Jan. 2001 Vol. 222 No. 1  Drilling

Robert E. Snyder,  Editor

Synthetic drill fluids report, reluctant rig builders, flow assurance study

The Gulf of Mexico Newsletter reports that the Minerals Management Service (MMS) has released a new report on synthetic-based drilling fluids (SBFs). According to the report, Environmental impacts of synthetic-based drilling fluids, discharged drill cuttings contain between 5% and 15% of adhering drilling fluids. It indicates water-based drill fluids (WBFs) are used in drilling most offshore wells, but that use of SBFs is increasing.

According to the study, following discharge, SBFs clump together and settle rapidly through the water column, restricting the biological effects of SBF cuttings on sediments near the well location. Their estimated biodegradation half-life is estimated to be between 65 and 104 days. The report concludes that SBFs are unlikely to accumulate to concentrations that are directly toxic to the benthic fauna.

Within 3 to 5 years following cessation of SBF cuttings discharge, it is possible that concentrations of SBF in sediments will have fallen to low enough levels – and oxygen levels will have increased enough throughout the affected area – that a complete recovery is possible. Copies of the report can be obtained from the MMS public information office in New Orleans.

Canadian worker shortages. In Canada, oil/gas drillers launched a national campaign to fill 3,000 jobs immediately on rigs in Western Canada as natural gas prices climbed to new highs on worries about tight winter supplies.

The Canadian Association of Oilwell Drilling Contractors’ 90 members are "severely short of people" as oil/gas companies eagerly seek to step up the search for new reserves so they can increase production and take advantage of higher energy prices. For those interested in the positions, a toll-free line has been opened at 1-866 RIG WORK.

Reluctant rig builders. A commentary in the September / October Oilfield Appraiser notes that, as the industry continues to prosper with higher work rates and longer contracts, several of the larger contractors are starting to look at the cost of new rigs. The question being asked is "At what point will increased work rates make it feasible to invest in new rigs?"

You can make the numbers work now if you really want to, the commentary says. However, the current dayrates have only been in place for a few months and the risk involved in buying a new rig is more than the average contractor can take.

There is also another school of thought. It is very possible that the rig markets are just now being balanced between supply and demand. It is the report author’s opinion that, "Adding new rigs to the existing fleet will not happen because contractors are cautious. And rightly so, because they have had the unpleasant experience of seeing a market downturn in a few days and the resulting panic. Having a rig fleet balanced with demand is what we have needed for years – this is no time to build new rigs."

Additionally, dayrates are just now in line with what they should have been for the past five years as a direct result of added drilling and service work. Although current rates indicate we are near the breakeven point for new rigs, there is still a question of how long this boom will last, the report adds. Who of us is not asking that question?

Drilling records in Venezuela. A world record for drilling with a 12-1/4-in. bit has been set by Venezuela’s Sincor heavy crude project, in which Statoil has a 15% interest. The bit was used to deviate eight well paths to horizontal from vertical over a total length of 5,122 m (16,800 ft), compared with a previous record of 3,622 m (12,000 ft).

Sincor is developing a heavy crude field in the Zuata region, about 125 mi from the capital of Caracas. This area is estimated to contain 45 billion bbl oil. Seven rigs have drilled 100 extended-reach horizontal wells over the past 14 months. And early production from the field was due to begin by year-end 2000.

New DeepStar flow assurance initiative. DeepStar contractor Paragon Engineering Services, Inc. is presently underway with two deepwater studies that will engender industrywide information exchange while creating avenues for safe, reliable production in water depths exceeding 5,000 ft. Led by Paragon’s Chuck Horn, the studies, undertaken on behalf of DeepStar, in conjunction with the U.S. MMS, endeavor to build on lessons learned and avoid repeated flow assurance problems in ultra-deep water.

The two studies represent a joint industry effort to bring improved flow assurance for all operators of deepwater installations. At present, both majors and independents are experiencing problems for which there are technical resolutions. The goal is to get this information to all parties in the deepwater market.

The studies are titled: "Flow assurance practices / methods for deepwater facilities," and "Pipeline blockage remediation strategies for long-offset subsea flowlines and pipelines." They will specifically address difficulties associated with long distances, deepwater subsea tiebacks and capabilities for deepwater intervention.

DeepStar kicked off the two studies with a one-day workshop last summer. Industry response was overwhelming, with many of the workshop participants now requesting quarterly or semi-annual workshops to more quickly disseminate more technical data from operators and suppliers.

Over the next 12 months, the Paragon team will interview both GOM and UK North Sea operators to develop case studies of 20 or more projects to uncover data which will translate into more successful deepwater pursuits. Issues to be addressed include: actual case histories involving hydrate / paraffin formation, fluid dynamics analysis, production profiles, engineering / design, operations / maintenance programs and overall problem-solving efforts, with input from service companies commissioned to correct difficulties.

The Paragon / DeepStar team is considering a second flow assurance workshop for first quarter 2001. Topics for discussion include: pipeline insulation materials, developments for wax deposition control, pipeline repair technology for pipe-in-pipe, and development of a standard oil analysis testing program for deepwater assessment.