Five paragenetic associations are recognized in Fuyu reservoir of Qijia - gulong depression of Daqing oil field: 1) detrital illite permeation, glauconite and pyrite precipitation; 2) feldspar dissolution, kaolinite precipitation and the incipient quartz overgrowths; 3) early calcite cements; 4) postdate quartz overgrowths and pore - filling quartz, authigenetic illite and chlorite formation, feldspar overgrowths, petroleum injections, K - feldspar and calcite cement dissolution; 5) pore - filling calcite and calcite replacement. Five paragenetic associations are recognized in Fuyu reservoir of Qijia - gulong depression of Daqing oil field: 1) detrital illite permeation, glauconite and pyrite precipitation; 2) feldspar dissolution, kaolinite precipitation and the incipient quartz overgrowths; 3) early calcite cements; 4) postdate quartz overgrowths and pore - filling quartz, authigenetic illite and chlorite formation, feldspar overgrowths, petroleum injections, K - feldspar and calcite cement dissolution; 5) pore - filling calcite and calcite replacement.