Operator and logging contractor: LDEO-BRG

Hole: 2A (proposed site KGGH03-A)

Expedition: NGHP-1

Location: Krishna-Godavari Basin, Eastern India (Bay of Bengal)

Latitude: 15° 52.119' N

Longitude: 81° 49.358' E

Logging date: May 20-21, 2006

Sea floor depth (drillers'): 1069 mbrf

Sea floor depth (loggers'): 1066 mbrf

Total penetration: 1119 mbrf (50 mbsf)


Logging Tools


The logs were recorded using the LWD (Logging-While-Drilling) system, which allows the acquisition of open-hole logs using instruments that are part of the drill string itself. The advantages of this technique include being able to log in formations that would not provide a stable hole for wireline logging (e.g. the upper section of sedimentary formations) and logging a hole immediately after it is drilled, so that it is in good condition and largely free of wash-outs.

The following LWD tools were deployed in Hole 2A:


EcoScope (phase and attenuation resistivity, density, porosity, geochemistry, gamma ray, temperature and pressure)

geoVision (resistivity-at-the-bit and gamma ray)

sonicVision (velocity)

TeleScope (drilling parameters)


After tagging the sea floor, Hole 2A was spudded. To ensure that the LWD tools were powered up to measure real-time data for gas monitoring, it was decided to first drill with a relatively high pumping rate (350-400 gpm).  The first 10 m of the hole were drilled with a rotation rate of 10 rpm and a ROP of 25 m/h; the rotation rate was then increased to 30 rpm while keeping all the other parameters unchanged down to 40 mbsf, and finally to 60 rpm, keeping the ROP around 25 m/h. After this testing was concluded at about 50 mbsf, the tool string was pulled out of the hole and the ship was moved by about 3 m to Hole 2B.


For further questions about this hole, please contact:

Cristina Broglia

Phone: 845-365-8343

Fax: 845-365-3182

E-mail: Cristina Broglia