Recycling drilling process by-products

Paul Boughton

Fossil fuel prices may still be low but, as Sean Ottewell reports, demand remains strong for solutions that deal safely and economically with the by-products of oil and gas production.

Treating and recycling the by-products of the drilling process is a growing challenge for operators in the North Sea and a number of companies are now specialising in this activity.

One of the busiest is Total Waste Management Alliance (TWMA), which has already won over £10m-worth of clean-up contracts this year from companies such as Total, AGR and Maersk.

One of the company's main ongoing contracts is to supply its TCC-RotoMill (Fig.1) services on the Stena Spey at Petrofac's Don development.

Since the work started, TWMA says it has safely and successfully handled, processed and disposed of in excess of 1080 tonnes of drill cuttings, recovering over 300 barrels of oil during the process. This was returned to the client for re-use.

"Having the TCC-RotoMill on-site on the rig meant there was no costly downtime which can run at US$350 000 a day and also meant more than 2000 crane lifts and all associated logistics were avoided so it was clearly extremely successful in terms of environmental, cost and health and safety performance," said TWMA general manager Neil Thomson.

"The fact Petrofac chose to continue working with TWMA on the Stena Spey is a clearindication that the TCC-RotoMill is recognised as a cost-effective, safe and efficient solutionwith a significant range of benefits for the operator and the drilling crew," he added.

A spokesperson for Petrofac said, "The work TWMA is carrying out for us on the Stena Spey has avoided downtime and helped reinforce our safety-conscious approach in all our offshore operations."

TWMA works for a wide range of clients supplying services including the treatment, handling and recycling of the by-products of the drilling process both on and offshore. Last year it landed new projects with Total and Senergy, as well as extensions to existing contracts for BP, ExxonMobil and Oilexco.

One new contract for Total, which has been a client of TWMA for five years, is worth more than £10 million for three years work with the option of extending for a further two years. An additional contract for Total is to be carried out in Nigeria where TWMA has been operational for over two years at Onne, Port Harcourt, for cuttings handling, processing and bin hire.

Meanwhile, BP Egypt has extended its contract by a further two years. The contract covers all BP's drill cuttings handling, processing, slops, vessel healthcare and pit cleaning and has an additional value of £5 million.

Ronnie Garrick, managing director of TWMA, said: "Our business is growing significantly with increasing demand for our services leading to contract wins in domestic and international markets. We have invested in new equipment to make sure we can meet that demand from the oil and gas sector for the cost-effective environmental services we offer."

In addition, the recent introduction by TWMA's R&D department of a fully mobile form of the TCC-RotoMill - the TCCRotoTruck - means the technology is capable of travelling to virtually any location required globally by the oil and gas industry.

Accurate pipeline testing

In Oslo, Det Norske Veritas (DNV) has joined with Gassco to develop a new acoustic inspection method which allows the internal and external status of gas pipelines to be accurately characterised.

Measurements can now be made without reducing the gas flow, and the net effect is both a big improvement in the safety of gas pipelines and substantially reduced inspection costs.

This solves a long-standing problem for the oil and gas industry, which has previously had to reduce gas flows to check pipelines for possible maintenance requirements. Not only has that imposed considerable expense, but existing inspection methods have not been sufficiently reliable.

The world market for gas pipeline inspection is estimated to be in the order of US$300m/y, and the new method can be used both on land and offshore. Building on acoustic resonance principles, it is based on technology employed in the Second World War. DNV applied the same principle to develop a method for determining whether the tanks in the wrecked German battleship Blücher, which is located in the Oslo Fjord, contained water or oil.

So-called pigs are devices normally used not only to clean but also to carry out condition monitoring in pipelines. Attaching a simple 'necklace' to a standard cleaning pig will now make it possible to determine the condition through absolute measurements of the whole pipeline surface, a radical improvement.

Gassco has already tested the new technology on one of its gas pipelines and found the results highly interesting. Performance has been so good that Gassco and DNV have decided to establish a joint venture to commercialise the solution. The big oil companies have also begun to show an interest.

"For us, this means that inspection and maintenance costs can be sharply reduced while enhancing the quality of the inspections," says Brian Bjordal, president and ceo of Gassco. "Now wall thickness can be measured much more exactly. This technological advance probably has a global market potential."

"Gas pipeline inspection is revolutionised with this new technology," says Henrik O Madsen, ceo and president of DNV. "Based on acoustic half-wave resonance, it represents a technological quantum leap. The industry will now secure effective decision support for maintenance and repair, and we will enhance safety and cost-efficiency for the pipeline network."

A patented bioreactor

Meanwhile petroleum exploration management and operations company ATI Petroleum is celebrating the US Department of Commerce's decision to award it the first patent for bioreactor technology.

The bioreactor technology was created through a collaborative effort with the US Department of Energy, the US Environmental Protection Agency and ATI Petroleum's renewable energy division.

ATI Petroleum has conducted bioreactor trials in five locations, one in Bakersfield, Georgia, USA, and four additional pilot plants in Vietnam. All five pilot plants are capable of generating clean renewable energy, and reducing greenhouse gases and leakage from landfills to nearly zero. Most impressively, the bioreactor trials found that not only does the technology reduce greenhouse gas effects and carbon footprint, it also reduces the waste cycle time for landfills from 40 years to no more than a four-year decomposition time.

In the bioreactor trials, ATI Petroleum's engineers focused on operating, for purposes of commercialising, biogas technologies to decompose various types of biological material such as algae, farm animal waste, food waste, and municipal waste. Remarkably, says the company, in addition to decomposition the methane fumes collected from the waste are also contained and converted into useable electricity generation.

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