Workover Presentation [PDF]

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WELCOME TO PRESENTATION By



Prosanna Hazarika Utpal Kr. Doley DY.CED



WORK OVER OPERATION  The operations involved in maintenance and servicing, repairing, installation of down - hole production equipment etc in a cased hole / production well is termed as work-over operation



Rig Selection  Mobile work - over rig is used for this purpose. The rig is selected on the basis of total expected load to be handled



Rig in Operation in OIL  Presently OIL has 13 nos. of in house work – over rigs  In addition 2 nos. of Chartered Hired work over rigs are in operation.



Details of Mobile Work over rig SL. NO



OUTFIT



Rated Horse Power



Date of commissioning



Mast Height



Work over Depth, 2 7/8" OD Tbg



Drilling Depth, 4 1/2" OD Drill Pipe



1



BHEL - B



235 HP, MEDIUM DUTY



25/06/1988



102 ft



4572 M



1830 M



2



BHEL - C



235 HP, MEDIUM DUTY



15/03/1989



102 ft



4572 M



1830 M



3



BHEL- D



235 HP, MEDIUM DUTY



31/03/1989



102 ft



4572 M



1830 M



4



CARDWELL - B



250 HP, MEDIUM DUTY



20/10/1983



96 ft



4875 M



1830 M



5



CARDWELL - C



250 HP, MEDIUM DUTY



28/09/1983



96 ft



4875 M



1830 M



6



CARDWELL- K - 600



400 HP, HEAVY DUTY



10/6/1985



112 ft



7315 M



3000 M



7



KREMCO K- 600



250 HP, MEDIUM DUTY



18/02/1986



96 ft



3658 M



2000 M



8



SKYTOP - B



250 HP, MEDIUM DUTY



4/4/1978



95 ft



5185 M



2286 M



9



RG - 600 - A



600HP, HEAVY DUTY



21/02/2009



115 ft



6000 M



2500 M



10



RG - 600 - B



600HP, HEAVY DUTY



6/11/2008



115 ft



6000 M



2500 M



11



RG - 600 - C



600HP, HEAVY DUTY



25/11/2008



115 ft



6000 M



2500 M



12



RG - 600 - D



600HP, HEAVY DUTY



14/12/2008



115 ft



6000 M



2500 M



13



RG - 600 - E



600HP, HEAVY DUTY



7/10/2009



115 ft



6000 M



2500 M



14



ZJ - 20 (CH)



600HP, HEAVY DUTY



14/04/2008



115 ft



6096 M



2500 M



15



ZJ – 30 (CH)



750HP, HEAVY DUTY



23/02/2008



124 ft



7000 M



3000 M



Work-over Rig



Guy lines



Reasons for Work-over  To prevent water coning  To prevent excessive gas production in an oil well  To enhance production



 To control sand problems  Re-completing a new zone / reservoir  Completing in multiple reservoir



 Down hole Equipment & Cement repair



Contd…



Reasons for Work-over  To eliminate excessive water or gas production  To repair mechanical failure down hole equipments  To gain additional production through recompletion



 To evaluate potentially productive zones  To clean scaling of Tubing & Casing  To clean perforation plugging



 To replace production string



Contd…



Reasons for Work over  To control sand entering well bore from formation  To increase formation permeability  To install artificial lift system, bottom hole pump etc.  To repair or replace well head  Conversion of well



Work -over Operations  Re-perforation or extention perforation  Plug back and perforation higher up  Isolation Repair  Acidization  Cleaning of production string  Gravel pack  Casing repair and recovery



of



Contd…



Work over operations  Milling Bridge Plug, Drilling Cement Plug



 Fishing  Sand cleaning  Well head repair or replacement  Installation of artificial lift system, bottom



hole heater etc.  Cleaning of perforation, scaling in casing & tubing



Work over operations  Conversion of low producing well to water injection for increasing reservoir pressure.



 Conversion of dead well to water disposal well for pumping back formation water producing along with oil



Steps in Work-over Operation  Well Selection  Work-over Policy Preparation  Site Preparation  Security Deployment  Static and Outfit mobilization & placement  Work-over fluid preparation / collection  Well killing  Operations as per well plan Contd…



Steps in Work-over Operation  Rig-up Mast



 Well killing  Rig down of X-mass tree & rig up of BOP  Circulation  Tripping of Tubing  Specified jobs  Final Running in of Tubing  Rig down BOP



Contd...



Steps in Work-over Operation  Rig up X-mass tree  Enliven the well and Production Department.



hand over to



 Rig down Mast  Mobilize the Rig to new location as per plan



Down Hole Tools & Equipments Rotovert / Scrapper



Down Hole Tools & Equipments Flat Bottom Mill



Down Hole Tools & Equipments Reverse Circulating Junk Basket(RCJB)



Precautions during Rig-up & Rig- Down  All loose parts and tools shall be securely fastened.  High pr circulating fluid lines shall be securely bolted down  During R/downing the well head shall be protected against damage from sliding or falling object.  The raising and installation of heavy load shall be done during daylight hours unless adequate general lighting arrangements are provided at the place of work.



Common Terms in Drilling & Work-Over rigs  Derrick Platforms & floors  Crown Block & Traveling Block  Ladders & Guardrails & covers  Emergency escape device  Weight Indicator  Safety belts  Draw-works  Cathead & cat line  Tongs  Casing lines



MAIN EQUIPMENTS ARE  W/O RIG including mast & substructure  R / Table & Hoisting Equipments



 Static including bunkhouses



pumps,



 Precautions against Blowout  BOP & Controlling Unit  Well Control  Fire fighting equipments  Fencing & well security



tanks,



Safety Requirements  An area within 30 m of the well should be danger zone. All electrical equipments should be de - energized in case of emergency.  Adequate arrangements for fire fighting should be provided & portable fire extinguishers are available at different places. Crew must be well conversant with the use of fire extinguishers / fire pump



GENERAL PRECAUTIONS  A standard railings should guard every open sided D/Floor & D/board



 Rig should be provided with ladder arrangements.  Emergency escape device & Fall prevention device should be incorporated.



 To use Personal protection equipment (PPE) by every crew personnel.



GENERAL PRECAUTIONS  The well head should be well protected against falling objects  The D/Floor should be reasonably clean of oil, mud ,so as to prevent from slipping.  Floor saver and crown saver must be checked every day.  F/brake & Hydrometric brake system should be working condition always.  Casing line inspection must be carried out.



Safety Practice  At the beginning of every shift the instruments and controls at driller’s console, D/W’s, pumps, casing line, catline & BOP shall be examined by the SDE & he shall satisfy himself that these are in good working order  No person remains in position of danger at or near the rotary table during operation.



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