中国石油勘探 ›› 2016, Vol. 21 ›› Issue (4): 65-74.

• 石油地质 • 上一篇    下一篇

渤海海域黄河口凹陷斜坡带差异控藏作用及油气富集规律

薛永安,杨海风,徐长贵   

  1. 中海石油(中国)有限公司天津分公司
  • 出版日期:2016-07-15 发布日期:2016-07-15
  • 基金资助:
    国家科技重大专项“近海大中型油气田形成条件及勘探技术”(2011ZX05023-002)。

Differential Reservoir-controlling Effect and Hydrocarbon Enrichment of Slope Zone in Huanghekou Sag, Bohai Bay Basin

XueYongan, Yang Haifeng, Xu Changgui   

  1. CNOOC (China) Ltd. Tianjin Branch
  • Online:2016-07-15 Published:2016-07-15

摘要: 长期以来,渤海海域黄河口凹陷的油气勘探工作主要集中在中央构造脊和北部陡坡带,斜坡带勘探研究程度较低,油气成藏机理及其富集规律不清晰。基于斜坡带内部断坡组合、沉积特征、斜坡坡度和构造演化等4个方面的特征与差异,将黄河口凹陷西洼南部斜坡带和中洼南部斜坡带划分为同沉积微斜断坡型斜坡带与同沉积稳定断阶型斜坡带两种不同的类型。不同类型的斜坡带发育不同的构造样式,对沉积体系的展布、油气的运聚成藏和富集规律均有着明显的差异控制作用。同沉积微斜断坡型斜坡带为“横向阶梯式” 油气运移模式,新近系明化镇组是主要油气富集层系,油气在阶梯状运移过程中,成藏层系逐阶抬高,斜坡带越高部位,成藏层位越浅。同沉积稳定断阶型斜坡带为“垂向贯穿式” 油气运移模式,油气成藏具有近源成藏、含油气丰度高、深浅层复式成藏的特征,在平面上,斜坡带主干断裂的弯曲增压段是油气富集区。在此认识基础上指出了下步重点勘探方向。

关键词: 斜坡带类型, 差异控藏作用, 富集规律, 陆相断陷湖盆, 黄河口凹陷

Abstract: Oil and gas exploration operations in Huanghekou Sag, Bohai Bay Basin have been mainly conducted in the structural ridge in the central and steep slope zone in the north for a long time. The slope zone is not well explored or understood, and hydrocarbon accumulation and enrichment there is not clear. Based on the characteristics and differences in terms of four aspects of the slope zone including internal fault-slope combination, sedimentary characteristics, slope gradient and tectonic evolution, the southern slope zone of Huanghekou west subsag and the southern slope zone of Huanghekou central subsag can be classified as two categories: synsedimentary micro-oblique ramp type slope zone and synsedimentary stable fault terrace type slope zone. Different structural styles are developed in different types of slope zones which have significant differential controlling effect on the distribution of sedimentary system and hydrocarbon transport, accumulation and enrichment. Synsedimentary micro-oblique ramp type slope zone is of the “horizontal and stepwise” hydrocarbon transport model, where Neogene Minghuazhen formation is the dominant hydrocarbon enrichment series. During stepwise hydrocarbon transport, hydrocarbon accumulation series was lifted step by step and hydrocarbon accumulation horizon is shallower in higher positions of slope zone. Synsedimentary stable fault terrace type slope zone is of the “vertical through-going” hydrocarbon transport model, where hydrocarbon accumulation is close to the source, with high hydrocarbon abundance and deep-shallow composite hydrocarbon accumulation characteristics. On the plane, the bent pressurized section in principal faults of slope zone is hydrocarbon enrichment zone. These understandings provide a basis for further exploration.

Key words: slope zone type, differential reservoir controlling effect, enrichment pattern, continental faulted basin, the Huanghekou sag