- 责任者：Shao Xianjie (Department of Petroleum Engineering ; Yanshan University ; Qinhuangdao 066004 ; China) ; Wang Caifeng
- 刊名：Acta Petrolei Sinica
- 出版年：2013
- 卷期：34(4)
- 关键词：碳酸盐岩储集层 ; carbonate reservoirs ; 苏北盆地 ; Subei Basin
- 页码：p.701-711
- 图表：illus., 23 refs.
- 分类号：1003
- issnNo：ISSN0253-2697
- isbnNo：CN11-2128/TE
Based on observations of a large number of cast thin sections and rock cores, grain types of carbonates in the west slope of the Jinhu depression were identified to be mainly composed of bioclast, oolite, spherulite, algal stromatolite and arenite. Of which bioclast is abundant and predominated by Annelida Serpulidae of refines, which account for over 70 percent of the bioclast. And the other bioclast consists of algal, ostracod, brachiopod, gastropod, diatom, foraminifera and moss fossils. Although the amount of or- ganisms is large, their species, composed mainly of brackish halobios, are relatively monotonous with narrower salt tolerance. The mass fraction of boron in microelements averages 77.6 x 10-6 and the ratio of boron to gallium averages 3.6, indicating a brackish environment. The combination of sedimentary characteristics with analyses of organism assemblages and special minerals indicated a feature of a brackish lagoon environment as well, suggesting transgression or channels connecting with ocean during the deposition of the E~ f22 interval in the Jinhu depression. At that time, a suite of carbonates with 10-20 m in thickness was deposited widely in the west slope, indicating clear waters, relatively tranquil tectonic activities, slow lake-basin subsidence and deposition rate, and moder- ate compensation. Based on grain types and depositional characteristics, this suite of carbonates can be classified into four different sedimentary microfacies, i.e. mixed facies of terrigenous clastics and carbonates, oolite beach facies, bioclastie beach facies and cryp- tite facies. Vertically and horizontally each facies appears alternately. Dissolved pores are well-developed in bioclastic limestones which contain plenty of hydrocarbons. These carbonate reservoirs have been developed as a block of production succession in the Jin- hu depression and certain deliverability has been obtained.