Blanking Plug Sand Flushing via Downhole Tank
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Solution Overview
Problem
Sand and scale accumulation on top of blanking plugs and around ESP shafts in hydrocarbon wells leads to frequent ESP shutdowns, increased non-productive time, and premature pump failures, necessitating costly removal operations and potential well intervention delays.
Innovation Solution
A fluid tank is positioned above the blanking plug to agitate and displace accumulated sand and scale using dumped fluid, and a flushing tube is used to periodically flush away particulates, facilitating easier retrieval of the blanking plug and reducing ESP failures by maintaining fluid flow and preventing heat buildup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a blanking plug is installed in the wellbore to prevent fluid circulation around the ESP, then ESP shutdown due to fluid circulation is prevented, but sand and scale accumulation on top of the plug body occurs
Solution Approach 1:
The patent applies preliminary action by installing a flushing tube that extends from the surface to the blanking plug location before production begins. This allows periodic flushing operations to prevent sand and scale accumulation from reaching problematic levels, addressing the accumulation issue before it causes ESP shutdowns or retrieval difficulties
Solution Approach 2:
The patent uses hydraulic principles by pumping fluid through the flushing tube to create a high-velocity jet that agitates and displaces sand and scale accumulations. The fluid flow generates hydraulic force that removes particulate matter from the blanking plug surface, preventing the harmful accumulation effect
2Ease of operation
If sand and scale accumulate on top of the blanking plug, then retrieval of the blanking plug becomes difficult, but removing the blanking plug requires costly sand/scale removal operations
Solution Approach 1:
The flushing tube is installed in advance and can be used periodically to maintain the blanking plug surface clear of excessive sand and scale. This preliminary maintenance action prevents the need for costly removal operations and reduces non-productive time during well intervention by ensuring the plug remains retrievable
Solution Approach 2:
The system enables self-service by allowing periodic flushing operations to be performed from the surface without requiring workover crew or complex intervention equipment. The flushing tube delivers fluid directly to the blanking plug, enabling operators to clean accumulations themselves rather than requiring external removal services
3Reliability
If sand and scale accumulate around the ESP shaft, then ESP failures due to shaft rotation restriction occur, but preventing accumulation requires additional flushing infrastructure
Solution Approach 1:
The flushing tube serves multiple functions: it flushes sand and scale from the blanking plug surface, prevents accumulation around the ESP shaft, and maintains flow paths clear. This single infrastructure element addresses multiple protection needs, reducing overall system complexity while improving ESP reliability
Solution Approach 2:
The system uses hydraulic flow through the flushing tube to create a cleaning effect that reaches around the ESP shaft area. The fluid jet agitates and displaces sand and scale accumulations in hard-to-reach areas, preventing shaft rotation restriction without requiring complex mechanical cleaning devices
4Temperature
If adequate flow of produced fluid past the motor is required for cooling, then motor temperature is controlled, but solids blockage of pump flow path above the ESP causes rapid motor heat rise
Solution Approach 1:
The flushing tube is positioned to deliver fluid above the ESP where solids accumulate. By periodically flushing this area before complete blockage occurs, the system maintains adequate flow paths for motor cooling, preventing rapid heat rise and insulation breakdown before they can cause motor failure
Solution Approach 2:
The hydraulic flush creates a high-velocity fluid flow that clears solids blockage from the pump flow path above the ESP. This restores adequate cooling flow to the motor, preventing thermal damage caused by solids accumulation and maintaining proper operating temperature
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 solution effectively minimizes sand and scale accumulation, reduces the need for costly removal operations, prolongs ESP run life, and prevents pressure drops during oil well startup, enhancing well intervention efficiency and ESP integrity.
Implementation Method 1
fluid may be dumped from the fluid tank so as to agitate and displace sand, scale, and other particulate matter from the top of the blanking plug
Implementation Method 2
the lower end of the fluid tank may be equipped with one or more generally downwardly directed nozzles or jetting orifices for accelerating the dumped fluid against the accumulated sand, scale, or particulate matter
Implementation Method 3
Upon exiting the flushing tube, such pumped fluid will agitate and displace sand, scale, and other particulate matter that may have accumulated on top of the blanking plug
Data Source
AI summary
A system for producing fluids from a wellbore extending from a well surface to a fluid-producing formation has a Y-tool installed in fluid communication with the tubing string placed in the wellbore. A pump, which may be an electric submersible pump (ESP), is installed in the Y-tool for lifting fluids from the formation to the surface. A blanking plug is positioned in the tubing string between the upper and lower connections of the Y-tool. A flushing tank is run downhole to a position just above the blanking plug. Flushing fluid is dumped from an orifice or nozzle on the lower end of the flushing tank to agitate and disperse any accumulated sand, scale and other particulate matter on top of the blanking plug.