东海某凹陷平北区基底岩浆岩优质储层发育模式

The development model for high quality magmatic basement reservoir in a depression of East China Sea

  • 摘要: 综合利用岩心、薄片、压汞数据、测井曲线及储层物性等资料,对平北地区基底岩浆岩储层特征及优质储层发育条件等进行研究。结果表明,储层以花岗岩储层物性最好,其储集空间以构造缝、溶蚀缝和溶蚀孔为主,其中,构造缝占比61%,在作为良好的储集空间的同时,也为原生孔隙的连通起到至关重要的作用。本区花岗岩储层发育具Ⅰ型模式,即,整体呈漏斗形,上部地区因裂缝、溶蚀孔洞被充填而形成致密区,储层物性差;中部大气淡水淋滤和构造应力作用下,裂缝发育,具备优异的储集空间和孔喉条件,为优质储层发育区;下部大气淡水淋滤作用弱,构造应力影响小,裂缝不发育,储层物性最差。研究认为优质基底岩浆岩储层位于基底中上部,大气淡水淋滤作用强,构造应力强,断层、断裂较为发育的地区。

     

    Abstract: Cores, thin sections, mercury injection data and well logging reservoir properties are adopted for research of the characteristics of basement reservoir in order to explore the high quality hydrocarbon accumulation in the Pingbei region. It is revealed that granite is the best bedrock reservoir in the region. Structural fractures, corrosion fractures and corrosion holes provided most of the reservoir space, among which, structural fractures account for 61%. Granite reservoirs in the study area could be described with the model of typeⅠ. In general, it is funnel-like in shape. The upper part is rather dense because fractures and dissolution holes are filled by the deposits of later stage, and the reservoir physical properties are poor. The middle part of the granite, however, is abundant in fractures and has excellent reservoir space and pore throat conditions by leaching and tectonic stress. The lower part becomes dense again with weak leaching by atmospheric fresh water and little influence by tectonic stress. It is believed that high quality buried basement-hill reservoir should be located in the middle and upper part of the buried hill owing to strong leaching of faults and ruptures by atmospheric fresh water.

     

/

返回文章
返回