Deformable Particulate Fluid Pill for Horizontal Wellbore Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In horizontal wellbores, existing methods for building fluid-impermeable plugs to isolate high permeability zones and divert fluid flow to low permeability zones are inefficient due to gravitational settling of sand or proppant, leading to compromised isolation and time-consuming processes.
Innovation Solution
A fluid pill containing a well treatment composite with a dissolvable diverter and deformable particulate coated with a viscosifying polymer and crosslinking agent is pumped into the wellbore, allowing the diverter to dissociate and block high permeability zones, while the deformable particulate forms a thickened gel to create a fluid-impermeable plug in low permeability zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sand or proppant is used to build a plug in a horizontal wellbore, then the plug can provide hydraulic isolation, but gravitational settling causes the plug to settle along the bottom of the wellbore creating voids that compromise isolation
Solution Approach 1:
The patent changes the physical state and density parameters of the plug material by using a fluid pill that transforms from a pumpable slurry to a gelated solid structure. The fluid pill contains crosslinkable polymer that undergoes gelation to form a rigid, space-filling plug that does not settle under gravity, thereby maintaining reliable hydraulic isolation throughout the wellbore cross-section.
Solution Approach 2:
The invention uses a composite fluid pill composition containing crosslinkable polymer, particulate matter, and optionally foam or gas. This composite structure combines the flowability of liquid polymer with the structural integrity of particulate and foam elements, creating a material that can be pumped horizontally then set in place to form a stable, non-settling plug that provides complete wellbore isolation.
2Reliability
If multiple separate additives are used for plug formation, then the plug can achieve required isolation properties, but the process requires more surface space and time for handling and mixing
Solution Approach 1:
The patent merges multiple functional additives (crosslinkable polymer, particulate matter, foam, gas) into a single pre-mixed fluid pill composition. This unified formulation eliminates the need for separate handling and mixing of individual components at the wellsite, reducing both surface space requirements and the time needed for plug formation while maintaining reliable isolation performance.
Solution Approach 2:
The fluid pill is prepared in advance with all necessary components (polymer, particulate, crosslinking agents) already mixed and ready for injection. This preliminary preparation of the composite formulation eliminates on-site mixing operations and reduces the overall time required for plug formation, as the material is ready to be pumped and set immediately upon injection into the wellbore.
3Reliability
If a fluid pill with high sand concentration is pumped to form a sand plug, then hydraulic isolation can be achieved, but the sand settles during pumping creating channels that allow fluid to bypass the plug
Solution Approach 1:
The patent changes the rheological parameters of the carrier fluid by using crosslinkable polymer that increases viscosity and eventually gels. This parameter change allows high concentrations of particulate matter to be suspended stably during pumping without settling, and then the gelation process locks the particulate in place to form a stable, channel-free plug structure that provides reliable hydraulic isolation.
Solution Approach 2:
The invention creates a composite fluid pill where crosslinkable polymer binds with particulate matter to form a stable suspension that resists gravitational settling. The crosslinked polymer network acts as a binding matrix that holds particulate in place, preventing channel formation and ensuring stable composition throughout the plug structure for reliable isolation.
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
This method enhances wellbore isolation, reduces the need for separate additives and surface space, and shortens the time required for fracture closure and plug formation, improving hydrocarbon production from low permeability zones.
Implementation Method 1
a viscosifying polymer and crosslinking agent coated onto at least a portion of the surface of the core
Implementation Method 2
the deformable particulate forms a thickened gel to create a fluid-impermeable plug
Implementation Method 3
the dissolvable diverter dissociates from the core and blocks at least a portion of a high permeability zone
Implementation Method 4
the deformable particulate forms a thickened gel
Data Source
AI summary
A method for building a plug in a horizontal wellbore using a fluid pill containing a suspended well treatment composite. The well treatment composite contains a core comprising at least one deformable particulate and at least one dissolvable diverter. At least a portion of the surface of the core is coated with at least one viscosifying polymer and at least one crosslinking agent. The fluid pill is pumped into the wellbore at the end of a fracturing treatment and the fluid pill may be displaced by a displacement fluid. The fluid pill may be diverted to an area of lower permeability by disassociating the dissolvable diverter from the core. The disassociated diverter blocks an area of higher permeability. The sized particle distribution of the diverter is sufficient to at least partially block the penetration of fluid into the high permeability zone. In the lower permeability zone, a thickened gel is formed by the in-situ reaction of the viscosifying polymer and crosslinking. Deformable particulates in the gelled fluid form a bridge plug.