Downhole Formation Fluid Sampling with Dual-Port Barrier Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for sampling formation fluids in wells often result in contaminated samples due to the infiltration of drilling mud and other non-formation-originating fluids, making it difficult to obtain uncontaminated hydrocarbon samples.
Innovation Solution
A formation sample tool with at least one port is introduced into the wellbore, where a first fluid is used to clear a sample passage and a second fluid, such as a gellable composition, is injected to create a barrier around the passage, preventing contaminated fluids from entering and allowing uncontaminated formation fluid to be collected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If drilling mud is injected into the well during drilling operations, then the drill bit is cooled and lubricated and rock fragments are transported to the surface, but the drilling mud contaminates the formation fluid near the wellbore
Solution Approach 1:
The invention divides the formation fluid collection process into distinct segments: a cleaning fluid injection stage to remove drilling mud contamination, followed by a separate formation fluid sampling stage. This segmentation allows the harmful drilling mud to be removed before sampling, resolving the contradiction between maintaining drilling operations and obtaining clean samples.
Solution Approach 2:
The invention performs preliminary cleaning of the formation fluid pathway by injecting cleaning fluid through the sample tool before collecting the formation fluid sample. This preliminary action removes the drilling mud contamination that would otherwise be present, allowing clean sampling to proceed despite ongoing drilling operations that continue to inject drilling mud.
2Measurement precision
If a sample tool is introduced into the wellbore to collect formation fluid, then formation fluid samples can be obtained, but the samples are contaminated by drilling mud infiltrating the wellbore
Solution Approach 1:
The sample tool performs preliminary injection of cleaning fluid through its ports before collecting the formation fluid sample. This preliminary cleaning action removes drilling mud from the formation fluid pathway, ensuring that the subsequent sample is representative and uncontaminated, thus resolving the contradiction between obtaining samples and avoiding contamination.
Solution Approach 2:
The invention introduces a cleaning fluid as an intermediary substance that mediates between the contaminated wellbore environment and the sampling process. The cleaning fluid acts as a barrier and cleaning agent that removes drilling mud contamination, allowing the sample tool to obtain clean formation fluid samples despite the presence of drilling mud in the wellbore.
3Loss of time
If drilling operations continue during formation testing, then real-time decisions can be made, but the continuous injection of drilling mud prevents collection of uncontaminated samples
Solution Approach 1:
The sample tool performs preliminary cleaning fluid injection through its ports before sampling, allowing continuous drilling operations to proceed while still obtaining clean samples. This preliminary action resolves the contradiction by enabling real-time sampling capability without sacrificing sample quality, as the cleaning fluid removes drilling mud contamination that would otherwise be present during ongoing drilling.
Solution Approach 2:
The invention enables continuous useful action by allowing both drilling operations and formation fluid sampling to proceed simultaneously. The sample tool's ability to inject cleaning fluid and then collect samples while the drill string remains in place maintains continuous drilling operations and real-time decision-making capability while still obtaining reliable, uncontaminated samples.
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 method effectively isolates uncontaminated formation fluids, enabling accurate sampling and reducing contamination from drilling operations, thereby improving the reliability of hydrocarbon sampling.
Implementation Method 1
A first fluid is injected through the first port into the formation to clear a sample passage allowing access to uncontaminated formation fluid
Implementation Method 2
A second fluid is injected through the second port into the formation to provide a barrier adjacent to or around the sample passage
Data Source
AI summary
A method for collecting a formation fluid for testing includes introducing a formation sample tool having a first port and a second port into a wellbore. A first fluid is injected through the first port into the formation to clear a sample passage and allow access to uncontaminated formation fluid. A second fluid is injected through the second port into the formation to provide a barrier adjacent to or around the sample passage. A sample of the uncontaminated formation fluid is removed from the formation through the first port.