Apparatus for gaining access to a well via a lateral access passage includes a flexible conduit which is to be inserted into the well via the lateral access passage so as to deviate from a direction of lateral insertion to a generally downward direction down the well. The flexible conduit includes a probe at a front end thereof. The probe includes a spring at least 0.5 m in length. A probe container is provided for accommodating the probe before it is inserted into the well. A guide may be provided for insertion along the lateral access passage and for assisting deviation of the flexible conduit from the direction of lateral insertion.