Abstract:

An important progress has been made in exploring the crystal basement of the Xinglongtai buried-hill in the Liaohe Depression recent years. The deep drilling, such as in wells Xg7 and Xg8, has proved the existence of large-scale buried-hill inside reservoirs with a thousand-meter-range oil show, which have approximately one hundred million tons of reserves. An in-depth study on drilling cores and rock cuttings revealed that the Archaeozoic Xinglongtai crystal basement was made up of metamorphic and magmatic rocks, the former constituted mainly the buried-hill, while the latter formed hysterogenic viens dominated by well-developed neutral-acid magmatic rocks with a thickness from 1 to 50 meters and distributed at intervals in archaic metamorphic rocks of the buried-hill. A correlation of lithology with logging traces was established by studying physical properties of rocks, the lithology of crystal basement was identified through the dynamic integration of logging curves such as GR, DEN and CNL. The reservoir space of the buried-hill consisted mainly of tectonic fractures and broken intergranular pores. The development of reservoirs significantly depended on differences in lithology and the extent of tectonic reworking, namely, lithology was the primary factor under the same stress or vice versa. A predominant lithologic series was formed usually based on the quantity of dark minerals. These updated achievements have effectively guided the reserve calculation, exploration and development of the Xinglongtai buried-hill.

Key words: Xinglongtai buried-hill, crystal basement, physical property of rock, logging curve, reservoir character

摘要：

近年来渤海湾盆地辽河坳陷兴隆台潜山结晶基岩勘探获得重大突破，Xg7、Xg8等井深层钻探揭示了千余米含油幅度的大型潜山内幕油藏，形成了亿吨级储量规模。通过对潜山钻井取心、岩屑资料的详细研究，认为兴隆台结晶基底由变质岩和岩浆岩组成。变质岩是潜山的主体，岩浆岩为后期岩脉，以中酸性为主，厚度为1～50m，十分发育，在潜山古老的变质岩中穿插分布。通过岩石物理特征研究建立了岩性与测井曲线的对应关系，应用自然伽马、岩石密度与补偿中子等测井曲线来识别潜山结晶基岩的岩石类型。潜山储集空间类型主要为构造裂缝、破碎粒间孔等，岩性不同、构造改造程度不同，储层发育程度也不同。在同种应力作用下储层的发育程度取决于岩性，同种岩性储层的发育程度取决于应力，并按照暗色矿物含量的多少形成了优势岩性系列。这些最新的研究成果，有效地指导了兴隆台潜山的油气储量计算和勘探开发。

关键词: 兴隆台潜山, 结晶基岩, 岩石物理特征, 测井曲线, 储层特征