裂缝性低渗透砂岩油田合理注采井网

Optimal flooding patterns in fractured low-permeability sandstone reservoir

裂缝性低渗透油田的合理注采井网要能延缓方向性水窜、水淹时间和解决注不进水的问题 ,由于压力传导慢 ,注采井距不能过大 ,开发后期要能灵活调整井网。吉林油区已开发裂缝性低渗透油田采用过 4种注采井网开发 :正三角形斜反九点法注采井网 (扶余油田 ) ,井排方向与裂缝方向错开 2 2 .5°的注采井网 (新立油田 ) ,井排方向与裂缝方向错开 45°的注采井网 (新民油田 ) ,菱形反九点法面积注采井网 (民 43 8区块和大情字井油田 )。总结注采井网调整历程中的经验和教训 ,开发初期应采用小排距菱形反九点法面积注水 ,开发后期调整为线状注水 ;井排方向应与裂缝走向平行 ;若经济条件允许 ,开发后期用密井网注采 ,尽可能缩短油、水井排距。图 2表 2参

An optimized flooding pattern in fractured low permeability reservoir should delay directional water break through, prolong water flooded time, and deal with the problem of water injection failure. Because of the generally slow pressure transfer rate, the producer injector spacing should be relatively close so that the well pattern is flexible for adjustment during the late development phase. Four types of flooding patterns are used in the fractured low permeability reservoir of the Jilin Oilfield: ①skew inverted nine spot flooding arranged in an equilateral triangle pattern (Fuyu Oilfield); ②flooding pattern with the well array direction at 22.5° with the fracture strike (Xinli Oilfield); ③flooding pattern with the well array direction at 45° with the fracture strike (Xinmin Oilfield); ④skew inverted nine spot flooding arranged in a rhombic pattern (Min 43 8 block and Daqingzijing Oilfield). The skewed inverted nine spot pattern flooding with a close well spacing should be used during the initial development phase, and the pattern should be adjusted to linear flooding during the late development phase. The well array direction should be parallel to the fracture strike.