Biodegradable PHA Polymer Wellbore Fluid Additive

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Wellbore fluids are often lost to fractured, permeable, or porous formations during drilling, leading to instability and reduced production, and existing solutions are not environmentally friendly.

Innovation Solution

A wellbore fluid comprising an aqueous base and polyhydroxyalkanoate (PHA) latex polymer, which forms a filter cake to seal fractures and stabilize the wellbore, while being biodegradable and environmentally friendly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional wellbore fluids are used to control subsurface pressures and suspend cuttings, then wellbore operations can continue, but the fluids are lost to fractured, permeable, or porous formations causing fluid loss and wellbore instability

Engineering Contradiction:

Improvewellbore stabilityVSAvoidfluid loss

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies preliminary action by pre-coating the wellbore formation with a biodegradable polymer solution before drilling operations begin. This coating is applied in advance to seal fractures and reduce permeability of the formation, preventing fluid loss during subsequent drilling operations. The polymer is deposited on the formation surface and allowed to set before the wellbore is put into service.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses a biodegradable polymer as an intermediary substance between the wellbore fluid and the formation. This polymer coating acts as a mediator that prevents direct contact between the drilling fluid and the fractured/permeable formation, thereby reducing fluid loss while maintaining wellbore stability. The intermediary layer seals micro-fractures and reduces formation permeability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of substance

If non-biodegradable materials are used to seal fractures and reduce fluid loss, then fluid loss is reduced, but environmental harm increases

Engineering Contradiction:

Improvefluid lossVSAvoidenvironmental harm

Core Design Contradiction:

Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by selecting polymers with specific biodegradability parameters. The polymer must meet minimum biodegradation rates (e.g., 60% or greater under standard test conditions) while maintaining sufficient sealing performance. This changes the material parameter from non-biodegradable to biodegradable, eliminating environmental persistence while preserving fluid loss control functionality.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs biodegradable polymers that perform their sealing function temporarily during drilling operations and then naturally degrade after completion. These short-living materials serve their purpose of reducing fluid loss during the drilling phase and then break down into harmless substances, replacing permanent non-biodegradable sealants with temporary biodegradable ones.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Loss of substance

If polymer concentration is increased to improve filter cake quality and reduce fluid loss, then fluid loss control improves, but viscosity increases making the fluid harder to pump

Engineering Contradiction:

Improvefluid lossVSAvoidpumping energy

Core Design Contradiction:

Loss of substanceVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by optimizing the polymer concentration to a specific range that balances fluid loss control and pumpability. The concentration is controlled to provide sufficient filter cake quality and sealing performance while maintaining viscosity within acceptable limits for circulation. This involves selecting the minimum effective concentration that achieves the required biodegradability and sealing performance without excessive viscosity.

Inventive Principle:

Principle #35Parameter changes

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 PHA latex polymer effectively reduces fluid loss, enhances wellbore stability, and meets stringent environmental criteria, allowing for safe use in sensitive areas like the North Sea.

Implementation Method 1

the wellbore fluid includes an aqueous base fluid; and a plurality of particles of a polyhydroxyalkanoate latex polymer... which forms a filter cake to seal fractures and stabilize the wellbore

Methodology Applied

Scientific EffectFilter cake formation: Deposition (physical)

Implementation Method 2

The PHA latex polymer effectively reduces fluid loss, enhances wellbore stability, and meets stringent environmental criteria, allowing for safe use in sensitive areas like the North Sea

Methodology Applied

Scientific EffectBiodegradation: Decomposition (biological)

Data Source

PatentUS10745607B2Biodegradable additive suitable for use in wellbore fluids

Publication Date: 2020.08.18 SHCLUMBERGER NORGE AS

AI summary

A wellbore fluid comprising an aqueous base fluid and a plurality of particles of a polyhydroxyalkanoate latex polymer having the formula: [—O—CHR—(CH2)m—CO—]n, wherein m is a value ranging from 1 to 10 and n is a value equal to or less than 20000.