鄂尔多斯盆地中生界油藏连通性特征研究——以定边-安边以南地区为例

油藏连通性评价是油田开发和管理方案中必不可少的研究内容,而原油色谱指纹技术可以发挥重要作用。鄂尔多斯盆地定边—安边以南地区中生界油藏的原油色谱指纹参数的研究结果显示,该地区铁边城、定边和姬塬井区之间相同层位原油的色谱指纹特征相差较大,表明了它们之间的油藏流体不具有连通性。同一井区范围内,上三叠统延长组相同层段油藏原油色谱指纹分布特征相似,相互间流体连通性较好,而下侏罗统延安组相同层段油藏之间的原油色谱指纹分布特征大部分差异明显,表明它们之间的连通性较差。研究地区中生界油藏原油色谱指纹特征存在差异主要与油气运移过程有关,而且与油藏所在储层的古地理位置分布关系密切。

A Study of Mesozoic Oil Reservoir Connectivity in the Ordos Basin:A Case Study of the Southern Anbian-Dingbian Area

The assessment of oil connectivity makes up an indispensable part of the field production and field management scheme, in which the oil chromatographic fingerprint technology can play an important role. Studies of oil chromatographic fingerprint for the Mesozoic oil reservoir connectivity of the Ordos basin in southern Anbian-Dingbian area show that there exist significant differences in the fingerprint distribution between Tiebiancheng, Dingbian, Jiyuan, and Hujianshan well fields, suggesting that fluids in reservoirs of these well fields are not connected with each other. Within the limits of a well field, the distribution of crude oil chromatographic fingerprints reveals a good connectivity between different reservoirs of Upper Triassic Yanchang Formation and a poor connectivity between different reservoirs of Lower Jurassic Yan'an Formation. In the studied area, the differences in oil chromatographic fingerprint distribution between Yanchang Formation and Yan'an Formation reservoirs are probably caused by the migration of oil and gas, and are closely related to the heterogeneity of the ancient geographic location.