涠西探区W构造油气差异富集控制因素

Controlling Factors of Hydrocarbon Differential Enrichment In W Structure of Weixi Exploratory Area

粟莉 杨鹏程 张昆 许梦 白玉洪

SU Li YANG Pengcheng ZHANG Kun XU Meng BAI Yuhong

中国石油化工股份有限公司上海海洋油气分公司勘探开发研究院，上海　200120 中石化海洋石油工程有限公司上海特殊作业分公司，上海　200137

Institute of Exploration and Development, SINOPEC Shanghai Offshore Oil & Gas Company, Shanghai 200120, China SINOPEC Offshore Oilfield Services Company Shanghai Oilfield Services Division, Shanghai 200137, China

钻井揭示涠西探区W构造不同断块和层位油气富集程度具有明显的差异性，但控制因素不明。为了理清该构造油气差异富集的控制因素，对涠西探区不同断块的关键成藏要素进行了精细研究和对比，在明确油源及成藏期次的前提下，重点研究输导体系和保存条件对差异富集的控制作用。研究结果显示，W构造油气来源相同，成藏期均为中中新世之后，油气差异富集主要受油气疏导和断层封堵性的共同控制。W3Ⅱ、W3Ⅲ砂层组是区域盖层下的优势砂岩输导层，是油气富集的前提，优势砂岩输导层与油源断裂的关系以及区域盖层的分布是平面上油气差异富集的主控因素，直接盖层的发育程度是油气纵向上沿断层差异富集的主控因素，研究结果对涠西探区W构造下步油气勘探具有借鉴意义。

Drilling reveals that hydrocarbon enrichment in different fault blocks and horizons of Weixi exploration area W structure is obviously different, but the controlling factors are unknown. In order to clarify the controlling factors of the differential enrichment of hydrocarbon in this structure, the key accumulation factors of different fault blocks were studied and compared in detail. On the premise of clarifying the oil source and accumulation period, the control action of migration system and preservation conditions on differential enrichment was studied. The results show that hydrocarbons of W structure have the same source and the same petroleum accumulation period which is after the Middle Miocene. The differential enrichment of hydrocarbon is mainly controlled by oil and gas dredging and fault sealing. W3Ⅱand W3Ⅲ sand groups are the advantage sandstone conductive layers under the regional mudstone cap rock, which is the premise of hydrocarbon enrichment. The relationship between the dominant sandstone carrier layer and the oil source fault and the distribution of the regional cap rock are the main controlling factors of the differential enrichment of oil and gas on the plane. The development degree of the direct cap rock is the main controlling factor of the differential enrichment of oil and gas along the fault in the vertical direction. The research results have reference significance for the next hydrocarbon exploration in W structure of Weixi exploratory area.

https://doi.org/10.3969/j.issn.1008-2336.2022.04.007