Method for reducing water injection pressure of reservoir well

• Main Authors: QI YIN, LI CHUAN, TIAN XIAOJIE, DONG LIQUAN, LU HONGJUN, WU FURANG, LI JIANSHAN, CHEN WENBIN, GU YANLING, LIU JING, DUAN PENGHUI
• Format: Patent
• Language: Chinese; English
• Published: 16.01.2013
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

The invention relates to a method for reducing water injection pressure of a reservoir well. The method comprises the following steps of: 1, displacing 1 to 2 cubes of cleaning fluid, closing the well, reacting for 50 minutes, cleaning a shaft, an oil pipe and hole impurities, and displacing residual acid out of the shaft; 2, injecting a first front acid slug in a volume which is one time the volume of the shaft; 3, injecting a second main body acid slug in a volume which is twice the volume of the shaft by positive extrusion; 4, injecting a third rear acid slug in a volume which twice the volume of the shaft by positive extrusion; and 5, injecting a fourth surfactant slug in a volume which is 5 to 6 times the volume of the shaft by positive extrusion, wherein the concentration of the surfactant is 0.15 to 0.05 percent, and the balance is clean water. The water injection pressure of the ultra low-seepage compact water injection well is reduced through a comprehensive effect formed by different acting mechanis