酒西盆地老君庙油田古近纪L油藏富油因素分析

1.西安科技大学 期刊中心,陕西 西安 710054; 2.中国海洋石油总公司 北京研究总院,北京 100027

酒西盆地; 古近纪; L油藏; 构造背景; 沉积相带

Enrichment of the paleogene L Reservoir in Laojunmiao Oilfield of Jiuxi Basin
LI Ke-yong1,CHEN Quan-hong2

(1.Periodical Center,Xi'an University of Science and Technology,Xi'an 710054,China; 2.CNOOC Beijing General Research Institute,Beijing 100027,China)

Jiuxi Basin; Paleogene; L reservoir; tectonic setting; sedimentary facies belt

备注

酒西盆地为晚期型前陆盆地,老君庙油田位于盆地南部老君庙背斜带的中部,L油藏储层颗粒分选、磨圆较差,成分成熟度和结构成熟度较低,胶结物的成分主要为泥质和钙质,属中高孔隙中渗透含油好的油藏。依据岩心观察、野外露头以及钻井、测井等沉积相划分标志,老君庙油田L油藏主要发育河流、三角洲等2类沉积相,辫状河、三角洲平原、三角洲前缘等3类沉积亚相。老君庙油田古近纪L油藏上部沉积区域性的石油沟段棕红色泥岩盖层,L1,L2,L3储集砂体由于褶皱作用形成背斜圈闭,西部低洼地区为构造-岩性圈闭,其中控制油气运移和聚集的构造背景是成藏的地质基础,成岩作用形成的储集物性特点是成藏的前提,控制优质储层发育的沉积相带是成藏的必要条件,良好的生储盖组合配置是成藏的关键。

Laojunmiao Oilfield is located in the center of Laojunmiao anticline of the Jiuxi Basin,which is a advanced foreland basin.The grainsize sorting and psephicity of the L reservoir is poor,and the maturation of composition and structure is low,the main content of cement are shale and calcium,so the L reservoir is a good reservoir,with mid-high porosity and middle permeability. Based on the classification mark about sedimentary facies,including core observation,outcrop,drilling,logging and so on,the L reservoir can be divided into 2 sedimentary facies and 3 sedimentary subfacies,the facies are fluvialite and delta facies,the subfacies are braided fluvial and delta plain,delta front.The upper of the L reservoir deposited regional brown-red mudstone caprocks of Shiyougou formation,the sandbody of L1 and L2,L3 formed anticline reservoir due to the folding,there is structural-lithologic reservoir in the west,the tectonic settings of controling migration and accumulation are the geological background of accumulation,the physical property features of diagenesis reservoir are the premises of accumulation,the sedimentary facies which control the quality development of the reservoir are the necessary conditions of accumulation,the well assemblage for source-reservoir-cap is the key to accumulation.