Section 05 - Tripping & Backreaming Practices

 T

 T

h

h

is

is

is

is

t

t

h

h

e

e

m

m

o

o

s

s

t

t

im

im

p

p

o

o

r

r

t

t

a

a

n

n

t

t

s

s

u

u

b

b

j

j

e

e

c

c

t

t

o

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f

f

t

t

h

h

is

is

s

s

c

c

h

h

o

o

o

o

l

l

 –

 – The practices use

The practices used by most groups are

d by most groups are completely i

completely inappropriate

nappropriate

 –

 – The serious problem

The serious problems experienced a

s experienced are self-inflict

re self-inflicted, and

ed, and

unnecessary

unnecessary

This section will cover:

This section will cover:

¾

¾

What is required for safe tripping

What is required for safe tripping

¾

¾

Practices

Practices

¾

¾

BHA requirements

BHA requirements

¾

¾

Backreaming

Backreaming

¾

¾

Is it good or bad ?

Is it good or bad ?

Tripping & Backreaming Practices

Tripping & Backreaming Practices

Tripping & Backreaming Practices

Tripping & Backreaming Practices

•

•

Ba

Ba

ck

ck

-r

-r

ea

ea

mi

mi

ng o

ng o

r p

r p

um

um

pi

pi

ng

ng

ou

ou

t s

t s

ho

ho

ul

ul

d b

d b

e a

e a

vo

vo

id

id

ed

ed

whenever possible in high-angle wells

whenever possible in high-angle wells

 –

 –

The ability to trip

The ability to trip

out

out

without

without

 pumping or backre

 pumping or backre

aming is a

aming is a

critical objective

critical objective

 – 

 – 

Choosing any practice or equipment that forces you to

Choosing any practice or equipment that forces you to

backream to trip out makes a mockery of risk-management

backream to trip out makes a mockery of risk-management

•• Beca

Because b

use back-r

ack-reami

eaming a

ng and/or

nd/or pumpi

pumping o

ng out

ut are

are the

the singl

single-mo

e-most

st

dangerous operation in any ER well

dangerous operation in any ER well

 –

 – Maximum risk of stuck

Maximum risk of stuck pipe, and of destabi

pipe, and of destabilizing the wellbore

lizing the wellbore

 –

 – It is also time consumin

It is also time consuming, and destructive on B

g, and destructive on BHA equipment

HA equipment

 –

 – Engineers :

Engineers :

Classic train-wreck story

Classic train-wreck story

•

•

K&

K&

M s

M s

ee

ee

/ r

/ r

ev

ev

ie

ie

w a l

w a l

ot

ot

of

of

hi

hi

gh

gh

-a

-a

ng

ng

le

le

tr

tr

ai

ai

n w

n w

re

re

ck

ck

s

s

 –

 – Most have al

Most have almost identica

most identical chain-of-eve

l chain-of-events

nts

 –

 – 2 common theme

2 common themes :

s :

•• Those

Those that

that had b

had bad hol

ad hole cle

e cleaning

aning while

while drill

drilling (

ing (but t

but they t

hey thoug

hought it

ht it

was good).

was good). These also

These also tend to

tend to have poor

have poor tripping p

tripping practices.

ractices.

 –

 – More common with mo

More common with motor BHAs

tor BHAs

 –

 – Note –

Note – Can have good h

Can have good hole cleaning with moto

ole cleaning with motors !!

rs !!

•• Tho

Those t

se that

hat had

had goo

good ho

d hole c

le clea

leanin

ning wh

g while

ile dri

drilli

lling,

ng, but

but sti

still h

ll have

ave poo

poor 

r 

tripping practices.

tripping practices.

 –

 – This has become the mo

This has become the most common of the two,

st common of the two, ever since RSS became

ever since RSS became

 popular 

 popular 

 –

Say operator is drilling high or medium angle hole

Say operator is drilling high or medium angle hole

1

1..

N

No

o p

prro

ob

blleem

ms

s d

drriilllliin

ng

g tto

o T

TD

D

••

G

Go

oo

od h

d hol

ole c

e cle

lean

anin

ing w

g wh

hil

ile d

e dri

rill

llin

ing

g, a

, an

nd n

d no c

o cav

avin

ing

gs r

s reepo

port

rted

ed

••

H

Ho

ow

w d

do

o tth

heey

y k

kn

no

ow

w iit w

t waas g

s go

oo

od

d h

ho

olle

e cclleeaan

niin

ng

g ??

••

N

No

o ttiig

gh

ht

t h

ho

olle

e aat

t cco

on

nn

neeccttiio

on

nss

••

G

Go

oo

od

d ccu

uttttiin

ng

gs

s ffllo

ow

w

2.

2. At TD

At TD, hol

, hole is cl

e is clean

eaned up

ed up

•• Mu

Multi

ltipl

ple b

e bot

otto

toms

ms up

up ci

circ

rcul

ulat

ated

ed at

at TD

TD

•• Sh

Shak

aker

ers c

s cle

lean

an up

up qu

quit

ite s

e soo

oon …

n …

team thi

team

thinks hol

nks hole

e m

must be

ust be cl

cle

ean

an

••

IIn r

n re

eal

aliity

ty,

, hol

hole

e cl

cle

eani

aning s

ng sys

yste

tem

m has

has sh

shut d

ut dow

own w

n whe

hen l

n low

ow--RP

RPM

M

used for clean-up cycle

used for clean-up cycle

3.

3. Tri

Trip com

p comme

menc

nces

es

•• S

So

oo

on

n p

pu

ulllls t

s tiig

gh

htt..

•• At

Atte

temp

mpt to

t to ba

back

ck-r

-rea

eam t

m thr

hru t

u tig

ight

ht sp

spot

ot

•• Ho

Hole p

le pack

acks of

s off (i

f (init

nitiati

iating

ng cir

circul

culati

ation o

on or so

r soon

on afte

after)

r)

•• 1

1

st

st

_{cavings reported at this point}

_{cavings reported at this point}

4

4..

B

Baacck

k--rreeaam

miin

ng

g cco

on

nttiin

nu

uees

s …

…

••

P

Paacck

kiin

ng

g o

offf

f aalll

l tth

he

e w

waay

y tto

o tth

he

e ssh

ho

oee

••

Re

Rela

lati

tiv

vel

ely

y li

litt

ttle

le cu

cutt

ttin

ings

gs w

wh

hil

ile

e b

bac

ack-

k-re

ream

amin

ing,

g, u

unt

ntil

il

30

30

o

o

, then

, then

shakers blind with lot’s of cuttings…

shakers blind with lot’s of cuttings…

a

an

nd

d cavings

cavings

..

••

P

Paacck

ks

s o

offf

f aallsso

o iin

nssiid

de

e ccaassiin

ng

g

5. Trip Back In

5. Trip Back In

••

F

Fo

or s

r so

om

me r

e reeaasso

on

n, t

, th

he t

e trrip

ip b

baacck

k--iin i

n is w

s wh

his

istl

tlee--ccle

leaan

n…

…

despite the nightmarish trip out…

Tripping & Backreaming Practices

Tripping & Backreaming Practices

What we will cover in this section:

What we will cover in this section:

•

•

P

P

a

a

r

r

t

t

1

1

–

–

W

W

h

h

a

a

t

t

i

i

s

s

h

h

a

a

p

p

p

p

e

e

n

n

i

i

n

n

g

g

d

d

o

o

w

w

n

n

h

h

o

o

l

l

e

e

•

•

P

P

a

a

r

r

t 2

t 2

–

–

H

H

o

o

w t

w t

o e

o e

na

na

b

b

l

l

e t

e t

r

r

ip

ip

p

p

i

i

ng

ng

o

o

n e

n e

l

l

e

e

va

va

t

t

o

o

r

r

s

s

•

•

P

P

a

a

r

r

t

t

3

3

–

–

T

T

r

r

i

i

p

p

p

p

i

i

n

n

g

g

p

p

r

r

o

o

c

c

e

e

d

d

u

u

r

r

e

e

s

s

•

•

P

P

a

a

r

r

t 4

t 4

–

–

B

B

a

a

c

c

k

k

r

r

e

e

a

a

m

m

i

i

n

n

g p

g p

r

r

o

o

c

c

e

e

d

d

u

u

r

r

e

e

s

s

Tripping & Backreaming Practices

Tripping & Backreaming Practices

•

•

P

P

a

a

r

r

t

t

1

1

–

–

W

W

h

h

a

a

t

t

i

i

s

s

h

h

a

a

p

p

p

p

e

e

n

n

i

i

n

n

g

g

d

d

o

o

w

w

n

n

h

h

o

o

l

l

e

e

 –

 – How does the c

How does the cuttings bed & BHA

uttings bed & BHA interact when tripp

interact when tripping ?

ing ?

•• Tr

Trou

oubl

ble-

e-fr

free t

ee tri

ripp

ppin

ing, v

g, vs ti

s tigh

ght ho

t hole

le

•• Nor

Normal

mal tri

trippi

pping vs

ng vs. Ba

. Back-

ck-rea

reami

ming vs

ng vs. Pum

. Pumpin

ping Out

g Out

 –

 – Separating my

Separating myth from reality

th from reality

 –

What happens downhole when POOH ?

What happens downhole when POOH ?

Most people visualize that tripping looks something like this …

Most people visualize that tripping looks something like this …

And

What really happens

What really happens

downhole when POOH ?

downhole when POOH ?

What happens downhole when tripping in a deviated well ?

What happens downhole when tripping in a deviated well ?

 –

 – Firstly, assume

Firstly, assume that

that

the

the

ho

ho

l

l

e

e

i

i

s

s

N

N

O

O

T

T

1

1

0

0

0

0

%

%

c

c

l

l

e

e

a

a

n

n

 –

 –

Even with a thorough c

Even with a thorough clean-up

lean-up

 –

 –

Even with Rotary Steering Tools !

Even with Rotary Stee

ring Tools !

 –

 – The BHA does

The BHA does NOT pull cuttings u

NOT pull cuttings up the hole

p the hole

 –

 –

Cuttings

Cuttings

f

f

l

l

o

o

w

w

a

a

rou

rou

nd

nd

the BHA, until they become too compressed

the BHA, until they

become too compressed

 –

 –

BHA design is critical to “flow a

BHA design is criti

cal to “flow around”

round” ability

ability

 –

What happens downhole

What happens downhole

when POOH ?

when POOH ?

•• When

When pulli

pulling o

ng out, t

ut, the B

he BHA p

HA pulls

ulls up t

up throu

hrough th

gh the di

e dirt …

rt …

•• For a

For a trou

trouble-f

ble-free

ree trip,

trip, the

the dirt

dirt must

must flow

flow aroun

around the

d the BHA as

BHA as the

the

BHA moves through the bed

What really happens

What really happens

downhole when POOH ?

downhole when POOH ?

The dirt must be able to flow through the bit & BHA

The dirt must be able to flow through the bit & BHA

••

Just like mud, we have a serious problem when the dirt

Just like mud, we have a serious problem when the dirt

can’t get past the BHA

can’t get past the BHA

When driller sees tight hole …

When driller sees tight hole …

what is happening downhole ?

what is happening downhole ?

 Video Clip

 Video Clip

If this component blocks the flow of dirt,

If this component blocks the flow of dirt,

then tight hole looks like this …

What is tight hole ?

What is tight hole ?

 Note that thi

 Note that this volume of dirt

s volume of dirt is small …

is small …

•• Only re

Only require

quires kilogr

s kilograms (no

ams (not tons) to be stu

t tons) to be stuck)

ck)

Unfortunately

Unfortunately, this is

, this is the most common situation

the most common situation

•• Beca

Because of

use of typi

typical b

cal bit & B

it & BHA des

HA designs

igns

•If you pull too far, you can’t go

•If you pull too far, you can’t go back down

back down

•Turning pumps on is

Backreaming Practices

Backreaming Practices

What is backreaming?

What is backreaming?

St

Sta

and

nda

arrd tr

d triip

p

 –

 – no rotation or

no rotation or circulation,

circulation, harmless cutti

harmless cuttings bed by-passed

ngs bed by-passed

Backreaming

Backreaming

 –

 – rotate and cir

rotate and circulate while POOH, cut

culate while POOH, cuttings bed fully rem

tings bed fully removed

oved

from the bottom of the hole. Cuttings drop out to form a dune above the BHA

from the bottom of the hole. Cuttings drop out to form a dune above the BHA

Backreaming Practices

Backreaming Practices

Backreaming Practices

Backreaming Practices

Pumping Out is Even Worse!

Pumping Out is Even Worse!

Pumping Out

Pumping Out

 –

 – dirt still pile

dirt still piles up behind the

s up behind the BHA due to high ve

BHA due to high velocity around

locity around

the bit, stabilizers, and drill collars, but the

the bit, stabilizers, and drill collars, but the

conveyor belt is off!

conveyor belt is off!

 Video Clip

 Video Clip

Backreaming Basics

Backreaming Basics

•• Wha

What are t

t are the dow

he downsi

nsides/

des/ris

risks as

ks associ

sociate

ated wit

d with

h

Backreaming?

Backreaming?

 –

 – Stuck pipe

Stuck pipe

 –

 – BHA equipme

BHA equipment failures due to vi

nt failures due to vibration

bration

 –

 – Key seating

Key seating

 –

 – Lost returns (if pac

Lost returns (if packoffs exceed fra

koffs exceed fracture gradient)

cture gradient)

 – 

Backreaming Basics

Backreaming Basics

•• Bac

Backre

kreami

aming its

ng itself do

elf doesn

esn’t dam

’t damage th

age the wel

e wellbo

lbore…

re…

 –

 – Rather, it is the

Rather, it is the

Hydraulic Hammer

Hydraulic Hammer

effect that causes all the

effect that causes all the

 problems…

 problems…

 –

 – Sudden large ECD

Sudden large ECD pressure shock

pressure shock below pack-off 

below pack-off 

•• Same

Same princ

principle

iple will

will destr

destroy p

oy pipel

ipelines,

ines, powe

power sta

r stations

tions, et

, etc ..

c ...Why

.Why

expect it to be less severe in a wellbore?

expect it to be less severe in a wellbore?

Hydraulic Hammer 

Hydraulic Hammer 

•• Wha

What PW

t PWD se

D sees wh

es when hy

en hydrau

draulic h

lic hamm

ammer oc

er occur

curs …

s …

•• Pre

Press

ssure s

ure spik

pikes a

es are of

re often “

ten “off t

off the s

he scal

cale”

e”

•• Reme

Remember,

mber, when

when you s

you see a p

ee a pack-

ack-off at

off at surfa

surface, yo

ce, you only

u only see

see

what’s left are dampening thru the bit, BHA & drillstring

what’s left are dampening thru the bit, BHA & drillstring

   3

   3

  p

  p

  p

  p

  g

  g

  s

  s

  c

  c

  a

  a

   l

   l

  e

  e

 Normal drilling ECD …

Backreaming Basics

Backreaming Basics

•• In

Inter

terpr

pret

etati

ation of “

on of “we

well

llbo

bore st

re stab

abil

ility

ity”” pr

probl

oblem

ems cha

s chang

nges

es

entirely if the wellbore has been “

entirely if the wellbore has been “

H

Ham

amm

me

erre

ed

d

””

 –

 – Often, the presen

Often, the presence of cavings afte

ce of cavings after packoffs is perc

r packoffs is perceived as

eived as

the very cause of the packoffs

the very cause of the packoffs

•• K&M c

K&M conte

ontend th

nd that i

at it is

t is more

more like

likely th

ly the pa

e packoff

ckoff crea

created t

ted the ca

he cavings

vings

due to the hammer effect

due to the hammer effect

•• Evi

Eviden

dence

ce of t

of this

his is “

is “wel

wellbo

lbore

re stab

stabili

ility”

ty” pro

proble

blems o

ms ofte

ften go

n go awa

away wh

y when

en

tripping practices are modified (due to

Tripping & Backreaming Practices

Tripping & Backreaming Practices

•

•

P

P

a

a

r

r

t 2

t 2

–

–

H

H

o

o

w

w

to

to

e

e

na

na

bl

bl

e

e

tr

tr

i

i

pp

pp

i

i

ng

ng

o

o

n e

n e

l

l

e

e

v

v

a

a

to

to

r

r

s

s

M

Many

any op

ope

errato

atorrs s

s say

ay “

“d

don’

on’t b

t back-

ack-rre

eam

am un

unlle

es

ss y

s you h

ou hav

ave

e to …

to …”

”

B

But e

ut exp

xpe

erriie

ence

nced

d E

ER

R p

pe

eop

oplle

e “

“kn

know

ow”

” that

that no-

no-m

mat

atte

ter

r w

what t

hat the

he

pr

proce

ocedur

dure

es s

s say

ay,

, that’

that’s t

s th

he

e on

onlly

y w

way

ay the

they

y can

can g

ge

et out of

t out of the

the

hole

hole

 T

 T

h

h

e

e

a

a

b

b

ilit

ilit

y

y

t

t

o

o

t

t

r

r

ip

ip

r

r

e

e

g

g

u

u

la

la

r

r

ly

ly

o

o

n

n

e

e

le

le

v

v

a

a

t

t

o

o

r

r

s

s

is

is

p

p

o

o

s

s

s

s

ib

ib

le

le

 –

How clean must the hole be for tripping ?

How clean must the hole be for tripping ?

−

−

It depends on the bit & BHA ...

It depends on the bit & BHA ...

BHA components are critical

BHA components are critical

to ability to trip

to ability to trip

BHA components are critical

BHA components are critical

to ability to trip

to ability to trip

••

Un

Unle

less

ss th

the

e BH

BHA

A co

comp

mpon

onen

ents

ts ar

are

e ad

addr

dres

esse

sed

d as

as a

a hi

high

gh pr

prio

iori

rity

ty ….

….

 –

 –

Conventional tr

Conventional tripping may be

ipping may be impossible desp

impossible despite best prac

ite best practices

tices

 – 

 – 

IIt onl

t only t

y take

akes on

s one

e com

compon

pone

ent to m

nt to make

ake a B

a BH

HA

A un

un--tr

triipp

ppabl

able

e

••

No matter how much circulation is done

No matter how much circulation is done

 – 

 – 

 Th

 Th

is

is

m

m

a

a

k

k

e

e

s

s

a

a

m

m

o

o

c

c

k

k

e

e

ry

ry

o

o

f

f

e

e

v

v

e

e

ry

ry

ris

ris

k

k

m

m

a

a

n

n

a

a

g

g

e

e

m

m

e

e

n

n

t

t

p

p

re

re

c

c

a

a

u

u

t

t

io

io

n

n

w

w

e

e

m

m

a

a

k

k

e

e

,

,

if 

if 

this isn’t addressed as the highest priority

this isn’t addressed as the highest priority

 THI

 THI

S

S

I

I

S

S

THE S

THE S

I

I

NG

NG

L

L

E B

E B

I

I

G

G

G

G

E

E

S

S

T

T

THI

THI

NG

NG

YO

YO

U

U

CA

CA

N

N

D

D

O

O

TO

TO

RED

RED

UC

UC

E

E

(

BHA design for tripping

BHA design for tripping

What needs to be done to bit & BHA ?

What needs to be done to bit & BHA ?

 –

 – Junk-slot-area & junk-slot-tortuosit

Junk-slot-area & junk-slot-tortuosity are key BHA

y are key BHA

design priorities

design priorities

•• Rem

Remove s

ove slee

leeve st

ve stabi

abiliz

lizers o

ers on big

n big-OD c

-OD coll

ollars

ars

 –

 – 6¾”

6¾” tools for 8½”

tools for 8½” hole, 5”

hole, 5” tools for 6 ½”

tools for 6 ½” hole

hole

 –

 – Especially on RSS, motor

Especially on RSS, motors and MWD-LWD tools

s and MWD-LWD tools

 –

 – Shoot for a mini

Shoot for a minimum of 30% open

mum of 30% open area

area

•• Or d

Or dow

owns

nsiz

ize to s

e to sma

mall

ller c

er col

olla

lars

rs

 –

 – Eg. 6 ¼”

Eg. 6 ¼” tools instead of 6 ¾

tools instead of 6 ¾”” for 8 ½”

for 8 ½” hole (or drill 8 ¾

hole (or drill 8 ¾”)

”)

Sleeve vs. Integral Blade

Sleeve vs. Integral Blade

How a

How a Sleeve Stabilizer

Sleeve Stabilizer

sees

sees

How an

Component Trip-ability Example

Component Trip-ability Example

Consider this New Zealand ER Well…

Consider this New Zealand ER Well…

•• 9

9

1

1

_//

2

2

”” tang

tangent to

ent to ±610

±6100m (20

0m (20,000

,000’) MD

’) MD

•• Exc

Excell

ellent HC p

ent HC param

aramete

eters

rs

o

o 700

700 gpm

gpm / 15

/ 150 rp

0 rpm

m

o

o 3xBU clean

3xBU cleanup cycles

up cycles, shakers clea

, shakers clean after 2xBU

n after 2xBU

•• Previ

Previous wells ha

ous wells have never ha

ve never had proble

d problems tripp

ms tripping

ing

o

…However, the bits have changes “a bit”…

…However, the bits have changes “a bit”…

Trip

Trip

#1 (

#1 (

5 Bl

5 Bl

ade, 14

ade, 14

.5in

.5in

_JSA)

_JSA)

No problems, very similar to behavior on first well (similar bit)

No problems, very similar to behavior on first well (similar bit)

Minor 20-30k “

Minor 20-30k “

peak”

peak”

over pu

over pu

ll in places

ll in places

(fairly sli

(fairly sli

ck on average)

ck on average)

Aver

Aver

age

age

F

F

F

F

=

=

0.1

0.1

6 –

6 –

0.18

0.18

Trip

Trip

#2 (

#2 (

9 Bl

9 Bl

ade, 12

ade, 12

.5in

.5in

_JSA)

_JSA)

Long and troublesome trip with several intermediate circulation

Long and troublesome trip with several intermediate circulation

points required due to 50-60 k overpull in several locations

points required due to 50-60 k overpull in several locations

Average FF = 0.19-0.20

Average FF = 0.19-0.20

Trip

Trip

#3 (

#3 (

8 Bl

8 Bl

ade, 20

ade, 20

.9in

.9in

_JSA)

_JSA)

Very smooth trip with the fewest number of tight spots of all the

Very smooth trip with the fewest number of tight spots of all the

tr

tr

ips

ips

out

out

.

.

“

“

P

P

eak”

eak”

overpu

overpu

ll

ll

of <

of <

15k.

15k.

Average FF = 0.16-0.18

Bit Design for Tripping

Bit Design for Tripping

 –

 – Straighten up highly tortuous component

Straighten up highly tortuous componentss

Prioritize Bit Junkslot Area

Prioritize Bit Junkslot Area

 –

 – Steel body bit

Steel body bits have much larg

s have much larger JSA than Matrix

er JSA than Matrix

 –

 – Better impa

Better impact resistance

ct resistance with Steel too

with Steel too

12 ¼”, 6-Blade

12 ¼”, 6-Blade

Steel

Steel

Body Bit

Body Bit

12 ¼”, 6-Blade

12 ¼”, 6-Blade

Matrix

Matrix

Body Bit

Body Bit

Bit Design for Tripping

Bit Design for Tripping

BHA Design for Tripping

BHA Design for Tripping

 –

 – A very effective

A very effective option to enable n

option to enable normal tripping with

ormal tripping with

“tigh

“tight”

t” comp

componen

onents is t

ts is to enl

o enlarge

arge the h

the hole

ole

•• Usi

Using Re

ng Ream

am-Wh

-While

ile-Dr

-Drill

illing (

ing (RWD

RWD) und

) under-

er-rea

reamer

merss

•• Ve

Very

ry po

popu

pula

lar i

r in t

n the

he No

Nort

rth Se

h Seaa

Under-Reamer Considerations

Under-Reamer Considerations

How the

How theBHA

BHA

sees a “Dirty”

sees a “Dirty”

under-reamed hole….

under-reamed hole….

Ho

How

w Casing

Casing

sees a “Dirty”

sees a “Dirty”

unde

underr--rre

eam

ame

ed

d hol

hole

e…

…

••

K&

K&M r

M rec

ecom

omme

mend

nd th

this

is as

as a s

a sho

hort

rt-t

-ter

erm “

m “ba

band

nd-a

-aid

id”,

”, un

unti

til t

l the

he

root cause is fixed, due to side effects of using RWD

root cause is fixed, due to side effects of using RWD

 –

 –

The danger of th

The danger of this technique is th

is technique is the “false sense

e “false sense of security”

of security”

gained from a trouble-free trip out prior to running casing…

gained from a trouble-free trip out prior to running casing…

 Video Clip

 Video Clip

Hole Cleanup Practices

Hole Cleanup Practices

 T

 T

h

h

e

e

h

h

o

o

le

le

m

m

u

u

s

s

t

t

b

b

e

e

c

c

le

le

a

a

n

n

e

e

d

d

u

u

p

p

p

p

r

r

io

io

r

r

t

t

o

o

t

t

r

r

ip

ip

p

p

in

in

g

g

•• To

To be s

be suc

ucce

cess

ssfu

ful, t

l, the f

he fol

ollo

lowi

wing i

ng is ne

s nece

cess

ssar

ary :

y :

 –

 – Conveyor belt must be turned on (> 120 rpm)

Conveyor belt must be turned on (> 120 rpm)

 –

 – Sufficient circulation is required

Sufficient circulation is required

•• Mu

Mult

ltip

iple B

le BU re

U requ

quir

ired a

ed at > 1

t > 120 r

20 rpm

pm

•• Lo

Look

okin

ing f

g for

or at

at le

leas

ast 2

t 2 wa

wave

vess

Cleaning up for a trip

Cleaning up for a trip

•• Th

The C

e Con

onve

veyo

yor b

r bel

elt r

t req

equi

uire

res >

s > 12

120 r

0 rpm

pm

•• Co

Comm

mmon

on di

dire

rect

ctio

iona

nal-

l-dr

dril

illi

ling

ng pr

prac

acti

tice

ce ….

….

•RPM is often slowed whenever off-bottom

•RPM is often slowed whenever off-bottom

(see next slide)

(see next slide)

•Hence, hole cleaning system is shut-down, convincing the team that

•Hence, hole cleaning system is shut-down, convincing the team that

the hole is clean

the hole is clean

•

•

Cuttings don’t know if the bit is on or off bottom !!

Cuttings don’t know if the bit is on or off bottom !!

•• Conve

Conveyor be

yor belt mu

lt must be on

st be on when bi

when bit is off

t is off-bott

-bottom too

om too..

This is one of the most common mistakes

This is one of the most common mistakes

…

RP

RPM vs Time lo

M vs Time lo g - Clean up on

g - Clean up on 18 July

18 July

2 200 4 400 6 600 8 800 1 10000 1 12200 1 14400 1 16600    P    P    i    i  p  p  e  e    R    R    P    P    M    M R

RPPM drops fM drops from 138rpm rom 138rpm to 80+ to 80+ rpm.rpm. Cleanup is therefore largely Cleanup is therefore largely non-existant, and tripping starts in dirty existant, and tripping starts in dirty hole hole    d    d    D    D  r  r    i    i    l    l    l    l    i    i  n  n  g  g  .  .    S    S    t    t  a  a  r  r    t    t  c  c    l    l  e  e  a  a

  n   n   u   u   p   p

Time-log showing RPM at end of

Time-log showing RPM at end of drilling, and then

drilling, and then

during clean-up cycle

during clean-up cycle

••

Drill

Drilling RPM = 13

ing RPM = 138, clean

8, clean-up RPM onl

-up RPM only 80 –

y 80 – 90

90

•• Shaker

Shakers clean

s cleaned up

ed up soon .

soon ... hole

.. hole was in

was interpre

terpreted as

ted as clean

clean

••

This was thei

This was theirr expect

expected result sinc

ed result since they were using a

e they were using a

rotary-steerable !

rotary-steerable !

Hole Cleanup Practices

Hole Cleanup Practices

How much clean-up is necessary ?

How much clean-up is necessary ?

Cleaning up takes time

Cleaning up takes time

 –

 – Bottoms up is irrelevant for high angle wells

Bottoms up is irrelevant for high angle wells

•• Ex

Expe

pect

ct 2 –

2 – 4+

4+ x B

x BU f

U for

or cl

clea

eanu

nup t

p tim

imee

 –

 – This is very sensiti

This is very sensitive to angle ab

ve to angle above 70

ove 70

o

o

₍

₍

_see

_see

_nex

_nex

_{t pa}

_{t pa}

_ge)

_ge)

 –

 – Patience is

Patience is critical

critical

•• AN

AND

D on

only

ly “c

“con

onve

veyo

yor b

r bel

elt O

t ON”

N” ti

time

me co

coun

unts

ts

 –

Effective C

Effective Circu

ircu lation Volum

lation Volum e vs.

e vs. Angle

Angle

20,000' (6000m) tangent length, shallow KOP

20,000' (6000m) tangent length, shallow KOP

1 1 2 2 3 3 4 4 5 5 6 6 7 7    M    M    i    i  n  n . .    C    C    i    i  r  r  c  c   u   u    l    l  a  a    t    t    i    i  o  o  n  n    V    V  o  o    l    l  u  u  m  m   e   e

This gives some feel for

This gives some feel for how much circulation is

how much circulation is

necessary for different angles

necessary for different angles

•• Note

Note –

– only

only conv

convey o

ey or be

r belt cir

lt circulatio

culation co

n counts

unts !!

This is a mi

This is a minimu

nimum volum

m volume requir

e requirement …

ement … the

the

“talk

“talking”

ing” at the s

at the shakers

hakers takes p

takes priori

riority in

ty in

decision-making.

decision-making.

 Notice how “gut feel”

 Notice how “gut feel” and “experience

and “experience

 betray you, once ang

 betray you, once angle gets > 70

le gets > 70

o

o

Hole Cleanup Practices

Hole Cleanup Practices

 –

 – You are looking for a

You are looking for at least 2 waves

t least 2 waves of cuttings

of cuttings

•• Sa

Salt

ltat

atio

ion

n fflo

low

w si

side

de eeff

ffeecctt

•• If yo

If you’ve

u’ve been

been drill

drilling s

ing start

tart-stop

-stop styl

style, th

e, then e

en expec

xpect mo

t more wa

re waves

ves

Hole Cleanup Practices

Hole Cleanup Practices

A 2

A 2

n

nd

d

_{wave of cuttings flow is very common, if} 

_{wave of cuttings flow is very common, if} 

cir

circulati

culation c

on conti

ontinue

nues (wit

s (with the c

h the con

onve

veyo

yor

r be

bellt on)

t on)

••

Si

Sim

miilla

ar

r to g

to grra

ave

vel

l pa

packi

cking

ng, i

, in r

n re

eve

verrs

se

e

      V       V      o             l       o              l       u      u              m       m        e              e              c              c             u               u              t        t        t        t       i       i        n       n        g              g              s       s      

Norm

Norma

all

circulation

circulation

At

At >

>8

80

0

_,

_{, 2}

₂

_wave

_{waveis ofte}

_{is often}

_n

after

after 3

3

_{bottoms up}

_{bottoms up}

1

1 22 33 44

••

It

It’’s e

s eaassy t

y to g

o geet s

t su

ucck

keerreed

d--iin t

n to s

o stto

op

p

clean-up when 1

clean-up when 1

st

st

_{wave finishes at}

_{wave finishes at}

_{1 x BU}

_{1 x BU}

••

Sh

Shak

aker

ers w

s wil

ill r

l red

edu

uce

ce to

to a b

a bac

ackg

kgro

rou

und

nd le

lev

vel

el

(fines will never clean up)

(fines will never clean up)

••

IIf

f the

therre

e a

arre

e s

sti

tilll

l c

cutti

utting

ngs

s s

sti

tilll

l o

on

n

the

the s

shake

hakerrs

s, t

, the

he hol

hole

e iis

s N

NO

OT

T ye

yet cl

t cle

ean …

an …

 –

Hole Cleanup Practices

Hole Cleanup Practices

Cleaning-up for a trip

Cleaning-up for a trip

 – 

 – 

 Th

 This

is p

pro

roc

ce

es

ss

s d

do

oe

es

s le

lea

av

ve

e c

cu

uttttin

ing

gs

s in

in tth

he

e h

ho

ole

le

 –

 – The hole doesn’t have to be completely clean.

The hole doesn’t have to be completely clean.

 –

Tripping practices

Tripping practices

When hole has cleaned up …

When hole has cleaned up …

 –

 – Trip out on elevators

Trip out on elevators

(i.e. no pumping or backreaming)

(i.e. no pumping or backreaming)

 –

 – Back-reaming is only to be used as a last-resort

Back-reaming is only to be used as a last-resort

option

•

•

P

P

a

a

r

r

t 3

t 3

–

–

T

T

r

r

i

i

p

p

p

p

i

i

n

n

g O

g O

u

u

t P

t P

r

r

o

o

c

c

e

e

d

d

u

u

r

r

e

e

s

s

 –

 – Following the road-m

Following the road-map

ap

•• How

How to

to id

iden

enti

tify

fy “a

“abn

bnor

orma

mal”

l” fr

from

om “n

“nor

orma

mal”

l”

•• Ho

How t

w to

o id

iden

enti

tify

fy “a

“a le

ledg

dge”

e” fr

from

om “c

“cut

utti

ting

ngs”

s”

 –

 – How to respond to ti

How to respond to tight hole

ght hole

•• D

Do

o’’s

s &

& D

Do

on

n’’ttss

 –

Tripping Out Procedure

Tripping Out Procedure

1

1.. P

Pu

ulll

l o

ou

ut

t o

of

f h

ho

ollee

without

without

rotation or circulation

rotation or circulation

•• Tr

Trip

ip sp

spee

eed i

d is

s im

impo

port

rtan

ant …

t … co

cont

ntro

rols

ls sp

spee

eed o

d of d

f dir

irt f

t flo

low

w

through the stabilizers & bit

through the stabilizers & bit

•• Ti

Tigh

ghte

ter

r BH

BHAs

As re

requ

quir

ire

e sl

slow

ower

er sp

spee

eeds

ds

2.

2. Mo

Monit

nitor P

or P/U w

/U wei

eight w

ght whil

hile tr

e tripp

ippin

ing out o

g out of hol

f holee

•• Com

Compar

pare re

e real-

al-tim

time to th

e to theo

eoret

retica

ical dra

l drag tre

g trends

nds (“r

(“road

oadmap

maps”

s”))

•• Mu

Must

st ha

have

ve a r

a roa

oad-

d-ma

map t

p to k

o kno

now w

w wha

hat “

t “no

norm

rmal

al”” is

is

(see following plots)

Using Road-Maps

Using Road-Maps

1.

1. If y

If you a

ou are t

re to m

o make

ake wis

wise de

e decis

cision

ions a

s abou

bout wh

t when “

en “som

someth

ething

ing is a

is abno

bnorma

rmal”,

l”,

you need to know what normal looks like …

you need to know what normal looks like …

Experienced hands assume that they know this

Experienced hands assume that they know this

…

… “

“I

I do

don’

n’t ne

t nee

ed a co

d a com

mpu

pute

ter

r to te

to telll l m

me

e w

whe

hen I

n I’’v

ve

e go

got ti

t tigh

ght ho

t holle

e”

”

2.

2. Pe

Peop

ople a

le als

lso as

o assu

sume t

me tha

hat th

t they a

ey are l

re loo

ooki

king f

ng for a s

or a sud

udde

den ch

n chan

ange

ge

Both of these are vertical hole logic, and are perhaps the most common

Both of these are vertical hole logic, and are perhaps the most common

reason wells get into trouble while tripping

reason wells get into trouble while tripping

•

•

If

If

we

we

ha

ha

d a g

d a g

en

en

ui

ui

ne

ne

ly

ly

cl

cl

ea

ea

n h

n h

ol

ol

e,

e,

an

an

d “

d “

le

le

dg

dg

es

es

”

”

we

we

re

re

th

th

e p

e p

ro

ro

bl

bl

em

em

, t

, t

he

he

n t

n t

hi

hi

s

s

logic is OK 

logic is OK 

•

•

Bu

Bu

t r

t r

em

em

em

em

be

be

r w

r w

e a

e a

re

re

lo

lo

ok

ok

in

in

g f

g f

or

or

di

di

rt b

rt b

ui

ui

ld

ld

-u

-u

p b

p b

et

et

we

we

en

en

st

st

ab

ab

il

il

iz

iz

er

er

s,

s,

wh

wh

ic

ic

h

h

15k 

15k 

Here is a tr

Here is a trip out, plotted against depth

ip out, plotted against depth

•• Is

Is th

this O

is OK ?

K ?

But this is about to get stuck …

But this is about to get stuck …

••

Can’t you see the train-wreck coming at you ?

Can’t you see the train-wreck coming at you ?

This is the next stand pulled ?

This is the next stand pulled ?

•• Wha

What is th

t is the ov

e over-

er-pul

pull ?

l ?

•• Loo

Looks l

ks like

ike 15

15 k ?

k ?

In real

In reality, h

ity, hole is

ole is “talki

“talking”

ng” to yo

to you

u

fo

for +/

r +/-- 10

10 st

stan

ands

ds

•And overpull is 45k -lbs

•And overpull is 45k -lbs

45k 

45k 

Classic indication of cuttings

Classic indication of cuttings

 building up is d

 building up is diverging PU loads

iverging PU loads

•• Bet

Betwee

ween “n

n “norma

ormal”

l” and a

and actu

ctual l

al load

oadss

•• Us

Usua

uall

lly ov

y over 4 –

er 4 – 5 st

5 stan

ands

ds

Tripping Out Procedure

Tripping Out Procedure

…

… cco

ont

ntiinu

nueed

d

••

IIf

f ttiig

ght ho

ht holle

e iis

s e

enco

ncounte

unterre

ed

d

 –

 – Either via roadma

Either via roadmap or not …

p or not …

••

F

For

or ttiig

ght s

ht sp

pot

ot o

or

r iincr

ncre

ea

as

siing

ng d

drrag

ag,, a

allw

wa

ay

ys

s a

as

ss

sum

ume

e tthe

he

problem is cuttings

problem is cuttings

 –

 – Run in the hole 2 to 5 s

Run in the hole 2 to 5 stands to get BHA

tands to get BHA away from tight

away from tight

spot

spot

••

If

If ob

obst

stru

ruct

ctio

ion i

n is d

s dir

irt,

t, yo

you

u mu

must

st un

un-p

-pac

ack

k th

the

e BH

BHA b

A bef

efor

ore

e do

doin

ing

g

anything else

anything else

 –

 –

If it took > 5 stands to p

If it took > 5 stands to pack the BHA, it will probably

ack the BHA, it will probably take that many

take that many

to un-pack it !!

to un-pack it !!

 –

 – Remember tha

Remember that cuttings can m

t cuttings can move down hole w

ove down hole with BHA (in

ith BHA (in

avalanche regime <65°±)!

Tripping Out Procedure

Tripping Out Procedure

Tight Spot Procedure

Tight Spot Procedure

(…continued)

(…continued)

••

C

Ciirrccu

ullaatte

e &

& rro

ottaatte

e aat

t >

> 1

12

20

0 rrp

pm

m ffo

or

r 3

30

0 m

miin

nu

utteess

 –

 –

Goal is to verify c

Goal is to verify cuttings dune, so a

uttings dune, so as not to waste tim

s not to waste time if otherwise

e if otherwise

 – 

 – 

C

Conv

onve

eyor

yor be

bellt m

t mus

ust be

t be on,

on, iif

f cutti

cutting

ngs ar

s are

e to be

to be m

move

oved

d

••

P

PO

OH

H ccaarreeffu

ulllly

y

without

without

rotation or circulation watching for the

rotation or circulation watching for the

tight spot to recur 

tight spot to recur 

 –

 –

If the tight spot

If the tight spot has moved up hol

has moved up hole, then obstructi

e, then obstruction was cuttings

on was cuttings

 –

Tripping Out Procedure

Tripping Out Procedure

Tight Spot Procedure

Tight Spot Procedure

…continued

…continued

•• IIf

f tth

he

e ttiig

gh

ht

t ssp

po

ot

t h

haass

N

NOT

OT

moved up hole, then genuine tight

moved up hole, then genuine tight

hole is likely (key

hole is likely (key seat, ledge, swelling formation, etc.)

seat, ledge, swelling formation, etc.)

 –

 – Circulating o

Circulating or backreaming

r backreaming may be used with c

may be used with caution

aution

 –

 – Must avoid pack-

Must avoid pack-off while circul

off while circulating or backre

ating or backreaming out of the

aming out of the hole

hole

••

R

Riis

sk of s

k of stuc

tuck

k pipe

pipe

••

Pressure damage to wellbore below pack-off 

Pressure damage to wellbore below pack-off 

••

Don’t want to lose returns

Don’t want to lose returns

 – 

Pipe Stretch Implications

Pipe Stretch Implications

-- V

Veerrttiiccaall:: P

Piicck

k--u

up w

p weeiig

gh

ht =

t = R

Ro

ottaattiin

ng w

g wt =

t = S

Sllaacck

k--o

offf w

f wtt

-- Hi

High

gh an

angl

gle:

e: We

Weig

ight

hts a

s are

re ve

very

ry di

diff

ffer

eren

ent …

t ….s

.so w

o wha

hat ?

t ?

Consider what’s actually happening downhole when the

Consider what’s actually happening downhole when the

weight indicator changes when you kick the rotary on …

weight indicator changes when you kick the rotary on …

-- BHA i

BHA imme

mmedia

diatel

tely suc

y sucks up t

ks up the ho

he hole, w

le, with m

ith miss

issing f

ing forc

orce loa

e load

d

-- ty

typ

pic

ical

al st

stre

retc

tch

h is

is 1

1’’ pe

per

r 1

10

000

00’’ MD

MD (i

(ie,

e, 1

12’

2’ at

at 1

12

200

000’

0’ M

MD)

D)

-- If

If you

you rot

rotate

ate wit

with a

h any

ny ten

tensio

sion r

n rem

emain

aining

ing …

…

Pipe Stretch Implications

Pipe Stretch Implications

The same thing happens while tripping in …

The same thing happens while tripping in …

-- How

How ma

many t

ny time

imes ha

s have y

ve you t

ou trie

ried to

d to rol

roll of

l off a

f a “le

“ledge

dge”” whi

while t

le trip

rippin

ping in

g in??

-- What

What happ

happens t

ens to the

o the bit

bit when

when rota

rotation

tion is i

is imita

mitated

ted with

with the

the strin

string in

g in

compression?

compression?

-- Th

The bi

e bit le

t leap

aps for

s forwa

ward

rd, unc

, uncon

ontr

trol

olla

labl

bly

y

-- This i

This is a r

s a reall

eally go

y good wa

od way to

y to destr

destroy a

oy a drill

drillstrin

string (if

g (if buckl

buckling

ing is

is

 present)!

 present)!

•

•

P

P

a

a

r

r

t 4

t 4

–

–

B

B

a

a

c

c

k

k

-

-

r

r

e

e

a

a

m

m

i

i

n

n

g O

g O

u

u

t P

t P

r

r

o

o

c

c

e

e

d

d

u

u

r

r

e

e

s

s

 –

 – When is back-r

When is back-reaming OK ?

eaming OK ?

 –

 – How to back-ream s

How to back-ream safely

afely

Backreaming Basics

Backreaming Basics

•• So

Som

met

etim

imes b

es bac

ackr

krea

eami

ming i

ng is ne

s nece

cess

ssar

ary …

y …

 –

 – Tight hole on trips

Tight hole on trips

 – 

 – 

after

after

verifying that the obstruction is NOT cuttings

verifying that the obstruction is NOT cuttings

 –

 – Swabbing (can

Swabbing (can’t trip conventiona

’t trip conventionally)

lly)

 –

 – When remova

When removal of ALL

l of ALL cuttings is nec

cuttings is necessary

essary

•• To cle

To clean up h

an up hole fo

ole for extr

r extreme c

eme casing

asing runs in

runs in ER well

ER wellss

•• Typ

Typica

ical “t

l “trig

rigger

ger”” is

is if c

if casi

asing

ng run

run is

is so

so cha

challe

llengi

nging

ng as

as to r

to requ

equire

ire

flotation

flotation