Method And Apparatus For Closure Of An Earth Borehole

Abstract

A method and an apparatus for closing an earth borehole, wherein an expandable closure body is inserted into the earth borehole and expanded in its diameter in order to seal the leak. The closure body, at least a part thereof, is moved beyond the lower end of the borehole to enter into the raw material filled cavity, and is expanded within the cavity below the borehole and, with an axially sealing surface, is urged from below against the cavity's sealing surrounding the borehole. With regard to the device, to achieve this, the expandable part has an expandable portion with an axially sealing surface which, once expanded, has a diameter significantly greater than the diameter of the borehole. In order to permit the sealing part being pushed against the borehole wall once it has been expanded inside the cavity, a reversible feed motion or advancing drive is provided.

1 . Method for closing an earth borehole comprising:
 introducing an expandable closure body into a borehole; and   expanding the closure body in its circumference to close the borehole;   wherein at least part of the closure body is moved out of the a lower end the borehole, and expanded within an earth cavity, and, with an axially sealing surface, it is urged from below against the a ceiling of the cavity surrounding the borehole.   
     
     
         2 . Method according to  claim 1 , wherein an expanding body is used, which, after expansion, is set, with an edge portion, onto the cavity's ceiling, and is splayed and spread out by retracting the expanding body towards the borehole in the direction opposite to the inserting direction. 
     
     
         3 . Method according to  claim 1 , wherein the closure body, together with a drill head, is inserted into the borehole via a boring bar, wherein the drilling head is positioned ahead of the closure body when considering the direction of insertion and is left in the cavity also after having closed the borehole. 
     
     
         4 . Method according to  claim 1 , wherein the closure body is transported through the borehole via a self-propelling vehicle which, after expansion of the closure body, is reversed back in the borehole until the closure body's axially sealing surface is in contact with the ceiling of the cavity. 
     
     
         5 . Method according to  claim 1 , wherein the cavity is a cavity containing liquid or gaseous crude materials and whose ceiling is approximately perpendicular to the direction of the borehole, wherein an axial sealing surface of the closing body is also approximately perpendicular to the direction of the borehole, wherein the closing device and the axial sealing surface are moved against the cavity's ceiling axially in the direction of the longitudinal axis of the earth borehole. 
     
     
         6 . Method according to  claim 1 , wherein the sealing of the borehole is achieved exclusively by axial pressure of an axial sealing surface against the ceiling in the direction of the longitudinal axis of the borehole, wherein the axially sealing surface is pressed against the cavity's ceiling by pressures exhibited by gas or fluid from within the cavity. 
     
     
         7 . Method according to  claim 1 , wherein the closing body contains an expandable umbrella element at whose outer margin an axial sealing surface is located, which umbrella element is expanded in the cavity below the borehole in such a fashion, that the closing body forms a concave dome towards the borehole, which dome shaped expanded umbrella is flattened and further expanded, locking or grabbing itself into the ceiling, as the pressure of the fluid or gas within the cavity is pushing against it back towards the borehole. 
     
     
         8 . Apparatus for closing and sealing an earth borehole comprising:
 an expandable closing device that, in the collapsed state, has a smaller diameter than a borehole,   wherein the closing device is provided with an axially sealing surface at an expandable sealing portion, whose diameter in the expanded state, is bigger than the borehole circumference, and a reversible feeding drive is provided for moving the closing device forwardly beyond the end of the earth borehole into a cavity below the borehole, and for moving the closing device backwards with the axial sealing surface being urged against a ceiling surrounding the borehole after expansion of said sealing portion.   
     
     
         9 . Apparatus according to  claim 8 , wherein the expandable sealing portion has a swinging or unfoldable umbrella element at whose outer margin the axial sealing surface is contained. 
     
     
         10 . Apparatus according to  claim 8 , wherein an expandable sealing part's roof which is facing the ceiling of the cavity, forms a concave, expansion or spreading body, whose outer margin forms the axial sealing surface. 
     
     
         11 . Apparatus according to  claim 8 , wherein the expansion or spreadable body is adapted to be deformable, such that said expansion or spreadable body is able to be flattened by the pressure exhibited by the fluid/gas within the cavity and as a result expand the axial sealing surface radially. 
     
     
         12 . Apparatus according to  claim 8 , wherein the expandable sealing part, in the expanded state, has a diameter of at least 150%, of the borehole diameter. 
     
     
         13 . Apparatus according to  claim 8 , wherein the axial sealing part forms a ring shaped surface, whose inner diameter is bigger than the diameter of the borehole. 
     
     
         14 . Apparatus according to  claim 8 , wherein the closing device comprises a valve mechanism which is situated in a connection channel, which has an opening towards the borehole as well as to the cavity so, when the valve mechanism is set ‘open’, fluid can stream from the cavity into the borehole. 
     
     
         15 . Apparatus according to  claim 8 , wherein the closing device in the expanded state, has an approximately planar impingement area extending approximately perpendicular to the longitudinal axis of the earth borehole, wherein the pressure exhibited by the fluid in the cavity acts upon said impingement area which is faced away from the ceiling and contains a surface area of more than 200% of the surface area of the borehole. 
     
     
         16 . Method according to  claim 1 , wherein the sealing of the borehole is achieved exclusively by axial pressure of an axial sealing surface against the ceiling in the direction of the longitudinal axis of the borehole, wherein the axially sealing surface is pressed against the cavity's ceiling by pressures exhibited by retraction of the closing device back towards the borehole. 
     
     
         17 . Apparatus according to  claim 8 , wherein an expandable sealing part's roof which is facing the ceiling of the cavity, forms a concave, expansion or spreading body, whose outer margin forms the axial sealing surface, and which expansion or spreading body, within the axially sealing surface, is sloped towards the centre of said closing body. 
     
     
         18 . Apparatus according to  claim 8 , wherein an expandable sealing part's roof which is facing the ceiling of the cavity, forms a concave, expansion or spreading body, whose outer margin forms the axial sealing surface, and which expansion or spreading body, within the axially sealing surface, is spaced apart from the ceiling of the cavity. 
     
     
         19 . Apparatus according to  claim 8 , wherein the expandable sealing part, in the expanded state, has a diameter of at least 200% of the borehole diameter. 
     
     
         20 . Apparatus according to  claim 8 , wherein the axial sealing part forms a ring shaped surface, whose inner diameter is bigger than the diameter of the borehole by at least  180 % of the borehole diameter.