Workover Presentation

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.

Thanks