Abstract: A settable thixotropic material comprises a thixotrope and a settable substance, the material being capable of gelling reversibly in a gelling time of less than 60 seconds. The thixotrope conveniently comprises a fine grained clay, especially smectite clays, e.g. hectorites. It is preferred to use synthetic smectite type clay colloids, and goods results have been obtained with the synthetic clay known as Laponite RDS. The settable material conveniently comprises cement, particularly Portland cement. The thixotropic material finds use generally in oilwell applications, e.g. to plug lost circulation zones, to repair damaged or corroded casing, as grouts, and to limit annular gas migration. The material also finds particular application in techniques for completion of horizontal wells completed with slotted or pre-drilled liners.

Abstract: A trailer (10) has a dropped center section (12) defining a well (16) for a coiled tubing reel (22). A mast (30) has a pair of posts (34) on which a carriage (32) is mounted for movement along posts (34). An injector head (36) is supported on carriage (32) for pivotal movement in a vertical plane relative to mast (30) and for horizontal movement along a tubular support member (38) of carriage (32) relative to mast (30). Mast (30) is pivotally mounted on the rear end of trailer (10) for movement away from trailer (10) for positioning over a wellhead. In a stored position, mast posts (34) fit alongside the ends of reel (22) so that to the total height of the stored coiled tubing rig is no more than 13½ feet for over the road travel.