Core Barrel and Related Drilling Apparatus and Method

Abstract

There is disclosed herein drilling apparatus, in particular for use in the field of oil prospecting, comprising: a first tubular member ( 1, 2, 3 ); a second tubular member ( 6, 7, 8, 9 ) mounted at least partly within the first tubular member so as to be reciprocally free in rotation with respect to the first tubular member about an axis ( 5 ); and a drill bit ( 4 ) operatively connected to one of the first or second tubular members so as to be rotated in response to the one tubular member being turned in order to effect drilling, characterised in that: the drilling apparatus further comprises a restoring member ( 18, 36 ) for applying a forces between the first tubular member and the second tubular member at least in respective first axial directions in response to relative displacement of the first tubular member and the second tubular member in the respective opposite axial directions. Also provided are a tubular assembly and a method of assembling tubular members.

1 - 19 . (canceled) 
     
     
         20 . A drilling apparatus for oil prospecting, comprising:
 a first tubular member;   a second tubular member mounted at least partly within the first tubular member so as to be reciprocally free in rotation about an axis with respect to the first tubular member;   a drill bit operably connected to one of the first or second tubular members so as to be rotated in response to the one tubular member being turned in order to effect drilling; and   a spring member for applying a force between the first tubular member and the second tubular member at least in a respective first axial direction in response to relative displacement of the first tubular member and the second tubular member in respective opposite axial directions.   
     
     
         21 . The drilling apparatus of  claim 20 , further comprising:
 an outer assembly formed by the first tubular member and the drill bit, wherein the first tubular member includes at least one outer tube and the drill bit is a core bit;   an inner assembly formed by the second tubular member and at least one core removal element, wherein the second tubular member includes at least one inner tube;   a holder configured to hold the inner assembly in the outer assembly, the holder including at least one rolling bearing arranged between the inner assembly and the outer assembly so that the inner and outer assemblies are reciprocally free in rotation; and   at least one spacer element formed in part by the spring member, wherein the spacer element is housed inside the outer assembly such that the spacer element bears against a bearing surface of one of the inner and outer assemblies and the rolling bearing to axially bias the rolling bearing away from the bearing surface.   
     
     
         22 . The drilling apparatus of  claim 20 , wherein the spacer element further comprises:
 an upstream tubular part that bears against the at least one outer tube;   a downstream tubular part that bears against the rolling bearing, wherein the spring member is arranged between the upstream and downstream tubular parts and bears against the upstream and downstream tubular parts to act axially thereon so as to move apart the upstream and downstream tubular parts; and   retaining features configured to limit the moving-apart of the upstream and downstream tubular parts.   
     
     
         23 . The drilling apparatus of  claim 22 , wherein the spring member comprises spring washers. 
     
     
         24 . The drilling apparatus of  claim 22 , wherein:
 one of the upstream and downstream tubular parts includes a female tubular end piece and the other tubular part includes a male tubular end piece configured to slide axially inside a cavity of the female tubular end piece; and   the spring member is housed at a bottom of the cavity such that the spring member bears against the male end piece pushed into the female end piece.   
     
     
         25 . The drilling apparatus of  claim 24 , wherein the retaining features comprise:
 a plurality of elongate slots extending in the axial direction in the female tubular end piece; and   locking elements coupled to the male tubular end piece so as to protrude radially into the elongate slots and to limit a spacing of the upstream and downstream tubular parts by bearing against one end of the elongate slots.   
     
     
         26 . The drilling apparatus of  claim 21 , wherein the holder further comprises an upstream rolling bearing and a downstream rolling bearing placed around one of the inner tubes and housed inside one of the outer tubes, the downstream rolling bearing being arranged between a downstream-facing first annular bearing surface of the one inner tube and an upstream-facing annular stop surface of the one outer tube, the upstream rolling bearing being arranged between an upstream-facing second annular bearing surface of the one inner tube and the spacer element, the first and second annular bearing surfaces of the one inner tube being located between the upstream and downstream rolling bearings. 
     
     
         27 . The drilling apparatus of  claim 26 , wherein:
 the first and second annular bearing surfaces of the one inner tube are provided on an annular flange that protrudes radially therefrom and is clamped between the upstream and downstream rolling bearings;   the upstream rolling bearing is axially spaced apart from the outer assembly by the spring member of the spacer element; and   the downstream rolling bearing is retained by the annular stop surface of the one outer tube.   
     
     
         28 . The drilling apparatus of  claim 26 , wherein:
 the one outer tube comprises an upstream section and a downstream section screwed to one another;   the spacer element bears between the upstream section and the upstream rolling bearing; and   the downstream section includes the annular stop surface on which the downstream rolling bearing bears, the screwing of the upstream section and the downstream section being adjustable to adjust an prestressed spring force of the spring member of the spacer element.   
     
     
         29 . The drilling apparatus of  claim 26 , further comprising an additional spacer element inserted between the downstream rolling bearing and the upstream-facing annular stop surface of the one outer tube. 
     
     
         30 . The drilling apparatus of  claim 29 , wherein the additional spacer element is a spring member. 
     
     
         31 . The drilling apparatus of  claim 26 , wherein:
 the one inner tube of the inner assembly is held by the holder at an upstream end; and   the one inner tube includes an outer thread at a downstream end configured to cooperate with an inner thread of another inner tube of the inner assembly in order to fix the inner assembly in an axially adjusted condition.   
     
     
         32 . The drilling apparatus of  claim 31 , further comprising a threaded locking nut arranged on the outer thread of the downstream end of the one inner tube, wherein the locking nut is clamped against the another inner tube when the inner assembly is in said axially adjusted condition. 
     
     
         33 . The drilling apparatus of  claim 31 , further comprising a locking washer clamped around the threaded downstream end of the one inner tube when the inner assembly is in the axially adjusted condition and located between a threaded locking nut and the another inner tube, wherein the locking washer is arranged to prevent any unscrewing of the locking nut and of the another inner tube on the threaded downstream end. 
     
     
         34 . The drilling apparatus of  claim 20 , wherein the drilling apparatus is a core barrel. 
     
     
         35 . A tubular assembly for oil prospecting, comprising:
 a first tubular member;   a second tubular member threaded part way onto a threaded portion of the first tubular member, the second tubular member configured to be threaded further onto or partially unthreaded from the first tubular member to adjust the assembled length of the first and second tubular members; and   a locking nut configured to be moved to a locking position to prevent the second tubular member being further threaded onto or unthreaded from the first tubular member.   
     
     
         36 . The tubular assembly of  claim 35 , further comprising:
 a locking washer including, respectively, corresponding notches or projections thereon to engage with projections or recesses on the second tubular member and the locking nut when the locking nut is moved to the locking position to prevent relative rotation between the second tubular member, the locking washer and the locking nut.   
     
     
         37 . The tubular assembly of  claim 36 , wherein:
 the first tubular member includes recesses that extend along at least a portion of the length thereof; and   the locking washer includes inner projections to engage in the recesses when the locking nut is moved to the locking position to prevent relative rotation between the locking washer and the first tubular member.   
     
     
         38 . A method of assembling tubular members for oil prospecting, comprising:
 threading a first tubular member part way onto a threaded portion of a second tubular member to obtain a desired assembled length of the first and second tubular members; and   moving a locking nut into a locking position to prevent the first tubular member from being further threaded onto or unthreaded from the second tubular member.   
     
     
         39 . The method of  claim 38 , further comprising providing a locking washer, and wherein moving the locking nut to the locking position prevents further relative rotation between the first tubular member, the locking washer and the locking nut and/or between the locking washer and the second tubular member.