似花状断裂密集带富油差异性——以渤海湾盆地南堡凹陷中浅层为例

在三维地震、钻井资料及前人研究成果基础上，利用联合剖面对比追踪，累计隆起幅度和盖层断接厚度等研究方法，分析了渤海湾盆地南堡凹陷中浅层似花状断裂密集带平面和垂向富油特征及其差异性，并建立了油气成藏模式。研究认为：①南堡凹陷内似花状断裂密集带较发育，展布方向主要为北东向，以背形断裂密集带为主；②平面上似花状断裂密集带内部及边部是油气富集的主要区域，内部较边部油气富集程度高，背形似花状断裂密集带较向形似花状断裂带油气富集程度高，背形似花状密集带内累计隆起幅度控制着油气富集程度上限；③垂向上油气富集程度受控于盖层断接厚度，东营组二段盖层断接厚度控制似花状断裂密集带内中浅层的油气聚集，馆陶组盖层断接厚度控制中浅层内垂向油气聚集层位；④背形似花状断裂密集带内累计隆起幅度较大区域，且东营组二段盖层断接厚度小于90～95m阈值区域为下一步勘探有利区。

Characterization of petroleum pooling patterns in dense flower-like fault belts: Taking the middle and shallow layers in Nanpu Sag of Bohai Bay Basin as an example

A study was carried out to investigate oil and gas pooling patterns in belts with densely-distributed flower-like faults in the middle and shallow layers of Nanpu Sag,Bohai Gulf Basin.Methods such as composite profile comparison and tracing,cumulative uplift amplitude and cap rock juxtaposition thickness analyses and etc.,were resorted to analyze or establish oil pooling patterns and disparities across (horizontally and vertically) the belts based on seismic and drilling data as well as previous studies.The results indicate that (1) flower-like faults,mostly antiformal faults,are well developed and densely distributed in NE-trending belts of the Sag; (2) horizontally,oil and gas mainly enrich in the inner (containing more pools) and marginal parts of the belts,with enrichment degree being higher in the inner part than in the marginal part and higher in the antiformal dense flower-like fault belt than in the synformal belt,and uplift amplitude controls the upper limits of oil and gas pooling in the antiformal flower-like dense fault belt; (3) vertically,oil and gas pooling is conditioned by cap rock juxtaposition thickness-the juxtaposition thickness of E₃d² and N₁₊₂g (both cap rocks) in the Sag were observed to have a control over the oil and gas pooling in the middle and shallow layers in belts with densely-distributed flo-wer-like faults; (4) areas in the antiformal dense flower-like belts with larger cumulative uplift amplitude and juxtaposition thickness of the E₃d² being less than 90m~95m are considered potential exploration targets in the Sag.