| 摘要 |
A drilling fluid delivery system for use in drilling boreholes with a drill bit, the system comprising: a primary flow circuit having a relatively high flow rate for transferring drilling fluid to and from the drill bit; a secondary flow circuit having a relatively low flow rate for transferring drilling fluid to and from the primary flow circuit; and a cuttings transfer system, such as a hydrocyclone or a rotating filter, between the primary and secondary flow circuits which, in use, receives fluid containing cuttings from the primary circuit, separates the fluid into a first stream that contains substantially no cuttings and a second stream containing cuttings, the first stream being returned to the primary flow circuit and the second stream being directed to the secondary flow circuit. |
