Downhole Valve Assembly for Simultaneous Pretest Sequences
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Solution Overview
Problem
The existing methods for performing pretests of downhole fluids in wellbore operations are time-consuming due to the need for separate pressure buildup in multiple flowlines, which delays the overall fluid sampling and testing process.
Innovation Solution
A method and system that control a valve assembly to allow simultaneous fluid flow and pressure buildup in both the sample line and guard line flowlines, enabling the transition between pretest sequences without waiting for the initial fluid to stabilize, thereby reducing the overall time required for pretesting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate pressure buildup is performed in multiple flowlines sequentially, then each flowline can be tested individually, but the overall pretest time is substantially increased
Solution Approach 1:
The patent combines multiple pretest operations into a single simultaneous operation by enabling fluid drawdown through both the sample line and guard line at the same time. The valve assembly is configured to allow parallel flow paths, and the pump system operates to draw fluid through both lines concurrently, eliminating the need for sequential testing and substantially reducing total pretest time.
Solution Approach 2:
The system maintains continuous useful action by performing pressure buildup and fluid drawdown operations simultaneously in multiple flowlines. Rather than waiting for one line to complete its pretest before starting another, the system keeps all flowlines active at the same time, maximizing the utilization of equipment and minimizing idle time between measurements.
2Loss of information
If multiple pretest sequences are performed at different stations, then comprehensive fluid analysis is achieved, but the total operation time is substantially impacted
Solution Approach 1:
The system performs preliminary pressure buildup in multiple flowlines simultaneously before initiating fluid drawdown. By pre-establishing pressure conditions in all lines at once rather than sequentially, the system prepares all measurement pathways in advance, enabling immediate transition to fluid sampling and reducing the overall time required to gather comprehensive fluid property data from multiple stations.
3Reliability
If sequential pretesting of sample line and guard line is performed, then individual line performance is evaluated, but the transition time between sequences increases total duration
Solution Approach 1:
The valve assembly is designed with dynamic switching capability that allows rapid transition between different flow configurations. The system can dynamically adjust valve positions to switch between testing different flowlines or to test them in combination, enabling flexible and rapid reconfiguration without lengthy manual intervention or system repositioning, thus maintaining reliability while reducing overall test duration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces the time needed for pressure buildup in both sets of flowlines, optimizing the fluid sampling process and improving the efficiency of downhole fluid analysis by allowing simultaneous pressure buildup, thus accelerating the pretesting process.
Implementation Method 1
The pump may be used to draw the obtained fluid through a sample line and/or a guard line
Data Source
AI summary
A method including positioning a downhole acquisition tool in a wellbore in a geological formation; performing a pretest sequence to gather at least one of pressure or mobility information based on downhole acquisition from a sample line, a guard line, or both while the downhole acquisition tool is within the wellbore. The pretest sequence includes controlling a valve assembly to a first valve configuration that may allow the fluid to flow into the downhole tool via one or more flowlines toward a pretest system. The one or more flowlines include the sample line only, the guard line only, or both the sample line and the guard line; and drawing in the fluid through the one or more flowlines. The method also includes controlling the valve assembly to a second valve configuration. The second valve configuration is different from the first valve configuration and may block the one or more flowlines from drawing in the fluid.