Well completion transformation integrated process matched with coiled tubing windowing and sidetrack drilling of horizontal well in casing

The invention discloses a well completion transformation integrated process matched with a coiled tubing windowing sidetrack drilling horizontal well in a casing. The well completion transformation integrated process comprises a well drilling process, a well completion process and a maintenance process. The drilling technology comprises the following steps that S1, a whipstock is fed into a target layer of an oil well and fixed; s2, windowing a sleeve of the target layer of the oil well; s3, a deflecting section is excavated; s4, horizontal section oil well excavation is conducted, and a pore throat of an oil and gas reservoir is protected in the excavation process; the well completion technology comprises the following steps that S5, a high-pressure water column is used for conducting staged fracturing on the horizontal section oil well; s6, the fractured horizontal section oil well is subjected to sand washing, and a sand prevention layer is arranged after sand washing is completed; the maintenance process