The Magnolia field, located in the deepwater region of the Gulf of Mexico,
produces oil and gas from a tension leg platform (TLP) in 4,673 ft of water.
The reservoirs comprise several stacked sandstone intervals within the early to
mid Pleistocene with some minor production from the Miocene and Pliocene sands.
A total of eight wells have been completed, with the majority of the production
from the B25 sandstone. The formation-particle size is fine-grained sand to
coarse silt and has relatively low K*H compared to other deepwater reservoirs.
The reservoirs are significantly overpressured, highly compartmentalized,
highly compacted, and have experienced significant pressure declines in excess
of 8,000 psi in some cases during production.
The wells were completed with cased-hole frac packs and each completion
included a permanent downhole gauge, enabling interpretation of the K*H and
skin throughout the producing history of the wells to date. The perforating
guns, frac fluids, and screens were extensively tested before completion. The
perforation-shot size and density was carefully chosen and tested to achieve
the required production. Well test results matched inflow analysis predictions.
The initial skin values generally met expectations and improved during
production because of a combination of well cleanup and reduced reservoir
permeability from compaction. Proppant integrity has been maintained under
extreme depletion (>8,000 psi) conditions. Productivity was measured using
perforation tunnel permeability (Kpt) analysis. The
Kpt values were analyzed over the course of production and
compared to similar type completions. The Kpt benchmark
analysis shows that the completions are among the best in class. Well
productivity has met or is above expectations, and the longevity has exceeded
expectations in most cases.
© 2009. Society of Petroleum Engineers
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- Original manuscript received:
13 August 2007
- Meeting paper published:
11 November 2007
- Revised manuscript received:
2 May 2008
- Manuscript approved:
21 August 2008
- Published online:
9 July 2009
- Version of record:
23 December 2009