Berlajut ke tampilan berikutnya .

Teknik Reservoir 1

.

Perhitungan Cadangan (1)

RFOOIPEUR

Cadangan (reserve) adalah jumlah hidrokarbon yang dapat diproduksi secara eknomis dari suatu reservoar.

Bila diketahui kumulatif produksi, Qp

pQEUR ReserveRemaining

CumulativeCumulative

19.9 BSTB19.9 BSTB

Remaining Reserves of Primary Recovery

4.8 BSTB

EOR TargetEOR Target

36.5 BSTB36.5 BSTB 7.8%7.8%

32.6%32.6%

59.6%59.6%

Total OOIP: Total OOIP: 61.1 BSTB61.1 BSTB

Global EOR Target in Indonesia

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Perhitungan Cadangan (2)

Metode Volumetrik

oi

oi

B

SAhN

7758 N = OOIP, STB

A = luas, acreh = ketebalan, ft = porositas, fraksiSoi = saturasi minyak awal, fraksiBoi = faktor volume formasi minyak awal, RB/STBRB = reservoar barelSTB = stock tank barrel

bblft5.614

Acft435607758

3

2

................815.41RF

.

Perhitungan Cadangan (3)

RF = recovery factor at pb, % OOIP = porositas, fraksiSwi = saturasi minyak awal, fraksiBob = faktor volume formasi minyak

pada pb, RB/STBk = permeabilitas absolut, Darcyab = viskositas minyak, cPpb = bubble point pressure, psiapa = abandonment pressure, psia

1741.0

3722.0

0979.01611.0

1815.41

a

bwi

obob

w

p

pS

k

B

SRF

RF untuk solution gas drive reservoar:

RF untuk water drive reservoar:

2159.0

1903.0

0770.00422.0

1898.54

a

iwi

oi

wi

ob

w

p

pS

k

B

SRF

RF = recovery factor at pb, % OOIP = porositas, fraksiSwi = saturasi minyak awal, fraksiBoi = faktor volume formasi minyak awal,

RB/STBwi = viskositas air awal, cPoi = viskositas minyak awal, cPpi = tekanan awal, psia

.

Perhitungan Cadangan (4)

Metode Material Balance

(RB) PVin decrease andexpansion

waterconnate todue HCPV ofExpansion

(RB) gas gascap ofExpansion

(RB) gas dissolved plus oil ofExpansion (RB) withdrawal

dUndergroun

oi

gi

NB

GBm

(RB) oil of volumeinitial

(RB) gas of volumeinitial

Expansion of oil + dissolved gas

)RB( expansion Liquid oio BBN

)RB( expansion gas Liberated gssi BRRN

.

Perhitungan Cadangan (5)

Expansion of the gascap gas

(RB) gascap theof volumeTotal oigi mNBGB

)RB( 1gascap theofExpansion

gi

goi B

BmNB

(RB) at gascap theof Volume ggi

oi BB

mNBp

G = Initial gascap gas, scfBgi = faktor volume formasi gas awal,

bbl/scfBg = faktor volume formasi gas pada p

.

Perhitungan Cadangan (6)

Expansion of the connate water and formation

(RB) 1

1

PV waterconnate theofExpansion

pcS-S

mNB

pcS

wwiwi

oi

wwi

)RB(

1

1PVin Change pc

S

mNBf

wi

oi

p = pi - pcw = water compressibility, psia-1

cf = formation compressibility, psia-1

)RB( 1

1PVin changes Total pS

ccSmNB

wi

fwwioi

.

Perhitungan Cadangan (6)

Underground withdrawal

(RB) l withdrawauderground Total gspop BRRBN

p = Cumulative oil produced, STBRp = Cumulative gas oil ratio, scf/STBRs = Initial gas solubility, scf/STB

.

Perhitungan Cadangan (6)

General Material Balance Equation

We = Cumulative water influx from aquifer, STBWp = Cumulative amount of aquifer water produced, STBBw = water formation volume factor, RB/STB

wpewc

fwcw

gi

g

oi

gssioiooigspop

BWWpS

cScm

B

Bm

B

BRRBBNBBRRBN

111

.

Perhitungan Cadangan (6)Recovery Factor for Solution Gas Drive

Assumed:No initial gascapNo water influx into the oil reservoir

Above bubble point pressure (undersaturated oil reservoir)

pcB

B

N

NRF e

ob

oi

p

p

p

b

b

pB

BBccScSc

Sc

oi

oioofwwoo

wce

;

1

1

Below bubble point pressure (saturated oil reservoir)

Assumed:Changes in PV is negligible once solution gas develops in the reservoir

gspo

gssioio

p

p

p BRRB

BRRBB

N

NRF