fishing in drilling operations

8/17/2019 Fishing in drilling operations

1/19

hing Techniques for Drilling Operations

1


2/19

Defnition o Fishing Types o Fish

Causes o Fish To fsh or not to fsh

Dierent methods torecover fsh Fisher Man

Conclusions 2


3/19

Fish:- fsh is any undesira!le o!"ect #such as $ pipe $tools$ %ire line $%hich can not

!e removed rom a !orehole %ith ordinarypractices&

Fishing:- Fishing is any action ta'en

%hich attempts to remove a fsh rom a!orehole& For e(ample $ lo%ering a magnetinto the !ore hole or the purpose oremoving a cone lost rom a drill !it is

fshing& )emoving a !ro'en %ire line and a *


4/19

Types of sh:-

Tu!ular :-drill pipe$ drill collars$ casing$logging tools$ test tools$ and tu!ing&

Miscellaneous :- %ire line$ hand tools$

tong parts$ slip segments$ !it cones$chains$ and "un'

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5/19

CAUSES OF FISH:,erhaps the most important aspect ofshing is to ascertain the events %hichcaused the fsh to occur& ithout'no%ing the causation correct tool

selection and procedures %ill !eimpossi!le&

.perator error

/0uipment decline


6/19

DIFFERENTIAL STICKING:

Usually occurs after the drill string is

idle.mud cake thickness is a factor as well

as excessive overbalance. not effective.

CAVING ZONE: Caused by low

density mud. big problem in horizontal

wells and high angle wells . Reactivefiltrate may be a factor in shales. Cantcirculate but may be able to move drill

string a little .

3


7/19

S!E""I#$ %O#ES: Could !e salt

or dia!etic shale&

FI"TE& CA'E: Thic' flter ca'e can

reduce the hole diameter & 4suallyoccur in consort %ith dierentialreduce flter ca'e thic'ness &&

5


8/19

E(UI)*E#T FAI"U&E: May

need to polish %ith mill & )etrieve%ith overshot&

&EDUCED )I)E DIA*ETE&:Try rolling !ac' diameter& Maysidetrac' i a mill is used& ,ro!a!ly

a!andon %ell&

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9/19

+U#': Try magnet or "un'!as'et& Try mill &Try "ets& Tryacid&

CE*E#T E&&O&: Try%ash pipe i outside & Try

mill& 7 inside use drill !it&

)AC'ET OFF: 7 can

circulate raise circulationrate& )aise viscosity i innear vertical hole& May !ea!le to %ash over &,ro!a!lysidetrac' !orehole&

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10/19

To sh or not to sh:

There are at least three popular methods or deciding

%hether to fsh or not to fsh & They are

7& Fish or no more than t%o days %ithout progress

77& 9rea' even Charts as a Decision Tool

777& /stimate o cost

1;


11/19

#O *O&E THA# T!O DA,S !ITHOUT )&O$&ESS *E

ion method !ased on drilling e(perience&

hose fshing operations in %hich the fsh not e(tracted %ithin t%o dayssuccessul fsh e(traction and sidetrac's %ere re0uired %ith the e(ceptishing operation=*& days>

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12/19

Dierent methods to recover fsh:-

Free point determination

?electing a location to !ac'- o a stuc' string o

pipe is assisted %ith a ree point tool& 7n mostcases the desira!le location to !ac' o %ill !e at acollar "ust a!ove the stuc' point &

The ree point tool identifes the depth at %hich a

stuc' string can moved and not moved&

12


13/19

-ac. /o0)roce1ure

The term !ac'-o reers to separating the ree piperom the stuc' pipe at a threaded connection at or

"ust a!ove the ree point& 7t is accomplished !yplacing an e(plosive charge=string shot2 across

the connection3 The string shot consists ofthe e4plosi5e asse67ly an1 equip6ent necessary to reach the point o detonation do%nhole& The !ac'ing o operation is perormed !yrunning the e(plosive charge on %ire line to

@et hand tor0ue is then applied andsomeoverpull is maintained until the e(plosivecharge is run to the !ac' o point&

1*


14/19

D7FF/)/that the pressure %ithinthe %ell!ore e(ceeds the pore pressure & The s'etchsho%s the mechanics o dierential stic'ing&

F&EEI#$ DIFFE&E#TIA"", STUC' )I)EThere are fve methods o reeing dierentially stuc' pipe&.ne re0uires that the mud ca'e !e destroyed& T%o are!ased on the sound principles that the pressure in the

annulus must !e reduced& The circulation o oil into theannulus is the more popular o the t%o& The procedure isto circulate a 0uantity o oil into the annulus a!ove thestuc' point sucient to lo%er the dierential pressure

!et%een the mud and the pore pressure& 1+


15/19

FI&ST *ETHOD The frst method involves circulating a volume o oilinto the stuc' pipe and displacing it into the annulus

to a location %here the oil is a!ove the stuc' point& This reduces the eective pressure at the stuc' onein the drill hole &

SECO#D *ETHOD: The second method o reeing dierentially stuc' pipeis to pump oil or %ater into the pipe and then !leed theoil or %ater rom the pipe& This procedure drops the

mud level in the annulus %hich in turn reduce thepressure o the mud at the stuc' point&

1


16/19

THI&D *ETHOD The Esoa' method & chemical %ash %hich is

designed to !rea' the flter ca'e is circulatedacross the stuc' one and is then allo%ed time toreact %ith the flter ca'e & thereater the chemical%ash %hich remained !e lo% the one isperiodically circulated across the one the one &During the soa'ing $ the drill string is stretched andrela(ed in tension & arring is through to !e o littlepractical value & signifcant variation is to slac'o and then pull on the drill string &

volume o chemical %ash o 2 to; !arrels isusually sucient&

13


17/19

FOU&TH *ETHOD popular method o reeing stuc' pipe in %hichpressure control is critical is the drill stem test method

& The essentials o the method is that the drill string is!ac'ed o "ust a!ove the stuc' one #a drill stem testtool is run$ set$ and opened a!ove the one & The testtool is pulled out o the hole and the once stuc' string

is retrieved %ith a scre% in su! or overshot&FIFTH *ETHOD

This is the 0uic'est o all & slac' o a portion o all&?lac' o a portion o or all o the %eight o the drill

string onto the stuc' one & 7ncrease the pumppressure until the saety pin in the pop o valueshears & ,ull the once stuc' string up the hole & Themechanism is that the drill string up the hole & themechanism is that the drill string is !uc'led !y the

slac' o and e(tended !y the pump pressure& The 15


18/19

ConclusionFishing is a comple( and ris'y operation& ll

mem!ers o the drilling team must contri!ute to itssuccess& The engineer must approve the selectiono tools and procedures$ 'eeping in mind %ellcontrol and saety& The geologist should supplyoset logs or the purpose o determining %ashoutareas$ and he should prepare an evaluation o the%ells progress as a prospect& 7 sucient reserveshave !een drilled a!ove the fsh$ it may !e cheaperto plug !ac'& 7 it is evident that the %ell is running

lo%$ it may !e advisa!le to a!andon it !eorethro%ing good money ater !ad& ccounting must'eep day to day costs and pro"ections %ith %hich toadvise the operations personnel %ho ultimately

must choose %hatcourse to ollo%&16


19/19

TG

fishing in drilling operations

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