塔河油田12区中下奥陶统储层特征及发育控制因素

Characteristics and controlling factors of the Middle and Lower Ordovieian carbonates in the 12th district of the Tahe Oil Field

海涛 姚俊波 李柏颉 丁磊 张世亮 刘洪光

Hai Tao Yao Junbo Li Bojie Ding Lei Zhang Shiliang Liu Hongguang

中国石化西北油田分公司采油二厂, 新疆轮台 841604

No.2 Oil Production Plant, SINOPEC Northwest Company, Luntai, Xingjiang 841604, China

塔河油田12区主要开发层系为中-下奥陶统碳酸盐岩,多期构造运动和岩溶作用的叠加使得该区中下奥陶统岩溶缝洞发育程度高,同时也造成储层发育分布更为复杂。综合利用地震、取心、薄片、测井、测试等资料,重点探讨塔河油田12区中下奥陶统缝洞型油藏储层发育特征及发育主控因素。结果表明,12区中下奥陶统主要发育3类储层类型:溶洞型、裂缝-孔洞型和裂缝型。原生孔隙占储集空间比例小,岩溶洞穴是主要的储集空间,次生裂缝-孔洞为次要储集空间,溶蚀扩大缝可作为有利连通通道。对断裂控储特征、沿断裂储层发育差异性以及沿古河道多种控储模式等研究认为,暗河管道和地表河边部残丘是储层发育最有利区,溶蚀断裂面是有利部位。

The Middle-Lower Ordovician reservoir is considered the main developing interval in the 12th district of the Tahe Oil Field. Multi-phase orogeneses and karstifications are the main cause for the highly matured dissolved fissures and caves within the Middle-Lower Ordovician, which may also result in complex reservoir heterogeneity. This paper comprehensively utilizes data of seismic survey, coring, thin section, logging and laboratory test to clarify the fissure-cave reservoir characteristics within the Middle-Lower Ordovician in the 12th district of the Tahe Oil Field, and further discusses its dominating factor. The results indicate that, three reservoir types exist in the study area:cave type, fissure-cave type and fissure type. Primary pores take up only a tiny proportion in the accumulating spaces. Kart caves type occupies the majority, with the secondary fissure-cave type ranking behind. Dissolved fissure may undertake a favorable connecting conduit. Moreover, the reservoir dominating by fissure-fracture system, developing dissimilarly along the fissure-fracture system, may be controlled by multiple developing model along the paleochannel. Those findings may imply that underground-river conduit and monadnock existing in the lateral side of surface river are supreme zones for reservoir developing, while the dissolved fracture surface follows.

https://doi.org/10.11781/sysydz2015S1016