Verification of fitness of offshore Drilling Rigs

Rule 30 on the above subject requires independent verification of fit for

purpose condition, which is the ability of the installation to perform
intended function. Requirements as per sub-rule (2) includes, assessment
of design and construction of the installation in relation to the conditions
under which it is to be installed and used; designing, constructing,
installing and maintaining the installation in accordance with recognized
standards;

and

maintaining

valid

certificate

of

fitness

for

the

installation.
Actions required, for complying with the requirements of Rule 30 include:
a. Design / construction verification by independent party.
b. Fit for purpose status of an installation is to be ensured through
certification by an independent reputed party or by any member of
the classification society.
c. Valid certificate means certificate issued by an independent party
(including any member of the classification society) for a fixed time
period.
d. Certification / classification should include verification of the drilling
system.
This guidance note is being issued to specify the detailed elements to be
addressed by Operator, to demonstrate that Mobile Offshore Drilling rig
(MODU) has been designed and maintained for the identified operating
and environmental conditions, in compliance with the Rule 30.
AA

Documents

required

to

be

submitted

to

demonstrate

compliance are:
1.
2.
3.

Classification certificate.
MODU safety certificate.
Certification of drilling system and other related equipment.
1

4.

Description of operations which may be carried out by the MODU

under implied limitations resulting from:
a. Risk analyses
b. Extreme condition (damaged stability)
c. Extreme environment
d. Simultaneous operations
e. Impairment of safety critical equipment

BB

Alternate certification requirements

These requirements are to be met in the absence of evidence of
compliance against point 2 and 3 of AA above.
Explanatory note:
1.

Unless it is specifically asked for from classification society (would be

in

form

of

additional

notation),

the

classification

requirements

normally do not cover equipment used exclusively for drilling and

related operations.
a.
Machinery, electrical and piping systems used exclusively for
drilling purposes are not covered by the requirements, except
in so far as their design or arrangement may affect the safety
b.

of the unit.
The assessment of the required holding capacity, arrangement
and operation of position mooring equipment and dynamic
positioning equipment used for station-keeping activities in
connection with the units operation is the responsibility of the

2.

owner, and is not included in the requirements.

MODU safety certificate may not be the requirement of the flag state,
where MODU is registered.

The requirements of the following referred applicable standards for

the listed equipment shall be met to demonstrate that drilling
systems are in compliance with requirements of the Petroleum and
Natural Gas (Safety in Offshore Operations) Rules, 2008 and MODU
is thus fit for purpose:
S.
No.
1.

Equipment

Verification requirements

Drilling
structure,
drill
floor,
sub

A.

Reference
Standard

Derrick / structures
i.

Structures
have
been
designed and fabricated by API
2

Spec

structure,
lifting
equipment.

manufacturers as per API

Spec 4F / ISO 13626 or
equivalent. This verification
should
include
structural
safety level (refer sections 6
and B.6 of API Spec 4F / ISO
13626).

4F / ISO
13626

ii.

Different
categories
inspection(s)
of
derrick, API RP 4G
structures and drill floor
have been carried out as per
section 6 of API RP 4G or
equivalent
and
OEMs
recommendations,
besides
NDE
as
considered
necessary.

iii.

Repair and modification of

structures (if carried out,
based on inspection) have
been carried out as per
section 7 and 8 respectively
of API RP 4G or equivalent
and
OEMs
recommendations.
Quality
control
of
repair
and
modification
has
been
ensured
in
line
with
requirements of section 11 of
API SPEC 4F / ISO 13626 or
equivalent.

B.

API RP 4G

API
Spec
4F / ISO
13626

Drilling equipment
i.

Installation, inspection and

maintenance of IC engines API
Spec
have been carried out as per 7C-11F
API
Spec
7C-11F
or
equivalent
and
OEMs
recommendations.
For
minimizing potential fires
and/or explosions in the
operations of IC engines
requirements
given
in
Appendix A of API Spec 7C11F or equivalent, are being
followed. Functional testing
of
safety
devices
and
emergency stop function has
been carried out.
3

ii.

Design,
inspection
and API RP 7G
operating limits of drill stem
components is as per API RP
7G or equivalent.

iii.

Design of drilling equipment API

Spec
(rotary
equipment,
slush 7K / ISO
pumps, power tongs and 14693
draw works) is as per API
Spec 7K / ISO 14693 or
equivalent.

iv.

Inspection, maintenance and

repair of rotary equipment,
slush pumps, power tongs API RP 7L
and draw works has been
carried out as per API RP 7L
or equivalent and OEMs
recommendations.
Inspection has included NDE
and/or opening of equipment
as
considered
necessary.
Functional testing of safety
devices and emergency stop
function has been carried
out.

v.

Design of drilling hoisting

equipment is as per API Spec
8A and API Spec 8C / ISO
13535 or equivalent.

API
Spec
8A and
API
Spec
8C /
ISO 13535

vi.

Inspection, maintenance and

repair of hoisting equipment
are as per API RP 8B / ISO
13534 or equivalent and API
RP
OEMs
recommendations. 8B / ISO
Inspection
of
hoisting 13534
equipment has focused on
structural
integrity
and
personnel
protection.
Category
III
and
IV
inspection
has
included
NDE / MPI and/or opening of
equipment as considered
necessary. Functional testing
of
safety
devices
and
emergency stop function has
been carried out.

vii.

Minimum requirements and

terms of acceptance of steel
4

API
9A /

Spec

wire ropes as per API Spec ISO 10425

9A / ISO 10425 or equivalent
are being followed.
viii.

ix.

x.

2.

Well Control
Systems:
blow
out
preventers,
diverters,
marine
risers, choke
and
kill
system,
control
systems for
well control
equipment.

A.

B.

Field care (inspection) and

use of wire rope and API RP 9B
evaluation of rotary drilling
line has been carried out as
per API RP 9B or equivalent.
Inspection of piping and
piping systems has been API RP 570
carried out as per API RP and
570 and API RP 574.
API RP 574
Pressure vessels have been
inspected
externally
and
internally;
thickness
measurement
/
crack
detection tests have been
carried
out
as
deemed
necessary. Pressure testing
at a pressure equal to
maximum allowable working
pressure has been carried
out.
Safety
valves
/
instrumentation have been
tested.
Design
of
drill
through
equipment / blowout prevention
equipment ram and annular
blowout preventers, hydraulic
connectors,
drilling
spools,
adaptors etc. is as per API Spec
16A / ISO 13533 or equivalent.
Records
of
maintenance
(including major inspection as
per section 17.10.3 of API RP 53
and OEMs recommendations)
have been reviewed. Installation
and
testing
(complete
performance testing including
functional and pressure tests) of
blow out control equipment is
being carried out in line with API
RP 53 or OISD-RP-174 or
equivalent.
Design and maintenance of
diverter systems is as per API RP
64 or equivalent. Inspection and
5

API
Spec
16A / ISO
13533

API RP 53
or
OISD-RP174

API RP 64
or
OISD-RP-

testing of diverter systems has 174

been carried out as per API RP
64
or
OISD-RP-174
or
equivalent.
C.

D.

3.

Design of choke and kill systems

is as per API Spec 16C or
equivalent. Pressure testing of
choke and kill systems is being
carried out in line with API RP 53
or OISD-RP-174 or equivalent.
Flexible choke and kill lines and
choke manifold are inspected as
per section 17.10.3 of API RP-53
and OEMs recommendations.
Design of control systems for
well control equipment and
diverter equipment is as per API
Spec 16D or OISD-RP-174 or
equivalent
and
performance
requirements/ testing, inspection
and maintenance is as per API
RP16E
or
OISD-RP-174
or
equivalent
and
OEMs
recommendations.

Marine drilling riser systems for

floating drilling operations have
been selected, operated and
maintained in line with API RP
16Q or equivalent. Design,
manufacture and fabrication of
marine drilling riser equipment
used in conjunction with a
subsea blowout preventer (BOP)
stack is as per API Spec 16F /
ISO 13624-1 & ISO 13624-2 or
equivalent.
Design
and
standards of performance for
marine drilling riser coupling is
as per API Spec 16R or
equivalent. Risers and riser
couplings / joints are being
inspected for wear, cracks and
corrosion;
thickness
measurement has been carried
out as required.
Man
riding Selection of man riding equipment is
equipment
done ensuring that equipment is
6

API
16C

Spec

API RP 53
or
OISD-RP174

API
Spec
16D
or
OISD-RP174
API RP16E
or
OISDRP-174

API
16Q

RP

API
Spec
16F /
ISO
13624-1 &
ISO
13624-2
API
16R

Spec

4.

5.

6.

suitable for man riding operations, and

the equipment are inspected and
maintained regularly.
Station
Verify that MODUs station keeping and
keeping
stability characteristics are suitable for
systems:
the environmental (including sea bed
anchoring,
and soil conditions) and operating
mooring,
conditions envelope. Inspection and
dynamic
maintenance of mooring hardware is as
positioning,
per API RP 2I or equivalent and OEMs
compensator recommendations;
and
design,
and
manufacturing and maintenance of
disconnection synthetic fiber ropes for offshore
systems.
mooring is as per API RP 2 SM or
equivalent.
Drilling fluid
handling and
cementing
system
Electrical
Systems

Physical condition of the equipment is

satisfactory
and
instrumentation,
safety alarms and pressure safety
valves are being tested regularly.
A.
Design and maintenance of
MODU
electrical systems is as per IMO code
MODU code.
B.

7.

Safety
systems
(exclude
items which
are covered
by
MODU
safety
certificate,
provided the
rig has valid
MODU safety
certificate)

A.

B.
8.

Cranes
(If
classed
certificate
notation
does
not
cover cranes)

API
RP
2SK /
ISO
19901-7
(for station
keeping)
API RP 2I
API RP 2
SM
MODU
code(for
stability)

A.

B.

Inspection and functional testing

of emergency power system is
being carried out.
Inspection and testing of the
following safety systems is being
carried out periodically:

Fire detection system

Gas detection system

HC and H2S

Drilling operations related

alarm system

Life saving appliances

SCBA

Gas measuring devices

Firefighting system

Communication systems
Safety systems are as per MODU
code
requirements,
as
applicable.
Design and testing of pedestal API
mounted offshore cranes are as 2C
per API Spec 2C or equivalent.
Operations and maintenance of
offshore cranes are as per API
RP 2D or equivalent. Inspection
7

Spec

API RP 2D

has
focused
on
structural
integrity and includes:
Blocks and sheaves
Wire
ropes
and
end
attachments
Hooks
Bearings
Shackles
Securing arrangements
Support structure
Axle pin and housing
C.

Inspection and function testing

has included:
Correct
adjustment
of
brakes
Resistance measurement
of electrical systems
Leakages
in
hydraulic
systems

D.

9.

Load charts have been verified

by carrying out load tests as per
applicable
requirements.
Functional testing of safety
devices and emergency stop
function are being carried out.
Helideck (If Inspection has included:
classed
Structural integrity of deck and
certificate
supporting structure
notation
Surface of deck
does
not
Obstacles and marking
cover
Safety net
helideck)
Fire safety arrangements

The validity of certificate shall be 5 years, provided follow up

midterm survey / inspection is carried out within 3 years period
from date of certification.
___________________________________________________________________________