| 摘要 |
<p>The present invention relates to a downhole power system (1) comprising a tubing string (2) comprising a pressurised fluid (3), a turbine (4) for converting energy from the pressurised fluid into rotation of a shaft (5), a tool (6, 6a) powered by the turbine, wherein a constant flow downhole assembly (7) is arranged between the tubing string and the turbine for providing a substantially constant flow of the pressurised fluid to the turbine, wherein the constant flow downhole assembly has an assembly axis (9) and comprises a body (15) comprising a main bore (16) having a bore inlet (17) and at least one bore outlet (18), a hollow piston (19) having a piston inlet (32) and a piston outlet (33), said hollow piston being arranged in the main bore, and a spring (34) arranged in the main bore, said spring being compressed upon movement of the piston in a first direction (35), and wherein the bore inlet is in fluid communication with the piston inlet and the piston inlet is smaller than the bore inlet so as to force the piston to move in the first direction. The present invention also relates to a constant flow downhole assembly and to a method for proving a substantially constant flow of fluid into a turbine of the downhole power system.</p> |
