| 摘要 |
<p>A centraliser segment (11) comprising a first collar portion(15), a second collar portion (17) and bow element (19) extending between said first collar portion and said second collar portion to maintain the collar portions in spaced relation to each other, said bow portions having an intermediate portion which lies to one side of the plane accommodating the collar portions, a first connector element (21) provided at one end of the collar portions and second connector element (23) provided at the other end of the collar portions, said first connector elements are engagable with said second connector elements of the same or another centraliser segment such that one or more said centraliser segments are connectable together to form a centraliser which in use is capable of being received around a borehole casing, said first and second connector element having an adjustment element which can cause the diameter of the centraliser can be varied by operation of the adjustment element (41) wherein the adjustment is controllably and continuously variable over a range of diameters.</p> |
