57172797-stuck-pipe (2)

8/13/2019 57172797-Stuck-Pipe (2)

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STUCK PIPE

DEFINITIONS

STUCK

PIPEPlanned operations are suspended when down hole forces prevent pulling the

string out of the hole.

TIGHT HOLEDown hole forces restrict string movement above normal operating conditions

(a usual warning indicator of a stuck pipe event).

TYPES AND CAUSES OF STUCK

A. Key-eating.

!. "aving.

". #nder gauge hole.

D. Differential stuck.

A. Key-eating$

%his usually occurs in deviated holes when the drill pipe wears into the wall of the

hole. ince the drill pipe is the smallest diameter in the drill string& the larger diameter

tool 'oints and drill collars can get stuck when making a trip.Key-eating is recognied by the following characteristics$

. till having circulation.

*. "an rotate pipe.

+. ,ay be able to move drill pipe down.

olution$

nce the Key-eating has been formed& the smallest diameter portion of its

configuration must be reamed out with some sort of reaming device.

!. "aving in$

"auses$

. nsufficient mud weight.*. /etting shales causing sloughing.

+. nsufficient carrying capacity of the drilling fluid.

0. %ectonically stressed and brittle shales.

"aving is recognied by the following characteristics$

. "an not circulate.

*. "an not move the pipe(sometimes the pipe can be moved down words but not up.

+. "an not rotate the pipe.

olution$

. ncrease mud weight to balance formation pressure if possible.

*. #se drilling fluid that will not wet or hydrate the shales and at the same time

stabilie shales such as Kcl-Polymer ,ud.+. ncrease the carrying capacity of the drilling fluid by increasing 1P.

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". #nder gauge hole$

"auses$

. #nder gauge drilling assembly.

*. Plastic following formations(such as salt or soft formations) caused by overburden

pressures.

+. 2locculated mud and aggregated mud causes thick filter cake.0. /all cake build upon a porous formation in an already gauge hole.

3. All of these can be complicated by additions of drilled solids to the drilling

assembly& commonly refereed as (!it !alling).

olution$

. "heck the gauge of the drilling assembly.

*. ncrease mud weight to control formation pressures.

+. 4educe filtration to form a smaller wall cake.

0. 4educe bit balling by $

• "hange to inhibitive mud.

• Add surfactants (detergent).

• lugs (having nut plug 5 caustic soda 5 spersene).

• 4edicoat.

6!$ /hen bit is balled& getting high tor7ue& no progress.

D. Differential ticking$

Differential sticking is defined as the sticking of pipe at one side of hole against a

permeable formation because the drilling fluid pressure e8ceeds the pore fluid

pressure of the formation& which causes break of the formation& which by turn will

cause a complete loss. And thus the tendency of sucking of drill string to any side of

pore hole is possible. Differential sticking may occur in any area of drilling but

mostly occurs where deep wells are drilled with high density mud.Differential sticking is characteried by$

. Drill with lowest mud weight practical.

*. ,aintain low filtration rate.

+. #se lubricate.

0. Do not allow the pipe to remain motionless for any period of time.

3. #se s7uare& he8agonal& or spherical drill collars.

9. "hange to 6:;4,#<.

=. #; a spotting fluid (;6:4-P%).

ENVIRO-SPOT spotting flui fo!"#tion fo! $%% &&ls

/;>?%

(PP>)

=.+ @ * 0 9

<

(!!<)

93 3 30 0B 3 00

;6:4-P%

33 gal Drum

9 9 9 9 9 9

/A%;4

(!!<)

* *9 ** * @

!A4%;

@@ lb. bag

C 0@ *3@ +3@ 093 3=@

tart with re7uired volume of oil& add ;6:4-P%& water and barite in that order

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CAUSES OF SETTLED CUTTING

HOLE CLEANING IS AFFECTED (Y , (ASIC FACTORS

FACTOR AFFECT• RATE OF PENETRATION

• Determines the cuttings volume in returning

mud• HOLE STA(ILITY • "avings load added to the returning mud

• ANNULAR VELOCITY • <ifts the cuttings

• 'UD RHEOLOGY • uspend and carry the cuttings

• CIRCULATING TI'E • %ransport the cuttings to surface

• HOLE ANGLE• 4educes the ability to clean the hole

SETTLED CUTTINGS NEAR VERTICAL .ELL(ORE /0 123

CAUSE*

• D4<<;D "#%%6> A4; 6% %4A6P4%;D #% 2 %?; ?<; D#;

% </ A66#<A4 :;<"%1 A6D 4 P4 ,#D P4P;4%;.

/?;6 "4"#<A%6> %PP;D& %?; "#%%6> 2A<< PA"K D/6

%?; ?<; A6D PA"K 22 %?; D4<< %46>.

2>#4;.

/A466>$• ?>? 4P& </ P#,P 4A%;& <%%<; % 6 "4"#<A%6> %,; A%

"66;"%6& %4E#;& D4A> A6D P#,P P4;#4; 6"4;A;.

• :;4 P#<< 2 <P& P#,P #4>; % !4;AK "4"#<A%6

• 2<< 6 !%%,.

6D"A%6$• <K;<1 % ""#4 6 "66;"%6& P!<; D#46> %4P.

• "4"#<A%6> 4;%4"%;D 4 ,P!<;.

24% A"%6$• APP<1 </ P#,P P4;#4; (*@@-0@@ psi)

• Apply tor7ue and 'ar down with ma8imum trip load.

• "irculate clean to avoid recurrence.

P4;:;6%:; A"%6$• "6%4<& 4P& ,AF,G; A66#<A4 :;<"%1.

• ,A6%A6 #22";6% >;< %4;6>%? A6D 1P.

• "4"#<A%; 3 %@ ,6#%; !;24; "66;"%6.

• "4"#<A%; ?<; "<;A6 !;24; P?.

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2>#4;

SETTLED CUTTINGS HIGH ANGLE .ELL(ORE /4123

CAUSE*

• D4<< "#%%6> ;%%<; 6 %?; </ D; 2 %?; ?<; A6D 24, A

"#%%6> !;D. %?; "#%%6> !;D !#<D A6D <D; D/6 A6D %?;

?<; PA"K6> 22 6 %?; D4<< %46>.

• /?<; P?& %?; "#%%6> !;D D4A>>;D #P/A4D !1 %?; !?A A6D

PA"K 22 %?; D4<< %46>.

.ARNING*

• ?<; A6><; >4A%;4 %?A6 +3 deg.

• D4<<6> /%? A D/6 ?<; ,%4.

• ?>? 4P& </ P#,P 4A%;& 6"4;A; 6 %4E#; A6D D4A>& 6"4;A;

6 P#,P P4;#4;.• 6"4;A; :;4 P#<< 6 %4P.

INDICATIONS*

• <K;<1 % ""#4 /?<; P?& P!<; /?<; D4<<6>.

• "4"#<A%6> P4;#4; 4;%4"%;D 4 ,P!<;.

FIRST ACTION*

• APP<1 </ P4;#4; ( @@ H 0@@ P ).

• IA4 D/6 /%? ,AF,#, %4P <AD. APP<1 %4E#; /%? "A#%6.

• "<;A6 ?<; % A:D 4;"#44;6";.

PREVENTIVE ACTION*

• 4;"4D %4;6D 6D"A%4 24 6AD;E#A%; ?<; "<;A66>.

• "6%4< 4P& ,A6%A6 ,#D P4P;4%;& "4"#<A%; A% ,AF,#,

4A%;& ,AF,G; %46> 4%A%6.

• "4"#<A%; ?<; "<;A6 !;24; P?& ;%A!<? A6 :;4 P#<< <,%.

• #; </ :?>? : /;;P.

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INDICATIONS OF SETTLED CUTTINGS

DRILLER

TRENDS

D4A> %4E#; P4;#4; %?;4

• DRILLING ncreasing&erratic ncreasing&erratic ncreasing • Pressure surges• >radual decrease in 4P

♦ CONNECTI

ON

ver pull off

slips

urge to

start

circulation

♦ !ack pressure before breaking

connection.

♦ !ack flow.

TRIPPING

OUT

ncreasing&erratic

ver pull offslips

wabbing

TRIPPING

IN

ncreaseing setdown weight.

ver pull offslips.

!egins with !?A below

depths of +3 hole angle

(ACK

REA'ING

ver pull offslips. ;rraticover pull

ncreasing&erratic ncreasing urge to start circulation. tring pistoning.

<oss of fluid possible.

PU'PING

OUT

ver pull offslips.

ncreasing&erratic ncreasing

urge to start circulation.

tring pistoning.

<oss of fluid possible

RIG TEAM INDICATIONS

SHAKER

TRENDS

<ow cuttings return rate for penetration& ;rratic cuttings returns& 6o cuttings

return& ?igh cuttings return on fine shaker screen and desilter mud cleaner.

LOGGER

TRENDS4ounded 4eground cuttings.

'UD

TRENDS

ncreasing P: J 1P. ncrease in low gravity solids& Possible mud weight

increase.

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PREVENTIVE ACTION• ,aintain the re7uired mud properties.

• "irculate the ma8imum recommended >P, for hole sie.

• Place more emphasis on annular velocity when designing the hydraulics for

*.*3 and larger hole sies. "onsider using a riser booster line when drilling .3

and smaller hole sies.

• Do not allow the penetration rate to e8ceed the ability to clean the hole.

• 4ecord tor7ue and drag trends for symptoms for inade7uate hole cleaning.

• "onsider a wiper trip after a long section with a down hole motor.

• /ipe the hole at full circulating rate as long as possible (3 H @ min.) before

connections& 4otate at ma8imum 4P, when possible.

• ,a8imie string motion when circulating the hole clean. #se ma8imum practical

4P,& rise the drill string slowly (3 minstd) and slack-off at a safe but fast rate (

minstd).

• "onsider pumping high-vis sweeps in low angle wells (L+3). "onsider low-vis

high-vis sweeps in higher angle wells (M+3).• D 6% %P "4"#<A%6> #6%< A<< /;;P 4;%#46.

• "irculate until the hole is clean& if the last sweep brings up e8cessive amounts of

cuttings& continue with hole cleaning operations. everal circulations may be

necessary.

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'INI'U' GP'

MINIMUM GPM VERSUS HOLE SIZE AND HOLE ANGLE

HOLE SI5E *9 =.3 H9 *.*3 .3ANGLE

INTERVAL

% 6 12 7g =@@ >P, 3@@ >P, 0@@ >P, +@@ >P,

12 - 22 7g *3@ >P, B3@ >P, 93@ >P, 03@ >P,

22 8 7g @@ >P, =3@ >P, 3@@ >P,

'INI'U' ROP

MAXIMUM ROP VERSUS HOLE SIZE AND HOLE ANGLE

HOLE SI5E *9 =.3 H9 *.*3 .3

ANGLE

INTERVAL

% 6 12 7g 9@ @ 33 *0@

12 - 22 7g 0@ =3 3 *3

22 8 7g 9@ =3 @@

Penetrt!"n rte #$!%e&!ne' re ('e% "n %e)$te *$% +r"+ert!e',

'INI'U' STROKES

MINIMUM CIRCULATING STROKES FACTOR CSF. TO CLEAN

HOLEHOLE SI5E *9 =.3 H9 *.*3 .3

ANGLE

INTERVAL

% 6 12 7g * .= .0 .0

12 - 22 7g *.3 *.3 . .9

22 8 7g + .* .=

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PROCEDURE*

$9 S7p#!#t7 t:7 ;7ll&o!7 into s7<tions &= :ol7 #ngl7 f!o" int7!>#l #&o>79

?9 'ultipl= 7#<: :ol7 s7<tion l7ngt: /S7<t9 Lt:3 &= CSF #n tot#sl t:7 #@ust7 "7#su!7 7pt:

/'D39

19 C#l<ul#t7 t:7 "ini"u" <i!<ul#ting st!o7s to <l7#n t:7 :ol79

Tot#l A@ust7 'D B (otto"s-Up Sts

'ini"u" Ci!<9 Sts ----------------------------------------------------

'7#su!7 D7pt:

EBA'PLE CALCULATION*

"A<"#<A%; %?; ,6,#, "4"#<A%6> %4K; 24 * N ?<;

?A:6> %?; 2<</6> P42<;.

. 24, @ 2% % 03@@ 2% ( 03@@ 2% ) ?A:; @ H +3 deg.

*. 24, 03@@ 2% % 93@@ 2% ( *@@@ 2% ) ?A:; +3 H 33 deg.

+. 24, 93@@ 2% % +@@@ 2% ( 93@@ 2% ) ?A:; 335 deg.

MULTIPLY EACH HOLE SECTION LENGTH BY CSF AND TOTAL THE

ADUST MEASURED DEPTH,

ADUSTED MD 0 / SECT9 LTH B CSF 3 8 / SECT LTH B CSF 3 8 / SECT LTH B CSF 3

/ 2%% B $9 3 8 / ?%%% B $9 3 8 / ,2%% B ? 3

,1%% 8 1,%% 8 $1%%% ??%% TOTAL AD)USTED 'D9

CALCULATE THE MINIMUM CIRCULATING STROKES RE1UIRED TO

CLEAN THE HOLE,

T"t& A%2$'te% MD X B"tt"*'-U+ St3'

M!n!*$* C!r4, St3' 0 ----------------------------------------------------

Me'$re% De+t5

**B@@ F 3@@@

O --------------------

+@@@

O *90*+ %4K;.

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HIGH ANGLE HOLE CLEANING GUID LINES / 4 12 7g 3

DRILLING

• ,aintain sufficient mud weight to stabilie the wellbore as hole angle andor formation

pressure increases.

• #se proper low-end rheology for hole sie and angle to ma8imie hole cleaning.• "irculate at ma8imum rate for hole sie and hole angle.

• <imit the 4P for the ma8imum recommended for hole sie and angle.

• !ack ream each stand (or stand) drilled with a down hole motor

• 4otate at a high 4P, (9@5). 4aise the drill string slowly (i.e.. 3minstand). <ower the

drill string at a safe but fast rate (i.e.. minstand).

• "ontinue back reaming if hole conditions dictate.

• "onsider a wiper trip after drilling a long section with a down hole motor to mechanically

agitate and remove cuttings bed.

• Pump a sweep pill if hole conditions do not improve. "onsider low-vis high-density

tandem sweeps. ptimie sweep type& volume and fre7uency pumped.

• "onsider reducing 4P or stop drilling and circulate until hole conditions improve.

CONNECTIONS• tart and stop drill string slowly. ;nsure ade7uate back reaming at a full circulation rate

prior to connections.

• Prepare crew and e7uipments to minimie connection time.

• 4ecord free rotating weight& pick-up weight& slack-off weight& off bottom tor7ue& and

circulating pressure for trend indications of inade7uate hole cleaning.

• Pull the slips and slowly rotate the drill string first& then increase pump speed slowly.

"arefully lower the drill string to bottom.

%4PP6>• "irculate to + 'oints off bottom while cleaning the hole to avoid dropping bottom hole

angle. "onsider sweeps (pills) to aid hole cleaning.

• 4otate at high 4P, (9@5) while cleaning the hole. 4aise the drill string slowly (i.e..

3minstand). <ower the drill string at a safe but fast rate (i.e.. minstand).

• ;nsure recommended minimum circulation strokes for hole sie and angle be pumped. *

to 0 times normal bottoms-up may be re7uired. "irculate until the shakers are clean.

• "onsider pumping a sweep (pill) to determine if additional circulation time is re7uired.

• nform the Driller of the measured depth and stand count when the top of the !?A

reaches the deepest anticipated cuttings bed.

• ,a8imum cuttings bed thickness is likely between 03 and 93 hole angle.

• Determine an over pull limit prior to pulling out of the hole (the lesser of !?A weightor +@&@@@lbs).

• f overpull limit occurs& run in stand and repeat hole cleaning guidelines from present

bit depth. /hen the shakers are clean& continue pulling out of the hole. f the overpull

limit is again reached& repeat procedure.

"A#%#<1 !A"K 4;A, 4 P#,P-#% %A6D /?;6 A "#%%6> !;D

P4;;6%QQ

(7 p#ti7nt several hole cleaning cycles may be re7uired to safety pull the drill string out of

the hole.

• 4ecord depths and stand count of high pick-up weights during the trip. "ompare these to

the drilling pick-up weights for the same depths to determine value of over pull.

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SHALE INSTA(ILITY

%he shale formation becomes unstable& breaks apart and falls into the wellbore

"?;,"A<<1%4;;D 'ECHANICALLY STRESSED

4;A"%:; ?A<;

GEO-PRESSURED SHALE HUDROPRESSURED

SHALE

OVER(URDEN STRESS TECTONIC STRESS

"?;,"A<<1 %4;;D ?A<;

4;A"%:; ?A<;

CAUSE*

• /ater sensitive shale drilled with little or no mud inhibition.

• hale absorbs water and swells into the wellbore.

• 4eaction is time dependably.

.ARNING*

• 2unnel viscosity& P:& 1P& ";" increase.

• %or7ue J drag increase.

• Pump pressure increase.

• "lay balls andor soft (mushy) cuttings at shaker.

• ver pull J swabbing.

• !?A balling (mud rings)INDICATIONS*

• >enerally occurs while P?& possible while drilling.

• "irculation impossible or highly restricted.

FIRST ACTION*

•

Apply low pump pressure (*@@ H 0@@ psi).• f P?& tor7ue up and 'ar down with ma8imum trip load.

• f P?& 'ar up with ma8imum trip load& D 6% APP<1

%4E#;.

PREVENTIVE ACTION*

• #se an inhibited mud.

• ,aintain mud properties.

• Plan wiper trips.

• ,inimie hole e8posure time.

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INDICATIONS OF REACTIVE CUTTINGS

DRILLER TRENDS DRAG TORUE PRESSURE OTHER

• DRILLING ncreasing mooth ncreasing&mooth ncreasing

• Pressure surges

• >radual decrease in 4P

• ,ud loss possible

♦ CONNECTIONver pull offslips

urge to start

circulation

♦ !ack pressure before

breaking connection.

♦ !ack flow.

TRIPPING OUTncreasing&mooth.

ver pull off slips wabbing

TRIPPING INncreaseing setdown weight. ver

pull off slips.

!egins at depth of

problem formation.

,ud loss possible

(ACK REA'ING

ver pull off slips. ncreasing&mooth ncreasing


tring pistoning.


PU'PING OUTncreasing&mooth.ver pull off slips.

ncreasing


tring pistoning.



SHAKER

TRENDS

oft clay balls. /et R mushy R clay ( >umbo ). 2low line plugging.

LOGGER

TRENDS<arge 7uantity of hydrated shale cuttings. ?igh value on shale swelling test.

'UD

TRENDS

?igh funnel vis. J yp& increasing pv& low gravity solids J ";". Possible

mud weight increase. <ow inhibitor content.

PREVENTIVE ACTION• Addition of various salts (potassium& sodium& calcium& etc.) to reduce the

chemical attraction of water of the shale.• Addition of various encapsulating (coating) polymers to reduce water contact with

the shale.

• #se oil and synthetic base mud to e8clude water contact with shale.

• ,inimie open hole time.

• Plan regular wiper reaming trips based on time& footage drilled or or the warning

signs of reactive shale.

• ;nsure ade7uate hydraulics for bit and hole cleaning.

• ,aintain re7uired mud properties and minimie low gravity solids.

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GEO 6 PRESSURED SHALE

CAUSE*• Drilling pressured shale with insufficient mud weight.

•

%he stressed shale fractures and caves into the wellbore..ARNING*• igns begin to occur as shale is drilled.

• ,ud logger trends indicate increasing pore pressure.

• %or7ue increase and drag on connections.

• ?ole fill on connections& bridges on trips& splintery shale caving.

• Possible background gas increase.

INDICATIONS*• <K;<1 % ""#4 6 %4PP6>& P!<; /?<; D4<<6>.

• ",P<;%; PA"K-22 <K;<1& ?<; !4D>6> P!<;.

• "4"#<A%6 4;%4"%;D 4 ,P!<;.FIRST ACTION*• Apply low pump pressure.

• Apply tor7ue& 'ar down with ma8imum trip load.

PREVENTIVE ACTION*• Ad'ust mud weight before drilling known pressured shale.

• lowly increase mud weight to stabilie shale.

• ,inimie swab surge pressures.

• ,inimie open hole e8posure time.

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HYDRO-PRESSURED SHALECAUSE*• ver time& shale pore pressure becomes charged by hydrostatic over balance.

• Drill string motion and wellbore pressure surges stress-cracks the unstable shale.

• %he shale falls into the wellbore and 'ams the string..ARNING*• >enerally follows a mud weight reduction.

• %or7ue and drag increase.

• hale caving at shakers.

INDICATIONS*• Possible while drilling or tripping.

• ?ole bridging or complete pack off possible.

• "irculation restricted or impossible.

FIRST ACTION*

• Apply low pump pressure (*@@-0@@ psi)• Apply tor7ue& 'ar down with ma8imum trip load.

• "irculate at ma8imum rate once circulation is established.

PREVENTIVE ACTION*• #se !,& !,& or ><1"< base mud if problem is suspected.

• f a mud weight reduction is necessary& reduce gradually over several circulations.

• ,inimie wellbore pressure surges.

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OVER(URDEN STRESS

CAUSE*• ,ud weight is insufficient to support the overburden.

• ,ud weight in not ad'usted as hole angle increases.

•

tressed shale fractures and falls into the wellbore..ARNING*• ?ole cleaning problems.

• %or7ue and drag increase.

• hale caving at shakers.

INDICATIONS*• "an occur while drilling or tripping.

• ?ole bridging or complete pack off possible.

• 4estricted "irculation or no circulation possible.

FIRST ACTION*

• Apply low pump pressure (*@@-0@@ psi)• Apply tor7ue& 'ar down with ma8imum trip load.

PREVENTIVE ACTION*• #se mud weight needed to stabilie to overburden.

• ncrease mud weight as hole angle increases.

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TECTONIC STRESS

CAUSE*• 6aturally occurring lateral forces in the formations.

• tressed shale fractures& falls into the wellbore and 'ams the drill string.

•

andstone s7ueees in causing undergauge hole..ARNING*• ,ountainous location.

• Prognosed tectonics.

• ;rratic tor7ue and drag.

• !locky shale caving.

• "reates elliptical wellbore.

INDICATIONS*• Possible while drilling or tripping.

• "irculation restricted or impossible.

FIRST ACTION*• Apply low pump pressure (*@@-0@@ psi)

• Apply tor7ue& 'ar down with ma8imum trip load.

PREVENTIVE ACTION*• ncrease mud weight if possible

• "irculate high density sweeps

• ,inimie wellbore pressure surges


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INDICATIONS OF MECHANICALLY STRESSED SHALE


• DRILLING ncreasing erratic ncreasing&erratic ncreasing

• ncrease 4P followed

by gradual decrease

pressure surges.


urge to start

circulation ♦ ?ole fill

TRIPPING OUTncreasing&erratic.

ver pull off slips wabbing

TRIPPING INncreaseing set

down weight.

!egins at depth of

problem formation.

?ole fill on bottom.

(ACK REA'ING ver pull off slips. ncreasing&erratic ncreasing


tring pistoning. <oss of fluid possible.

PU'PING OUTncreasing&erratic.

ver pull off slips. ncreasing


tring pistoning.



SHAKER

TRENDS

<arge& splintery or blocky shale caving. <arge volume of caving.

LOGGER

TRENDS

<arge 7uantity of splintery or blocky shale caving with striations. Possible

indications of increase in formation pressure. Prognosed mechanically

stressed shale.

'UD

TRENDSPossible slight increase in mud weight and plastic viscosity.

PREVENTIVE ACTION• "onsider offset well data andor computer models which simulate failure limits

when planning the mud weight for each hole section.

• ,ud weight increase with hole angle and %:D specific to the area to maintain

hole stability.

• ;8ploration wells& consult the ,ud <ogger for changes in formation pressure.

ncrease the mud weight cautiously until symptoms are no longer observed.

• f possible& increase the mud weight slowly ( @. H @.* ppg per day ) until the

desired density for a given depth is reached. %his will maintain an overbalance

against the hydrostatically sensitive shale.

• A>oi "u ;7ig:t !7u<tion after 5 day e8posure to hydrostatically sensitive

shale. f mud weight reduction is necessary reduce the mud weight gradually over

a time frame e7ual to the time of e8posure.

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• #se the haker ?andover 6otes to determine trends of cutting volume& sie and

shape.

• ,aintain mud properties to ensure hole cleaning.

• #se sweeps to help clean the hole.

• top drilling until the hole is circulated clean.


• Plan contingency to case-off the problem.

UNCONSOLIDATED FOR'ATION

CAUSE*• <ittle or no filter cake.

• #nbonded formation (sand& pea gravel& etc) can not be supported by hydrostatic

overbalance.

• andpea gravel falls into the hole and pack off the drill string.

.ARNING*• <ikely to occur as the formation is drilled.

• eepage loss likely.

• ncrease tor7ue and drag& pump pressure fluctuations.

• ?ole fill on connections& and trips.

• haker J desander over load.

INDICATIONS*• >enerally occurs in surface hole.

• "an occur while drilling or tripping.

•

udden pack off without warning.• "irculation impossible.

FIRST ACTION*• Apply low pump pressure (*@@-0@@ psi)

• Iar down with ma8imum trip load.

• Apply tor7ue with caution.

PREVENTIVE ACTION*• "ontrol fluid loss to provide an ade7uate filter cake.

• "ontrol drill suspected one.

• #se high vis sweeps.

• pot a gel pill before P?.• ,inimie trip speed.

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INDICATIONS OF UNCONSOLIDATED FORMATION


• DRILLING ncreasing erratic ncreasing&erratic ncreasing • Pressure surges.


urge to start

circulation ♦ ?ole fill

TRIPPING OUTncreasing&erratic.ver pull off slips

wabbing

TRIPPING INncreaseing set

down weight.

!egins at depth of

problem formation.


(ACK REA'ING ver pull off slips. ncreasing&erratic ncreasing


tring pistoning.


PU'PING OUTncreasing&erratic.

ver pull off slips. ncreasing


tring pistoning.



SHAKER

TRENDS

<arge volume of sand over shakers. and trap and desander over load.

LOGGER

TRENDS<arge 7uantity of sand in samples. Prognosed unconsolidated formation.

'UD

TRENDSncrease in mud weight and plastic viscosity. ?igh S sand content.

PREVENTIVE ACTION• Provide an effective filter cake for the hydrostatic overbalance to R push against R

and stabilie the formation.

• f possible& avoid e8cessive circulating time with the !?A oppositeunconsolidated formations to reduce hydraulic erosion.

• low down tripping speed when the !?A is opposite unconsolidated formations

to avoid mechanical damage.

• tart and stop drill string slowly to avoid pressure surges to unconsolidated

formations.

• "ontrol drill the suspected one to allow time for filter cake build up& minimie

annulus loading and to minimie annulus friction pressure.

• #se sweeps to help keep the hole clean.

• !e prepared for shaker& desilter& and desander over loads.

• ,inimie seepage loss with fine lost circulation material through these intervals.

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FRACTURED FOR'ATION"A#;$

• 6aturally fractured formations.

• Pieces of formations fall into the wellbore and 'am the drill string.

.ARNING*

• Prognosed fractured limestone& shale andor faults.

• <ikely to occur as formation is drilled.

• ,ud logger formation evaluation.

• !locky caving at shaker.

• ?ole fill on connections and trips.

INDICATIONS*

• <ikely during trips& possible while drilling.

• udden and erratic tor7ue and drag likely 'ust before sticking.

• "irculation may restricted.

FIRST ACTION*

• Do not apply tor7ue. Iar down with ma8imum trip load.

• "irculate high density high viscosity sweeps.

• pot acid if stuck in limestone.

PREVENTIVE ACTION*

• "irculate hole clean before drilling ahead.

• ,inimie seepage loss.

• low trip speed before !?A enters suspected one.

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INDICATIONS OF FRACTURED FORMATION


• DRILLINGudden& increasing

erratic udden& erratic 6o change

♦ CONNECTIONver pull off

slips 6o change ♦ ?ole fill

TRIPPING OUTncreasing&erratic.

ver pull off slips

TRIPPING INncreaseing setdown weight.

!egins at depth of

problem formation.


(ACK REA'INGver pull off slips.ncreasing& erratic

ncreasing&erratic 6o change Drag increase when

pumping.

PU'PING OUTver pull off slips&ncreasing&erratic.

6o change Drag increase when

pumping..


SHAKER

TRENDS

!locky or angular rock fragments.

LOGGER

TRENDSame as shaker trends. Possible offset well data clues. Prognosed fractured.

'UD

TRENDS 6o change.

PREVENTIVE ACTION

NOTE*/ith fractured formations& maintaining a good 7uality filter cake can help to supportthe formation in some cases. >enerally fractured formations re7uire time to stabilie.

Prior to this& the problem must be controlled with ade7uate mud properties& sweeps

and sufficient circulation time to keep the hole clean& ther recommendations$

• "irculate the hole clean before drilling ahead.

• 4estrict tripping speed when !?A is opposite fractured formations and fault

ones.

• tart and stop drill string slowly to avoid pressure surges to the wellbore.

• Anticipate reaming during trips. 4eam fractured one cautiously.

• !e prepared for the potential of lost circulation when drilling fractured formations.

• Problem likely to stabilie with time.

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CE'ENT (LOCKSCAUSE*

• "ement becomes unstable around casing show& open hole s7ueee plug or kick off

plug.

• ?ard cement chunks fall into the wellbore and 'ams the drill string.

.ARNING*

• ;8cessive casing rat hole.

• "ement s7ueee 'ob.

• "ement kick off plug.

• "ement caving at shaker andor in mud logger samples.

INDICATIONS*

• Problem can occur any time.

• udden& erratic tor7ue and drag 'ust before sticking.

• "irculation possible.

FIRST ACTION*• Attempt to break chunks with 'arring and tor7ue.

• Iar in the opposite direction of string movement prior to sticking.

• Apply 'arring force J tor7ue gradually.

• "irculate high density& high viscosity sweeps.

PREVENTIVE ACTION*

• ,inimie casing rathole.

• Allow sufficient curing time.

• 4eam casing show and open hole plugs thoroughly before drilling ahead.

• low trip speed before !?A enters casing show or plug depth.

PREVENTIVE ACTION• <imit casing rathole to minimie a source of cement blocks.

• everal s7ueee 'obs at the casing shoe increases the potential for cement blocks.

• Allow sufficient cement curing time before drilling out.

• 4eam casing rathole and open hole cement plugs slowly and thoroughly before

drilling ahead.

• ,aintain sufficient distance between the paths of platform wells to reduce the

possibility of cement blocks.

• 4educe tripping speed when !?A is entering the casing shoe or opposite open

hole cement plugs.• tart and stop the drill string slowly to avoid pressure surges to the wellbore.

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SOFT CE'ENTCAUSE*

• "irculation is attempted with the bottom of the drill string in soft cement 9

• Pump pressure causes the cement to flash set.

• ?igh penetration rate when cleaning out soft cement.

.ARNING*

• %ripping in hole after setting an open hole cement plug or after a cement 'ob.

• et down weight occurs above the theoretical top of cement.

INDICATIONS*

• ccurs as pump pressure is applied.

• "irculation highly restricted or impossible.

FIRST ACTION*

• !leed trapped pump pressure.

• Iar up with ma8imum trip load.

PREVENTIVE ACTION*

• Known cement set time.

• f set down weight is observed while 4?& pull * stands before circulating.

• tart circulation * stands above top of cement.

• "ontrol drill when cleaning out cement.

PREVENTIVE ACTION• Know the calculated top of cement ( %" ) before tripping in hole.

• Do not rely on the weight indicator to find the top of cement.

• !egin washing down * stands above the theoretical top of cement.

• f set down weight is observed when tripping in hole after cement operation& set back * stands before attempting circulation.

• Pre-treat the mud system with chemicals prior to drill out cement.

• :erify cement compressive strength with the cement company before drilling out.

• "ontrol drill when cleaning out soft cement.

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DIFFERENTIAL STICKING

CAUSES*• Drill string contacts a permeable one.

• /hen string movement stops& a static filter cake develops.

• ?igh over balance applies a differential sticking force to the drill string contact

area.

.ARNING*• Prognosed low pressure sands.

• <ong un stabilied !?A sections.

• ncreasing over pull& slack off weight or tor7ue to start string movement.

INDICATIONS*• ccurs after a period of no string movement.

• tring can not be rotated or moved.

•

"irculation unrestricted.FIRST ACTION*• Apply tor7ue and 'ar down with ma8imum trip load.

• pot a pipe-releasing pill if the string does not 'ar free.

PREVENTIVE ACTION*• ,aintain minimum re7uired mud weight.

• Keep string moving when !?A is opposite suspected ones.

• ,inimie seepage loss in low-pressure ones.

• ,inimie unstabilied !?A sections& use spiral D" J ?/DP.

• "ontrol drill suspected ones.

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INDICATIONS OF DIFFERENTIAL STICKING


• DRILLING Possible increase 6o change 6o change

♦ CONNECTIONncreasing over pull off slips.

6o change

TRIPPING OUTncreasing over pull off slips.

TRIPPING INncreasing over

pull off slips.

(ACK REA'INGncreasing over

pull off slips. 6o change 6o change

PU'PING OUTncreasing over pull off slips..

6o change


SHAKER

TRENDS

6o change

LOGGERTRENDS ?igh overbalanced. Permeable formation depth. Permeability data to estimatestricking potential.

'UD

TRENDS

ncreasing mud weight. ncreasing plastic viscosity and low gravity solids.

?igh AP water loss.

PREVENTIVE ACTION• Design the casing program to minimie overbalance to shallower hole formations.

• <imit mud weight to minimum re7uired for hole stability and well control.

• ,aintain fluid loss within specifications.

• ,inimie !?A length when possible.

• <imit the length of un stabilied !?A. #se spiral drill collars.

KEEP THE STRING MOVING. "onsider rotating the string during drilling and

tripping connections while !?A is potential sticking ones.

• Preplan to minimie the down time for operations that re7uire the sticking remains

static (surveys& minor repairs. ;tc.).

• n ones with high sticking potential& minimie seepage loss with plugging agents.

• Keep a pipe-releasing pill ready at the well site when differential sticking potential

is high.

8/13/2019 57172797-Stuck-Pipe (2)


.ELL (ORE GEO'ETRY?ole diameter andor angle relative to !?A geometry andor stifness will not allow

passage of the drill string.

BHA CHANGE DIRECTION / ANGLE CHANGE / HOLE ID DECREASE

STIFF

ASSE'(LY

K;1 ;A% ,"4 D><;> <;D>;

,!<; #6D;4>A#>;

24,A%6. ?<;

STIFF ASSE'(LY*CAUSE*• %he stiff !?A can not negotiate hole angle direction changes and becomes

'ammed.

.ARNING*• Doglegs present.

• Pulled stabiliers out of gauge.

• A new !?A design is picked up.

• udden set down weight.

INDICATIONS*

• ,ost likely to occur when 4?.• !?A at direction angle change depth.

• #nrestricted circulation.

FIRST ACTION*• f moving down when sticking occurred & 'ar up with ma8imum trip load& do not

apply tor7ue.

• f moving up& tor7ue up and 'ar down with ma8imum trip load.

PREVENTIVE ACTION*• ,inimie !?A changes& consider a reaming trip.

• <imit dogleg severity.

• low trip speeds before !?A enters suspected one& plan to ream.• <imit set down weight.

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KEY SEAT

CAUSE*• Abrupt change in angle or direction in medium soft medium hard formations.

• ?igh string tension and pipe rotation wears a slot into the formation.

•

/hile P?& the drill collars 'am into the slot..ARNING*• ?igh angle dogleg in upper hole section.

• <ong drilling hours with no wiper trips through the dogleg section.

• "yclic over pull at tool 'oint intervals on trips.

INDICATIONS*• ccurs only while P?.

• udden over pull as !?A reaches dogleg depth.

• #n restricted circulation.

• 2ree string movement below key seat depth possible if not stuck.

FIRST ACTION*• Apply tor7ue and 'ar down with ma8imum trip load.

• Attempt to rotate with low over pulls to work through dogleg.

PREVENTIVE ACTION*• ,inimie dogleg severity to + deg@@T or less.

• <imit over pulls through suspected intervals.

• Plan reamer andor wiper trips if a dogleg is present.

• 4un string reamer or key seat wiper if suspected.

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8/13/2019 57172797-Stuck-Pipe (2)


LEDGES

CAUSE*• nterbedded formations. oft rocks H wash out& hard rocks H in gauge.

• 2ractured faulted formations.

•

tabilier blades and tool upsets become stuck under ledges..ARNING*• Prognosed hard soft interbedded formations.

• Prognosed fractured faulted formations.

• udden erratic over pull.

INDICATIONS*• >enerally occurs when tripping.

• Possible when picking up for a connection.

• >enerally associated with micro doglegs.

• "irculation un restricted.

FIRST ACTION*• f moving up when sticking occurred& apply tor7ue and 'ar up with ma8imum trip

load.

• f moving down& 'ar up with ma8imum trip load& do not apply tor7ue.

PREVENTIVE ACTION*• ,inimie direction angle changes.

• ,inimie !?A changes.

• Plan reaming trips& ream with caution.


8/13/2019 57172797-Stuck-Pipe (2)


'O(ILE FOR'ATIONS

CAUSE*• ver burden weight s7ueees plastic salt or shale into the well bore.

• %he !?A becomes 'ammed in the under gauge hole.

.ARNING*• Prognosed salt or plastic shale.

• udden increases in over pull or set down weight.

• udden tor7ue increases with fast moving plastic formations.

INDICATIONS*• >enerally occurs while P?.

• Possible when 4? after a long period out of the hole.

• Possible while drilling if formation moves fast.

• ticking occurs when !?A at plastic one depth.

• "irculation un restricted or slight restriction possible.

FIRST ACTION*• f moving up apply tor7ue and 'ar down with ma8imum trip load.

• f moving down& 'ar up with ma8imum trip load& do not apply tor7ue.

• pot fresh water if in salt. (consider well control).

PREVENTIVE ACTION*• elect the correct mud system.

• ,aintain sufficient mud weight.

• Plan fre7uent reamingwiper trips.

• "onsider eccentric PD" bits.



8/13/2019 57172797-Stuck-Pipe (2)


UNDERGAUGE HOLE

CAUSE*• Drilling hard abrasive rock wears bit gauge protection.

• "ored hole section undergauge.

• 6ew bit is 'ammed into the undergauge hole section

.ARNING*• Prognosed abrasive sands.

• Pulled bit and stabiliers are undergauge.

• /hen PD" bit follows roller cone bit run.

• 4unning in hole after coring.

INDICATIONS*• ccurs only when 4?.

• udden set down weight.

• !it stuck near bottom or at top of core hole section.• "irculation un restricted or slightly restricted.

FIRST ACTION*• Iar up with ma8imum trip load. Do not apply tor7ue.

PREVENTIVE ACTION*• >auge pulled bit and stabiliers.

• 6ever force the bit through tight spots.

• 4eam the last + 'oints to bottom. !egin reaming + 'oints above core hole section.


8/13/2019 57172797-Stuck-Pipe (2)


T5e !n%!4t!"n' "6 7e&&("re #e"*etr8 +r"(&e*' re "('er9e% "n&8 75en BHA !'

*"9!n# !n t5e 5"&e 'e4t!"n 7!t5 t5e #e"*etr8 +r"(&e*,

INDICATIONS OF WELLBORE GEOMETRY PROBLEMS


• DRILLING ncreasing& erratic ncreasing& erratic 6o change• ,omentary over pull J set

down

♦ CONNECTIONncreasing&erratic

urge to startcirculation

♦ ,omentary over pull J set

down

TRIPPING OUT

ncreasing& erraticover pull with

!?A at problemone.

,omentary over pull J set

down

TRIPPING IN ncreasing& erratic.et down weight.

!egins at depth of problemformation.

(ACK REA'ING erratic erratic over pull 6o change ,omentary over pull

PU'PING OUTncreasing& erraticover pull

6o change ,omentary over pull


SHAKER TRENDS 6o change

LOGGER TRENDS 6o change.

'UD TRENDS 6o change.

PREVENTIVE ACTION• ptimie !?A design (run only what is re7uired ) and when possible& minimie !?A stiffness.

• Plan a reaming trip if new !?A is locked up andor a hole geometry problem is suspected.

• low down trip speed before !?A enters kick off or doglegs depth& depth of micro dogleg andor

ledges& mobile formation.

• ,inimie dogleg severity to + deg@@T or less. ,inimie rotating hours below a sharp dogleg

without a wiper or reaming trip.• "onsider using key seat wipers or drill string reamers if a key seat is suspected.

• <imit the length of rathole to avoid key seating the bottom of the casing. Do not start angle

building operations too close to the shoe.

• ,inimie sharp& fre7uent well bore course changes.

• Avoid prolonged circulation in suspected micro dogleg section to prevent hole wash out and

forming ledges.

• /ith mobile salts consider using a slightly under saturated mud system to allow a controlled wash

out. f necessary increase the mud weight to help slow down salt intrusion.

• "onsider drilling mobile salts with eccentric PD" bits. Plan regular wiper trips to keep the holesection open.

• #se hard faced stabiliers and select bits with e8tra gauge protection if abrasive formations are

drilled.• >auge the old bit and stabiliers as well as the bit and stabiliers picked up.

8/13/2019 57172797-Stuck-Pipe (2)


• !egin reaming 'oint above a cored hole section. As standard. Practice& ream the last stand or +

'oints back to bottom on all trip.

STUCK PIPE FREEING .ORKSHEET SU''ARI5ATION*

SUMMARIZATION FOR GENERAL INSTRUCTION TO BE FOLLOWED IN CASE OF STUCK PIPE

INITIAL ACTION

$9 If sti<ing o<<u!!7 ;:il7 "o>ing up #ppl= to!u7 #n @#! o;n ;it: "#i"u" t!ip lo#9

If sti<ing o<<u!!7 ;:il7 "o>ing o;n o not #ppl= to!u7 #n @#! up ;it: "#i"u" t!ip lo#9

?9 Stop o! !7u<7 <i!<ul#tion ;:7n <o<ing t:7 #n ;:7n @#!!ing o;n9

NOTE* In<!7#s7 pu"p p!7ssu!7 ;ill INCREASE t:7 :=!#uli< @#! up 6 &7lo; J DECREASE t:7

o;n 6 &7lo;9

19 Continu7 @#!!ing until t:7 st!ing is f!77 o! #n #lt7!n#ti>7 7<ision is "#79 )#!!ing fo! $%8 :ou!s "#=

&7 n7<7ss#!=9

SECONDARY ACTION

• Spot #<i if stu< in li"7 ston7 o! <:#l9 Spot f!7s: ;#t7! ;it: "o&il7 s#lt9

WHEN THE STRING COMES FREE:

In<!7#s7 <i!<ul#tion to "#i"u" !#t7 !ot#t7 #n ;o! t:7 st!ing 9

R7#" + &#< !7#" t:7 :ol7 s7<tion t:o!oug:l=9

Ci!<ul#t7 t:7 :ol7 <l7#n9

STUCK WHILE MOVING UP OR WITH STRING STATIC

ACTION TO ESTABLISH CIRCULATION

Appl= lo; pu"p p!7ssu!7 /?%%-%% psi39 '#int#in p!7ssu!7 if !7st!i<t7 <i!<ul#tion is possi&l79

DO NOT )AR UP APPLY TORUE

Sl#< off to 'ABI'U' s7t o;n ;7ig:t9 Allo; suffi<i7nt ti"7 fo! # :=!#uli< @#! to t!ip /-, "in fo!

long <=<l79 S77 @#! "#nu#l39 If t:7 st!ing o7s not <o"7 f!779 DO NOT )AR UP )#! DO.N until t:7 st!ing <o"7s f!77 o! #n

#lt7!n#ti>7 7<ision is "#79 )#!!ing o;n fo! $%8 :ou!s "#= &7 n7<7ss#!=9

WHEN CIRCULATION IS ESTABLISHED:

Slo;l= in<!7#s7 pu"p sp77 to "#i"i7 !#t79 .:7n possi&l7 ;o! t:7 st!ing #n <i!<ul#t7 t:7 :ol7

<l7#n f!o" &it 7pt:9

R7#" t:7 s7<tion until t:7 :ol7 is <l7#n9

If POOH to log #n + o! !un <#sing !7tu!n to &otto" #n <i!<ul#t7 t:7 :ol7 <l7#n9

8/13/2019 57172797-Stuck-Pipe (2)


SUMMARIZATION FOR GENERAL INSTRUCTION TO BE FOLLOWED IN CASE OF STUCK

PIPE WHILE MOVING UP OR WITH STRING STATIC

INITIAL ACTION

$- <i!<ul#t7 #t "#i"u" #llo;#&l7 !#t79

?- .o! 'ABI'U' li"it to!u7 o;n to t:7 stu< 7pt: #n :ol t:7 to!u7 in t:7 st!ing9

1- Stop o! !7u<7 t:7 pu"p sp77 to "ini"u"9

- Sl#< off to 'ABI'U' s7t 6 o;n li"it9

2- Allo; suffi<i7nt ti"7 fo! # :=!#uli< @#! to t!ip /-, "in fo! long <=<l79 S77 @#! "#nu#l39

,- If st!ing o7s not <o"7 f!77 :ol to!u7 in t:7 st!ing #n <ontinu7 @#!!ing o;n ;it: "#i"u" t!ip

lo#9

SECONDARY ACTION

• If t:7 st!ing o7s not <o"7 f!77 #ft7! 2 6 $% @#! &7lo; <ontinu7 @#!!ing ;:il7 p!7p#!ing # pip7 !7l7#sing

pill9

WHEN THE STRING COMES FREE:

Rot#t7 #n ;o! t:7 st!ing 9

Ci!<ul#t7 #t "#i"u" sp779

C:7< t:7 poo! "u sp7<ifi<#tions9

STUCK WHILE MOVING DOWN

ACTION TO ESTABLISH CIRCULATION

Appl= lo; pu"p p!7ssu!7 /?%%-%% psi39 '#int#in p!7ssu!7 if !7st!i<t7 <i!<ul#tion is possi&l79

DO NOT )AR DO.N APPLY TORUE

Appl= 'ABI'U' o>7! pull to @#!9 Allo; suffi<i7nt ti"7 fo! # :=!#uli< @#! to t!ip /- "in fo! long

<=<l79 S77 @#! "#nu#l39 If t:7 st!ing o7s not <o"7 f!779 DO NOT )AR DO.N )#! UP until t:7 st!ing is f!77 o! #n #lt7!n#ti>7

7<ision is "#79 )#!!ing up fo! $%8 :ou!s "#= &7 !7ui!79

WHEN CIRCULATION IS ESTABLISHED:

Slo;l= in<!7#s7 pu"p sp77 to "#i"i7 !#t79 .:7n possi&l7 ;o! t:7 st!ing #n <i!<ul#t7 t:7 :ol7

<l7#n f!o" &it 7pt:9

R7#" t:7 s7<tion until t:7 :ol7 is <l7#n9

Continu7 RIH until 7<7ssi>7 s7t o;n ;7ig:t is o&s7!>7 <i!<ul#t7 t:7 :ol7 <l7#n9

8/13/2019 57172797-Stuck-Pipe (2)


NOTE*Sin<7 there are many causes of the drill string becoming stuck in a bore hole.

dentifying the cause will be the key to determine the 7uickest and most economical

method of getting the pipe free.

%he following is a list of the various ways pipe may become stuck$

) Differential pressure sticking.

*) "uttings andor weight material settling.

+) !ridging due to an unstable well bore.

0) Key-seating.

3) oft clay or salt packing off the annuls.

9) ,ud or cement solidification.

=) Iamming bit into under gauge hole.

) Iunk dropped into the hole.

B) "ollapsed casing.

CO''ENTS*%he first si8 ways of pipe becoming stuck are directly or indirectly related to the

drilling fluid being used.

%he last three ways are purely mechanical.

f all the causes listed above& differential pressure sticking is normally the most

fre7uent and re7uires special attention. t is also the only cause that normally re7uires

the assistance of a mud engineer to prepare and spot a soak solution.

IDENTIFYING DIFFERENTIAL PRESSURE STICKING*) %he drill string was stationary when it became stuck.

*) A permeable formation is e8posed in the well bore.

+) %he hole can be circulated with normal pump pressure.

0) %he drill string can not be reciprocated or rotated.

3) %he mud has high solids and high fluid loss.

9) %he mud weight has been increased recently.

'ETHODS OF FREEING DIFFERENTIALLY STUCK PIPE*%he following information will deal with the remedies available to free differential

pressure stuck pipe. %he area of contact increases as the filter cake with time& thus

produces greater sticking forces. !ecause of this& a 7uick determination of the cause

followed by an immediate remedial step is imperative.

) pot a PP;-<AF soak solution ui<l=9 %he probability of freeing differentially

stuck pipe is inversely proportional to the time between actual sticking and final

spotting of the solution.

*) /ork pipe by tripping the 'ars both up and down if possible.

+) 4educe mud weight if possible.

0) 4un a drill stem test tool and relieve pressure.

3) Pump a slug of water down the drill string and let it u-tube.9) Pump some air to reduce the hydrostatic head.U

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%he buoyant weight of the pipe was 30&@@@ lbs. %o make the pipe in tension & the

initial pull 9@&@@@ and reference point was marked. An additional pull of 0@&@@@

pounds was made and the pipe stretched by an amount of +B.= inches.

C#l<ul#t7 t:7 f!77 pointM

SOLUTION*

(=+3&@@@) (9.9) (+B.=)

2p O O *&@@ ft.

(0@&@@@)

r

#sing fig. @.0.+

) ;nter the chart with 0@.@@@ pounds differential pull as left vertical

scale.

*) ,ove horiontally to the right until the 0 (9.9) is reached.+) 2rom above intersection& move vertically down and read +@3 ftinch.

2p O (+@3) +B.= O *&@ ft.

CALCULATIONS FOR SPOTTING PIPE-LAB SOAK SOLUTION

) After determining where you are stuck & with strong indications that you are

differentially stuck & a calculation must be made to determine how much soak

solution to mi8. ne would normally want to mi8 enough to cover the entire stuck

area and leave enough the drill string to move at least barrel every +@ minutes

for several hours& to make sure you keep the stuck one covered.

*) /e must also make calculations so that the soak solution will be spotted properly.

+) /e should also anticipate additional or e8cess pump pressure if we are spotting alighter soak solution than the mud in the hole.

EBA'PLE

Gi>7n*

) open hole to *&@@T.

*) 0 (9.9) D.P. *&@@@ long.

+) @@ ft. of 9 F * N drill collars.

0) tuck below *&@@T so we want to cover entire drill collar interval.

3) /e want enough soak solution left inside the drill string to move barrel every

+@ minutes for @ hours.

9) Pump output is @.+ bblstk.=) urface lines from pits to rotary table holds 3 bbls of mud.

) oak solution weights =.* lb.gal and mud weight 0 lb.gal.

B) Pump pressure while circulating 0 lb.gal at 0@ P, is &*@@ psi. pressure drop

inside the drill pipe is +@ psi@@@ ft. while inside the drill collar is +9 psi@@ ft.

Fin*

) !arrels of soak solution needed O - - - - - - - bbls

*) Pump stroke re7uired to spot the leading edge of the PP;-<AF soak solution at

the top of the collars O - - - - - - - strokes

+) ,a8imum pump pressure while moving soak solution down drill string at 0@

P,.

8/13/2019 57172797-Stuck-Pipe (2)


Solution*

W (.3)* H (9.*3)* (@@)

) A) :olume around drill collars O O *3. bbls.

@*B

!) :olume inside the drill string O (* bbl +@ min) (9@ min hr) (@ hrs)

O @ bbls

") %otal solution needed O @ 5 *3. O 1,9% &&ls

*) A) "apacity of surface lines O 3 bbls.

!) "apacity of D.P. O (@.@0** bblft) (*&@@@ ft) O [email protected] bbls.

") "apacity of D.". O (*.*3* @*B) F @@ F +.B0 bbls.

D) Annular capacity around D.". (above) O *3. bbls.

;) %otal fluid to move to spot O *@3.+ bbls.

*@3.+ bbls2) Pump strokes to spot O O &3@ stks

@.+ bblstk

+) A) ,a8imum pump pressure will occur when soak solution is longest inside drill

string& which will occur when the drill collars are full and the remainder is in the

drill pipe.

2rom *.". we find the capacity of the drill collars is +.B0 bbls& therefore if we

have +9 bbls of soak solution we must have +9 H +.B0 O +*.@9 bbls inside the drill

pipe.!) +*.@9 bbls @.@0** (bblft) O *&*33 ft. of soak solution in the drill pipe.

") %otal length of soak solution O *&*33 ft. 5 @@ ft. O +&@33 ft.

D) Differential density between mud eight and soak solution weight O 0 H = O 9.lb.gal.

;) <ength of soak solution times differential density times @.@3* O (+&@33 ft.) (9.

lb.gal) (@.@3*) O &@@ psi & which is the differential hydrostatic pressure

2) Decrease in pressure loss due to the length of soak solution O (+@) (**33@@@) (9.

0) 5 (+9) (@@@@) (9.0) O =+ psi.

>) %he e8pected pump pressure when the soak solution reaches the bit O 3== 5 *@@ H

=+ *9@0 psi.

NOTE*

If ;7 stopp7 pu"ping ;it: t:7 l7#ing 7g7 of t:7 so# solution #t t:7 &it ;7

s:oul s77 $2 psi on t:7 st#n pip7 g#ug79

PREVENTIVE 'EASURES!oth a positive differential pressure and a contact area& for this pressure to work on& are

necessary for pipe to become differentially stuck. %herefore& any thing that will reduce

contact area or differential pressure will help considerably to minimie or prevent

differential sticking.

) Keep mud weight to a safe minimum.

*) Keep solids content and fluid loss to an economic minimum

+) ,inimie the time during which the drill string is not being rotated or reciprocated.

0) #se a good mud lubricant such as <#!; 3+.

3) #se spiral or s7uare drill collars

9) #se heavy weight drill pipe to compensate for loss of weight by using smaller or

shorter drill collars.

=) #se good drilling and pipe handling practices.

8/13/2019 57172797-Stuck-Pipe (2)


) ptimie stabilier placement to minimie the contact area between the !?A and the

side of the well bore.

FIGURE $9 STUCK PIPE CAUSES AND RECO''ENDED FREEING

'ETHODS

.%#"K PP;

,echanical Differential ticking

Keyeating

/ellbore>eometry

nade7uate?ole "leaning

Iunk or "ollapsed

"ement4elated

tringIammed

tringIammed

?olePacked ff

tringIammed

tringIammed

/ork tringDown J

/ork tring#p if 4?

/ork tringDown if P?

/ork tringDown to ;stablish

r mprove"irculation

/ork tringDown J #p

/ork tring#p or Down

Pump Acid if Available

tringIammed

lump tringJ 4otate

4educe ,ud/t

#tilie

potting

57172797-stuck-pipe (2)

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