Downhole Pump Control for Formation Fluid Pressure Measurement
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Solution Overview
Problem
Current downhole tools face challenges in accurately measuring formation pressures due to contamination from drilling mud, leading to errors in reservoir characterization and optimization of well activities.
Innovation Solution
A method involving a downhole tool that draws formation fluid into a pressure test chamber, measures pressure, and operates pumps to route and mix fluids, including using an auxiliary fluid chamber to expel and mix fluids, ensuring accurate pressure measurements and reducing contamination effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If formation fluid is drawn into the pressure test chamber for measurement, then formation pressure can be measured, but drilling mud contamination occurs leading to measurement errors
Solution Approach 1:
The downhole tool is divided into separate functional chambers: a pressure test chamber for formation fluid and an auxiliary fluid chamber for drilling mud. This segmentation allows the tool to separately handle formation fluid and drilling mud, enabling accurate pressure measurements while managing contamination through dedicated fluid pathways and separate expulsion mechanisms.
2Ease of operation
If pumps are used to route formation fluid through the downhole tool, then fluid routing and mixing is achieved, but device complexity increases
Solution Approach 1:
The pump system is designed with multi-functionality where the same pump can route both formation fluid and drilling mud through different pathways. The pump can operate in different modes: routing formation fluid during pressure measurement, and subsequently routing drilling mud for cleanup. This universal routing capability reduces the need for separate dedicated pumps for each fluid type, thereby managing device complexity while maintaining operational flexibility.
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 allows for precise formation pressure measurement and characterization, reducing errors caused by drilling mud contamination, thereby optimizing well operations and reservoir understanding.
Implementation Method 1
fluid can be drawn from the formation into the tool through the intake by creating a negative pressure differential between the formation and the tool interior
Implementation Method 2
operating the flowline pump and the auxiliary pump simultaneously to regulate mixing of the formation fluid with the auxiliary fluid
Data Source
AI summary
A method includes drawing formation fluid from a formation into a pressure test chamber of a downhole tool while the downhole tool is positioned at a location within a wellbore. The method also includes, while the downhole remains positioned at the location, measuring pressure of the formation fluid drawn into the pressure test chamber and operating a first pump to route additional formation fluid from the formation through the downhole tool and out into the wellbore. Still further, the method includes operating a second pump to expel the formation fluid from the pressure test chamber and to mix the formation fluid with the additional formation fluid such that the formation fluid expelled from the pressure test chamber is also routed through the downhole tool and out into the wellbore along with the additional formation fluid.