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通过对26口井岩心观察,结合区域构造背景,在鄂尔多斯盆地富县探区三叠系延长组中识别出典型的震积岩。该区震积岩代表性沉积构造有液化砂脉、液化卷曲变形、环状层理、负载构造、球枕构造、微断层、微裂缝、震裂岩与震碎角砾岩,其中液化砂脉和液化卷曲变形是地震引起的主要软沉积变形构造。震积岩垂向序列划分为两类:一种以脆性变形为主,自下向上依次为下伏未震层,扰动层,微断层、微裂缝及震裂岩层段,液化卷曲变形层段,震碎角砾岩层段,液化砂脉层段及上覆未震层;另一种以软沉积变形为主,自下至上依次为下伏未震层,环状层段,扰动层,球枕构造及负载构造层段,液化砂脉及液化卷曲变形层,枕状层及上覆未震层。富县探区延长组中的震积岩说明在该盆地晚三叠世存在一个强地震事件活跃期;震积岩中的微裂缝、微断层、震裂岩及液化砂脉可改善储集层物性,同时震碎角砾岩和网状砂脉也是良好的储集层。
By observing the core of 26 wells and combining the regional tectonic setting, typical seismites are identified in the Triassic Yanchang Formation of Fuxian prospecting area, Ordos Basin. The representative sedimentary structures of the seismites in this area include liquefaction sands, liquefaction crimp deformation, annular bedding, loading structure, pillow structure, micro-faults, microfractures, shock rocks and shattering breccias, of which liquefied sands And liquefaction curl deformation is the main soft sedimentary deformation caused by the earthquake. The vertical sequence of seismites is divided into two types: one is mainly brittle deformation, and the other is the underlying unseismic layer, disturbance layer, micro-fault, micro-fracture and seismic rock section, liquefaction curl deformation section, seismic Broken breccia section, liquefied sand vein section and overlying unseismic layer; the other is mainly soft sedimentary deformation, from bottom to top are underlying unseismic layer, annular section, disturbance layer, ball and pillow structure And load structure section, liquefaction sands and liquefied curl deformation layer, pillow-like layer and overlying unseismic layer. Seismic sediments in the Yanchang Formation of the Fuxian prospecting area indicate that there was an active seismic event during the Late Triassic in the basin; micro-fractures, microseisms, shock rocks and liquefied sand veins in seismites can improve the reservoir Physical properties, along with shattering breccias and reticular sands, are also good reservoirs.