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随着沧东凹陷正向构造带油气藏勘探程度的不断提高,成藏区带规模发现遇到瓶颈,勘探思路必须由构造油气藏勘探向斜坡连续性油气藏勘探转变。通过对沧东凹陷南皮斜坡精细构造解释、沉积微相划分、烃源岩特征及区域控砂控藏机制的分析,获得南皮斜坡地质特征与油气成藏模式的认识。研究表明,南皮斜坡为宽缓继承性斜坡,构造呈现高、中、低斜坡三分性特点,古近系孔店组二段(孔二段Ek_2)发育辫状河三角洲沉积,孔店组一段(孔一段Ek_1)底部发育浅水三角洲、上部发育冲积扇沉积,有利砂体大面积发育,孔二段发育好—很好烃源岩,生烃强度大。以构造、砂体、烃源岩及已知油藏匹配,形成自源成藏、它源成藏两大成藏组合系统,并构建孔二段有效生油岩范围内,中斜坡孔二段主砂体区常规油藏聚集,低斜坡远端细粒沉积岩类与油页岩叠合形成致密油,含油气系统范围内常规油与致密油叠加连片,形成“连续性成藏”油气成藏模式;孔一段受孔二段有效烃源岩控制下,形成“底部砂组近源大面积充注、上部继承性断裂网状沟通”的复合聚油模式。
With the continuous exploration of oil and gas reservoirs in the positive tectonic zone of Cangdong depression, the bottleneck of the discovery of the scale of the reservoir zone has been encountered. Exploration ideas must be changed from the exploration of structural reservoirs to the continuous exploration of slopes. Based on the analysis of the fine structure interpretation, the sedimentary microfacies division, the source rock characteristics and the reservoir controlling mechanism of sand control in Nanpi slope in Cangdong depression, we can get the understanding of the geological features and hydrocarbon accumulation pattern of Nanpi slope. The study shows that the Nanpi slope is a gentle and inherited slope with a tectonic setting of high, middle and low slopes. The second member of the Kongdian Formation in the Paleogene (Ek_2 of Kong2) develops braided river delta deposits. The Kongdian Formation A shallow water delta developed at the bottom of Ek_1 and developed alluvial fan in the upper part. The favorable sand body is well developed, and the second member of Well K5 is well developed - a good source rock with strong hydrocarbon generation intensity. Matching with structure, sand body, source rock and known reservoir, it forms self-source accumulation and its source reservoir into two major reservoir-forming combination systems and constructs effective secondary source rocks in the second member of Kongzhu Formation. Conventional reservoirs in the sand body zone are aggregated, and the fine sedimentary rocks of the distal low-grade sedimentary rocks and oil shale overlap to form tight oil. The conventional oil and tight oil within the scope of the petroleum system are contiguous and contiguous to form a “continuous reservoir” Under the control of the effective source rock in the second member of the Kongmou Formation, the formation of a composite oil recovery model with “near-source large-area filling of bottom sand group and upper inherited fracture network communication” is formed.