Midland Basin Case Study
A growing pump-pressure residual pointed to a drill-string washout
Over three hours, actual pump pressure separated from the modeled response. The trend, considered with the supporting signals, helped field personnel distinguish a downhole washout from a surface pump problem.
- Three-hour developing signal
- Actual vs. modeled pressure
- Field diagnosis with supporting evidence
The signal developed over time
Actual pump pressure initially tracked the model, then moved progressively below it. The washout-belief indicator increased before the residual became large enough to dominate the display.
- Persistence separated the trend from a brief pressure fluctuation.
- The combined pressure and classification evidence narrowed the investigation to the drill string.
The model supplied a reference, not the diagnosis
Modeled-versus-actual pressure established the response expected for the current operating conditions. The sustained residual helped separate a downhole loss of hydraulic integrity from a surface pump problem and supported an earlier operational decision.
What the case does not prove
A pressure residual alone is not proof of a washout, and this case does not establish a universal alarm threshold or financial outcome. Pump state, flow, mud properties, surface equipment, persistence, and other channels remain part of the diagnosis.