Publication Name: The Sedimentary Basins of WA
Authors: K.H. Sit, P.M. Hillock and N.W.D. Miller
Publication Volume: 1
Date Published: July 1994
Number of Pages: 28
Reference Type: Book Section
Abstract:
The Maitland gas field lies 29 km northwest of Barrow Island in WA-149-P in the offshore Barrow Sub-basin. Maitland was first recognised on 1985 2-D seismic data as a near Base Tertiary amplitude anomaly. Subsequentinterpretation of 1989 and 1991 2-D seismic infill data showed a well-defined anomaly covering approximately
40 km2 with no structural closure. Polarity and velocity comparisons with sonic and synthetic seismogram data
from Tryal Rocks-1 and West Barrow-1 indicated that a litho-density effect was unlikely. Detailed amplitude
versus offset analysis and modelling suggested the presence of a significant gas accumulation.
Maitland-1, drilled in August - September 1992, intersected a 23 m - thick, very fine-grained glauconitic sandstone of possible late Paleocene age at 1238.1-1261.1 mSS, and which yielded 15 percent ditch gas on
penetration. This sand was difficult to evaluate due to poor hole conditions and a low resistivity, low contrast
log response. A peak production rate of 8.54 MMSCFD gas was recorded after two drill stem tests on a %" choke.
The well was plugged and abandoned as a gas discovery. Maitland is a significant find which opens up a new play
at base Tertiary level in the offshore Carnarvon Basin. However, the play demands careful analysis and interpretation for success.