UK operators increase funding for drill cuttings study

Members of the UK Offshore Operators Association are putting up another �4.5 million to finance the second phase of a joint industry initiative to deal with accumulations of drill cuttings on the seabed. The volumes of cuttings at production sites are estimated at 700,000 cu m in the central North Sea and 500,000 cu m in the northern North Sea.


The 30 members of the UK Offshore Operators Association (UKOOA) will pay another �4.5 million to finance the second phase of a joint industry initiative to deal with accumulations of drill cuttings on the seabed, officials said Monday.

The initiative also is supported by the Norwegian Oil and Gas Industry Trade Association, OLF.

The program, which has the backing of all operators with drill cuttings accumulations at production sites on the UK continental shelf, is intended to determine whether it would be better to lift those cuttings from the seabed or leave them in place.

If the cuttings are to be lifted, participants must then decide whether to reinject them into wells or to bring them ashore for treatment. If the cuttings are left in place, officials must determine whether to allow natural degradation, apply enhanced bioremediation, or cover the cuttings.

There is no proven remediation method. Officials have said enhanced bioremediation is too theoretical as yet, but merits further investigation.

Covering the drill cuttings accumulations is still a potential solution, they said.

If lifting to the surface is attempted, officials said, there are issues related to the secondary contamination of seawater as a result of the accumulations being disturbed and to the significant volumes of water which would be pumped up along with the solid materials.

Reinjection to the reservoir is technically feasible but not possible for all North Sea fields. Its legal status is also uncertain, said officials. They said natural degradation also merits further consideration

The volumes of cuttings at production sites are estimated at 700,000 cu m in the central North Sea and 500,000 cu m in the northern North Sea. Characteristics of each accumulation vary greatly, depending on the types of muds used while drilling, the volumes drilled, cuttings discharge methods, water depth, and currents.

Data are being collected from samples of accumulations at five North Sea fields�Ekofisk, Maureen, Beryl, Blenheim, and Bladon�that offer a representative range of different cuttings accumulation types and sizes. Further surveying and sampling of accumulations will be required, using a representative �base� range of cuttings piles with different characteristics, said UKOOA officials.

Program officials have awarded contracts in 10 new study areas. Final reports are expected by the end of 2001.

The new program builds on a study completed earlier this year and reflects feedback from meetings with stakeholders and an independent group of scientists who are monitoring the initiative�s progress, officials said. It combines survey work with laboratory testing and field trials, enlisting research organizations from around Europe, said officials.

Meanwhile, researchers are trying to determine whether the accumulations drilled predominantly with water-based muds are toxic. Others are investigating whether cuttings drilled with oil-based muds have any effect on the food chain

Yet another contractor is doing a 12-month study to determine how the characteristics of accumulations change over time.

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