Multi-drain drilling and petroleum production start-up device

A drilling and petroleum production start-up device of a drilling well comprising a master well and at least one branched well opening into said master well, said device comprising an outer tube having an inner wall, and at least one take-off assembly fastened in situ in said outer tube and incorporating several take-off tubes, at least one of which has a lower end which communicates with a branched well, a space located between said take-off tubes and the inner wall of the outer tube being filled with cement, in order to produce a take-off assembly in the form of a compact and rigid block, said device incorporating a receptacle fastened to the take-off assembly and possessing bores in which upper ends of the take-off tubes are received, a movable connection assembly being interposed between the take-off assembly and surface means necessary for the working of the drilling well, wherein the connection assembly incorporates at least three hollow lengthening pieces having opposing ends, one of said lengthening pieces being capable of being received by one of its ends in one of the take-off tubes, its other end communicating with the surface of the drilling well, and means of blocking the other take-off tube or tubes.