High-Salinity Produced Water Precipitation for Seawater Desulfation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high sulfate content in seawater used for oil and gas operations leads to sulfate scale formation and toxic hydrogen sulfide production, causing formation damage and performance issues in drilling and recovery applications.
Innovation Solution
A method involving the addition of produced water to seawater to form a precipitating solution, followed by agitation and separation of precipitates, using alkaline earth metal halides as precipitating agents to reduce sulfate levels, and optionally employing flocculating agents for enhanced agglomeration and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If seawater is used for drilling operations, then water supply availability is improved, but sulfate scale formation and formation damage occur
Solution Approach 1:
The patent applies preliminary action by removing sulfate ions from seawater through ion exchange resins before the seawater is injected into the wellbore. This pre-treatment prevents sulfate scale formation downstream by reducing sulfate concentration to below 100 ppm, thereby eliminating the harmful effect while maintaining the benefit of using seawater for drilling operations
Solution Approach 2:
The patent extracts the harmful sulfate ions from seawater using ion exchange resins. The ion exchange process selectively removes sulfate ions from the seawater stream, separating the harmful component (sulfate) from the useful component (water), allowing the treated seawater to be safely used for drilling operations without causing scale formation
2Object-affected harmful factors
If sulfate levels are reduced through treatment, then scale formation is prevented, but treatment cost increases
Solution Approach 1:
The patent uses ion exchange resins that can be regenerated in-place through chemical treatment, effectively creating a reusable but ultimately replaceable system. The resins are relatively inexpensive compared to nanofiltration membranes and can be regenerated multiple times, providing a cost-effective solution for sulfate removal while maintaining scale prevention benefits
Solution Approach 2:
The ion exchange system is designed to be self-regenerating through in-place chemical treatment cycles. The resins automatically regenerate without requiring removal or replacement, reducing operational costs and maintenance complexity while continuously preventing scale formation through sustained sulfate removal
3Quantity of substance
If nanofiltration is used for sulfate removal, then sulfate levels are reduced effectively, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex nanofiltration membranes with simpler, regenerable ion exchange resins. The resins achieve comparable sulfate removal effectiveness but with significantly reduced system complexity, lower capital costs, and simpler operation and maintenance requirements, making the treatment system more economically viable
Solution Approach 2:
The patent changes the treatment mechanism from physical filtration (nanofiltration) to chemical ion exchange. This parameter change in the removal mechanism simplifies the system design by eliminating the need for high-pressure pumps, membrane housings, and complex filtration systems, while achieving the same sulfate concentration reduction through chemical resin-bed exchange
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
Effectively reduces sulfate concentrations below threshold levels, preventing scale formation and enabling safe use of seawater in oil and gas operations, while recycling produced water and addressing water supply shortages.
Implementation Method 1
adding an amount of a produced water to an amount of a sulfated seawater to form a first precipitating solution, agitating the first precipitating solution thereby forming a first precipitate
Implementation Method 2
adding a precipitating agent to an amount of a sulfated seawater to form a second precipitating solution including a second precipitate
Implementation Method 3
agitating the first precipitating solution thereby forming a first precipitate
Implementation Method 4
separating the first precipitate from the sulfated seawater to produce a desulfated seawater
Implementation Method 5
separating the second precipitate from the sulfated seawater to produce a desulfated seawater
Implementation Method 6
employing flocculating agents for enhanced agglomeration and removal
Data Source
AI summary
A method of desulfating seawater includes adding a produced water to a sulfated seawater, forming a first precipitate, separating the first precipitate from the sulfated seawater, measuring the sulfate ion concentration of the desulfated seawater, adding a precipitating agent to the sulfated seawater, and separating a second precipitate from the sulfated seawater. Another method of desulfating seawater includes determining concentrations of sulfates in a sulfated seawater and a precipitating agent in a produced water, adding the produced water to the sulfated seawater based on the determined concentrations of sulfates in the sulfated seawater and the precipitating agent in the produced water, forming a first precipitate, separating the first precipitate from the sulfated seawater, measuring the sulfate ion concentration of the desulfated seawater, adding a precipitating agent to a sulfated seawater, and separating a second precipitate from the sulfated seawater.