气顶油气藏细分油藏类型协同精细开发研究

Development Features and Coordinated Fine Adjusting for Gas-Cap Oil & Gas Reservoirs

气顶油气藏在开发中存在气油比迅速上升,油井产量快速下降,检泵周期短等问题,开发难度逐步加大。为此,引入气顶指数,结合对储层地质认识、生产动态特征分析和现场实验的成果,提出细分油藏类型,协同精细开发的技术思路。将气顶油气藏细分为气顶油藏和油环气藏,两类油藏能量、开发特征差异较大,采取两套井网协同注水开发。对于油环气藏,采取边部注水,平衡气顶、油环能量的调整方式;对于气顶油藏,采取面积注水,整体补充油藏能量的调整方式。现场实施表明,该调整方式能取得较好的开发效果,提高采收率5%,该成果对气顶油气藏开发具有较好的指导意义。

For gas-cap oil reservoir,the gas-oil ratio and formation pressure dropped so fast that oil production fell over the period and resulted in short pump detection duration. Therefore,gas cap index is introduced,and combined with the understanding of reservoir geology,the analysis of production dynamic characteristics and the results of field experiments,the technical idea of subdividing reservoir types and cooperating fine development is put forward. The gas-cap oil & gas reservoir is divided into gas-cap reservoir and oil-ring gas reservoir. The energy and development characteristics of the two types of reservoirs are quite different. Two sets of well patterns are adopted for water injection development. For the oil ring gas reservoir,the adjustment mode keeps the energy balance between the gas cap and the oil ring by the side injection water. For the gas top oil reservoir,the area injection is adopted to supplement the adjustment of the energy of the reservoir as a whole. The field implementation shows that the adjustment method can achieve better development effect and increase the recovery rate by 5%,which has a guiding significance for the development of gas-cap reservoirs.