Autonomous Formation Pressure Testing with Adaptive Drawdown Control
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Solution Overview
Problem
Formation testing tools face limitations in real-time communication with the surface, leading to compromised data quality and inefficient operations due to limited capability to adjust testing parameters dynamically in response to varying reservoir or formation properties.
Innovation Solution
A downhole formation tester equipped with a local controller that performs autonomous pressure testing, using automated decision-making to control drawdowns and buildups, allowing for adaptive testing based on real-time data analysis and criteria satisfaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If operators preprogram a fixed series of steps for the tool to perform, then the tool can operate autonomously with sufficient processing capabilities, but the procedure becomes neither efficient nor optimal due to varying reservoir or formation properties
Solution Approach 1:
The patent implements dynamic adjustment of testing parameters by the downhole tool based on real-time pressure data and formation characteristics. The system transitions from static preprogrammed sequences to dynamic adaptive control, where drawdown rates, buildup times, and testing parameters are automatically adjusted according to actual formation responses, resolving the contradiction between autonomous operation and adaptability.
Solution Approach 2:
The system incorporates real-time feedback mechanisms where pressure data collected during drawdown and buildup operations is continuously analyzed by the downhole processor. This feedback enables the tool to evaluate formation characteristics and automatically adjust subsequent testing parameters, creating a closed-loop control system that maintains both autonomy and adaptability to varying formation properties.
2Extent of automation
If the tool has sufficient processing capabilities to use mathematical models to predict tool response, then intelligent decision making can be replicated downhole, but the device complexity increases
Solution Approach 1:
The patent implements preliminary action by pre-programming multiple drawdown and buildup sequences with associated decision logic into the downhole controller before deployment. The system includes pre-configured mathematical models and criteria for evaluating formation responses, enabling intelligent decision-making without requiring complex real-time processing capabilities during operation.
Solution Approach 2:
The system replicates surface operator decision-making capabilities by embedding simplified mathematical models and evaluation algorithms directly in the downhole controller. This copying of intelligent decision-making functions allows the tool to autonomously evaluate formation characteristics and adjust testing parameters without requiring excessive processing power or communication with the surface.
3Measurement precision
If operators cannot monitor pressures in real time due to communication limitations, then data quality may be compromised, but real-time monitoring requires communication infrastructure that may not be available
Solution Approach 1:
The patent implements self-service by enabling the downhole tool to autonomously evaluate its own operational status and data quality. The controller continuously monitors pressure data, evaluates formation responses against pre-configured criteria, and automatically determines whether testing objectives have been met, eliminating the need for real-time surface monitoring and communication.
Solution Approach 2:
The system performs preliminary evaluation and decision-making downhole before data transmission to the surface. By pre-configuring evaluation criteria and performing real-time analysis at the wellsite, the system ensures data quality assessment occurs independently of communication availability, with results transmitted to the surface after the fact.
Data Source
AI summary
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.