摘要
利用岩心、薄片、测井以及地化分析测试资料,研究塔中地区奥陶系鹰山组深部碳酸盐岩的埋藏岩溶作用特征、期次及对储层分布的控制机理。研究表明,在鹰山组中共识别出三期不同发育规模、程度和缝洞发育特征的埋藏岩溶作用。第一期发生于晚加里东期至早海西期,在全区均有分布,但其溶蚀作用较弱;第二期发生于晚海西期至印支期,受构造作用、先期孔洞层和有利沉积相带的控制明显,并且可能与晚海西期岩浆热液活动有关,形成的缝洞多为方解石和萤石充填;第三期发育于喜山期,受走滑断裂和裂缝发育的控制,形成的缝洞多为轻质原油和天然气充填;整体上深部埋藏溶蚀作用常与有机质热演变过程中伴随的酸性流体及热液溶蚀碳酸盐矿物有关,主要沿先期孔洞层及断裂发生溶蚀作用,具有期次多、规模不等、近端溶蚀及远端胶结等特性,形成的溶蚀孔洞具有对原有缝洞系统的继承性,是储层形成及优化改造的关键因素。
By using of cores,core slices,logging and geochemical analysis of test data,researchers studied the characteristics,stages and the control mechanism for reservoir distribution of buried karstification in the deep carbonate rocks of Ordovician Yingshan Formation in Tazhong area. Researches showed that three periods of different development scales,degrees and karst-fracture characteristics of buried karstification in Ordovician Yingshan Formation have been identified. The first period which occurred in the Late Caledonian to the Early Hercynian period distributed in the whole region,but its corrosion is weak; the second occurred in the Late Hercynian to the Early Indosinian period is obviously controlled by tectonic action,previous pore layers and favorable sedimentary facies belts,and may be associated with the magmatic hydrothermalism activity of the Late Hercynian period,thus fracture and pore forming are filled with calcite and fluorite; the third happened in the Himalayan period,controlled by strike-slip faults and fracture development,then fractures and holes are filled by light crude oil and natural gas. Overall,the deep burial dissolution usually associated with acidichydrothermal fluid and dissolution of carbonate minerals which are related to the thermal evolution of organic matter,and often the early dissolution occured along the previous pore and fracture cracks with the characteristics of multi-stages,unequal sizes,proximal dissolution and distal cementation,solution cave forming on the inheritance of original fracture-cave system,which is a key factor in the reconstruction of reservoir formation and optimization.
出处
《现代地质》
CAS
CSCD
北大核心
2015年第3期665-674,共10页
Geoscience
基金
国家科技重大专项"塔里木盆地海相碳酸盐岩油气资源潜力
有利勘探区带评价与目标优选"(2011ZX05004-004)
四川省重点学科建设项目(SZD0414)
关键词
岩溶期次
溶蚀充填
埋藏岩溶作用
鹰山组
塔中地区
karstification period
dissolution and filling
buried karstification
Yingshan Formation
Tazhong area
