Study on the Division of Remaining Recoverable Reserves Abundance in Specific Reservoirs

The Yanchang group Chang 6 reservoir in the Tiebiancheng area, after decades of exploitation, exhibits localized zones of relatively high permeability but is predominantly characterized as an extra-low permeability oil reservoir with minimal natural productivity. The reservoir’s strong heterogeneity poses challenges in achieving production targets, resulting in significant variations in well yields. Therefore, a scientific division of potential zones within the blocks, targeted exploitation strategies are necessary. This study classifies the recoverable reserves abundance of the Chang 6 reservoir in the Tiebiancheng area into four distinct types, based on the analysis of two oilfield indicators: material potential field and flow state field. These types are categorized as follows: high velocity and high abundance (Type I), low velocity and high abundance (Type II), high velocity and low abundance (Type III), and low velocity and low abundance (Type IV). Moreover, tailored exploitation strategies are proposed, considering the characteristics of different favorable target zones. A computational simulation of regional oil production, with zoning exploitation strategies taken into account, indicates an anticipated cumulative oil production of 1463·10⁴ m³ by 2027, whereas the cumulative oil production of the control group is projected to reach 1387·10⁴ m³, resulting in a notable difference of 76·10⁴ m³, signifying a considerable improvement in the recovery rate.