Downhole tool loss is an ordinary operational event. Drilling and completion operations put expensive equipment into a hostile environment, some of it does not come back, and every well service contract provides for that. The clause is usually short, the valuation schedule is usually a spreadsheet appended as an exhibit, and both are typically agreed once and rarely revisited.
That is where the exposure sits. The charge is calculated by the service company from a schedule the operator holds a copy of but does not treat as controlled data. The depreciation adjustment depends on tool age or running hours that the service company records. The point at which equipment becomes lost rather than merely stuck depends on a fishing time limit that may or may not have been defined. Each of these is a contract term, and each is commonly resolved in favor of whoever has the better records.
Operators who tighten this up do not usually find widespread overbilling. They find a consistent pattern of small discrepancies: superseded schedule versions applied, depreciation calculated on a basis different from the one agreed, fishing time billed beyond the contractual limit, and replacement mobilization charged where the contract allocated it elsewhere. Individually minor, collectively material across a drilling program.
Where lost in hole charges drift from the contract
Five patterns account for most of the variance operators find when they reconcile these charges properly.
- Superseded schedule applied, the invoice uses a current price list rather than the exhibit version in force when the contract was signed or last amended.
- Depreciation basis substituted, the contract specifies running hours or years in service and the charge is calculated on a different basis, usually the one more favorable to the biller.
- Undefined loss point, without a fishing time limit, the boundary between recoverable stuck pipe and lost equipment is argued after the fact rather than applied.
- Fishing cost allocation unclear, the contract may allocate fishing time to either party or split it at a threshold, and invoices frequently ignore the split.
- No tool age evidence retained, the adjustment depends on service history the operator never receives, so the depreciation figure cannot be verified at all.
The remedy is structural rather than adversarial. The valuation schedule, the depreciation basis and the fishing terms belong in the operator system as structured data attached to the contract, with version control, exactly as insurance and indemnity terms should be.
Record the schedule version, its effective date and the date of each amendment, and keep superseded versions accessible. When a charge arrives, the first check is which version applies at the date of loss, not whether the price looks reasonable. Operators who cannot answer that question quickly generally accept the version the service company presents, which is how quiet price drift enters a multi-year drilling program.
Five controls for lost in hole billing
Each control names the term to extract, the evidence to require and the reconciliation step that closes it.
- Schedule version control. Hold the valuation exhibit as data with an effective date, keep prior versions, and verify each charge against the version in force at the loss date rather than the current list.
- Depreciation basis and evidence. Extract the agreed basis, whether years in service, running hours or a stated percentage step, and require the service company to supply the tool history supporting the adjustment.
- Defined loss point and fishing limit. Capture the number of hours or attempts after which equipment is deemed lost, and the party bearing fishing cost before and after that point.
- Replacement and mobilization allocation. Record who bears the cost of mobilizing a replacement tool and whether standby time during fishing is chargeable, since these often exceed the tool value itself.
- Charge reconciliation at ticket level. Match each lost in hole charge to the field ticket, the daily report and the schedule version, and hold unreconciled charges rather than approving them into the well cost.
A five-step roadmap for controlling lost in hole exposure
Step 1, Digitize the valuation exhibits
Load every service contract valuation schedule into structured fields with effective dates, so a tool can be priced by reference to a version rather than by locating a spreadsheet in an email. This single step resolves most version disputes before they start.
Step 2, Extract the fishing and loss terms per contract
Capture the fishing time limit, the loss determination point and the cost allocation before and after that point as fields against the contract. Field supervisors making real-time decisions should be able to see the contractual limit.
Step 3, Require tool history with every charge
Make service history a condition of invoice approval where the contract provides for a depreciation adjustment. A charge that cannot evidence tool age cannot evidence its own calculation.
Step 4, Reconcile at the well, not at the month end
Match lost in hole charges to field tickets and daily drilling reports while the operational record is fresh. Reconciliation attempted at well close, against a bundle of accumulated invoices, recovers far less.
Step 5, Feed the pattern back into the next negotiation
Report lost in hole charges by contractor, tool type and well, showing schedule version, depreciation basis and fishing time billed. The recurring exposures become specific negotiation items rather than a general complaint about service cost.
See service contract exhibits as controlled data
Valuation schedules, depreciation bases and fishing limits held against the contract with version control and reconciliation.
Why field decisions need the contract terms in view
The most expensive moment in a lost in hole event is the fishing decision, and it is taken by people who do not have the contract in front of them. A rig supervisor deciding whether to continue fishing or sidetrack is weighing rig time, formation risk and the probability of recovery. If the contract says fishing time is at the operator cost after twelve hours, or that equipment is deemed lost after a defined number of attempts, that boundary should be visible in the operational decision rather than discovered during invoice review weeks later. Making the terms available at the wellsite is a data problem, not a legal one: the relevant fields are few, they change rarely, and they can be surfaced in the same systems that already carry approved rates and contractor qualification status. Operators who have done this report that the value shows up less in disputed invoices and more in better-timed decisions, because the cost boundary is known while it can still be acted on, which is the same argument behind obligation management for energy and mining.
Control matrix for lost in hole charges
The pattern below names the term, the evidence and the reconciliation for each element of a typical charge.
| Element | Contract term to extract | Evidence required | Reconciliation point |
|---|---|---|---|
| Tool value | Valuation schedule and version | Schedule in force at loss date | Invoice against schedule version |
| Depreciation | Basis, steps and cap | Tool service history or hours | Adjustment recalculated |
| Loss determination | Fishing limit or attempts | Daily report and field ticket | Loss point confirmed |
| Fishing cost | Allocation before and after limit | Time log against limit | Hours billed within allocation |
| Replacement | Mobilization cost allocation | Mobilization ticket | Charge matched to allocation |
Lost in hole charges are a small clause with a long tail. The controls that keep them defensible are unglamorous: hold the valuation exhibit as versioned data rather than an attachment, extract the depreciation basis and require the service history that supports it, define the loss point and the fishing cost split and make both visible at the wellsite, and reconcile each charge to a field ticket while the operational record is current. The result is not an adversarial relationship with service companies. It is a billing process where both parties are working from the same schedule version and the same definition of when a tool is lost.
For related guidance, see Take-or-pay and minimum volume clauses, where value leaks, Decommissioning and abandonment obligation tracking and A working guide to demurrage claim tracking.
