Function Testing, Test Frequencies, and Test Tools

A function test asks whether equipment operates

Function testing checks movement, response time, operating pressure, fluid use and the intended sequence. The syllabus includes testing before installation, on installation and during well operations. The actual schedule and conditions come from the operations manual and applicable requirements. Do not infer one universal weekly or fourteen-day rule from a training example.

Tests must suit the current assembly and barrier state. A blind or shear function cannot be actuated onto an unqualified item merely because a calendar interval has arrived. Confirm pipe and tool position, test prerequisites and alternate containment. Distinguish an actual function from a simulation and record which was performed. The test is successful only when its defined acceptance criteria are met.

Use supplied closing data

A training table may give a specific annular model a maximum closing time of 45 seconds and a qualified ram model 30 seconds under stated conditions. A 40-second annular result satisfies that time limit; a 35-second ram result does not. This is a supplied-data exercise, not a universal limit by bore diameter. Pressure, fluid, configuration and measurement start/finish points must match the criteria.

A command timestamp and a panel lamp can differ from full actuator travel. Record the actual method used to establish completion. The relevant hydraulic pressure and fluid-volume response support the result. A fast selector movement with no actuator response fails the intended test even if the command arrived immediately.

Pressure test tools have their own ratings

A test plug can isolate a pressure-test boundary from the casing or formation only in its qualified arrangement. Check its sealing direction, location, landing, pressure rating, load capacity and the monitored lower side. The test can impose substantial axial force on a plug. At 5,000 psi across a supplied effective area of 20 in², theoretical force is 100,000 lb. The tool and support arrangement must be qualified for the actual load and conditions.

A cup tester relies on a different seal and often exposes casing to test pressure. The permitted pressure considers the cup/tool rating and the approved casing integrity limit, including service and wear—not nominal casing burst alone. A test plug's isolation cannot be assumed just because it was lowered to a given depth. Verify it as the procedure directs.

Accessories can change the boundary

Wear bushings, running tools and temporary assemblies may block ports, prevent sealing or affect the test-tool landing. Their removal or positioning depends on the qualified test arrangement. Do not state that every wear bushing must always be retrieved for every possible test. Read the drawing and procedure, identify what is exposed and confirm pressure reaches the intended component.

Test strings, valves, hoses and gauges must have suitable ratings and connections. A lower-rated adapter can become the binding limit. Instrument range should permit a meaningful reading of both low and high stages as required. If separate gauges are used, identify the communicating taps and calibration records. An isolated gauge does not provide a valid test result.

Diverter function and flow verification

A diverter test checks the open outlet, packing-element operation, valve sequence and interlocks against the actual layout. Flow or venting verification demonstrates that the selected route is unobstructed. Test direction, volume, instrumentation and fluid follow the specified criteria. Function feedback does not alone prove an eroded or blocked vent can pass the required flow.

The test must not create a closed pressure system beyond the diverter's limits. Confirm the vent path before sealing the upward route, observe the selected destination and monitor for leaks. Record whether both the control sequence and flow route passed. Restore the top-hole operating line-up and communicate any limitation before entering the shallow-gas interval.

Failure and return to service

Slow or incomplete movement can reflect inadequate supply, air in a circuit, leakage, obstruction, regulator problems or actuator failure. Secure the well using the available qualified barrier and inform the supervisor. Repair under controlled isolation, then repeat the relevant function and pressure verification. A pressure test cannot excuse a function that fails to operate when needed.

Keep the equipment identity, configuration, pressure, time, volume, observations, result and approval. A meaningful handover states which functions are tested, inhibited or unresolved and which alternatives remain available. This connects maintenance evidence to the operator's response capability, rather than presenting a calendar checkmark as proof that every BOP and valve is ready.

Supplied function limits