DIFF Subgroup
E21B 33/13 Methods or devices for cementing, for plugging holes, crevices or the like
Introduced: September 1968
Full Title
Sealing or packing boreholes or wells > in the borehole > Methods or devices for cementing, for plugging holes, crevices or the like
IPC and CPC are identically structured here. All 4 subcodes exist in both systems.
Child Classifications
Navigate with arrow keys, Enter to open
- E21B 33/138 Plastering the borehole wall; Injecting into the formation IPC+CPC Available in IPC and CPC