Finally,four kinds of local accumulation models have been established:①south part of well hei157 on the syncline fault deep depression area,hydrocarbon source rock of Neng 1 Member offered hydrocarbon,migrated downward under overpressure,oil-source fault communication,reverse faults control oil accumulation;②north part of well hei157 on the syncline fault deep depression area,hydrocarbon source rock of Qing 1 Member offered hydrocarbon,oil selective filling distributary channel and the local structure formed by fault combination in intensively faulted zone;③inside the syncline transition ramp area,structure-lithological and lithological trap control oil accumulation;④ inside the syncline transition steep slope area, lithological traps control oil accumulation.