Downhole Sampling Bottle Pressure Compensation Mechanism

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Solution Overview

Problem

Downhole sampling bottles face challenges in extreme conditions, including high temperatures and pressures, which can damage the equipment and compromise the accuracy of fluid samples due to air trapped within, leading to pressure differentials and contamination from wellbore fluids.

Innovation Solution

A pressure and temperature-compensated fluid sample container with interconnected chambers and pistons that maintain wellbore pressure, preventing sudden fluid inrush and expansion, and isolating the sample from contaminants using a buffer fluid and piston mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a simple sampling bottle is used, then the device complexity is low, but the reliability of sample integrity under extreme downhole conditions deteriorates

Engineering Contradiction:

Improvesample integrityVSAvoidbottle structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The sampling bottle is divided into multiple sealed chambers (sample chamber, buffer chamber, expansion chamber) with pistons separating them. This segmentation allows each chamber to independently manage specific functions (sample containment, pressure buffering, thermal expansion) while working together to maintain overall sample integrity under extreme conditions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A buffer fluid and piston mechanism are introduced as intermediaries between the sample and the external downhole environment. The buffer chamber with piston acts as a mediator that absorbs pressure fluctuations and thermal expansion effects, preventing direct transmission of these disturbances to the sample chamber and thus protecting sample integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If air is trapped within the sampling bottle, then the device complexity is reduced, but harmful pressure differentials and contamination are generated

Engineering Contradiction:

Improvesample purityVSAvoidchamber configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Air and other gases are completely extracted from the sampling bottle during the manufacturing process. The bottle is evacuated to create a vacuum, then backfilled with formation fluid or inert gas. This extraction eliminates the harmful effects of trapped air (pressure differentials, expansion, contamination) while the multi-chamber configuration manages the remaining fluid volumes appropriately.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The sampling bottle is filled with an inert atmosphere (vacuum or inert gas) to prevent chemical reactions and contamination of the sample. This creates a chemically stable environment that preserves sample purity while the multi-chamber design manages physical parameters.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

3Reliability

If the sampling bottle is exposed to extreme downhole conditions, then the productivity of sampling operations is maintained, but the bottle and sample are damaged

Engineering Contradiction:

Improvesample qualityVSAvoiddownhole environmental effects

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The buffer chamber is pre-filled with buffer fluid and equipped with a piston to provide beforehand cushioning against pressure fluctuations and thermal expansion. This cushioning capacity is built into the system before downhole deployment, allowing it to absorb and mitigate the harmful effects of extreme downhole conditions before they can damage the sample or bottle.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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

The solution effectively maintains the integrity of the fluid samples by preventing expansion and contamination, ensuring accurate petrophysical characteristics and reducing degradation during sampling and conveyance to the surface.

Implementation Method 1

air trapped within the sampling bottle may cause large pressure differentials

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

the fourth portion is fluidly connected with a space external to the sampling bottle

Methodology Applied

Scientific EffectPressure equalization: Pressure Gradient

Implementation Method 3

maintain wellbore pressure, preventing sudden fluid inrush and expansion

Methodology Applied

Scientific EffectPressure transmission: Pascal's Law

Implementation Method 4

preventing expansion and contamination, ensuring accurate petrophysical characteristics

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10677053B2Fluid compensation system for downhole sampling bottle

Publication Date: 2020.06.09 SCHLUMBERGER TECH CORP

AI summary

A formation fluid sampling bottle having a first chamber and a first piston slidably disposed within the first chamber and dividing the first chamber into first and second portions. The sampling bottle has a second chamber and a second piston slidably disposed within the second chamber and dividing the second chamber into third and fourth portions. The third portion of the second chamber is fluidly connected with the second portion of the first chamber, and the fourth portion of the second chamber is fluidly connected with a space external to the sampling bottle.