Method for displacing crude oil in low-permeability reservoir

• Main Authors: YOU YANPING, YIN XIANGXIANG, SHAN HAIDAN, YANG LEI, LIU YANG, GUO XIAOGUANG
• Format: Patent
• Language: Chinese; English
• Published: 10.06.2022
• Subjects: ADHESIVES; CHEMISTRY; DYES; EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE; METALLURGY; MINING; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; PAINTS; POLISHES

The invention provides a method for displacing crude oil in a low-permeability oil reservoir, which comprises the following steps of: drilling at least two wells in the low-permeability oil reservoir, and injecting nitrogen into the first well to carry out a nitrogen flooding stage; in the nitrogen flooding stage, when the oil production amount of injecting 104 cubic meters of nitrogen is smaller than 2.5 tons, the nitrogen and foam combination flooding stage is carried out in the first well; and in the nitrogen and foam composite flooding stage, when the produced oil quantity of the injected 104 square nitrogen and 10 square foaming agent composite solution is smaller than 2.5 tons, the nitrogen and foam micro-dispersing agent profile control and flooding stage is carried out in the first well. According to the method, the problems that water injection development of the low-permeability reservoir is difficult and energy decline is fast can be effectively solved, the problem that the later-stage effect of si