
GAS AND OIL FIELD DEVELOPMENT AREA

Numerous production platforms, under - water construction work on wellheads drilling rigs, driving tenders and support vessesl exist within the Oilfield Development Areas enclosed by pecked lines. As all these features can not be charted, special caution should be exercised by vessels navigating in the vicinity. Vessels are advised not to enter these areas and those entering will do so at their own risk for which Government of India will not be liable in any way. The Government of India has established 500 -metre Safety Zone around each installation in these Oilfield Development Areas. Mariners should not enter these Safety Zones. Forther details in Notice to Mariners Special Edition Notice No 20.are as follows:

Special Notice No. 20: DEVELOPMENT OF OFFSHORE OIL AND GAS FIELDS

     
Seismic Surveys.
        
1.    	Seismic surveys for offshore oil and mineral resource explorations are conducted in and around Indian waters. Details of these surveys are generally broadcast to mariners as a Radio Navigational Warning or by Notices to Mariners. It is seldom practicable to publish details of the areas of operation except in general terms and vessels carrying out seismic surveys may, therefore, be encountered without prior notice. Seismic survey vessels operate either alone or in company and may tow a sensing device in the form of buoyant cable streamed one to two nautical miles astern. The sensing device may be on the surface or at depths down to approximately 12 metres (40 feet) and an orange buoy usually attached to the end  of  cable, displays quick flashing light and carries a radar reflector. 

2.    	In  the  process  of  the survey, repeated shock waves are created by using at any level  from  the  bottom  to  the  surface,  explosive charges, compressed air, mechanical liberators or by electrical means. Occasionally, explosive charges of up to 2000 lbs are used. The seismic surveys vessels will usually be making way through the water but sometimes stop for extended periods. 
        
3.    	Seismic survey vessels which are unable to manoeuvre are required to carry the lights and signals, described in Rule 27 of International Regulations for Preventing Collisions at Sea, 1972 and should be given a wide berth (2 to 21/2 miles). 
        
4.    	If charges are being fired by radio or electrically triggered detonators, survey vessels may suspend radio and radar transmission to avoid accidental firings. Vessels being called by light are, therefore, to answer by the same means and not by radio. 
        
5.    	Charges may  be  contained in a variety of cylinders, tubes or bags which may be marked as "Dangerous".  No attempt  to recover such items should be made and if any is inadvertently taken aboard in trawlers, etc., should be jettisoned immediately.
        
 Oil Rigs and Production Platforms.
        
6.    	There are two types of drilling rigs in use at present in Indian Offshore fields:-
        
(a)	Jack-up Rigs: -  These  are  propelled/towed  in positions where their  steel  legs  are  lowered  to  the seabed;  the  drilling platform is then jacked-up clear of the water. They are generally used in depths upto 100 metres.
         
 (b)	Dynamic Positioning Drill ships: - These are built with a tall drilling rig amidship and usually with a helicopter deck near the stern. A typical drill ship has a displacement of 14,000 tons, a length of 135m and a maximum speed of 14 Knots. For drilling in depths of less than 200 metres, 8-point anchoring system is used.  When drilling in deep water, their position is maintained by dynamic positioning equipment which enables these drill ships to keep on stations above the borehole. A feature  of  the drill ships with automated station- keeping facilities is their ability to manoeuvre accurately, with  the aid of thrusters fitted with controlled pitch propellers. These are used in depths above 200 metres.
        
Wellheads.
        
7.    	In the course of exploratory work, numerous wells are drilled to find the extent of the field. Wells which will not be required again are sealed with cement plug below the seabed and abandoned. 

8.   	 Other wells, known are suspended wells, which may be required at a later date have their wellheads capped and left with a pipe and other equipment projecting from the seabed. Such wellheads are sometimes marked by buoys to assist recovery and to warn the mariners that they are a hazard to navigation or fishing. List of unused capped pipes of oil rigs are placed at Appendix A.


Production Platforms/Water Injection/Process Platforms.
        
9.    	These are massive structure carrying drilling and production equipment, oil and gas separation and treating plants, pumpline stations, electricity generators, cranes and helicopter landing deck. They are marked by lights, fog signals, and on some platforms flares burn at times. Production Platforms are charted. Platforms stand singly or in groups, linked to each other by pipelines and bridges. Process platforms are manned round the clock and have residential accommodation. A trunk pipeline connects them to the shore/storage tanker/tanker loading buoy or a floating terminal. 

Subsea Structure / Wellheads.

10.	These structures are basically Wellheads, pipeline, etc. and manifolds installed at the seabed in deepwater area/shallow water area and need to be protected from any possible damages due to anchoring and sinking of vessels.

Loading and Unloading System.
   
11.   	A variety of moorings, generally referred to a Single Point Mooring (SPM) have been developed to enable large vessels to moor by their bows to either load or unload their cargoes. There are at present Single Buoy Moorings (SBM) moored in Bombay oilfield and at Vadinar offshore oil terminal to facilitate oil tankers to be moored for transportation of crude. 
        
 Safety Zones.
        
12.   	Under International law, a coastal state may construct and maintain on the continental shelf installations and other devices necessary for the exploration of its natural resources, establish Safety Zones around such installations and devices and take within these zones measures necessary for their protection.
        
13.   	Safety zones may extend to a distance of 500 metres around installations and other devices, measured from each point of their outer edges. Ships of all nationalities are required to respect these safety zones.
        
14.   	Several  coastal  states  have made provisions in their  National Law to cover the establishment  of  safety  zones  and  have  made  infringement  of the declared zones a criminal offence. Since the type of  offshore  installation  subject  to safety  zone  differ  from  State to State, mariners are advised always to assume the existence of a  safety  zone  unless  they  have  information  to  the  contrary. Installation and devices include fixed production platforms, mobile exploration rigs, tanker loading moorings and seabed installations including submerged wellheads. The  Government  of  India  has  established  500-metre safety zones  around  each  installation  in  the  oil  field development areas. Mariners should not enter these safety zones

15.   	Some coastal states have declared Prohibition on entry into, or on fishing and anchoring within, areas extending beyond 500 metres from the installations.  Publication  of the details of such  wider  areas  is  solely  for  the  safety  and convenience  of  shipping  and  implies  no  recognition  of the  international  validity  of  such  restrictions.  See also "The Mariners Handbook" (BA NP 100), chapter 1 section 1.

Warning to Mariners.

16.   	Fixed platforms, wellheads, SBMs and pipelines are normally charted. The mobile rigs move from site to site  at irregular   intervals  and  details  of  their  movements  and  positions  are  promulgated  to  shipping  by  means  of   Radio Navigational Warnings and Temporary Notices to Mariners.

17.   	It is essential that all vessels keep well clear of these structures; underwater and surface hazards to navigation exist in their vicinity and in any case consequences of damage of collision could be disastrous.
        
18.   	Within certain oilfields which are being developed or are already producing oil and gas the limits of which are charted, there are likely to be construction and maintenance vessels including submarine crafts, divers and obstruction, possibly marked by buoys. Supply vessels and in some cases, tankers, frequently manoeuvre within these fields, Mariners are strongly advised to keep outside such areas.

19.	Vessels encountering uncharted oil platforms/ structures are to report the matter immediately at following addresses: -      
	
	1.	Chief Hydrographer to the Government of India
		P. O. Box No. 75
		107-A Rajpur Road
  		Dehradun - India - 248 001
		Telephone: - 91-135-2747365, 2747360
		Fax: - 91-135-2748373
		Email: inho_marinesafety@dataone.in
		       inho@dataone.in 

	2.	Flag Officer: - Offshore Defence Advisory Group;
		15th Floor, F-Wing
		Cuffe Parade	
		Mumbai: - 400 005
			Telephone: - 022-22181424, 22752479
			Fax: - 91-22 22151906

Light and Fog Signals.

20.   Offshore structure operating in Indian waters will carry the following internationally agreed marking:-  

(a)	White lights on the horizontal extremities of the structure flashing in uniform morse 'U' every 15 secs., range 10 miles.
	(b)	A fixed red light on the highest point of the structure.
	(c)	Illuminated identification.
	(d)	A signal sounding morse 'U' every 30secs. When the visibility is less than 2 nautical miles.


APPENDIX 'A'
(To Accompany Special Notice to Mariners No. 20)
Source: Offshore Defence Advisory Group


UNUSED CAPPED PIPES LOCATIONS IN BRITISH GAS EXPLORATION AND 
PRODUCTION INDIA LTD.(BGEP) (PANNA, MUKTA AND TAPTI)

Well Name	Latitude	Longitude
SWT-1		2022'05''.65	7149'36''.98
SWT-2		2028'41''.97	7151'50''.81
SWP-1		1917'24''.37	7156'11''.80
MB-1		1920'12''.58	7147'25''.41
PL		1916'19''.37	7159'59''.22
AA-1		1925'24''.04	7158'24''.51
MD-1		1916'59''.06	7144'53''.20
MOON-1		2039'00''.03	7205'43''.05
STE-1		2030'48''.97	7157'02''.36
BS-1		1919'26''.26	7200'06''.75
BS-3		1920'13''.50	7202'35''.30
BS-4		1921'53''.12	7200'34''.50
BS-5		1923'05''.28	7158'15''.55
BS-6		1919'24''.75	7200'33''.49
BS-8		1918'27''.12	7202'43''.20
BS-9		1916'56''.04	7158'56''.04
PBM-1		1921'11''.09	7203'07''.53



UNUSED CAPPED PIPES LOCATIONS IN HARDY 
EXPLORATION & PRODUCTION (INDIA) LTD

Well Name	Latitude	Longitude
PY-3 "Oil Field Area" enclosed by the following five co-ordinates.
A	1119'14''	8003'33''
B	1120'16''	8001'00''
C	1118'17''	7958'38''
D	1114'07''	7958'13''
E	1113'45''	8002'12''
Within the above notified area, four sub sea wells are located at the following co-ordinates.
Well PY3-2	1117'48''	8000'55''
Well PY3-3	1116'56''	8000'16''
Well PY3-D3S	1116'24''	7959'47''
Well PY3-D4	1116'25''	8000'58''


UNUSED CAPPED PIPES LOCATIONS IN HINDUSTAN OIL EXPLORATION 
COMPANY LTD (HOEC).

Well Name	Latitude	Longitude
Co-ordinates of PY-1 Block
	A	7852'51"	1131'16''
	B	7055'05"	1133'31''
	C	8000'00"	1129'53''
	D	7957'20"	1128'48''



UNUSED CAPPED PIPES LOCATIONS IN GUJARAT 
STATE PETROLEUM CORPORATION (GSPC) LTD

Well Name	Latitude	Longitude
KG-01		1649'37''.77	8229'35''.14	
KG-11		1654'36''.33	8227'47''.92
KG-08		1640'09''.45	8225'43''.28
KG-17		1640'09''.65	8225'43''.17
KG-15		1640'09''.59	8225'43''.10
KG-16		1640'02''.65	8227'46''.70
KG-28		1640'09''.72	8225'43''.25
KG-30		1702'06''.41	8231'14''.11
KG-19		1641'48''.01	8231'45''.56
BRU-1		1706'35''.20	8232'09''.13
KG-22		1642'57''.86	8228'50''.29
KG-31		1641'00''.00	8226'14''.99