OIM vs Toolpusher: Roles, Reporting Lines, and Salary Difference

If you are a driller eyeing the next promotion, two job titles dominate the conversation: Toolpusher and Offshore Installation Manager. They are not the same role. They do not carry the same authority. They do not carry the same risk. And they do not pay the same. This guide explains exactly how the two roles differ, who reports to whom, and how to plan a path that takes you from one to the other.

The short answer

The Toolpusher runs the drilling operation. The Offshore Installation Manager (OIM) runs the installation. The Toolpusher reports to the OIM. On most Mobile Offshore Units (MOUs) the Toolpusher is the senior drilling-side role; the OIM is the senior role on the entire MOU.

Think of it this way: if the rig is a ship, the Toolpusher is the chief engineer of the drilling plant and the OIM is the captain of the vessel.

What a Toolpusher does

The Toolpusher is the senior person on the drilling floor. They are responsible for the safe, efficient execution of the drilling programme: rig-up, rig-down, tripping, drilling, casing, cementing, well control, mud systems. The Toolpusher manages the drilling crew — drillers, assistant drillers, derrickmen, motormen, roughnecks, roustabouts — and coordinates with the company man (the operator’s representative) on programme execution.

A Toolpusher’s day:

Pre-tour planning with the on-tour driller and the company man.
Walking the floor — checking equipment, drilling parameters, mud weights, kick monitoring.
Approving and coordinating well-control drills and BOP tests.
Logging drilling progress against AFE (authorisation for expenditure).
Hand-over to the night Toolpusher and a written hand-over to the OIM.

A Toolpusher does not own the ballast plan, the marine plan, the helideck, the accommodation, the crane operations, or the emergency response of the entire MOU — those belong to other heads of department or to the OIM.

What an OIM does

The OIM is the master of the installation. They are accountable for everything that happens on the MOU — drilling, marine, deck, cranes, accommodation, helideck, catering, security, safety, environment, and emergency response. Heads of department (Toolpusher, Barge Supervisor, Chief Mechanic, Chief Electrician, Crane Foreman, Camp Boss, Helicopter Landing Officer) report to the OIM.

In an emergency, the OIM is the on-scene commander. They make the call to shut down operations, evacuate non-essential personnel, or abandon the installation. Under most flag-state regimes (including Liberia / LISCR) and most operator safety cases, the OIM holds the legal duty for the safety of the installation and the persons onboard.

For a fuller picture of the role, see the Offshore Installation Manager Job Description.

Reporting line at a glance

A typical drilling MOU reporting line:

OIM (top of the installation)
Toolpusher (drilling)
Driller → Assistant Driller → Derrickman → Motorman → Roughneck → Roustabout
Barge Supervisor / Barge Master (marine, ballast, station-keeping)
Ballast Control Operator (BCO)
Chief Mechanic / Chief Electrician (technical)
Crane Foreman (lifting)
Helicopter Landing Officer (HLO)
Camp Boss (accommodation, catering)

On a non-drilling MOU (accommodation barge, pipe-lay barge, construction barge) the reporting line is similar but without the Toolpusher branch. The Project Engineer or Pipelay Superintendent typically takes that slot.

Authority and accountability

Dimension	Toolpusher	OIM
Scope of authority	Drilling operations	Entire installation
Direct reports	Drill crew (drillers down to roustabouts)	All heads of department
Operator-side counterpart	Company man / drilling supervisor	OIM-onshore / rig manager
Emergency role	Coordinates drilling shutdown	On-scene commander
Legal duty-holder under safety case	No (in most regimes)	Yes
Decision authority on stop-work	Drilling-related	All operations

Salary comparison

Salary varies by region, vessel type, day rate, and operator, but the OIM consistently out-earns the Toolpusher by 20–40 percent.

United States (Gulf of Mexico): Toolpusher USD 95,000–140,000; OIM USD 120,000–180,000.
United Kingdom (North Sea): Toolpusher GBP 65,000–95,000; OIM GBP 80,000–120,000.
Middle East / Gulf Cooperation Council: Toolpusher USD 90,000–125,000 (often tax-free); OIM USD 130,000–170,000 (often tax-free).
West Africa, Brazil, South-East Asia: broadly similar to GCC ranges, with a project / day-rate uplift on harsher contracts.

For more salary detail, see our breakdown: How Much Does an Offshore Installation Manager Earn.

How a Toolpusher becomes an OIM

The Toolpusher → OIM path is the most common route to the seat on a drilling MOU. The transition typically requires:

Time onboard MOUs — most flag states require 4+ years of MOU service, including 1+ years in a supervisory role. Toolpusher experience covers this comfortably.
BCO (MOU Stability) — most Toolpushers do not naturally hold this; you will need to take it before the OIM course.
IWCF Well Control Level 2 or higher — most Toolpushers already hold this.
The OIM Course — five days, IMO A.1079(28) aligned, flag-state approved (LISCR for most candidates). The course is the formal certification step.

If you are a Toolpusher with the experience and the BCO and IWCF certificates in place, the Liberia-approved OIM Course is the next certificate on your path.

What if you are on a non-drilling MOU?

You can still progress to OIM. The path on accommodation barges, pipe-lay barges, and construction barges runs through Barge Supervisor or Project Engineer rather than Toolpusher. The OIM certificate is the same; the experience evidence you submit will reflect your vessel type. The IMO A.1079(28) framework was written for non-propulsion units of every kind, not just drilling rigs.

Common questions

Is the OIM always more senior than the Toolpusher?

On the MOU, yes. Onshore, both report to the rig manager / asset manager.

Can a Toolpusher be the OIM as well?

On smaller installations or during certain operations some operators allow a combined role, but most flag states and operator safety cases require them to be separate appointments.

Do I need to be a Toolpusher to become an OIM?

No. Barge Supervisor, BCO, mechanical / electrical supervisor, and senior officer are all valid feeder roles, especially for non-drilling MOUs.

How long does the move from Toolpusher to OIM take?

Once you have the prerequisite certificates and your operator confirms the seat, the OIM course itself is a five-day commitment. The longer pole is securing the appointment — typically a 6–18-month internal promotion process.

Ready to make the move? The Offshore Installation Manager (OIM) Course is the formal certification step from Toolpusher to OIM. Liberia (LISCR) approved, IMO A.1079(28) aligned, delivered live online over five days. See the OIM Course Prerequisites to confirm you are eligible.