低渗透油藏合理井网系统的研究

Study on Reasonable Well Spacing System of Low Permeability Reservoirs

低渗透油藏受特殊的成藏条件、沉积环境影响,具有孔隙结构复杂、孔喉半径细小,油藏渗透率低,一般小于50×10-3μm2;储层非均质严重,平面渗透率级差最高达几百个数量级;驱替压力大、存在一定的启动压力;天然裂缝发育且存在人工裂缝等特点;因此,在不同渗透率级差下,如何建立起有效的驱替半径,建立合理、经济的井网井距,对提高低渗油藏水驱油效率及采收率,提高低渗透油藏的开发水平具有十分重要的意义。以低渗透油藏唐157井区为例进行研究,建立了合适的井网井距。

Low permeability reservoirs have complex pore structure,small pore throat size,low permeability(less than 50×10-3 μm2)because they were influenced by special accumulation conditions and sedimentary environment;heterogeneity of the reservoir is serious,the highest areal permeability contrast is hundreds orders of magnitude;displacement pressure for the reservoir is big,there is certain start-up pressure;and there is natural fracture development and artificial fracture characteristics;therefore,under different permeability contrast,how to set up effective displacement radius and establish reasonable and economic well pattern is very significance to improve oil displacement efficiency and oil recovery and increase development level for the low permeability reservoir.In this paper,low permeability reservoir,Tang 157 well area as a case,was studied,proper well pattern was established.