Double-wall-base structure after deep drilling well shaft breaks bottom of well wall and construction method

Abstract

The invention provides a double-wall-base structure after a deep drilling well shaft breaks the bottom of a well wall, and relates to the technical field of well drilling construction. The double-wall-base structure is arranged below the well wall of a drilling section, and the double-wall-base structure comprises an auxiliary wall base connected with the lower end of the well wall of the drilling section; the upper end of a transition section well wall is connected with the lower end of the auxiliary wall base; a main wall base is connected with the lower end of the transition section well wall, and the main wall base is located below the auxiliary wall base; the thick of the auxiliary wall base is smaller than the thick of the main wall base, according to the double-wall-base structure, the phenomenon that an upper drilling well wall is pulled open among a plurality of sections due to the fact that a ingate on the lower portion of a drilling well shaft located in the thick unconsolidated formation thin bed rock condition is damaged and repaired for multiple times is effectively avoided, water gushing and sand bursting are prevented from submerging a mine, and the possibility of accidents is reduced.

Description

technical field [0001] The invention relates to the technical field of drilling construction, in particular to a double-wall seat structure after breaking the well wall and bottom of a deep drilling shaft. Background technique [0002] After the borehole wall barrel is sunk to the bottom and filled and cemented, the borehole wall structure is in a stable stress state. When the bottom of the borehole wall is cut by blasting method, if it is removed at one time, the lower support constraint is released, and the lower end surface of the borehole wall barrel is in a suspended state, which is very easy to cause cracks or damage at the weak vertical bearing capacity of the drilling borehole wall internodes. It is unfavorable to the force and waterproof of the well wall, and affects the safe use of the wellbore. [0003] If the drilling wellbore in the condition of thick loose bed and thin bedrock is damaged repeatedly by the lower horse head gate, the upper drilling well wall wil...

AI Technical Summary

Problems solved by technology

When the bottom of the borehole wall is cut by blasting method, if it is removed at one time, the lower support constraint is released, and the lower end surface of the borehole wall barrel is in a suspended state, which is very easy to cause cracks or damage at the weak vertical bearing capacity of the drilling borehole wall internodes. It is unfavorable to the force and waterproof of the well wall, and affects the safe use of the wellbore

[0003] If the drilling wellbore located in the condition of thick loose bed and thin bedrock is repeatedly damaged by the lower horse head gate, the upper drilling well wall will be pulled apart at multiple nodes, resulting in water gushing and sand flooding the mine, which will cause major economic losses

Images