Patent ID: 11965389
Assignee: SOUTHWEST PETROLEUM UNIVERSITY
Field: Civil engineering (Other fields)
Classification: CPC E  Y | IPC E

Claim 6:
7. The patching construction method using a hydraulic variable-grade expansion tool for blocking during drilling according to claim 1, wherein enabling the positions of the tapered centering sub (8), the split supporting subs (10) and the expansion cone (11) to be exchanged comprises:
arranging the positions in such a first order of the expansion cone (11), the tapered centering sub (8) and the split supporting subs (10), so as to form the rear placement of the variable-grade expansion tool and to be suitable for a straight well section;
arranging the positions in such a second order of the tapered centering sub (8), the expansion cone (11) and the split supporting subs (10), so as to from the middle placement of the variable-grade expansion tool and to be suitable for a straight well section and an oil and gas well with a hole angle of less than 55 degrees; and
arranging the positions in such a third order of the tapered centering sub (8), the split supporting subs (10) and the expansion cone (11), so as to form the front placement of the variable-grade expansion tool and to be suitable for a horizontal well section and an oil and gas well with a hole angle greater than 55 degrees.