Autonomous Formation Pressure Test Process for Formation Evaluation Tool
AssigneePrecision Energy Services, Inc.
InventorJeffery James Hemsing
Life of this patent
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AssigneePrecision Energy Services, Inc.
InventorJeffery James Hemsing
Estimating the term…
A formation tester places an isolation device, preferably a probe, in fluid communication with a formation to determine formation pressures. The tester's controller uses a pressure pre-test process to autonomously control operation. The controller measures drawdown pressure and interval as the tester draws down pressure in flowline coupled to the probe. If the drawdown pressure indicates a dry test has occurred, the process is aborted. Otherwise, the controller measures buildup pressure and interval by allowing buildup of pressure of the flowline. The controller permits this to continue until the interval is longer than the drawdown interval and/or until a rate of the buildup falls below a predetermined rate. If the buildup pressure is too tight relative to the drawdown pressure, the controller aborts the test. Eventually, the controller measures a final buildup pressure when the buildup terminates. A new drawdown rate and volume can be determined for subsequent formation tests.
A formation tester, comprising:
The formation tester of claim A, wherein the second flow rate is determined based on the first flow rate scaled by the ratio of a specified pressure differential relative to the difference between the first buildup pressure and the first drawdown pressure.
Dependencies are inferred from the claim text.