A field procedure for confirming scale before treating it

Carbonate, sulphate, iron sulphide and mixed scale were restricting chokes and flowlines across the field. A rising differential pressure was being read as proof of scale and flushes were scheduled on that alone. Some of those lines had a rate change, a temperature change or an instrument fault instead, and the flush achieved nothing. Flushing crews and chemicals were being spent on the wrong wells.

We wrote the workflow with the operator's production chemists and the well services team. Trend alerts on upstream and downstream pressure, choke setting, flowline differential pressure, rate and temperature. A location hypothesis: choke, flowline or both. Field confirmation by inspection, photographs and a sample. Chemistry assessment with the inhibitor history. A work order ranked by risk and recoverable production. Treatment by flush, choke change or chemicals. A post-job review comparing restored rate with the expectation. Before a work order is raised, the procedure requires rate change, temperature, choke position, reservoir change, emulsion, sand and instrument health to be ruled out and recorded.

Flush and treatment schedules were tied to confirmed cases with the recoverable production written on the work order. Wells with recurring scale got a control plan with inhibitor and a flush interval instead of a repeated reactive flush.