Field-by-field roll-up of the Lower-Tertiary play.
#Lower Tertiary Field Summary - Gulf of Mexico
⚠️ SUPERSEDED 2026-05-03 by reports/lower_tertiary/comprehensive_2026.md (#377). This summary remains the roster source-of-record (10 GoM Lower Tertiary fields) but is no longer the canonical narrative report. Generate the comprehensive replacement via uv run worldenergydata lower-tertiary comprehensive-report or python scripts/reporting/assemble_lt_comprehensive.py.
Generated: January 19, 2026 Data Through: July 2025
#Portfolio Overview
| Metric |
Value |
| Total Oil Production | 685.0 MMBBL |
| Total Gas Production | 144.1 BCF |
| Active Producing Fields | 6 |
| Total Wells | 158 API12 |
| Active Leases | 19 federal |
| Production Period | 25 years (Sep 2000 - Jul 2025) |
#Field Details
#Producing Fields
| Field |
System |
Water Depth |
Leases |
Wells |
Cum Oil (MMBBL) |
Cum Gas (BCF) |
% Total |
| Jack/St. Malo | Subsea 15K | 7,240 ft | 6 | 26 | 412.46 | 98.70 | 60.2% |
| Stones | Subsea 15K | 9,525 ft | 1 | 8 | 84.68 | 12.56 | 12.4% |
| Julia | Tieback 15K | 7,335 ft | 1 | 5 | 71.56 | 7.31 | 10.4% |
| Big Foot | Dry Tree | 5,190 ft | 1 | 15 | 68.96 | 16.62 | 10.1% |
| Cascade/Chinook | Subsea 15K | 8,200 ft | 2 | 3 | 37.79 | 6.33 | 5.5% |
| Anchor | Subsea 20K | 5,080 ft | 2 | 5 | 9.51 | 2.59 | 1.4% |
#Under Development / Pre-FID
| Field |
System |
Water Depth |
Leases |
Status |
| Shenandoah | Subsea 20K | 5,800 ft | 2 | Under Development |
| Kaskida | Subsea 20K | 5,860 ft | 2 | Pre-FID |
| Tiber | Subsea 20K | 4,130 ft | 1 | Pre-FID |
| North Platte | Subsea 20K | 5,840 ft | 2 | Pre-FID |
#Top Producing Leases
| Rank |
Lease |
Field |
Cum Oil (MMBBL) |
% Total |
| 1 | G21245 | Jack | 209.53 | 30.6% |
| 2 | G17015 | St. Malo | 130.73 | 19.1% |
| 3 | G17001 | Stones | 84.68 | 12.4% |
| 4 | G20351 | Julia | 71.56 | 10.4% |
| 5 | G16942 | Big Foot | 68.96 | 10.1% |
#Production by Development System
| System Type |
Description |
Fields |
Cum Oil (MMBBL) |
% Total |
| Subsea 15K | First-gen HPHT (15,000 psi) | Jack/St. Malo, Stones, Cascade/Chinook | 534.93 | 78.1% |
| Tieback 15K | Tieback to existing host | Julia | 71.56 | 10.4% |
| Dry Tree | Surface wellheads on TLP/Spar | Big Foot | 68.96 | 10.1% |
| Subsea 20K | Next-gen ultra-HPHT (20,000 psi) | Anchor | 9.51 | 1.4% |
#Key Insights
- Market Dominance: Jack/St. Malo accounts for 60.2% of total Lower Tertiary production
- Concentration: Top 3 developments represent 83.0% of cumulative output
- Technology Evolution: 20K psi subsea systems represent the frontier of deepwater development
- Water Depth: Stones is the deepest producing field at 9,525 ft
- Future Growth: 4 pre-FID/development fields represent significant upside potential
#Data Sources & Freshness
| Data Source |
Description |
Last Data Available |
Download Date |
| BSEE OGOR Production | Historical production archives | July 2025 | October 15, 2025 |
| BSEE 2024 Annual | Complete 2024 production year | December 2024 | August 10, 2025 |
| FDAS V30 Lease Mapping | Verified lease-to-field mappings | October 2024 | October 2024 |
| Economic Assumptions | Price decks, fiscal terms, CAPEX/OPEX | December 2024 | December 20, 2024 |
| Field Configurations | Water depths, systems, lease counts | October 2024 | October 21, 2024 |
#Notes
- Production data covers September 2000 through July 2025 (25 years)
- BSEE data is published monthly with approximately 2-month lag
- Pre-FID fields show exploration/appraisal well counts only
- Economic assumptions based on industry benchmarks through December 2024
- Interactive Report:
reports/lower_tertiary_field_summary.html - Production Data:
results/fdas_production/e_production_by_development_*.csv - Field Configs:
config/analysis/lower_tertiary/fields/ - Lease Mapping:
config/analysis/lower_tertiary/lease_mapping_fdas.yml - Economic Params:
config/analysis/lower_tertiary/economic_assumptions.yml
*World Energy Data | Lower Tertiary Field Analysis*