Downhole In-Situ Mixing Using Dual Concentric Flow Channels
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Solution Overview
Problem
Current methods for addressing lost circulation in well drilling operations are inadequate due to inaccuracies in timing chemical reactions for lost circulation materials (LCMs), leading to premature or delayed setting, which can result in ineffective plugging of fracture zones and increased costs and time.
Innovation Solution
A retainer-mixer assembly (RMA) tool is used to mix two fluids in-situ downhole, forming a curing composition that sets at an accelerated rate, preventing premature or late setting by using a static mixer section and dual path tubing to separate and mix fluids just before reaching the loss zone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pre-mixed chemical systems are pumped from the wellhead with delayed reaction rates, then the LCM is intended to harden or cure in the loss zone, but the chemical reaction may begin too soon and set inside the drill pipe or begin too late so that the LCM is lost into the loss zone and does not effectively plug the fracture
Solution Approach 1:
The chemical system is divided into two separate components that are pumped through separate flow channels (inner and outer channels) to the mixing device. This segmentation allows each component to be transported independently without premature reaction, and mixing occurs only at the designated location through the mixing device, ensuring precise timing control at the loss zone.
Solution Approach 2:
A mixing device acts as an intermediary mechanism that combines the two separate chemical components at the precise location of the loss zone. The mixing device controls the timing and location of the chemical reaction, preventing premature setting in the drill pipe while ensuring the LCM is properly mixed and delivered to plug the fracture effectively.
2Manufacturing precision
If chemical reaction rates are delayed to reach the loss zone, then the LCM should cure in place, but premature setting inside the drill pipe or delayed setting in the loss zone occurs
Solution Approach 1:
The LCM system is segmented into two separate chemical components transported through distinct flow paths. This ensures that each component reaches the loss zone without premature reaction, and the final mixing occurs precisely at the target location, achieving accurate placement and reliable fracture plugging.
Solution Approach 2:
The two chemical components are prepared and transported separately through the drill pipe in a preliminary state, ready for mixing but not yet reacted. This preliminary separation allows the system to reach the loss zone with both components intact, and the mixing action occurs immediately upon contact at the loss zone, ensuring precise placement.
3Device complexity
If single flow channel is used for LCM delivery, then the system is simpler, but accurate mixing and timing control at the loss zone cannot be achieved
Solution Approach 1:
The fluid delivery system is segmented into two separate flow channels (inner and outer channels) that transport different chemical components independently. This segmentation enables precise control over each component's delivery and mixing timing, achieving accurate LCM mixing at the loss zone despite the increased system complexity.
Solution Approach 2:
The system transitions from a single-dimensional flow path to a multi-dimensional dual-channel configuration. The inner and outer flow channels provide separate transport paths for the two chemical components, enabling independent control and precise mixing at the loss zone, with the mixing device serving as the convergence point for both channels.
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 RMA tool ensures accurate and timely mixing and setting of LCMs, effectively sealing loss circulation zones and regaining control of the well, reducing operational costs and time by preventing fluid loss.
Implementation Method 1
a static mixer section of the annular body having at least one static mixing blade extending through a downstream portion of the flow passage
Implementation Method 2
When the gate member is in a closed configuration, an upstream portion of the inner flow passage is sealed from a downstream portion of the inner flow passage by the gate member
Implementation Method 3
The first fluid and the second fluid are mixed in the static mixer section to form a curing composition, which may be used to fill the downhole location. The curing composition is allowed to set
Data Source
AI summary
A tool for use in a wellbore includes an annular body having an inner flow passage extending axially therethrough, at least one gripping member positioned around an outer perimeter of a retainer section of the annular body, and a gate member positioned in the inner flow passage. When the gate member is in a closed configuration, an upstream portion of the inner flow passage is sealed from a downstream portion of the inner flow passage by the gate member. When the gate member is in an open configuration, the upstream portion of the inner flow passage is fluidly connected to the downstream portion of the inner flow passage. At least one static mixing blade extends through the downstream portion of the inner flow passage to mix fluid when it flows through the open gate member.