Mars Field: A Giant Matures
R. David Garner, M. C. Jacobi, M. G. Kraenzle, D. Palm, H. R. H. Roach, and J. van der Horst
Shell Exploration & Production Co., New Orleans, Louisiana
Many deepwater fields in the Gulf of Mexico that were developed in the early and mid-1990s are beginning to mature. Shell Co.’s Mars Field is one such field. It was discovered in 1989 with the drilling of Mississippi Canyon Block 763 Well #1. A tension leg platform was installed in May 1996 with production beginning in July 1996. In the succeeding eight years, Mars has produced over 350 million barrels of oil and 400 billion cubic feet of gas. Reserves are located in twenty-four Miocene and Pliocene-aged turbidite sandstone reservoirs deposited in a salt withdrawal mini-basin bounded by allocthonous salt bodies. Six reservoirs contain greater than fifty percent of the field’s proven reserves. Consequently, primary development has largely been focused on them.
However, as the field has matured and production rates commenced to decline, subsurface and engineering efforts are increasingly focused on sustaining and prolonging high production rates and bringing new volumes on-line. What could once be done relatively easily in shallower waters using additional wells, structures and facilities – redevelopment – is more problematic in three thousand feet of water. Redevelopment of a deepwater field is extremely challenging because of limited well slots, high ultimate wells, weight and space limitations, subsurface uncertainty and the ever-present specter of compaction-related well failure.
The timely and cost effective application of new technologies will be critical to mitigating many of the risks associated with redevelopment. At Mars, redevelopment will be managed through the application of both new and established methods, including but not limited to 4 dimensional seismic, "intelligent" well systems, innovative drilling and completion techniques and good old fashioned surveillance and water injection.
AAPG Search and Discovery Article #90032©2004 GCAGS 54th Annual Convention, San Antonio, Texas, October 10-12, 2004