# Relationship history for MSHA mine 1600825

Current hierarchy: **Schlumberger Ltd → M-I L L C → AMELIA BARITE 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Hughes Tool Company et al → AMELIA BARITE PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** G H Fluid Services Inc → AMELIA BARITE PLANT; 1950-01-01 to 1981-03-09; source msha-controller-operator-history
- **controller_controls_mine:** Galveston Houston Company → AMELIA BARITE PLANT; 1950-01-01 to 1981-03-09; source msha-controller-operator-history
- **controller_controls_operator:** Galveston Houston Company → G H Fluid Services Inc; 1950-01-01 to 1981-03-09; source msha-controller-operator-history
- **operator_operates_mine:** Dowell Div/Dow Chemical U S A → AMELIA BARITE PLANT; 1981-03-10 to 1985-01-08; source msha-controller-operator-history
- **controller_controls_mine:** Dow Chemical Company → AMELIA BARITE PLANT; 1981-03-10 to 1985-01-08; source msha-controller-operator-history
- **controller_controls_operator:** Dow Chemical Company → Dowell Div/Dow Chemical U S A; 1981-03-10 to 1985-01-08; source msha-controller-operator-history
- **operator_operates_mine:** Dowell Schlumberger Inc → AMELIA BARITE PLANT; 1985-01-09 to 1985-04-23; source msha-controller-operator-history
- **controller_controls_mine:** Dowell Schlumberger Inc → AMELIA BARITE PLANT; 1985-01-09 to 1985-04-23; source msha-controller-operator-history
- **controller_controls_operator:** Dowell Schlumberger Inc → Dowell Schlumberger Inc; 1985-01-09 to 1985-04-23; source msha-controller-operator-history
- **operator_operates_mine:** Hughes Drilling Fluids → AMELIA BARITE PLANT; 1985-04-24 to 1988-02-11; source msha-controller-operator-history
- **controller_controls_operator:** Hughes Tool Company et al → Hughes Drilling Fluids; 1985-04-24 to 1988-02-11; source msha-controller-operator-history
- **controller_controls_operator:** W R Grace & Company et al → Hughes Drilling Fluids; 1985-04-24 to 1988-02-11; source msha-controller-operator-history
- **controller_controls_mine:** Dresser Industries Inc et al → AMELIA BARITE PLANT; 1987-01-19 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** International Drilling Fluids Inc → AMELIA BARITE PLANT; 1988-02-12 to 1991-07-15; source msha-controller-operator-history
- **controller_controls_mine:** English China Clays PLC → AMELIA BARITE PLANT; 1988-02-12 to 1991-07-15; source msha-controller-operator-history
- **controller_controls_operator:** English China Clays PLC → International Drilling Fluids Inc; 1988-02-12 to 1991-07-15; source msha-controller-operator-history
- **operator_operates_mine:** International Drilling Fluids Inc → AMELIA BARITE PLANT; 1991-07-16 to 1992-11-30; source msha-controller-operator-history
- **controller_controls_mine:** New London PLC → AMELIA BARITE PLANT; 1991-07-16 to 1992-11-30; source msha-controller-operator-history
- **controller_controls_operator:** New London PLC → International Drilling Fluids Inc; 1991-07-16 to 1992-11-30; source msha-controller-operator-history
- **operator_operates_mine:** M-I Drilling Fluids Company → AMELIA BARITE PLANT; 1992-12-01 to 1994-02-27; source msha-controller-operator-history
- **controller_controls_operator:** Dresser Industries Inc et al → M-I Drilling Fluids Company; 1992-12-01 to 1994-02-27; source msha-controller-operator-history
- **controller_controls_operator:** Halliburton Co et al → M-I Drilling Fluids Company; 1992-12-01 to 1994-02-27; source msha-controller-operator-history
- **operator_operates_mine:** M-I L L C → AMELIA BARITE PLANT; 1994-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Schlumberger Ltd → AMELIA BARITE PLANT; 1994-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Schlumberger Ltd → M-I L L C; 1994-02-28 to current/open; source msha-controller-operator-history