DIFF Main Group
E21B 37/00 Methods or apparatus for cleaning boreholes or wells (E21B21/00 takes precedence)
Introduced: September 1968
Title
Titles differ between systems:
IPC: Methods or apparatus for cleaning boreholes or wells
CPC: Methods or apparatus for cleaning boreholes or wells (E21B21/00 takes precedence)
Full Title
Full titles differ between systems:
IPC:
Methods or apparatus for cleaning boreholes or wells
CPC:
Methods or apparatus for cleaning boreholes or wells (E21B21/00 takes precedence)
IPC and CPC are identically structured here. All 4 subcodes exist in both systems.
1 shared codes have differing titles between IPC and CPC.
Child Classifications
Navigate with arrow keys, Enter to open
- E21B 37/06 using chemical means for preventing or limiting the deposition of paraffins or like substances since 1980 IPC+CPC Available in IPC and CPC
- E21B 37/08 cleaning in situ of down-hole filters, screens, or gravel packs (E21B37/06 takes precedence) since 1980 IPC+CPC Available in IPC and CPC