# Relationship history for MSHA mine 2601418

Current hierarchy: **Schlumberger Ltd → M-I LLC → Clipper Mine**

- 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

- **operator_operates_mine:** Imco Services → Clipper Mine; 1950-01-01 to 1988-05-16; source msha-controller-operator-history
- **controller_controls_mine:** Halliburton Company → Clipper Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Halliburton Company → Imco Services; 1950-01-01 to 1988-05-16; source msha-controller-operator-history
- **controller_controls_mine:** Dresser Industries Inc et al → Clipper Mine; 1987-01-19 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** M-I Drilling Fluids Company → Clipper Mine; 1988-05-17 to 2002-11-05; source msha-controller-operator-history
- **controller_controls_operator:** Dresser Industries Inc et al → M-I Drilling Fluids Company; 1988-05-17 to 2002-11-05; source msha-controller-operator-history
- **controller_controls_operator:** Halliburton Co et al → M-I Drilling Fluids Company; 1988-05-17 to 2002-11-05; source msha-controller-operator-history
- **controller_controls_mine:** Schlumberger Ltd → Clipper Mine; 1994-02-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** M-I LLC → Clipper Mine; 2002-11-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Schlumberger Ltd → M-I LLC; 2002-11-06 to current/open; source msha-controller-operator-history