Hydraulic Fractures and Horizontal Wells(1)

8/10/2019 Hydraulic Fractures and Horizontal Wells(1)

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Hydraulic

Fractures

and

HoriWells

Furqan Hussain

PTRL 2019 RESERVOIR ENGINEERING

School

of

Petroleum

Engineering


2/13

PTRL 2019 RESERVOIR ENGINEERING

Flowregimesforhydraulicfract


3/13

Flow regimes for horizontal wells

Early time radial flow

Early time linear flow

Late time radial flow

Late time linear flow


4/13

Horizontal Wells

j. L 1

OIL


5/13

Horizontal wells

s rvo

ir het e

ro

g

n ity

- Horizontal wells contact a larger area of the reservoir than ve

rti

cal

wells. n reservoirs which display complex and difficult to predict

heterogeneity carbonates, channel point bar sands, braided stream

systems a

nd

reservoirs) , horizontal wells

ca

n connect regions

of high permeability rock which are separated by regions of w per

meability.

UNSW

TH L N V ~ S T V Of W SOU

TH W

L S


6/13

Horizontal wells

s rvoi

r flow

pro l

em s

-

The

grea

ter

length of horizontal wells may res

ult

in smaller pressure

gradients increased productivity) when c

omp

ared to vert ical wells

flo

wing at the sa

me

rate. This can be importa

nt

in allowing produc

t i

on

of heavier crudes at economi

ca

l rat es a

nd

reducing or completely

eli

min

ation

th

e detrirnental effect s of wa

ter

a

nd

gas coning.

- n sands where wa

ter

coning is a problem horizontal wells can be placed

near

the top

of the

sa

nd increasing the vertical dist ance

bet

ween the

perforations a

nd the

water-oil contact and therefore increasing recov

ery w

hen

compared with a ve

rti

cal well in

th

e

sa ne sa

nd. Recovery is

also

in

creas

ed

because

the

cone for a similar sit uation exist s in a

sand

su

bje

ct

to

gas coning with

the

horizontal well being placed at

the

base

of

the sa

nd.

- n low permeability reservoirs it is possible

to

place multiple t ransverse

fractures along the length of the well a

nd

gr

ea

tly increase

produ

ct ivity

over

th

at

po

ssible with a verti

ca

l well.

UNSW

TH L N V ~ S T V Of W SOU

TH W

L S


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Horizontal well in a compartmentalized reservoir

O L

UNSW

l [ VNf\. tR SITV

f

N[\1

SOUT

\ vAlfS.


8/13

Horizontal wells in stratified reservoirs

t

4360

4400

500

75 1 125 15 175 2

Distance along the section It


9/13

Long-reach horizontal wells

designer well with turns n the

horizontal

plane

.

Adapted from Teel reference 2.)

U SW


10/13

Drainage areas for horizontal and vertical wells in a fractured reservoir

r l

L _

kx

L ky kx

VERTICAL WELL

FR CTURES

UNSW

T \ ~ 1 \ . f R S I W r

M\ 1/ TH

WI\LCS


11/13

Drainage areas for isotropic reservoirs

Horizontal well

Vertical well


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Drainage areas for isotropic reservoirs

L

2ye

xe= ye

Av = (2xe)(2ye)

2xe

xe xe

2ye

Ah = L(2ye) +Av

VERTICAL WELL

HORIZONTAL WELL

0

I

-.

UNSW

H liNI\ Ul.Sin r 1\,(W SOlilH V.."LES


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Drainage areas for horizontal wells

... K

2490 1

WELL LENGTH 1

000

ft

DRAINAGE AREA74ocres

I 6 7

WELL LENGTH

2000 ft

DRAINAGE AREA 10 8

acres

ly, :1

2.34

1

y, 1490

Hydraulic Fractures and Horizontal Wells(1)

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