The invention discloses a water control type
workover fluid and a preparation method thereof. The water control type
workover fluid is prepared from the following components in parts by weight: 2 parts of a clay stabilizer, 0.2-1 part of a high-temperature chelating agent, 0.5-1 part of a
corrosion inhibition bactericide, 1-2 parts of a waterproof locking agent, 5 parts of a
phase change agent and 100 parts of filtered
seawater. The method comprises the following steps: filtering the filtered
seawater until
suspended particles are less than 30 microns in standard value, sequentially adding a clay stabilizer, a high-temperature chelating agent, a
corrosion inhibition bactericide, a water blocking prevention agent and a
phase change agent, and uniformly stirring to obtain the water control type
workover fluid. After the workover fluid enters a reservoir, the
oil phase starting pressure can be reduced, the oil-water interfacial tension can be reduced, the effect of inhibiting
water content rising after well workover is achieved, the workover fluid can be matched with different field operation types, and the
recovery period of an
oil well can be shortened.