The invention discloses a preparation method of a lignite resin
drilling fluid filtrate
reducer, and relates to the technical field of
petroleum and
natural gas drilling engineering. The method comprises the following steps: carrying out
superfine grinding on lignite, carrying out
alkaline hydrolysis pretreatment on waste nylon PA66, alkalizing lignite
powder, carrying out sulfonation reaction on the alkalized lignite
powder and
phosphorous acid to introduce phosphonic acid groups, carrying out cross-linking with tetrabutyl
titanate to form a three-dimensional
network structure, and adding a nano-
montmorillonite suspension to realize physical enhancement. A
reaction product is subjected to freeze-
drying, a porous structure is reserved, and then the product and
polyethylene glycol 400 are mixed and granulated. By utilizing
humic acid functional group
grafting, inorganic-organic composite cross-linking and waste
raw material recycling technologies, the product still keeps excellent
filtration loss control capability at the high temperature of 200 DEG C and in a saturated
salt solution, the high-temperature and high-pressure
filtration loss is less than or equal to 6.50 mL, the
viscosity retention rate is greater than or equal to 92.8%, the lubricating coefficient
reduction rate is greater than or equal to 48.5%, and the product has the advantages of
temperature resistance,
salt resistance,
environmental protection and low cost, and is suitable for industrial production. And the method is suitable for deep oil-gas
drilling engineering.