METHODS AND APPARATUS FOR FORMING AN OFFSHORE WELL

A method for forming an offshore well comprises forming a well structure (1) which includes a lower well portion extending below a seabed and an upper well portion (2) extending upwardly between the seabed (18) and a terminating upper end (3) of the well structure, wherein the well structure comprises a plurality of concentrically arranged tubular strings (22) and at least one annulus (48) defined therebetween. The method includes steps for minimising the bending stiffness of the upper well portion. In one example minimising the bending stiffness of the upper well portion may comprise partially filling at least one annulus with cement (52) to a height which: is intermediate the seabed and the terminating upper end of the well structure. In another example minimising the bending stiffness of the upper well portion may comprise providing a cement disruptor within at least one annulus and locating cement within said at least one annulus to define a cement sheath, wherein the cement disruptor, for example sleeve (122), reduces resistance of at least a portion of the cement sheath to bending of the upper well portion. In a further example minimising the bending stiffness of the upper well portion may comprise locating a flexible material within at least one annulus; and In a further example minimising the bending stiffness of the upper well portion may comprise varying the bending stiffness along at least one of the plurality of tubular strings.