Releasing And Reversing Overshot
Type DLT-T Releasable Reversing Overshot, a new type of fishing tool, has many advantages owned by various overshot, box tap and the like. Its distinguishing features are as follows: to unscrew and recover the stuck fish; To release the fish down hole if necessary; to circulate the washing fluid as one of the accessories for reversing tools. It is widely used in well servicing.
Related products
GS (I) Type Casing Brusher is one of the indispensable auxiliary tools for well completion, testing and downhole operation. Its main purpose is to remove the residual attachments after the scraping operation of downhole casing inner wall scraper and protect the cleanness of casing inner wall, so as to facilitate the normal operation of all drilling tools. It is usually used with casing scraper.GS (I) Type Casing Brusher is not suitable for drilling operation.
YTQC Type Drill String Fishing Magnet is one of the auxiliary tools to ensure the normal drilling operation and bottom hole cleaning in the process of downhole accident treatment. The main feature of this product is that it works together with the grinding shoes in the fishing operation, which is different from the previous method of lifting the drill after milling, and then connecting the drill string with the strong magnetic fishing tool to go down the well for cleaning bottom hole , saving a trip down the well operation, which not only saves the drilling cost, but also saves the fishing operation time.
TIANHE Reverse Circulation Junk Basket (RCJB) is designed to remove all types of small junk objects from the well hole. The tool’s main feature is that it eliminates the possibility of pulling a wet string during fishing operation with its reverse drainage design. The RCJB can also be used as a fish magnet when fitted with a magnet insert, while maintaining its reverse fluid circulation feature.
Structure and Application
Consisting of top sub, spring, bowl, retaining seat, slip, control key, seal ring, seal seat, guide and so on. The upper end of top sub is connected with other tools and drill tool. The lower end of top sub is connected with bowl equipped with spring in the interior. There are three control keys uniformly distributed in the inner wall of the upper end of bowl. the control keys are used to control the position of retaining seat. Three keys are inserted separately in three grooves in the tapered interior section of lower end in bowl where three keys are used to transmit torque. The tapered interior section produces a pinch force against the slip to trigger the fishing operation. The inclined angle among three control keys play an important role in retaining conformance of the slip with the bowl to ensure that the tools can be released easily from the fish.
The retaining seat is installed at the upper end of the external bowl where the three keys are placed. The retaining seat not only can slide axially, but also rotates round the axial line moving with the slip which is installed in the internal circular recess.

Specifications - Table 2 Releasing and Reversing Overshot connection RH











