Downhole Solids Collector Segmentation for Slugging Prevention
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Solution Overview
Problem
Long horizontal wells in the oil and gas industry face issues with slugging flows, which can lead to premature failure of artificial lift systems due to solid accumulation, causing liquid starvation and gas production cessation.
Innovation Solution
A system comprising a receptacle and tubings in the wellbore that separates fluid streams into gas and liquid components, with check valves controlling flow to prevent slugging by reversing the liquid stream direction and using an artificial lift system to manage pressure and solids accumulation, allowing for efficient removal of solids and prevention of system failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solids accumulate in the sump, then the pump can run dry or be starved of liquids, but the system continues to operate until failure occurs
Solution Approach 1:
The system divides the wellbore into multiple annular regions (first, second, and third annuli) with separate flow paths. The first annulus handles gas-liquid separation, the second annulus manages liquid-solids separation, and the third annulus transports produced fluids to surface. This segmentation prevents solids from reaching the pump while maintaining continuous production.
Solution Approach 2:
The patent introduces intermediate separation regions and annular flow paths as mediators between the wellbore and pump. These intermediaries (separation regions, annuli, and flow control devices) prevent direct contact between solids and the pump, allowing the pump to operate reliably without ingesting accumulated solids.
2Reliability
If the pump is shut in to prevent liquid starvation and solids ingestion, then pump damage is avoided, but gas production stops and the entire system becomes inoperative
Solution Approach 1:
The system segments fluid streams into separate annular pathways, allowing gas to flow through the first annulus while liquids and solids are managed in the second annulus. This segmentation enables continuous gas production while preventing solids from reaching the pump, eliminating the need to shut in the pump.
Solution Approach 2:
The patent extracts solids from the fluid stream in the second annulus before the fluid reaches the pump. By taking out solids through the solids sump and preventing them from entering the pump inlet, the system maintains pump operation and continuous gas production without risk of solids ingestion.
3Reliability
If multiple separation regions and annuli are added to prevent solids accumulation, then pump reliability improves, but device complexity increases
Solution Approach 1:
The system uses multi-functional components where the same annular structure serves multiple purposes. For example, the first annulus functions as both a flow conduit and a gas-liquid separation region, while the second annulus serves as both a transport pathway and a solids separation zone. This multi-functionality reduces the need for separate dedicated components for each function.
Solution Approach 2:
The patent employs a nested structure where tubing is disposed within the wellbore, forming annuli between the tubing and wellbore wall. Additional components are nested within these annuli, creating a compact hierarchical arrangement that maximizes space utilization while maintaining complex separation functions.
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 system effectively elongates production operations by preventing slugging and solid accumulation, improving the economic viability of long horizontal wells by maintaining continuous fluid production and reducing maintenance needs.
Implementation Method 1
a first separation region formed at an end of the first annulus to separate a fluid stream carrying solids into a first separated stream that is reversed in direction into the second annulus and a second separated stream that continues to move in an uphole direction into the third annulus
Implementation Method 2
a second separation region formed at an end of the first tubing to separate the first separated stream into a third separated stream that is reversed in direction into the first tubing and a fourth separated stream that continues to move in a downhole direction into the chamber
Implementation Method 3
The artificial lift system may be operable in a first mode to lift the third separated stream received in the first tubing up the second tubing and in a second mode to increase the fluid pressure within the chamber to at least a threshold pressure at which the check valve opens
Data Source
AI summary
A solids collector is disposed at an end of a tubing in a wellbore. At a top of the solids collector, a reservoir fluid stream carrying solids is separated into a solids-liquid stream that is reversed into an annulus in the solids collector and a gas stream that continues to move uphole in the wellbore. At an end of the annulus in the solids collector, the solids-liquid stream is separated into a liquid stream that moves up the tubing and solids that are accumulated in the solids collector.