METHOD OF OBJECT POSITIONING, ORIENTATION AND FIXATION AT PRESET DEPTHS, METHOD OF DRILLING AND REPEATED REENTRY INTO WELL SIDE BRANCHES AND LANDING-AND-ORIENTING UNIT FOR EMBODIMENT OF METHODS

摘要

FIELD: well directional drilling. SUBSTANCE: well casing is provided with nipples located at preset depths. Each landing and orienting sleeve has characteristic landing profile and is provided with shoe having bevel on its bottom with point directed upward, orienting recess and surfaces of spiral inclined planes extending from point to orienting recess. Landing-and-orienting unit is designed for lowering in casing string and installed into position of engagement with conjugated landing profile of one of casing string nipples. Landing-and-orienting unit has internal tubular executing mandrel capable of forward motion to lowering position when landing pawls and orienting key may move over radius to pass by internal obstacles in casing string and to fixation position when landing pawls and orienting key are locked relative to conjugated landing profile of landing and orienting sleeves. In lowering, the unit passes through nonconjugated landing and orienting sleeves and stops moving only when landing pawls have landing profile conjugated with profile of landing and orienting sleeves. EFFECT: higher efficiency of drilling of directional wells in preset direction. 21 cl, 18 dwg