inverted nine-spot pattern meaning in English

反九点井网

The study gets the following conclusions : 1 ) inverted nine - spot pattern water flooding is used in the early stage of the development , while linear water flooding is used in the later stage ; 2 ) well array is parallel to the fracture trend ; 3 ) the well arrangement of barycentric position method is a suitable pattern adjustment method in the later period of the development in low permeable oil fields
研究认为，一是油田开发初期注采方式采用反九点法面积注水，开发后期调整为线状注水方式；二是井排方向与裂缝走向平行；三是“重心位置”布井方式对低渗透油田开发后期是较为适合的井网调整方式。