Characterization of Multi -Porosity Unconventional ... slides/2… · Characterization of Multi -Porosity Unconventional Reservoirs and their ... to tight gas to shale gas to tight

Characterization of Multi-Porosity

Unconventional Reservoirs and their Relationship to Oil and Gas Productivity

Roberto Aguilera,

CNOOC Nexen Chair on Tight Oil and Unconventional Gas Schulich School of Engineering,

University of Calgary March 10, 2015

OBJECTIVES

Discuss multi-porosity unconventional reservoirs.

Show that there is a continuum that goes from conventional to tight gas to shale gas to tight oil

to shale oil reservoirs Relate pore throat apertures to oil and gas rates

in vertical and horizontal wells. Make the work tractable by using actual

published data.

Slide 2

Multi-Porosity • Unconventional Reservoirs 2

A multidisciplinary integration of:

Geoscience (G) Formation evaluation (F)

Reservoir drilling, completion and stimulation (R) Reservoir engineering (RE)

Economics and externalities (EE)

Focus is on increasing production rates and ultimate recoveries economically and responsably from tight oil and unconventional gas reservoirs

GFREE

3

Dual-porosity Triple-porosity Multi-porosity in shales Effect on water saturation Flow units: from conventional , to tight gas, to

shale gas, to tight oil, to shale oil, to condensate reservoirs

Link of petrophysics with decline analysis Conclusions

OUTLINE

4

(A) Frontier Formation, (B) William Fork, (c) Travis peak, (D) Travis Peak : Shanley et al., 2004

5

Cadomin Fm. - Elmworth Deep Basin (7-23-69-13W6)

(Moslow, 2005)

microfracture cross-cutting clasts and sandy matrix

2

3 slot

1

Intg. Ø

Flourescence

2660.m Ø=5.0%, Kmax=24mD

6

Porosity in Organic Matter (Barnett Shale) (Ruppel and Loucks, 2008)

7

Porosity in Organic Matter

SEM Imaging , thin section Colorado Shale (courtesy D. Rokosh, ERCB, SPE 137795)

COLORADO SHALE (CANADA)

8

DUAL POROSITY Matrix and Fractures

(or Matrix and Slot Porosity)

9

BORAI’S DATA (SPE FE, 1987) Area= 10,000 Km2, 5 Formations in 14 Abu Dhabi Fields

10

11

Porosity Exponent m, Mesa Verde Formation, USA (Data Source: Byrnes et al., Kansas Geological Survey, 2006)

Fit Using Dual Porosity Model (Matrix and Slots)

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2

2.1

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18

Routine Porosity

Arc

hie

cem

enta

tion

expo

nent

m

Core Dataphi2=0.002, mb=1.75phi2=0.001, mb=1.86phi2=0.0007, mb=1.97

12

POSTDAM (CAMBRIAN), QUEBEC, mb=1.77, mf = 1.2, φ2 = 0.65%

1.0

1.5

2.0

0.00 0.02 0.04 0.06 0.08 0.10TOTAL POROSITY

DU

AL-

POR

OSI

TY E

XPO

NEN

T, m

Core Data

Dual-phi Model

13 SPE114174

f

f

b2

2

1'

φ

φφφ

−

−=

2lnln)1(φφ

−−= ff mmf

φφφφ

log}'/])(1[){(

1log

−

−+=

− bff mb

mm vvm

Dual Porosity Model (Matrix and Fractures), mf = 1.0 or >1.0 Source: Aguilera, SPE 114174, 2008

m = porosity exponent of composite system of matrix and fractures

mb = porosity exponent of the matrix Ø = total porosity, fraction

Øb = matrix porosity of unfractured plug, fraction Ø2 = fracture porosity = v Ø, fraction

v = partitioning coefficient

Last equation valid for φ2 greater than zero 14

CHART FOR EVALUATING NATURALLY FRACTURED RESERVOIRS (mb=2.2)

1.0

1.2

1.4

1.6

1.8

2.0

2.2

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00

MATRIX POROSITY, φb

DU

AL

POR

OSI

TY E

XPO

NEN

T, m

TOTAL POROSITY, φ4 8 12 16 20 24 28 30 35 40 45 50 60 70 80 90 99.99

v=0.058

v=0.10

v=0.20

v=0.30

v=0.40

v=0.50

v=0.70

v=0.90

(Aguilera, 2003) 15

mf =

TRIPLE POROSITY Matrix, Fractures and Non-Effective Porosity

SILICICLASTICS

16

Schematic of Triple Porosity Model (Source: Al Ghamdi et al., SPE 132879, 2010)

Non touching vugs (or non-effective porosity)

Fractures

Matrix

17

Tight Gas Sand Petrography courtesy of ConocoPhillips 18

Triple Porosity Model (nomenclature as in previous equations)

2

2

(1 )log(1 ) /

log

b

ncnc m

bvm

φφφ φ φ

φ

−

−− + + − =

Al Ghamdi et al, SPE 132879

19

m = porosity exponent of triple porosity system


Øb = matrix porosity of unfractured plug, fraction Ønc = non-connected (or isolated) porosity = vnc Ø, fraction

vnc = vug porosity ratio

20

TRIPLE POROSITY MODEL, mb = 2.0 m

Shales: Multiple Porosity Rocks

• (1) adsorbed gas into the kerogen material • (2) free gas trapped in nonorganic inter-particle

(matrix) porosity • (3) free gas trapped in microfracture porosity • (4) free gas stored in fractures created during

stimulation of the shale reservoir • (5) free gas trapped in a pore network developed

within the organic matter or kerogen

21

Porosities in Shales SPE 171638, 2014

22

φφφφ

log/)1(

)1(logker22

2ker

ker

−−+−

+−

=− bm

bt

tt V

VVm

m = porosity exponent (multiple porosities)


Øb = matrix porosity scaled to bulk volume of the matrix, fraction Vtker = total volume of kerogen = Øorg+Øads+Vdiff, fraction

Slide 23

Modified Pickett crossplot including variable values of m calculated with multiple porosity model (SPE 171638)

Zone 1: φ = 5%, φm = 3.9%, φ2= 0.63%, φorg = 0.9%, φads = 0.2%

Passey

23

MATERIAL BALANCE APPLICATION (Lopez and Aguilera, SPE 165681, 2013)

Contribution of free gas, adsorbed gas and diffusion gas from kerogen to total cumulative gas production in Devonian shale gas reservoirs (Appalachian Basin)

Slide 24

24

FLOW UNITS: FROM CONVENTIONAL TO TIGHT GAS TO

SHALE GAS TO TIGHT OIL TO SHALE OIL RESERVOIR

(THERE IS A CONTINUUM)

25

FLOW UNIT

A flow unit is defined as a stratigraphically continuous reservoir subdivision characterized by a similar pore type (Hartmann and Beaumont, 1999), for example by a similar rp35

(Aguilera, 2002):

rp35=2.665 (k/100φ)^0.45

Slide 26


Conventional vs. Continuous Type Accumulations (Used mostly to Explain Tight Gas)

(Pollastro and Schenk; 2002, Moslow, 2008)

Slide 27


Real Data Conventional and

Low Permeability Rocks

Slide 28


Elk City Oil Field (Sneider et al., 1983)

One-Column Format

Slide 29


Unconventional Reservoirs, Elk City Oil Field (SPE 165350, 2013) Data from Sneider et al., 1983

One-Column Format

Slide 30


Unconventional Reservoirs (Elk City Oil Field) Slide 31

Sneider et al, 1983 Multi-Porosity


Unconventional Reservoirs, Cardium SS, Pembina Oil Field (Source of Data: MacKenzie, 1975)

Slide 32


Slide 33

Multi-Porosity • Unconventional Reservoirs

Real Data Shale Gas

33

Flow Units

34

Unconventional Reservoirs: Shale Gas (SPE 132845)

Slide 35


Slide 36


Real Data Shale Gas and Tight Gas

36

Unconventional Reservoirs: Shale Gas and Tight Gas (SPE 132845)

One-Column Format

Slide 37


Flow Units

GFREE RESEARCH PROJECT

38

Slide 39


Real Data Tight Oil

39

Unconventional Reservoirs: Bakken Tight Oil

One-Column Format

Slide 40


Unconventional Reservoirs, Cardium SS, Pembina Oil Field (Source of Data: MacKenzie, 1975; Hamm and Struyk, 2011)

Slide 41


Unconventional Reservoirs: Tight and Shale

One-Column Format

Slide 42


Flow Units

1.0E-12

1.0E-11

1.0E-10

1.0E-09

1.0E-08

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

0 2 4 6 8 10 12 14 16

PER

MEA

BILI

TY (M

D)

POROSITY

FHR, B SOFT SHALES

0.040.0250.014

rp35microns0.55

NIKANASSIN

0.15MARCELLUS

HURON

BC CANADA

CRUSHED SAMPLES?

0.004

UTICA

UTICA

B.DEL

B.FW

B.M1H

0.0005

0.00005


43

Slide 44


Theoretical Data Pore Scale Modeling

44

Flow Units (Pore Scale Modeling)

Rahmanian et al., SPE 133611 Microsimulation at the pore throat level: • Pore throat radii • Permeability • Porosity • Relative perms • Cap pressures • Electrical properties • Rock Mechanics • Stimulation • Prod allocation in commingled completions


Knudsen Number

Viscous Flow

Diffusion Dominated Flow

45

Microsimulation at the pore throat

level will supplement

results of rp, k, phi, rel perms, cap pressures,

electrical properties, rock

mechanics

Brittle? Ductile? Type of

Stimulation? Effect of Sw,

mud Filtrate, leak-off on embedment?

Unconventional Reservoirs and Potential Oil and Gas Rates


Microsimulation at the pore throat

level will supplement

results of rp, k, phi, rel perms, cap pressures,

electrical properties, rock

mechanics

Brittle Ductile Type of

Stimulation Effect of Sw,

mud Filtrate, leak-off on embedment

Unconventional Reservoirs and Potential Oil and Gas Rates


Conden-sate

47

OIL RATE VS. rP35 (Source of rate data: Martin, Solomon and Hartmann, 1997)

(Source of rp35 data: Aguilera, 2002-2003)q = 295.87(rp35)

1.4703

R2 = 0.9992

0.1

1

10

100

1000

10000

0.01 0.1 1 10

PORE THROAT APERTURE rP35

© Servipetrol, Dr. Roberto Aguilera, 2004

OIL

RA

TE, B

/D

Publishedsources

Best fit

Gaspe HTD potential / well ˜ 120 BOPD

HTD

r p35

˜ 0

.3 to

1.5

μm(or gas equivalent)

48

Vertical Well

OIL RATE VS. rP35 (Source of rate data: Martin, Solomon and Hartmann, 1997)

(Source of rp35 data: Aguilera, 2002-2003)q = 295.87(rp35)

1.4703

R2 = 0.9992

0.1

1

10

100

1000

10000

0.01 0.1 1 10

PORE THROAT APERTURE rP35

© Servipetrol, Dr. Roberto Aguilera, 2004

OIL

RA

TE, B

/D

Publishedsources

Best fit

Gaspe HTD potential / well ˜ 120 BOPD

HTD

r p35

˜ 0

.3 to

1.5

μm(or gas equivalent)

49

JUNEX PRESS RELEASE, Feb 23, 2015: 316 BOPD Non-stimulated horizontal well, Forillon Formation

PETROPHYSICAL DUAL, TRIPLE AND MULTIPLE POROSITY MODELS DISCUSSED PREVIOUSLY

CAN BE LINKED TO OIL AND GAS PRODUCTIVITY

50

Linear Flow in a Dual-Porosity Reservoir towards a Hydraulic Fracture of Infinite Conductivity

(Adapted from Aguilera, SPE 16442, 1987)

51

DECLINE ANALYSIS IN INFINITE-ACTING TRIPLE POROSITY RESERVOIR WITH RESTRICTED INTERPOROSITY FLOW DOMINATED BY LINEAR/BILINEAR FLOW

(Leguizamon and Aguilera, SPE 142727, 2011)

52

qD = dimensionless rate, tD = dimensionless time, w = storativity ratio, f = function, cc = commingled completion exponent, d = dual, t= triple

Infinite-Acting Linear Reservoir with Restricted Interporosity Flow

53

-0.5

Infinite-Acting Reservoir with Unrestricted Interporosity Flow

54

-0.5

55

56

57

58

59

60

61

62

63

64

65

Tight Gas Field, Well i1

66

Triple Porosity q Decline Commingled Completion Production Matching

1.E+03

1.E+04

1.E+05

1.E+06

1.E+01 1.E+02 1.E+03 1.E+04 1.E+05

q, m

3 / d

Time, hours

Well 1

Measured Rate Calculated rateHistory Matching Well 2

67


68


69


70

BDF

Slide 71

Inter-linear Flow Period


Slide 72

1.E-06

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

1.E+03qD

tD

Decline Rate with Unrestricted Inter-Linear Transition FlowTriple Porosity Model Dominated by Linear Flow

Linear Flow (slope = -0.5)

Unrestricted Transition (slope ∼ -0.75)

Linear

Transition

Linear


73 Hamm and Struik (2011)

Slope – 0.75

Slide 74


Slope – 0.75

Slide 75


Conclusions

• Multi-porosity models allow integration of petrophysical and production decline analysis and provide input data for material balance (and simulation) studies.

• There is a continuum between conventional gas, tight gas and shale gas reservoirs (same for oil reservoirs).

76

Acknowledgements

Paper # • Paper Title • Presenter Name

CNOOC NEXEN GFREE Research Team

Schulich School of Engineering at U of C Servipetrol Ltd.

Slide 77


Thank You Paper # • Paper Title • Presenter Name

Slide 78


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Characterization of Multi -Porosity Unconventional ... slides/2… · Characterization of Multi -Porosity Unconventional Reservoirs and their ... to tight gas to shale gas to tight