What Is Control of Well Insurance? (OEE Explained for Oilfield Contracts)

Control of well insurance, also called operators extra expense or OEE, covers the cost of regaining control of an oil or gas well after a blowout or other loss of control, including well-control efforts, redrilling the lost hole, and cleanup of resulting seepage or pollution. Standard general liability and property policies exclude these costs, so drilling and well-servicing contracts require it as separate, dedicated coverage. If you hire oilfield contractors, control of well is one of the coverages a generic certificate check will miss, because it usually sits on a form of its own and never appears on the ACORD 25 general liability line.

A blowout is the kind of event that turns a routine job into a multi-million-dollar problem in hours. That is why operators and the contracts teams who verify insurance treat control of well as a distinct check, not a line item folded into general liability. This guide explains what the coverage does, how it differs from the policies you already track, who needs it, and how to confirm it is actually in force before a crew starts drilling.

What does control of well insurance cover?

Control of well insurance covers the operator's own costs to deal with a well that has gotten out of control. The coverage is usually written in three grouped parts that work together. The first responds to the expense of regaining control: the firefighting, capping, killing and intervention work needed to stop an uncontrolled flow. The second covers redrilling or restoring the well to the depth and condition it was in before the event. The third covers seepage, pollution and cleanup that result from the loss of control, which general liability typically excludes for the operator's own site.

Because these costs fall on the operator rather than on a third party, control of well is structured differently from liability coverage. It protects the balance sheet of the party responsible for the well, not an injured outsider. That distinction is exactly why it has to be verified on its own terms.

Is control of well the same as general liability?

No. General liability responds to bodily injury and property damage a contractor causes to third parties, and it almost always excludes the cost of controlling a well and the pollution that follows a blowout. Control of well fills that gap with first-party coverage for the well-control event itself. The two are complementary, not interchangeable.

This is the trap in a quick certificate review. A drilling contractor can show a healthy general liability limit on its ACORD 25 and still carry no control of well coverage at all, because the two live in different places. Confirming a strong general liability limit tells you nothing about whether the catastrophic well-control exposure is covered. You have to look for the control of well coverage specifically, and it is frequently documented on a separate certificate or endorsement rather than the standard liability form.

What is operators extra expense (OEE)?

Operators extra expense, or OEE, is the policy form that delivers control of well coverage, so in practice the two terms are used interchangeably. The name reflects what it pays for: the extra expenses an operator incurs to bring a well back under control and restore it. When a master service agreement asks for control of well coverage, the certificate you receive will often reference an OEE policy and its limit.

OEE can also include extensions that matter for a verification check, such as care, custody and control coverage for third-party equipment downhole, and making-of-hole or evacuation expense. The limits for these extensions are often much lower than the headline control of well limit, so reading the full policy structure, not just the top number, is part of doing the check properly.

Who needs control of well insurance?

Control of well coverage is carried by the party with an interest in the well: operators, non-operating working interest owners, and the drilling and well-servicing contractors whose work can cause a loss of control. Which party buys it, and at what limit, is spelled out in the drilling contract or the master service agreement. Many joint operating agreements also independently require specified well-control limits.

For a company verifying contractor insurance, the question is not whether control of well exists somewhere in the program but whether the contractor you are putting to work carries the limit your contract requires for the scope it is performing. A wireline crew, a workover rig and a plug-and-abandonment contractor each carry different exposure, and the requirement should follow the scope.

How much control of well coverage is required?

Required limits vary by operator, well type and depth, and there is no single national number. Insurers commonly size an account's well-control limit in relation to the authorization for expenditure for the well, and state financial-responsibility rules in producing states such as Texas, Oklahoma, New Mexico, Louisiana and Wyoming add their own requirements. The figure that matters for verification is the one written into your drilling contract or MSA, because that is the obligation you are enforcing.

Whatever the number, the work is the same: read the required limit out of the contract, then confirm the certificate or OEE policy meets it before the contractor mobilizes. Treating control of well as a contract-specific requirement, rather than a generic checkbox, is what keeps a short limit from slipping through.

Does control of well insurance appear on a certificate of insurance?

Not on the standard ACORD 25 liability section. Control of well and OEE coverage is usually evidenced on a separate certificate or by an endorsement, because the standard certificate form has no line for it. That is the single most common reason a control of well requirement goes unverified: the reviewer checks the ACORD 25, sees the familiar coverage lines, and never asks for the separate evidence.

When you collect certificates, treat control of well as its own document to request and read, alongside any contractors pollution liability that the scope requires. Reading the right forms is the same discipline behind certificate of insurance verification generally: confirm the coverage that the contract requires is actually in force, on the correct form, at the correct limit, and current.

Verifying control of well across many contractors

One well is manageable by hand. A drilling program with dozens of contractors across many pads is not, especially when control of well, pollution and high umbrella limits all have to be checked against a different requirement for each scope. This is where COI tracking for oil and gas earns its place: it reads each contractor certificate, checks it against the requirements in the matching master service agreement, and flags anything short, missing or expired before a crew reaches location.

The same approach handles the rest of the insurance program too. Additional insured and waiver of subrogation status, which back the knock-for-knock structure these contracts rely on, can be confirmed the same way you confirm a limit. If you want the mechanics of how those endorsements work, our explainer on additional insured versus certificate holder walks through the difference, and pulling every contractor certificate into one place is what certificate of insurance management software is built to do. Field and construction crews are tracked the same way as subcontractor COIs for contractors.

Verifying coverage is one step in a larger contractor-onboarding workflow. Many operators send the master service agreement out for signature with an online tool like document e-signing software, abstract the insurance and indemnity terms out of long contracts and leases with AI lease and contract abstraction, and manage field-service spend through purchase order management software. Keeping insurance verification automated keeps it from being the step that holds up a job.

The bottom line

Control of well insurance, or OEE, is the coverage that pays to bring a blown-out well back under control and clean up after it, and general liability does not replace it. If your contracts require it, do not assume a clean ACORD 25 means it is there. Ask for the separate evidence, read the limit against what the contract requires, and confirm it is current before the work starts. Across a full drilling program, automating that check is the difference between knowing every contractor is covered and finding out otherwise after a loss.