Borehole Fluid Sampling Valve Coordination

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing fluid sampling tools in boreholes face challenges in controlling flow across openings, leading to undesirable invasion of well fluids due to high hydrostatic pressure, which results in backflow and contamination of samples.

Innovation Solution

The use of a plurality of pumps and coordinated valve control, where the operation of the pumps and valves are synchronized to maintain a positive pressure differential, ensuring that fluid sampling occurs only when the pressure in the line is greater than the borehole pressure, thereby minimizing or eliminating backflow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fluid sampling tools have openings that allow fluid communication between the tool interior and the borehole environment, then fluid sampling capability is enabled, but well fluids invade the sampling tool due to high hydrostatic pressure causing backflow and sample contamination

Engineering Contradiction:

Improvefluid sampling capabilityVSAvoidbackflow and sample contamination

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary actions by pre-positioning multiple valves (borehole exit valve, sample line valve, tank valve) and pumps in specific states before sampling begins. The borehole exit valve is closed beforehand to prevent backflow, while the sample line valve and tank valve are opened in advance to establish proper flow paths. This preliminary configuration ensures that when sampling starts, the system is already in the correct state to prevent contamination while enabling fluid retrieval.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The sample line acts as an intermediary between the formation and the sampling tank, allowing controlled fluid transfer. The coordinated valve system serves as a mediator that regulates flow through this intermediary pathway, ensuring that fluids pass through the sample line under controlled pressure conditions rather than directly invading the tool interior through uncontrolled openings.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If high hydrostatic pressure is present in the borehole, then formation fluids can be retrieved, but this same pressure causes undesirable invasion and backflow into the sampling tool

Engineering Contradiction:

Improveformation fluid retrievalVSAvoidbackflow

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The borehole exit valve is closed in advance before sampling begins, preventing high-pressure well fluids from invading the tool interior. This preliminary closure maintains the pressure differential needed for fluid retrieval while blocking the harmful backflow path, allowing the system to benefit from high hydrostatic pressure without suffering its detrimental effects.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system segments the fluid pathway into distinct controlled sections using multiple valves. The borehole exit valve separates the high-pressure borehole environment from the tool interior, while the sample line valve and tank valve create a separate controlled sampling pathway. This segmentation allows high pressure to be harnessed for fluid retrieval in one section while preventing its harmful effects in another section.

Inventive Principle:

Principle #1Segmentation

3Manufacturing precision

If valve control is implemented to prevent backflow, then sample purity is improved, but system complexity increases due to multiple valves and coordinated control requirements

Engineering Contradiction:

Improvesample purityVSAvoidvalve coordination system

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The valve system is pre-configured in specific positions before sampling begins, with the borehole exit valve closed and the sample line valve and tank valve opened. This preliminary configuration simplifies the control process during sampling, as the valves are already in their optimal positions and require minimal adjustment, reducing the operational complexity despite having multiple valves.

Inventive Principle:

Principle #10Preliminary action

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 effectively prevents backflow and ensures the retrieval of pristine formation fluids by controlling the flow across borehole exits, enhancing the accuracy and reliability of fluid sampling in hydrocarbon reservoirs.

Implementation Method 1

retrieving fluids from the formation using a plurality of pumps

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

controlling a flow of the retrieved fluids using at least a first valve and a second valve... to maintain a positive pressure differential

Methodology Applied

Scientific EffectPressure differential control: Pressure Gradient

Data Source

PatentUS8997861B2Methods and devices for filling tanks with no backflow from the borehole exit

Publication Date: 2015.04.07 BAKER HUGHES CO

AI summary

A method for sampling fluid from a subsurface formation includes retrieving fluids from the formation using a plurality of pumps. The method also includes the steps of controlling a flow of the retrieved fluids using at least a first valve and a second valve and estimating an operating parameter of at least one pump of the plurality of pumps. The method further includes the step of controlling the first valve and the second valve using the estimated operating parameter to initiate a fluid sampling event.