Biodegradable Drilling Fluid Shear-Dependent Viscosity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional drilling fluids face challenges in maintaining optimal viscosity in different shear rate regions, leading to inefficient cuttings transport and hole cleaning, especially in varying environmental conditions, and pose environmental concerns due to non-biodegradable additives.
Innovation Solution
A drilling fluid comprising water, biodegradable fibers made of polyhydroxyalkanoate, and a biodegradable polysaccharide thickener, which maintains high viscosity in low shear rate regions while keeping fluidity in high shear rate regions, enhancing cuttings transport and hole cleaning capabilities while being environmentally friendly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the viscosity of the drilling fluid is kept low in the high shear rate region, then the pressure loss in the drill pipe is reduced and thrust of jet flow is increased, but the viscosity in the low shear rate region is reduced excessively causing insufficient cuttings transport capability
Solution Approach 1:
The drilling fluid exhibits dynamic viscosity changes based on shear rate conditions. In high shear rate regions (inside drill pipe), the fluid maintains low viscosity to reduce pressure loss. In low shear rate regions (annulus), the fluid maintains high viscosity to improve cuttings transport. This dynamic adaptation resolves the contradiction between energy loss and productivity.
Solution Approach 2:
The patent uses pseudoplastic and Bingham fluid additives that change their viscosity parameters based on shear rate. By controlling the concentration and type of these additives, the fluid achieves different viscosity states in different regions, allowing low pressure loss in high shear zones while maintaining high cuttings transport capability in low shear zones.
2Productivity
If the viscosity of the drilling fluid is increased in the low shear rate region, then the efficiency of cuttings transport is improved, but the viscosity in the high shear rate region is also increased causing loss of fluidity
Solution Approach 1:
The drilling fluid dynamically adjusts its viscosity based on local shear rate conditions. In the annulus (low shear rate), the fluid becomes more viscous to enhance cuttings transport efficiency. In the drill pipe (high shear rate), the fluid remains fluid to ensure easy circulation. This dynamic behavior eliminates the need to choose between the two opposing requirements.
Solution Approach 2:
The fluid achieves different quality characteristics in different spatial locations. The pseudoplastic and Bingham fluid properties create local viscosity variations: high viscosity in the annulus for cuttings transport and low viscosity in the drill pipe for fluidity. This local differentiation resolves the contradiction between productivity and ease of operation.
3Productivity
If conventional non-biodegradable additives are used to maintain optimal viscosity, then the drilling performance is improved, but environmental harm is caused due to non-biodegradable components
Solution Approach 1:
The patent substitutes conventional non-biodegradable additives with biodegradable pseudoplastic and Bingham fluid additives. These biodegradable additives maintain the necessary viscosity parameters for optimal drilling performance while being environmentally friendly. The concentration and molecular structure of these additives are carefully controlled to achieve the desired rheological properties without compromising drilling performance.
Solution Approach 2:
The patent converts the potential harm of additive persistence in the environment into a benefit by using biodegradable additives. These additives provide the necessary viscosity control for improved drilling performance during operation, then naturally degrade after use, eliminating environmental contamination. This transforms the harmful aspect of additive usage into a beneficial environmentally friendly solution.
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 drilling fluid effectively improves cuttings transport and hole cleaning efficiency across different shear rate regions and reduces environmental impact by using biodegradable components that decompose easily, minimizing environmental load.
Implementation Method 1
the viscosity of the drilling fluid in the low shear rate region is reduced excessively, the properties of the drilling fluid deviate from pseudoplastic fluid properties or Bingham fluid properties
Implementation Method 2
the properties of the drilling fluid deviate from pseudoplastic fluid properties or Bingham fluid properties, which are necessary rheological properties for the drilling fluid
Implementation Method 3
biodegradable components that decompose easily, minimizing environmental load
Data Source
AI summary
An object of the present invention is to provide an environmentally friendly drilling fluid that has excellent cuttings transport capability and excellent hole cleaning capability. A drilling fluid according to the present disclosure is a drilling fluid containing water, biodegradable fibers, and a thickener. The thickener contains a biodegradable polysaccharide. The content of the biodegradable polysaccharide in the drilling fluid is greater than or equal to 0.01 g/L and less than or equal to 5 g/L.