The invention provides a
modified starch-based temporary plugging agent suitable for oil-based
drilling fluid as well as a preparation method and application of the
modified starch-based temporary plugging agent. The preparation method of the
modified starch-based temporary plugging agent comprises the following steps: adding
starch sodium octenylsuccinate into water, uniformly stirring, then adding
acrylamide,
butyl acrylate, 2-acrylamido-2-methylpropanesulfonic acid and N, N '-
methylene bisacrylamide, uniformly stirring, and adjusting the pH value to 6-8 to obtain a water phase; adding the emulsifier into the
white oil, and uniformly stirring to obtain an
oil phase; adding the water phase into the
oil phase, and emulsifying to obtain an
emulsion; adding an initiator into the obtained
emulsion, and reacting to obtain a reaction solution; and adding
ethanol into the obtained reaction liquid for
precipitation, centrifuging, washing,
drying and
grinding to obtain the product. The temporary plugging agent disclosed by the invention is stable in dispersion in an oil-based
drilling fluid system, high in high-temperature plugging capacity, capable of efficiently plugging a high-permeability channel and automatically degrading, and capable of meeting the plugging and reservoir protection requirements of the deep well oil-based
drilling fluid.