| 摘要 |
The present invention relates to a downhole casing string (1) for insertion in a borehole (2), the downhole casing string having a first end (4) nearest a top of the borehole and a second end (5) furthest away from the top, the downhole casing string extending along a longitudinal axis (6) and comprising at least one opening (7) during production to let hydrocarbon-containing fluid from the reservoir into the downhole casing string, a plurality of casing parts (8) having end sections (9) and a base section (10) between the end sections, the base section having an outer diameter (D o ), and at least one annular projecting element (11) having an outer face (12) and at least one helical groove (14a) arranged in or on the outer face and having an overall outer diameter (D oo ) which is larger than the outer diameter of the base section. Furthermore, the invention relates to a downhole casing string system for completing a well downhole and to a method of implementing a casing string according to the invention. |
