| 摘要 |
A tubing unloader (10) for draining liquid from production tubing (20) in an oil well (12). The tubing unloader (10) has a hollow throughbore (36) so as to form a part of the production tubing (20) until it is necessary to drain the production tubing (20). The tubing unloader (10) has two basic parts which telescopically cooperate to close or open drain holes (67a, 67b) in the tubing unloader (10). The bottom portion of the tubing unloader (10) is a hollow cylinder configured as an outer mandrel body (30) having a pair of J-slots (80a, 80b) formed on an internal surface. The top portion of the tubing unloader is a hollow cylinder configured as an inner mandrel (32) having a pair of J-lugs (40a, 40b) protruding from its external surface. The inner mandrel (32) includes a sliding valve (90) and is telescopically received in the outer mandrel body (30) in slide fit relationship with the J-lugs (40a, 40b) slidingly engaged in the J-slots (80a, 80b).
|
