关键词: 致密油, 页岩油, 裙边油, 非常规资源, 成藏模型, 盆地模拟, 鄂尔多斯盆地

Abstract:

Chang 8 reservoir of Yanchang Formation in Xiasiwan area of Ordos Basin is a typical lowporosity and low permeability sandstone reservoir. The fractures have a significant impact on hydrocarbon accumulation and the oilfield development effect as the fractures can be as the effective space and the main seepage channel of low permeability reservoir. Therefore, the characteristics and the identifications of the fracture are the key research work to the evaluation of the reservoir in this area. Based on regional geology, well logging, well drilling and core data in Xiasiwan area, fracture characteristics were analyzed by the study of tectonic stress field, slices and conventional logging analysis. Through the comparison between the palaeotectonic stress field and the modern tectonic stress field, the favorable distribution
position of the fractures is analyzed and the main orientation affected by regional tectonic movement is NE 70°, which can provide a strong basis for suitable arrangement ofwell patterns. The data of rock slices indicate that micro-fractures are well developed and have better connectivity. By combiningwith the intersection identification method of deep-probe resistivity and acoustic time and the response characteristics of conventional logging for fractures, the single well fractures can be identified, and it is concluded that conventional logging data is more inclined to identify the fractures developed inmudstone.

Key words: tight oil, shale oil, halo oil, unconventional resources, accumulation model, basin modeling, Ordos Basin