利用油田开发资料重新认识油气成藏——以渤海湾盆地南堡35-2油田馆陶组为例

Re-recognition of hydrocarbon accumulation regularity based on oilfield development data:A case study of the Guantao Formation in NB35-2 oilfield, Bohai Bay Basin

全洪慧 陈建波 别旭伟 张章 张振杰

Quan Honghui Chen Jianbo Bie Xuwei Zhang Zhang Zhang Zhenjie

西北大学 大陆动力学国家重点实验室, 西安 710069 2. 西北大学 地质学系, 西安 710069 3. 中海石油(中国)有限公司 天津分公司, 天津 300452

State Key Laboratory of Continental Dynamics, Northwest University, Xi'an, Shaanxi 710069, China 2. Department of Geology, Northwest University, Xi'an, Shaaxi 710069, China 3. CNOOC Tianjin Branch, Tianjin 300452, China

针对渤海湾盆地南堡35-2油田投产后实际生产特点与初始地质认识存在较大差异的问题，综合利用钻井、录井、测井并结合生产动态等资料对其古构造、沉积特征、成藏模式进行了重新认识，并对其资源潜力进行了重新评估。研究表明：馆陶组油气聚集具有“古构造控制沉积相带、古构造控制油气聚集”的特点，具体为（1）南堡35-2油田潜山的古构造格局控制了沉积相带的分布规律，控制了油气的整体运聚特征，该结论不同于前人得出的油藏主要受控于岩性而不受控于构造的结论；（2）馆陶组沉积相类型为辫状河沉积，油藏主体分布于主河道叠合连片区，砂体的空间展布对油气的再次分配起着一定作用；（3）南堡35-2油田的成藏模式表现为“断裂控藏，深聚浅调”的特点，边界大断层及潜山不整合面为深层“油源网”，使原油在深层馆陶组储层聚集，后期浅层次级断层活动强烈，部分原油被调整到浅层明化镇组形成次生油藏。南堡35-2油田馆陶组资源潜力十分可观，储量规模可能为之前预测的3倍。

According to the contradiction between production and geological understanding of the NB35-2 Oilfield, Bohai Bay Basin, we re-analyzed paleostructure, depositional features and the reservoir forming model as well as resource potential based on drilling, logging, seismic and production performance data. Paleostructures controlled sedimentary facies and hydrocarbon accumulation in the Guantao Formation. (1) Petroleum migration and accumulation were controlled by palaeogeomorphology of the buried hill area in NB35-2 block, which is different from the previous research results that reservoirs were restricted by lithology rather than structure. (2) Braided river sedimentary facies are predominant in the Guantao Formation. Reservoirs mainly distribute over superimposed, linked areas of main stream channels, and the space distribution of sand bodies is controlled by the secondary accumulation and distribution of oil and gas to some extent. (3) In the NB35-2 oilfield, faults controlled hydrocarbon accumulation, and hydrocarbon mainly accumulated in deep strata and migrated to shallow strata. Boundary faults and unconformities worked as a "resource network" and allowed hydrocarbons to accumulate in the Guantao Formation. Secondary faults were active in the shallow formations during late stage, and made crude oil migrate to the Minghuazhen Formation and form secondary oil pools. The Guantao Formation in the NB35-2 oilfield has a great petroleum potential, and may be 3 times larger than the previous estimation.

国家科技重大专项“渤海海域大中型油气田地质特征”（2011ZX05023-006-002）和“近海隐蔽油气藏勘探技术”（2011ZX05023-002）资助。

https://doi.org/10.11781/sysydz201605592