Application of a Transient Near-Wellbore / Reservoir Simulator For … · 2019. 8. 16. · Application of a Transient Near-Wellbore / Reservoir Simulator For Complex Completions Design

Application of a Transient Near-Wellbore / Reservoir

Simulator For Complex Completions Design

2019-NAPS-2.2AUTHORS: Jim Gilliat, Parry Hillis, Bill Myers, Rajani Satti, Baker Hughes (a GE company)

DALLAS - FORT WORTH. AUGUST 5-6, 2019.

AGENDA

2019-NAPS Application of a Transient Near-Wellbore / Reservoir Simulator For Complex Completions Design

INTRODUCTION

NUMERICAL MODEL

APPLICATION EXAMPLESDropped objects Incident diagnostics Impact on lubricator valves Integrity of a sand management system

CONCLUSIONS

INTRODUCTION

WHY IS TRANSIENCE IMPORTANT TO COMPLETIONS ?

Success of a well completion job is driven by careful understanding of transient physics that

entails

complex geometries

material properties,

fluid dynamics,

geomechanics

and most importantly, a wide range of temporal scales (microseconds to days)

Examples of transient events (desired or undesired) that are typically encountered during well-completions are described below: Water hammer, a pressure transience or surge that travels up or down the wellbore Ball drop for multizone plug-n-perf operations Sliding sleeve operations, Setting a packer, Detonation of perforating guns, where the dynamic explosive energy from shaped charges penetrates

the casing, creates perforation tunnels, tunnel clean-up enhanced by transient underbalance.


INTRODUCTION

THE NEED FOR MODELING TOOL …

Limited data from downhole measurements

Fit-for-purpose transient, well-completion simulators that incorporate the following

features are currently not available within the industry:

Transient wellbore-reservoir-perforation-fracture simulator that captures extremely short

duration events (few milliseconds to seconds).

Comprehensive representation of downhole geometry including tubing, packers, plugs,

valves, perforating assemblies, stimulation mechanisms etc.

Applications focused on generic dynamic events encountered during well completions

This work presents the philosophy and application of a transient wellbore-reservoir-

perforation-fracture simulator that’s used for modeling dynamic completion events.


INTRODUCTION

PHILOSOPHY OF OUR NUMERICAL MODEL

Mathematical Model:

• The mathematical model is based on an explicit coupling

of independent reservoir (qR), wellbore (qw), and tool

stress fields (σ).

• The dynamics of each model are coupled through the

boundary conditions between the reservoir and wellbore

(B), and the force conditions between the wellbore fluids

and the completion tools (F) as shown in Figure

Numerical Schemes:

• Split-scheme integration for robust flux conservation and

shock capturing capabilities.

• Riemann solvers


APPLICATION EXAMPLE # 1

DROPPED TOOLS IN A WELLBORE

Instances of dropped tools or objects can be classified into two categories an object or a working tool is accidently dropped into the

wellbore planned operation of a ball being dropped and pumped

downhole to seat on a plug.

Fundamental experiment of a metal bar with transient gages dropped into a wellbore is discussed here.

Transient velocity is compared between the experimental (from the gage) and computed (transient simulator) data.

The transient profile of velocity and most importantly, the instant when the metal bar contacts the water interface is accurately captured by the computational software.



FIELD INCIDENT DIAGNOSTICS

Completion scenario of a well in the Middle East

A new and novel liner tool assembly was utilized in a well, where the liner tool included various components that were to be activated during the setting and installation of the liner/liner hanger assembly, prior to cementing operations.

The tool’s operation required the application of workstring pressure differential to a setting tool to shear, starting the setting sequence. After many attempts, the required differential pressure could not be achieved.

A failed component was suspected, generating a leak path. The majority of the tools remained in the well, below the set liner hanger, therefore retrieval and investigation of the tools was not possible.


Tool setting depth, bottom, MD and TVD 2,951 m

Plug Back TD, MD and TVD 3,101 m

Open Hole diameter 8.50”

Tool / Liner OD 7.655” (Cplg for 7” 32#)

Wellbore fluid 12.1# mud, poor condition, “highly viscous”

Formation Pressure @ setting depth 4,050 psi

BHT, F 210°F

APPLICATION EXAMPLE # 2FIELD INCIDENT DIAGNOSTICS


One such avenue of investigation was initiated when it was

reported that the tools “dropped” by approximately two feet

while setting the slips when the liner was at depth.

Using the transient wellbore-reservoir simulator, a simulation

was conducted using the as-run well and tool string information,

and the fluid properties of the drilling mud.

Investigation of pressure differential failure points

Investigation of undesired leak paths

Water hammer effects of the fluids inside and outside of the

tool string.

These spikes indicated that more than sufficient pressure

differential to cause failure of these components can occur

under the conditions modeled.

Learnings of the investigation were incorporated: components

were re-engineered to increase the differential pressure ratings,

robust operation procedures were introduced to reduce the

chance of reoccurrence.

APPLICATION EXAMPLE # 3IMPACT ON LUBRICATOR VALVE


• Effect of impact on a lubricator valve was examined if the

perforating string in a wellbore was inadvertently dropped.

• The near wellbore simulator was used to investigate the

following:

Compression failure of the valve.

How the bouncing of the perforating assembly causes

additional compressional loads on the valve

G force loading on the valve at the moment of impact

Software can be used as a risk mitigation tool for in many

types of environments and situations.

Most importantly, the insight provided by transient fluid

variables like pressure, velocity along with tool movement is

invaluable in ensuring the safety and efficiency of a

completion operation.

Impact

Tool String bouncing



• Effect of impact on a lubricator valve was examined if the

perforating string in a wellbore was inadvertently dropped.

• The near wellbore simulator was used to investigate the

following:

Compression failure of the valve.

How the bouncing of the perforating assembly causes

additional compressional loads on the valve

G force loading on the valve at the moment of impact

Software can be used as a risk mitigation tool for in many

types of environments and situations.

Most importantly, the insight provided by transient fluid

variables like pressure, velocity along with tool movement is

invaluable in ensuring the safety and efficiency of a

completion operation.

IMPACT ON LUBRICATOR VALVE

APPLICATION EXAMPLE # 4SAND MANAGEMENT SYSTEM: INTEGRITY ANALYSIS


• Examine the integrity of a novel sand management screen

system

• Customer in Azerbaijan was concerned about blowing of a ball seat after the production packer is set and the if the subsequent pressure surge could damage the sand management screen

• The transient simulator was used to setup pressure points along the body of the screen and at various points along the completion.

• The simulator has a “valve” feature that can be used to replicate the rapid pressure release.

• pseudo pressure points were then placed along the tool string to monitor pressures and differentials.

• The permeability of the screen and the formation behind it was also accounted for to ensure an accurate measure of differential pressure across the tools

Valve (ball seat)

Quantum packer

Perforated joint

Swell packer 1

Blank pipe

Swell packer 2

Sand screen

Production packer

APPLICATION EXAMPLE # 4SAND MANAGEMENT SYSTEM: INTEGRITY ANALYSIS


• As the valve opens, a pressure wave travels down the string towards the screen.

• It is interesting to note that the model predicts turbulence as the fluid passes the perforated pup joint in the string.

• The pressure surge attenuates quickly, by the time the wave reaches the screen the peak pressure is only 1,300 psi and the maximum differential across the screen is estimated at 300psi.

• From the results of the model, it was deemed that the peak and differential pressures did not present an issue and the completion was successfully deployed.

Pressure at the production packer

Pressure at the perforated joint

Pressure at the sand screen

DALLAS - FORT WORTH. AUGUST 5-6, 2019. QUESTIONS? THANK YOU

2019-NAPS-2.2AUTHORS: Jim Gilliat, Parry Hillis, Bill Myers, Rajani Satti, Baker Hughes (a GE company)

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Application of a Transient Near-Wellbore / Reservoir Simulator For … · 2019. 8. 16. · Application of a Transient Near-Wellbore / Reservoir Simulator For Complex Completions Design