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 re-completion

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 of perforation

Plug back and perforation higher up

Isolation Repair

Acidization

Cleaning of production string

Gravel pack

Casing repair and recovery

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 hand over to Production Department.

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 pumps, tanks, bunkhouses

Precautions against Blowout

BOP & Controlling Unit

Well Control

Fire fighting equipments

Fencing & well security

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