Longshore changes in the microfacies and distribution of clastic barrier coastal sandbodies: a case from the Benxi formation in the Ordos Basin, China

• DOI: 10.1007/s13202-024-01760-4
• Publication Date: 2024-02-27T02:02:12Z
• Authors: Xiangzhen Meng; Renhai Pu; Tiancai Dou; Gang Liu; Hujun Gong; Ming Song; Yujie Fan
• Keywords: Shoal; Terrigenous sediment

Abstract The Benxi Formation in the Ordos Basin is an important gas-producing layer Yanchang gas field. There are critical changes microfacies type and extension trend of sandbodies, which affects understanding reservoir formation deployment development wells. Based on many core thin section observations, as well statistical analyzes sandstone thickness percentage content from 1446 wells, we analyzed coastal control factors type, planar morphology distribution Fm sandbodies results indicate that field generally composed terrigenous clastic barrier deposits a medium to small tidal range environment, but wave action southern region weak, forming typical sandbars backbarrier deposits. actions north change more strongly, three major sandbodies: reworked barriers, shoals incised valley filled channels. arranged belt or bead-like pattern parallel shoreline distributed longshore near provenance. oval-shaped shoal dispersed further shoreline, filling channel controlled by ancient geomorphic grooves. This research has guiding significance for identification evaluation reservoirs similar geological settings.