Abstract: A method of sealing a fluid leakage path 106, such as a fluid leakage path through a wall 104 of a structure 102. In an embodiment, the method comprises supplying a loss control composition 114 to a region of a wall 104 of a structure 102 having a fluid leakage path 106 and causing the loss control composition 114 to enter and propagate along at least a portion of the fluid leakage path 106. The loss control composition 114 comprises a mixture of at least one fluid and particles of material 116a, 116b suspended in the fluid. The particles of material 116a, 116b are configured to become trapped within the fluid leakage path 106 as the loss control composition 114 propagates along the at least a portion of the fluid leakage path 106 such that the particles of material 116a, 116b accumulate within the fluid leakage path 106 thereby sealing the fluid leakage path 106.

Abstract: A method of inhibiting leakage of a fluid through a defect (4) in a wall of a pipe (2), comprising the steps: introducing a loss control medium (30) into a first portion of a pipe (2); conveying the loss control medium (30) along the pipe from the first portion to a second portion of the pipe, wherein the second portion is embedded in a porous medium and has a defect (4) through which fluid conveyed by the pipe during normal use leaks into the porous medium; and applying a pressure to the loss control medium (30) such that at least a portion of the loss control medium (30) is expelled from the pipe through the defect (4) into the porous medium thereby causing the loss control medium to accumulate within the porous medium in the vicinity of the defect which inhibits flow of a liquid through the defect into the porous medium.

Abstract: A method of inhibiting leakage of a fluid through a defect (4) in a wall of a pipe (2), comprising the steps: introducing a loss control medium (30) into a first portion of a pipe (2); conveying the loss control medium (30) along the pipe from the first portion to a second portion of the pipe, wherein the second portion is embedded in a porous medium and has a defect (4) through which fluid conveyed by the pipe during normal use leaks into the porous medium; and applying a pressure to the loss control medium (30) such that at least a portion of the loss control medium (30) is expelled from the pipe through the defect (4) into the porous medium thereby causing the loss control medium to accumulate within the porous medium in the vicinity of the defect which inhibits flow of a liquid through the defect into the porous medium.