胜利油区渤南洼陷沙四上亚段深部储层形成机理

从地壳的断块型结构、深大断裂发育、地幔上隆、岩石圈减薄、大地热流值增高、幔源火成岩广泛发育、以及胜利油区无机幔源二氧化碳气藏的存在、高温热液蚀变矿物硅灰石、低温热液蚀变矿物片钠铝石的发现、沙四段碳酸盐胶结物氧、锶同位素特征、与东非裂谷基伍湖类似的金属离子含量、粘土矿物异常演化等方面论证了早第三纪渤南洼陷普遍存在着与亚碱性-碱性岩浆有关的沉积、成岩期后的热液活动.结果表明深部储层具备产生耗散结构的一切条件,初始强酸性含矿深部热流体是形成次生孔隙的主要因素之一.阐述了脉动性深部热流体双扩散循环对流机制.

Deep reservoir forming mechanism in the upper part of the fourth member of Shahejie Formation in Bonan subsag of Shengli Oil Field

The features of fault block types of the crust,well developed deep-fault,Moho uplifting and lithosphere thinned and geothermal flux going up,and extensively developed igneous rocks of mantle source rocks in Bonan subsag show that the deep thermal fluid related to subalkali-alkali magma existed in this area in Paleogene period.In addition,there existed mantle inorganic CO₂ pool,and the findings of the high hydrothermal altered mineral-wollastonite and low values of hydrothermal altered mineral-NaAICO₃, ⁸⁷Sr/⁸⁶Sr, δ¹⁸O were found.The metal-rich ions and clay mineral were abnormally evolved.It is proved that the deep reservoir possesses all conditions of dissipation system, and the deep thermal fluid with initial strong acid is one of the most important factors forming secondary pores.The double-diffusive-circula-tive convection mechanism of pulsating deep thermal fluid is expounded in this paper.