Modulated Fracturing Pump Control for Pressure-Pulse Monitoring
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Solution Overview
Problem
Conventional methods for monitoring hydraulic fracturing, such as radionuclide and microseismic monitoring, pose environmental hazards and have high error rates, while sudden changes in loading can cause electrical shutdowns leading to well damage and require remedial actions.
Innovation Solution
A system utilizing fluid flow modulation to generate pressure pulses for wellbore and formation diagnostics, employing a combination of electrically driven and engine-driven pumps to control injection flow rates, allowing for real-time pressure diagnostics and fracture monitoring, reducing the risk of electrical shutdowns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If radionuclide monitoring is used to monitor hydraulic fracturing progress, then monitoring capability is provided, but environmental hazards are created due to radioactive material usage
Solution Approach 1:
The patent replaces radionuclide monitoring with acoustic signal generation and detection. Electrically driven pumps generate acoustic signals by modulating fluid flow rates, and acoustic sensors detect these signals to monitor fracture growth. This substitutes the harmful radionuclide-based detection system with an acoustic field-based system, eliminating environmental hazards while maintaining monitoring capability.
Solution Approach 2:
The patent introduces acoustic signals as an intermediary medium between the pumping system and the formation. Instead of injecting radioactive materials directly into the formation, acoustic signals are transmitted through the fluid column to interact with the formation and extract information about fracture characteristics, thereby avoiding direct contact with harmful substances.
2Difficulty of detecting and measuring
If microseismic monitoring is used to monitor hydraulic fracturing progress, then monitoring capability is provided, but error rate is high
Solution Approach 1:
The patent implements a feedback control system where acoustic signals are continuously generated and detected during the fracturing process. The detected acoustic signals provide real-time information about fracture growth, which is fed back to the control system to adjust pumping parameters dynamically. This continuous feedback loop enables precise real-time monitoring and control, significantly improving measurement precision compared to conventional microseismic methods.
Solution Approach 2:
The patent uses periodic modulation of fluid flow rates to generate acoustic signals at specific frequencies. By modulating the flow rate periodically and detecting the corresponding acoustic signals, the system can resolve temporal and spatial characteristics of fracture growth with high precision. The periodic action enables clear signal separation and enhanced measurement accuracy.
3Productivity
If electrical power supply is used to drive pumps during hydraulic fracturing, then pumping capability is provided, but sudden loading changes cause equipment damage and power outages
Solution Approach 1:
The patent employs dynamically controllable electrically driven pumps with variable speed capability. Instead of operating at fixed speed, the pumps can dynamically adjust their rotation speed in response to changing fracturing conditions and power supply constraints. This dynamic control allows the system to maintain productivity while preventing sudden loading changes that would damage equipment or cause power outages.
Solution Approach 2:
The patent incorporates preliminary action through advance warning systems and control algorithms that detect approaching power supply limits or problematic loading conditions before they cause equipment damage or blackouts. The control system proactively adjusts pump operation to prevent harmful transients, ensuring continuous reliable operation.
4Power
If electrical pump shutdowns occur during hydraulic fracturing, then power management is achieved, but proppant falls out of suspension causing well damage
Solution Approach 1:
The patent maintains continuity of useful action by using multiple electrically driven pumps that can operate independently. When one pump experiences a power issue or needs maintenance, the other pump(s) continue to provide fluid circulation, preventing proppant settling. This ensures continuous fracturing operation without interruption, eliminating the harmful effect of proppant precipitation while allowing flexible power management.
Solution Approach 2:
The patent prepares for potential power interruptions or pump failures by having redundant pumping capacity and control strategies in place beforehand. The system is designed with sufficient excess capacity so that temporary shutdowns or reduced operation do not cause proppant to fall out of suspension, thereby cushioning against the harmful effects of power management decisions.
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
Enables precise control of fracture growth and wellbore conditions, minimizing environmental hazards and equipment damage by providing real-time feedback for optimal fracturing operations.
Implementation Method 1
modulating a flow rate of the pump system to generate a pressure pulse in the wellbore
Implementation Method 2
the acoustic signal may interact with the formation and a reflected signal may be detected
Data Source
AI summary
A system for hydraulic fracturing with a modulating flow rate includes a first electric pump system electrically coupled to a power supply and fluidly coupled to one or more first wellbores; a second electric pump system electrically coupled to the power supply and fluidly coupled to one or more second wellbores; and a controller configured to control the first electric pump system to increase a flow rate of the first electric pump system and concurrently control the second electric pump system to decrease a flow rate of the second electric pump system such that a combined rate of change of electric power demand of the first electric pump system and the second electric pump system is less than a stiffness of the power supply.