复杂小断块油藏立体井网开发模式研究

Developing model of complex small fault-block reservoir with tridimensional well pattern

关富佳1 ,刘德华1 ,颜 明

长江大学油气钻采工程湖北省重点实验室，湖北 荆州 434023 中海石油有限公司湛江分公司研究院，广东 湛江 524000

复杂小断块油藏由于断块分割作用，断块碎小、形态各异，每个断块就是一个独立的开发单元。开发上主要表现为油藏能量明显不足，且由于断块面积小，很难用完善的常规面积井网进行注水开发，致使油藏产量递减快。针对复杂小断块油藏的地质和开发的特殊性，提出了以最大限度控制储量为前提，以“少井高产”为理念，以水平井控制优势油砂体，直井、定向井完善注采关系为布井方法的立体井网优化控制理论。在部署井网时，主要考虑断块平面几何形态、断块规模、油砂体空间分布特征等因素，同时考虑储层非均质性、渗透率方向性对水驱效果的影响。实际小断块油藏的虚拟开发结果表明，基于立体井网理论的水平井-直井联合井网， 较直井井网能够更好地开发复杂小断块油藏。

Fault blocks are small and have different shapes because of the segmentation role of fault-block in complex small fault-block reservoirs, and each fault-block is an individual development unit. The reservoir energy is obviously insufficient for development. It is hard to conduct the waterflooding with conventional areal pattern due to the small fault-block areas so as to create a rapid drop of production. Considering the features of geology and development in the complex fault-block reservoirs, the optimization theory of tridimensional well pattern is proposed based on the idea of making controlled reserves maximize and gaining high production by few wells, and on the methods of controlling the main reservoir sands by horizontal well and of improving the injection-production well patterns of vertical well and direction well. The plane geometric shape of fault-block, fault-block size and the spatial distribution of reservoir sands should be considered when the well patterns are disposed. At the same time, the effect of reservoir heterogeneity and permeability directivity on waterflooding effectiveness is also considered. The virtual development result of small fault-block reservoir shows that the combined well pattern of horizontal well and vertical well has a better development effect than the well pattern of vertical well for the complex small fault-block reservoirs based on the theory of tridimensional well pattern.