Abstract

Study on the technology that sidetracking horizontal wells with ultra-short radius to select boundary layer has certain practical meaning. But recently this kind of research, especially the study on sidetracking position for horizontal well, is less or even none. In this paper, on the basis of the potential superposition method and the equivalent flowing resistance method, the cumulative oil production calculation model of the horizontal well after sidetracking is established. Then the dimensionless height from the top is introduced to modify the model with the means of numerical simulation. Therefore set up the relationship between the cumulative oil production and six factors such as cumulative oil production, effective thickness, the dimensionless height from the top, average permeability, oil and water wells, the average remaining oil saturation and completeness of drilling stage for horizontal well. By combining break-even analysis, layer selection method of ultra-short radius horizontal wells is determined. A relevant chart is also obtained. The method established in this paper can help to choose the optimal layer of sidetracking horizontal well with ultra-short radius.