Abstract: The present invention provides a down-hole tool guide apparatus 6 suitable for use in controlling movement of a down-hole apparatus 1 provided with a pressurised working fluid supply in a borehole P. The apparatus comprises: a body 7 having a chamber 13 in which is slidably mounted a piston 14. A high pressure end 13a of the chamber 13 is connected 36 to the pressurised working fluid supply 10 for supplying pressurised working fluid to a high pressure side 32 of said piston 14. A low pressure end 13b of the chamber 13 is connected with the outside of the guide apparatus 6 and is provided with a spring 16 for applying a biasing force to the low pressure side 17 of the piston 14 corresponding to a predetermined threshold pressure of the pressurised fluid supply at the high pressure side of the piston 14. The body 7 mounts at least one shoe 25 having an engagement face 26.