A Comparison of Different Turbidite Plays in the Yinggehai and Qiongdongnan Basins of the South China Sea
Richard K. Cardwell and John W. Norris
Three different types
of turbidite plays have been drilled in the Yinggehai
and Qiongdongnan basins of the South China Sea: slope fan turbidites, bottomset
turbidites, and channel fill turbidites. Each play type had a distinctive
well
log signature, lithology, seismic reflector geometry, and reservoir character.
Slope fan turbidites are encountered in the YA 21-1-3 well
.
Well
logs are
characterized by a ratty SP curve, and mud logs indicate that the turbidites are
composed of up to 80 m of sands and silts. Seismic profiles show that these
turbidites are found in a distributary channel and level system on the shelf.
Bottomset turbidites are encountered in the LD 15-1-1 well
.
Well
logs are
characterized by an upward coarsening SP curve, and mud logs indicate that the
turbidites are composed of up to 10 m of silty sand. Seismic profiles show these
turbidites are deposited by the slumping of shelf sands during a continuous
lowstand progradation.
Channel fill turbidites are encountered in the LD 30-1-1 well
.
Well
logs are
characterized by a blocky SP curve, and mud logs indicate that the turbidites
are composed of up to 100 m of massive sand. Seismic profiles show that these
turbidites are associated with channel systems that trend parallel to the local
basin axis. Distinct cut and fill geometries indicate that the turbidite sands
were deposited in a preexisting channel cut.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California