Drifting tubing
A method of checking for restrictions in a string of tubing formed of a plurality of tubing sections. The method involves providing a profile in the tubing string, providing a drift member adapted to engage with the profile, passing the drift member through the tubing string, and determining whether the drift member has engaged with the profile prior to separating the tubing sections.
1. Apparatus for identifying the presence of an undesirable bore restriction in a tubing string located in a drilled bore, the apparatus comprising a drift member and a profile location in a tubing string, the drift member being adapted to pass through tubing string from a proximal end of the string and to engage the profile, wherein the engagement of the drift member with the profile is operator detectable from the proximal end of the tubing, wherein the drift member is configured such that engagement of the drift member with the profile restricts fluid flow through the tubing and such that engagement with a restriction other than the profile restricts fluid flow through the tubing to a lesser extent.
2. The apparatus of claim 1 , wherein the drift member comprises a sleeve having an external profile and defining an internal flow restriction and one or more ports are provided in the sleeve wall forwardly of the internal flow restriction and the external profile, whereby if the leading end of the sleeve encounters and engages a restriction fluid may flow through the annulus between the trailing end of the sleeve and the tubing, through the flow ports and into the interior of the sleeve, and then through the leading end of the sleeve.
3. A method of checking for undesirable restrictions in a string of tubing located in a drilled bore and comprising a plurality of tubing sections, the method comprising:
providing a profile in the tubing string;
providing a drift member adapted to engage with said profile;
pumping the drift member through the tubing sting from a proximal end of the tubing to engage a restriction in the tubing;
determining whether the drift member has engaged with said profile prior to retrieving the string from the bore and separating the tubing sections; and
identifying the location of the restriction by identifying the location of the drift member in the tubing from said proximal end of the tubing.
4. A method of checking for undesirable restrictions in a string of tubing located in a drilled bore and comprising a plurality of tubing sections, the method comprising:
providing a profile in the tubing string;
providing a drift member adapted to engage with said profile;
pumping the drift member through the tubing string; and
determining the location of a restriction in the tubing engaged by the drift member by identifying a volume of fluid pumped into the tubing behind the drift member.