松辽盆地登娄库——永安地区油气成藏模式研究

Study on Hydrocarbon Accumulation Models in Denglouku-Yongan Area of Songliao Basin

在已了解的松辽盆地登娄库一永安地区构造和沉积演化特点的基础上,利用现有钻井的岩心资料、测井资料和地震资料,对该地区的成藏模式特征从运移方式和生储盖空间组合两个方面上进行了研究和分类,分析了各自形成的主控因素。研究表明,该区域地层具有断坳双层结构,按油气运移类型划分,在断陷期主要发育两种油气成藏模式,分别为原生油气成藏模式和次生油气成藏模式;在坳陷期主要发育次生油气成藏模式和混生油气藏。从储层与烃源岩的空间组合上来看,区域内主要发育有上生下储、下生上储和自生自储这三种油气成藏模式。形成这些不同成藏模式的主要因素是该区深至基底的大型断裂构造和继承性断裂、反转构造以及固有沉积环境等。

Basing on the understanding about the tectonic and sedimentation evolution characteristics in Denglouku-Yongan area of Songliao Basin, study on hydrocarbon accumulation model has been conducted on the basis of coring, logging and seismic data, with focus on hydrocarbon migration ways and spatial combination of source rocks, reservoirs and cap rocks. In addition, the main controlling factors on hydrocarbon accumulation have been analyzed. The study results indicated that the stratigraphy in this area are characterized by double faulted sag structure, developed during rifting stage and depression stage in work area. During rifling stage, there are two hydrocarbon accumulation modes, including primary oil and gas reservoir formation and secondary oil and gas reservoir formation. During depression stage, secondary oil and gas reservoir formation and mixed oil and gas reservoir formation pattern are dominated in this area. On the basis of spatial combination of source rocks, reservoirs and cap rocks, there are three kinds of oil and gas reservoir formation models, including upper generation and lower reserving, upper reserving and lower generation, and generation and reserving in situ. The main controlling factors for so many different kinds of oil and gas reservoir formation models in this area are mainly large scale faults extending into basement, the inherited faulted structures, reversed structures, and the particular sedimentary environments.