鄂尔多斯盆地姬塬地区延长组砂岩储层中存在大量天然裂缝。裂缝类型为弱构造变形区形成的高角度构造裂缝，走向以北西—南东向为主，其次为北东—南西向；延长组低渗透致密储层的形成和燕山早期构造运动的改造是裂缝形成的重要条件；裂缝的大量存在，使该区石油运聚具有独特的裂缝型垂向多点式充注运聚模式，形成了同一区块垂向多油层叠合、平面上发育多个含油富集区的油藏分布特征。

Natural fractures developed well in sandstone reservoirs of Upper Triassic Yanchang Formation in Jiyuan area, Ordos Basin. The fractures are high angle tectoclase generated in the slight tectonized areas. These fractures are generallyNW-SE striking, though some are NE-SWstriking. Lowpermeability sandstone reservoirs and the Yanshanian Movement are the key elements for the formation of these fractures. Because of the existence of the tectoclase, a uniquely petroleum migration and accumulation model is formed in this area: petroleum migrates to upper reservoirs through fracture multipoint; meanwhile, the distribution of oil reservoir is multi-area in horizon, and many oil reservoirs in vertical in the same areas.