Craig E. Butler¹, Susan K. Towe¹

(1) Phillips Petroleum Co, Bellaire, TX

ABSTRACT: Chinook Field, Main Pass 283 and Viosca Knoll 734: A Case Study

The Chinook Field covers parts of two blocks in the Eastern Gulf of Mexico, Main Pass 283 and Viosca Knoll 734. The field was discovered in 1997 by the Main Pass 283 # 1 sidetrack well and put on production by the operator, EXXONMobil in October of 1999. Cumulative production to date is about 5.3 BCF of gas and 2.2 MMBO from 3 wells. Additional drilling is scheduled for late 2000. Chinook produces from middle Miocene deepwater channel/levee complexes draping a south plunging structural nose. Seismic amplitude anomalies are associated with these oil and gas condensate reservoirs. A key issue at Chinook is the degree of connectivity between the levee and channel facies, i.e. producing wells located in the channel facies must see contribution from the levees for the field to be economic. Nearby fields, especially Santa Fe-Snyders' Pabst Field (Main Pass 259) were used as analogs. Volume estimates made from standard amplitude extractions at Pabst Field were unable to match production.

AVO modeling suggested that hydrocarbon bearing sand and wet sand should have opposite polarity. Polarity reversal along key seismic reflections had also been observed throughout the seismic volume. To preserve the sign and relative amplitude strength of the reflection, an average amplitude was extracted over a small window. The resulting maps provided a better match to the Pabst Field production and increased our confidence that sufficient connectivity likely existed at Chinook to be economic.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado