# Relationship history for MSHA mine 4104675

Current hierarchy: **Schlumberger Ltd → M-I Swaco-A Schlumberger Company → Galveston GBT Barite Grinding Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Schlumberger Ltd → Galveston GBT Barite Grinding Plant; 1994-02-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** M-I Swaco-A Schlumberger Company → Galveston GBT Barite Grinding Plant; 2007-08-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Schlumberger Ltd → M-I Swaco-A Schlumberger Company; 2007-08-03 to current/open; source msha-controller-operator-history