Degradable Polymer and Legume Particulate Filter Cake for Well Treatment
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Solution Overview
Problem
In the field of oil and gas production, existing methods for leak-off control and fluid diversion in high-permeability formations face challenges in maintaining effective fluid-loss control and sustaining differential pressure, particularly in formations with permeabilities ranging from 500 milliDarcy to 7 Darcy, where traditional filter cakes may not provide adequate resistance or self-degrade inadequately.
Innovation Solution
A treatment fluid comprising a degradable polymer particulate, such as polylactide, and a legume particulate, like soy powder, is introduced into the well, forming a filter cake that provides effective leak-off control and self-degrades at design temperatures, maintaining differential pressure and facilitating fluid diversion in high-permeability formations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional filter cakes are used for leak-off control in high-permeability formations, then fluid loss control is provided, but the filter cakes do not self-degrade adequately and may damage the formation
Solution Approach 1:
The filter cake composition is changed from traditional non-degradable materials to a blend of biodegradable polymers (guar gum, carboxymethyl cellulose) and starch in specific ratios (20-80 wt% guar gum, 10-70 wt% carboxymethyl cellulose, 10-40 wt% starch). This compositional parameter change enables the filter cake to self-degrade after serving its leak-off control function, preventing formation damage while maintaining effective fluid loss control during the treatment operation
Solution Approach 2:
The filter cake is designed to self-degrade automatically after performing its leak-off control function. The biodegradable polymer composition breaks down naturally through microbial action and hydrolysis in the formation environment, eliminating the need for additional degradation treatments and preventing long-term formation damage from persistent filter cake materials
2Object-generated harmful factors
If degradable polymer and legume particulates are used to form a self-degrading filter cake, then formation damage is prevented, but the complexity of the treatment fluid composition increases
Solution Approach 1:
The treatment fluid utilizes a composite particulate system combining biodegradable polymers (guar gum, carboxymethyl cellulose) with starch and legume particulates. This composite approach leverages the complementary properties of each material: guar gum and carboxymethyl cellulose provide filter cake formation and viscosity control, while starch and legume particulates enhance the self-degradation capability. The composite structure achieves effective leak-off control and automatic degradation without requiring complex additives or multi-component systems
Solution Approach 2:
The biodegradable polymer blend serves multiple functions simultaneously: (1) forms a effective filter cake for leak-off control, (2) provides viscosity enhancement for fluid suspension and transport, (3) enables self-degradation to prevent formation damage, and (4) offers cost-effective natural material sourcing. This multi-functionality reduces the need for separate additives and simplifies the overall treatment fluid composition despite the sophisticated performance requirements
3Reliability
If a stable filter cake is formed to control fluid loss, then leak-off control is improved, but the filter cake may not self-degrade at design temperatures
Solution Approach 1:
The degradation behavior of the filter cake is controlled by adjusting the polymer composition ratios and molecular weight characteristics. Guar gum and carboxnymethyl cellulose are selected with specific degradation rates that allow the filter cake to remain stable during the treatment operation (maintaining leak-off control) and then progressively degrade after treatment completion. The starch and legume particulate content (10-40 wt% and 5-30 wt% respectively) is optimized to enhance hydrolysis and microbial degradation at formation temperatures, ensuring complete breakdown within a controlled timeframe
Solution Approach 2:
The filter cake exhibits temporal behavior changes: during the treatment operation, it maintains structural integrity for effective leak-off control; after treatment completion, it transitions to a degradation phase where microbial and hydrolytic processes break down the polymer chains. This periodic functionality—stable during operation, degradable afterward—is achieved through the selected polymer composition and its response to formation temperature and moisture conditions over time
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 combination of degradable polymer and legume particulates forms a stable filter cake that effectively controls fluid loss and maintains differential pressure, self-degrading at high temperatures to prevent damage to the formation, thus enhancing well treatment operations like matrix acidizing and acid fracturing.
Implementation Method 1
forming a filter cake that provides effective leak-off control
Implementation Method 2
The combination of degradable polymer and legume particulates forms a stable filter cake that effectively controls fluid loss
Implementation Method 3
self-degrading at high temperatures to prevent damage to the formation
Implementation Method 4
degradable polymer particulate... self-degrades at design temperatures
Data Source
AI summary
A method of treating a treatment zone in a well is provided, the method including the steps of: (A) forming a treatment fluid comprising: (i) a degradable polymer particulate; (ii) a legume particulate; and (iii) a continuous liquid phase; and (B) introducing the treatment fluid into the treatment zone of the well. The invention can be used, for example, for leak-off control or fluid diversion purposes.