Pete 663 Net Pay

FORM FO RMA A TI TION ON EV EVA A L UA UATI TION ON PETE 663 NET SA SA ND/P ND/PA AY, RESOURCES, RESOURCES, AND A ND RESERVES RESERVES

Summer Sum mer 20 2010 10

DEFINING DEFIN ING NET NET PAY PA Y • Wha hatt is “ ne nett pay” pay” ? • Severa verall de defin finiti itions; ons; sometime sometimes s conf confusin using g determine ne reserv reserve es depe depend nds s on • How we determi objecti ob jectives ves and and data available – Static: resour resource ce and re r eserve calcul calcula ati tion ons; s; what w hat is the th ere and est stim ima ated re r eco covera verabl ble e? whatt will flow? flo w? – Dynamic: wha

• Data used us ed – – – – –

Logs Core Well tests Production Seismic

NET SAND / PAY, RESOURCE AND RESERVE DETERMINATIONS Methods

• Volumetric (Static) • Dynamic • Production History • Analogy

DETERMINING HYDROCARBONS IN-PLACE • Static Definition OOI P =7758 Ah (1 - Sw)/Boi

• Assumes net properties • Evaluating net – Identify any area without HC’s – Logs: apply series of criteria • (Sw > cutoff) AND (Vsh > cutoff) AND ( < cutoff) etc… • Compare with core, if available • Calibrate to seismic?

Fluid Distribution

INPUTS TO VOLUMETRIC RESERVES 001) BONANZA 1

GRC 0 - 160

SPC MV

I LDC 150

0. 2

40

0. 2

16

0. 2

10700

1. 95

2. 95

200

0. 45

CNLLC - 0. 15

SNC

ACAL 6

RHOC 200

150

DT us/ f 

50

MLLCF 200

Calculate

, Sw

h

10800

• Vshale • Thickness • Porosity 10900

NET OIL PAY ISOPACH MAP Dry Hole #2 2’

Well #2 45’ Well #4 49’

Well #5 64’ 60

Well #1 21’

Well #3 55’

50 40

Dry Hole #1 0’

20 0

SOME TERMINOLOGY

MORE TERMINOLOGY

 Al so , cal led True Stratigraphic Thickness (TST)

Measured Thickness (MT)

CORRELATION TECHNIQUES

DATUM

Marker beds

Log patterns

WELL-LOG CORRELATION

STRUCTURAL CROSS SECTION

DATUM

B Marker

RESERVOIR DETERMINATION

DEFINING NET PAY Common alternatives for net pay definition – Use static criteria

–

100

10

   D • (Sw > cutoff) AND (Vsh >   m  ,   y    t cutoff) AND ( < cutoff)    i    l    i 1    b   a etc…   e   m Try to correlate k with   r   e    P

log measurements

0.1

• Use core data 0.01 0

5

10 Porosity, %

15

2

DEFINING NET PAY Core data & logs for  net pay determination

100

– Define k cutoff e.g., 1mD

10

– Define φ value e.g. φ =10%    D   m – Apply net pay using log φ value φ >10% – Note errors arise • k > 1 AND

< 10) = 13%

> 10%

– 2 of 86 – Prob(k < 1 AND

• Prob(k > 1 |

0.1

<10%

– 11 of 86 – Prob (k >1 AND

• k < 1 AND

 ,   y    t    i    l    i 1    b   a   e   m   r   e    P

> 10) = 2%

<10%) = 24%

0.01 0

5

10 Porosity, %

15

20

DEFINING NET PAY 100

Deciding on predictor  log(s) – What controls perm? – Carbonates

10    D   m  ,   y    t    i    l    i 1    b   a   e   m   r   e    P

• Grain size and sorting less effect 0.1 • Diagenesis more important • Critical thresholds often seen – Below = 10, k variable –  Above = 10, k systematic

0.01 0

5

10 Porosity, %

15

2

RESERVOIR DETERMINATION

Net-to-Gross Determination

Defining Gross Thickness, Net Sand, and Net Pay

Measure thi ckness (MT) of  Well 1 < MT of Well 2

(Transitional)

Net Pay Map Determination  A) B)

C)

Combination Trap: Faulted Anticline and Stratigraphic Pinch-Out

Structure Map and Cross Section

Summary • OOIP = 7758 Ah (1 - Sw )/B oi • Oil reserves = OOIP x R.F. • OGIP = 43,560 Ah (1 - Sw )/B gi • Gas reserves = OGIP x R.F. • Remaining reserves = Reserves at original conditions - cumulative production