Application of Fluid Phenomena

8/12/2019 Application of Fluid Phenomena

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Application of Fluid Phenomena and Study of theMethod of Transient Characteristics of Downhole (Oil

and Gas) Fluidic Pulsating Tool using FLUENT-ANSYS

by

Bharat Pawar, Harit Naik, Tim Hunter

at

2011 ANSYS Users Conference

Pune


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2FOR INTERNAL USE ONLY

Loss of production or injectivity because of near

wellbore conductivity problems caused by

Scales

Paraffin

Migrating fines

Asphaltene deposits

Lost or dehydrated drilling mud

Well not producing at maximum potential

Ineffective stimulation treatments (acidizing,

fracturing, etc.) as a result of near wellbore

blockage or restrictions

Problem, Definition, and Objective

The objective of this paper is to review efforts to simulate the tool behavior using

FLUENT-ANSYS and study the application of fluid phenomena and transient

characteristics of fluid behavior surrounding the tool. Further, design parameters

are selected and fine-tuned based on simulation results to get the desired

frequency, mass flow rate (bbl/min), pressure drop, outlet vector plot, etc.


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Proprietary Pulsating Tool1

Inlet

Outlet 1

Outlet 2

Existing TechniquePulsating Tool

Proprietary pulsating tool is based on Coanda effect.

Several performance characteristics of this tool are further

enhanced with the help of FLUENT- ANSYS simulation.

Tool is run on coiled tubing

Unique design causes the tool to oscillate as fluid is pumped

through the tool.

Fluid can be acid, water, seawater, diesel, nitrified

fluids, etc.


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The principle of a fluid oscillator (FO) is the

Coanda effect. The Coanda effect is thetendency of a fluid jet to be attracted to a nearby

surface. This effect is explained with the help of

the figures below.2

Basic PrincipleCoanda Effect


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Transient FLUENT simulation of basic design

Parametric design optimization to identify critical geometrics

Conceptual design optimization to get further enhancement

Prototyping-I

Rapid prototyping and lab test

Design changes

Prototyping-II

Steel prototype and lab test

Correlation and designvalidation

Simulation Methodology


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Inlet throat

Feedback loops

Switching jet

Outlets

Pulsating Tool

The pulsating tool discussed here has

been specifically designed for high-pressure, submerged operation, along

with a specific oscillation frequency

target.

Cross-section of this pulsating tool pattern


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Input Parameters

Inlet pressure 500 to 2,000 psi

Mass flow rate 0.5 to 3 bbl/min

Outlet pressure Atmospheric

Flow media Water

Simulation type 2-D and 3-D (parallel

processing)Energy No energy equation activated

Turbulence model K-Omega SST

Solver Pressure-based, transient

Solution methods PISO-pv coupling and

standard pressure

discretization, second order

Convergence criteria 1e-5

Time step size 0.0002 sec

No. of time steps 2,000

Flow time 0.4 sec

Output Parameters

Mass flow rate

Pressure drop

Oscillation pattern

Oscillation frequency

Mass flow ratio

Vector plot

Simulation Parameters

Computational Domain of Pulsating Tool


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Parametric Optimization3

To visualize the oscillatory flow

through the tool, incremental snap-shots of relative fluid velocity were

saved during the transient response

simulation.

Parametersensitivity

A,BK are design

parameters


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FFT

Frequency, HzMass Flow At Outlets

Mass Flow Rate & Frequency From Outlet Port


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Time

Transient Modeling of Pulsating Tool

To visualize the oscillatory flow

through the tool, incremental snap-

shots of relative fluid velocity weresaved during the transient response

simulation.


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Prototyping and Test Setup

Example of EDM manufacturing process Experimental test setup

Manufacturing

Testing


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Benefits and Summary

For different inlet pressure, close correlation for mass flow rate and oscillation frequency

was observed between experimental measurement and FLUENT-ANSYS prediction.

FLUENT-ANSYS prediction of results helps accelerate product-development time.

New design of tool imparts lower oscillation frequency for deeper penetration into

formations.

Higher energy output over a narrower frequency range than a conventional tool.

No moving parts or seal; robust design.

This next-generation tool should effectively increase the efficiency of wells.4


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Challenges and Future Scope

Simulation was very sensitive to CFD mesh. Mesh-sensitivity study was carried

out to eliminate the mesh dependency.

New design involves thin, deep sections, which decrease the manufacturability

and life of the tool and insert.

Tool size limits the scope of intricate shapes. Efforts were made to keep it

simple and manufacturing-friendly.

Future scope is to test this tool in the field.


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Acknowledgement and References

The authors thank the management of Halliburton for their support and permission to

publish this paper. They would also like to express gratitude to all the team memberswho contributed to the job design, preparation, and execution of the operation to

achieve the results presented in this paper.

REFERENCES

1. Webb, E.D., Tucker, J.C., Meadows, M.L., and Pipkin, R.L. 2005. Apparatus and Method for Creating Pulsating Fluid Flow.

US Patent No. US6976507B1.

2. Webb, E.D., Schultz, R.L., Howard, R.G., and Tucker, J.C. 2006. Next Generation Fluidic Oscillator. Paper SPE 99855

presented at the SPE/ICoTA Coil Tubing Conference and Exhibition, The Woodlands, Texas, US, 45 April.

3. Roger, R.P. and Chan, S.C. 20033. Numerical Study of Fluidic Bistable Amplifiers. Paper AIAA 2003-3459 presented at 33rd

AIAA Fluid Dynamics Conference, Orlando Florida, USA, 2326 June.

4. Kritsanapkak, K. and Tirichine, S. 2010. Effectively Enhancing the NWB Stimulation Treatment using Fluidic Oscillation

Technique. Paper SPE 136065 presented at the SPE Production and Operations Conference and Exhibition, Tunis,

Tunisia, 810 June.


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Thank You.

Application of Fluid Phenomena

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