PDVSA INTEVEP Accumulation Process and Phenomena in Chamber Lift Completions Sergio Caicedo ASME/API Gas-Lift Workshop Houston, Texas, Spring 2002

PDVSAINTEVEP

Accumulation Process and Phenomena in Chamber Lift Completions


Sergio Caicedo

ASME/API Gas-Lift Workshop Houston, Texas, Spring 2002

PDVSAINTEVEP


OUTLINE

•Introduction•Two-packer Chamber Equations•Insert Chamber Equations•Algorithm•Results•Conclusions•Recommendations

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Chamber Lift Application Window

Particularly suitable for wells with very low reservoir pressure, high productivity

Chamber Lift Design Goal

Accumulate more liquid volume per bottom hole flowing pressure

Chamber Lift Main Problem

Formation Gas in the chamber

INTRODUCTION

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Production Cycle

Accumulation Stage

• Liquid Accumulation In Annulus and Tubing• Formation Gas Accumulation in Annulus• Described by Gas and Liquid balance coupled with

Reservoir inflow

Chamber DisplacementSlug LiftingVenting

INTRODUCTION

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TWO-PACKER CHAMBER COMPLETION

TWO-PACKER CHAMBER EQUATIONS

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anutubres VVV

dtZRTMVPd

mm wanangoutgin

)/(

anantubtop YPYP

Gas Balance in the annulus

Liquid Balance

Pressure relationship


Panu

Ptop

Yanu

Ytop

BleedingValve

OperatingValve

mgou

t

m

gres

StandingValve

Yperf

Ypinf

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antub

antub

tub

res YAA

YAV

ananch

antub

tub

anchan

gscoutgscres

YYY

PY

PYY

ZTA

VV

))(

1(

520)()460(7.14)(

2x2 System of Non LinearDifferential equations !!!


Panu

Ptop

Yanu

Ytop

BleedingValve

OperatingValve

mgou

t

m

gres

StandingValve

Yperf

Ypinf

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)( infpperftubtopwf YYYPP

)8.02.01(3600*24

615.53600*24

615.52

2

res

wf

res

wfmaxresres P

P

P

PQQV

),,(3600*24 oriftubanscdorif

gscout DPPfQ

V

Reservoir Inflow

Bottom Hole Flowing Pressure

Gas rate through the Bleeding Valve


Panu

Ptop

Yanu

Ytop

BleedingValve

OperatingValve

mgou

t

m

gres

StandingValve

Yperf

Ypinf

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INSERT CHAMBER COMPLETION

INSERT CHAMBER EQUATIONS

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22

11

antub

anan

tub

antub

tub

res YAA

YAA

YAV

11

1

11

1221

))(

1(

520)()460(7.14))1((

ananch

antub

tub

anchan

gscoutgscoutgscres

YYY

PY

PYY

ZTA

VVV

22

2

22

22

))(

1(

520)()460(7.14)(

ananch

antub

tub

anchan

gscoutgscres

YYY

PY

PYY

ZTA

VV

Gas Balance in the external annulus

Gas Balance in the internal annulus

Liquid Balance


Yperf

Panu1

Ptop

Yan

u1

Ytop

BleedingValves

OperatingValve

m1gou

t

mgres

Panu2

m

gres

m2gou

t

Yanu

2

StandingValve

Ypinf

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),,(3600*24 11

11 oriftuban

scdorifgscout DPPf

QV

),,(3600*24 212

22 orifanan

scdorifgscout DPPf

QV

Gas rate through the Bleeding Valves


Yperf

Panu1

Ptop

Yan

u1

Ytop

BleedingValves

OperatingValve

m1gou

t

mgres

Panu2

m

gres

m2gou

t

Yanu

2

StandingValve

Ypinf

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n

n

nan

ntub

n

n

n

n

b

b

Y

Y

a

a

a

a

2

1

22

12

21

11

tYYY ntub

ntub

ntub 1

tYYY nan

nan

nan 1

111 nan

ntubtop

nan YYPP

ttt nn 1

ALGORITHM

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The key to simulate the accumulation process in both cases is to introduce the proper initial conditions and suitable boundary or limit conditions.

For instance, the initial level in the annulus is zero because all the liquid has been displaced during the previous injection stage, meanwhile the initial liquid level depends on the fall back of the slug in the previous production cycle.

Among the limit conditions, the limit when the liquid level in the annulus approaches zero requires special care in order to keep the system consistent.

INITIAL AND BOUNDARY CONDITIONS

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Liquid Levels vs. Time for a 100-feet two-packer chamber with a 3/16" bleeding port and 10% of gas coming into the annulus

RESULTS

Nivel de fluido en el anular y en tuberia vs Tiempo

0

100

200

300

400

500

0 200 400 600 800 1000 1200 1400

T (seg)

Co

lum

na

(p

ies)

Yan

Ytub

Annular & Tubing Liquid Levels vs. Accumulation TimeC

olum

n (f

t)

Accumulation Time (s)

-- Annulus-- Tubing

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Liquid Levels vs. Time for a 100-feet two-packer chamber with a 1/32” bleeding port and 10% of gas coming into the annulus.


0

100

200

300

400

500

0 200 400 600 800 1000 1200 1400

T (seg)

Co

lum

na

(p

ies)

Yan

Ytub

Annular & Tubing Liquid Levels vs. Accumulation Time C

olum

n (f

t)


RESULTS

-- Annulus-- Tubing

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. Liquid Levels vs. Time for a 100-feet two-packer chamber with a 3/16” bleeding port and 50% of gas coming into the annulus.


0

100

200

300

400

500

0 200 400 600 800 1000 1200 1400

T (seg)

Co

lum

na

(p

ies)

Yan

Ytub

Annular & Tubing Liquid Levels vs. Accumulation Time

Col

umn

(ft)


RESULTS

-- Annulus-- Tubing

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Liquid Levels vs. Time for a 200-feet Insert Chamber with a 3/16” internal and external bleeding ports.

Annular & Tubing Liquid Levels vs. Accumulation Time C

olum

n (f

t)


RESULTS

-- Annulus1-- Annulus2 -- Tubing

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Liquid Levels vs. Time for a 200-feet Insert Chamber with a 3/16” internal and a 1” external bleeding ports


Col

umn

(ft)


RESULTS


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Liquid Levels vs. Time for a 200-feet Insert Chamber with 1" internal and external bleeding ports


Col

umn

(ft)


RESULTS


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11

1

11

121

))(

1(

520)()460(7.14))1((

ananch

antub

tub

anchan

gscoutgscres

YYY

PY

P

YYZT

A

VV

22

2

22

22

))(

1(

520)()460(7.14)(

ananch

antub

tub

anchan

gscoutgscres

YYY

PY

PYY

ZTA

VV

),,(3600*24 22

22 oriftuban

scdorifgscout DPPf

QV

Insert Chamber Improvement

RESULTS

Panu1

Ptop

Yan

u1

Ytop

BleedingValves

OperatingValve

m1gou

t

mgres

Panu2

m

gresm

2gout

Yan

u2

StandingValve

Yperf

Ypinf

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Liquid Levels vs. Time for a 200-feet Insert Chamber with a 3/16" internal and a 1/2" external bleeding ports


Col

umn

(ft)


RESULTS


PDVSAINTEVEP


The complexity of the accumulation process in chamber lift requires the previous analysis for a better sizing of the bleeding valves.

The coherence and physical behavior of the results along with the field experiences backups the theoretical model and the numerical method.

The slight differences between the two-packer and insert chambers completions do not allow applying the same practices in both installations.

CONCLUSIONS

PDVSAINTEVEP


In insert chamber completions it is highly recommended to connect directly the external annulus with the tubing whether it is possible.

Apply the model developed in this paper when designing or simulating wells with two-packer or insert chamber lift installations.

Start a research work in order to determine the gas percentages of separation that flow into the annulus and tubing in chamber lift installations in order to include that key information in the presented model.

RECOMMENDATIONS

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QUESTIONS ???

FEEL FREE PLEASE

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Thanks for your attentionThanks for your attention

Documents

PDVSA INTEVEP Accumulation Process and Phenomena in Chamber Lift Completions Sergio Caicedo ASME/API Gas-Lift Workshop Houston, Texas, Spring 2002