Organic Phase Mud Systems update
The Re-Assessment of the 'Z' Group for Organic Phase Mud
Systems
As OSPAR Decision 2000/3 effectively prevents the discharge of
Oil Phase Fluids (OPFs), except at <1% on cuttings, the UK
authorities had previously agreed OPF mud systems could be
registered on a 'worst case' formulation using a minimal data
set. However, it was recognised that the 'worst case'
formulations were unwieldy and not representative of the way in
which muds were sold or used offshore.
In addition, the Further Guidance on the Assessment of
the Toxicity of Substances under the Harmonised Pre-Screening
Scheme of OSPAR Recommendation 2000/4 (Reference Number 2000-4)
stated that, by 01 January 2007, all offshore chemicals must be
registered with full substance-by-substance toxicity
data.
Therefore, DTI, Cefas and the Drilling Fluid suppliers have
agreed that full ecotoxicological data at the substance level would
be required by Cefas for every component in OPF mud systems so as
to ensure that they are compatible with the HMCS by the required
date. Suppliers have therefore been submitting the
relevant data to Cefas from 1 September 2006.
There is no CHARM algorithm for the discharge of an OPF based
mud system. Therefore the base fluid and each individual
product will be classified using the process described in the Cefas
Guidelines for the classification of chemicals that cannot be
ranked by the CHARM model. Products will then be placed in
the OCNS groups (A-E) appropriate to their toxicity, biodegradation
and potential to bioaccumulate. The exceptions will be those
components which could also be used in a Water Based Mud (WBM)
system and are CHARMable. These components will continue to
be assessed using CHARM and ranked using the HQ. However, as
the product should never be discharged when used in an OPF mud
system, no RQ will be required. This process will effectively
replace the old 'Z' Group for OPF mud systems. The 'Z' Group
will no longer be recognised from 01 January 2007.
Guidance for Completing the PON15B and EEMS returns after 01
January 2007
Currently certified and approved 'worst case' mud systems
continue to be acceptable for recording in PON15B applications up
to 31 December 2006.
- Please note, for any PON15B that has been approved prior to 31
December 2006 on a 'worst case' mud system, it will not be
necessary to re-submit that PON after 01 January 2007 to itemise
the mud components. In addition, any Variation to that PON for an
increased use of the 'worst case' OPF mud system will not require
itemised mud components. EEMS returns for these PONs should
be completed using the current system.
However, any PON15B submitted on or after 01 January
2007 MUST record the individual components of the mud system to be
used offshore and each individual component MUST be fully
registered with Cefas.
The PON15: Section G1: Drilling Muds/Fluids and Chemicals
Section C1: Mud/Fluid data
The 'mud system' name is entered under the OPF section. No
further data need be entered as no CHARM assessment may be
made.
Please note, the 'mud system' name has been retained and may be
found on the Cefas website but after 01 January 2007 it will no
longer be recognised as a 'registered' product in new
applications.
Section C2: Mud/Fluid formulation and chemical data
| 'Chemical & formulation names' |
- enter the Product name as it appears in the
Cefas list |
| 'Chemical Function group' |
- example 'OPF' 'OPF additive' 'WBM additive, FLC,
etc |
| 'Chemical label code' |
- enter details from the Template |
| 'Estimated Use' |
- enter estimated Use* |
| 'Estimated Discharge' |
- enter '0' (zero) ** |
| 'Dosage (lb/bbl)' |
- there is no requirement to enter a dosage |
| 'HQ' |
- enter OCNS Group or HQ from the Template |
| 'RQ' |
- there will be no RQ ** |
| 'CHARM algorithm code' |
- leave blank |
| 'Discharge code' |
- enter appropriate code e.g. ZSS, ZDH, ZCR. |
*Estimated Use - including re-cycled
products
It is usual practice for 'mud' to be returned to shore for
re-cycling and the re-cycled mud is shipped to a rig.
Additional base oil and weighting agents, emulsifiers and Fluid
Loss Control (FLC) products are added as required offshore and can
be identified as individual products. The following
procedures have therefore been agreed by DTI, Cefas and Industry:
-
Procedure for Base Oil
PON15B Estimated Use
- It was agreed that the recycled mud could be regarded as
containing predominantly base oil and a weighting agent. Suppliers
analyse the recycled mud and can calculate the volume (weight) of
base oil contained in that mud.
- It was agreed that the base oil in the recycled mud and the
base oil to be added offshore would usually be the same product (if
the base oil is not the same product the predominant base oil would
be recorded). The predominant OPF name should be entered and
Estimated Use would be the total of calculated recycled base oil +
base oil taken offshore. (eg. Recycled base oil = 100t, added base
oil =200t; total estimated use = 300t)
EEMS Returns
- It was agreed that the base oil in the returned mud could be
calculated and this would be subtracted from the PON value to
populate the EEMS return. (e.g. estimated use = 300t - calculated
returned base oil = 150t; total use in EEMS = 150t). Through
discussion it has been determined that this procedure should not
cause any delays in providing returns within the stated permit
conditions.
Procedure for Weighting Agents
PON15B Estimated Use
- It was agreed that a similar process could be adopted for the
weighting agent and that a weight could be obtained from analysis
of the recycled mud.
- It was acknowledged that the accuracy of this calculation could
not be guaranteed and that other substances might affect the
calculation, but it was agreed that this was a very close
approximation to what was required.
EEMS Returns
- It was agreed that, as with the base oil, the tonnage of the
weighting agent in the returned mud could be calculated and
subtracted from the estimated use for an actual use in EEMS.
Through discussion it has been determined that this procedure
should not cause any delays in providing returns within the stated
permit conditions.
Procedure for Emulsifiers, FLCs and Other
components
PON15B Estimated Use
Other components such as emulsifiers, fluid loss additives etc
would only be present in back-loaded mud in very small quantities
and it would not be possible to accurately calculate them or even
approximate them.
- Therefore, it was agreed that for all other OPF products listed
in the PON15B the Estimated Use tonnages would be based on what was
directly supplied to the rig/installation.
EEMS Returns
- It was agreed that 'actual' use of all other OPF products at
the rig/installation would be recorded in EEMS.
Estimated Discharge **
The OSPAR Decision 2000/3 effectively prevents the discharge of
Oil Phase Fluids (OPFs), except at <1% on cuttings.
Therefore, in most cases, the Estimated Discharge of the base oil
will be '0'. If discharge on cuttings occurs, a calculated
Estimated Discharge tonnage should be entered and a full
description of the recovered-oil-from-cuttings process should be
provided in Section C: Justification.
Once all other additives have been mixed with the Base oil they
too will be subject to a '0' discharge. As there will be no
discharge of chemicals mixed with Base oil there is no requirement
for an RQ to be calculated for those products with a HQ
ranking.
Disposal Of Surplus Materials
The discharge of surplus materials is not permitted
under The Offshore Chemicals Regulations 2002. Surplus materials
should be retained on the rig/installation for future use OR
contained and returned to shore for future use or
disposal.