Table T4. Summary of 260 fluid hammer operations, Sites 1180 and 1181 (Rota-1).
|
Hole/test
|
Latitude
|
Longitude
|
Water depth (m)
|
Operation
(min) |
Flow
rate (spm) |
Penetration
depth (m) |
Material
|
Lost
circulation |
Rotation
|
Heave
(m) |
Hammer/bit
|
ROP
(m/hr) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Deck test | NA | 5 | 20-40 | NA | NA | NA | No | <0.6 | 260 FH/DCUR | NA | ||
| Flow test | 2150 | 5 | 20-40 | NA | NA | NA | No | <0.6 | 260 FH/DCUR | NA | ||
| 1180A | 14°19.25ŽN | 144°48.00ŽE | 2157 | 15 | 20-40 | 3 | Volcanic ash | No | No | <0.6 | 260 FH/DCUR | NA |
| 1180B | 14°19.25ŽN | 144°48.00ŽE | 2157 | 15 | 20-40 | 9 | Volcanic ash | Yes | No | <0.6 | 260 FH/DCUR | NA |
| 1180C | 14°18.51ŽN | 144°44.84ŽE | 2132 | 10 | 20-40 | 2.5 | Volcanic ash; rubble | Yes | No | <0.6 | 260 FH/DCUR | NA |
| 1181A | 14°19.26ŽN | 144°48.00ŽE | 995 | 5 | 20-40 | 2.5 | Volcanic ash; rubble | Yes | No | <0.6 | 260 FH/DCUR | NA |
| 1181B | 14°19.26ŽN | 144°48.00ŽE | 981 | 5 | 20-40 | 3 | Volcanic ash; rubble | Yes | No | <0.6 | 260 FH/DCUR | NA |
| 1181C | 14°19.26ŽN | 144°48.00ŽE | 970 | 10 | 20-40 | 3 | Volcanic ash; rubble | Yes | No | <0.6 | 260 FH/DCUR | NA |
Notes: ROP = rate of penetration. spm = strokes per minute (~5 U.S. gal/stroke [i.e., 20 strokes equals 100 U.S. gal/min.]) NA = not applicable. DCUR = dual cam underreamer bit, FCUB = flat-face underreamer bit. Only 40% of the optimum flow rate through the hammer allows the hammer to jet into the seafloor while being observed by the VIT. The hammer fired only a few times because sufficient material strength to close the hammer to initiate operation was not present. Only the hammer and underreamer bits were being used, no casing installation was attempted.