For the oil and gas industry, the trail of destruction caused by hurricanes begins well before landfall.

This year, there is a 70% probability that the Atlantic hurricane season, which runs from June 1 through Nov. 30 and includes the Gulf of Mexico (GoM), could bring between eight and 13 named storms, the National Oceanic and Atmospheric Administration (NOAA) said in its outlook. Of these storms, between three and six could develop into hurricanes, with two at most becoming major hurricanes.

Based on the hurricane outlook, the U.S. Energy Information Administration (EIA) said June 10 that its mean estimate of GoM storm-related disruptions includes 11.6 MMbbl of crude and 841 MMcm (29.7 Bcf) of natural gas this season.

In addition, the analysis, released as a supplement to the Short-Term Energy Outlook (STEO), estimates a 69% probability of production shut-in volumes being equal to or larger than those of 2013, which totaled 3.1 MMbbl of crude and 190 MMcm (6.7 Bcf) of natural gas.

Although the hurricane outlook is forecasting a below- to near-normal season, it takes only one major storm to cause damage.

When Hurricane Katrina barreled through the GoM in 2005, gaining strength over warm waters, the massive hurricane’s more than 170-mph wind speeds and gigantic waves toppled Shell’s Mars platform and Chevron’s Typhoon platform, sunk or significantly damaged many jackup rigs and halted operations, reducing production by more than 1 MMbbl/d. The Category 5 hurricane was followed by Hurricane Rita, adding to the damage.

In later years, additional hurricanes left their mark on the industry. Hurricanes Gustav and Ike, both designated as Category 4, caused nearly 100% of production capacity to be shut in at one point. “EIA estimates that these two storms [along with a tropical storm in July] resulted in the loss of 25% of the GoM crude oil and natural gas that would have been produced during the 2008 hurricane season,” according to the EIA’s supplement.

But the GoM has been quiet lately. The National Hurricane Center called 2013 “the quietest season in the past two decades,” with only two hurricanes despite previous predictions for an active season.

“The effects that named storms this year in the Atlantic will have on Gulf Coast crude oil and natural gas production will depend on their trajectory and strength,” the EIA said. “Last year, only one named storm—Tropical Storm Andrea—made landfall in the United States, and it did not cause any disruptions to crude oil or natural gas production.”

Only one oil and gas shut-in was reported in 2013.

Nowadays, growing onshore production—mainly from shale plays—is reducing the impact of hurricanes on oil and gas production. In 2013, the GoM supplied about 17% of U.S. crude oil production and 5% of dry gas production, down from 27% and 26%, respectively, in 1997.

However, more than 40% of the nation’s petroleum refining capacity and 30% of the natural gas processing plant capacity is along the GoM coast, EIA figures show.

Still, companies are reviewing emergency plans and keeping eyes on the forecast, considering that predictions can change.

Past storms have led to revised recommended practices, including two from the American Petroleum Institute concerning design and operation of mobile offshore drilling unit mooring systems, jackup rig locations and platform deck positioning. Guidelines also were released on tie-downs and applying updated metocean data to offshore structure designs.

A couple of companies have opted for disconnectable FPSO vessels, which could prove beneficial during harsh weather. Petrobras is using the BW Pioneer FPSO vessel in the Cascade and Chinook fields, which produced a company record 40,000 bbl/d in March. The vessel—which has an oil-processing capacity of 80,000 bbl/d and storage capacity of 600,000 bbl—features disconnectable turret mooring. The vessel is the first FPSO vessel in the U.S. GoM, with a turret and mooring system at 2,500 m (8,202 ft) water depth.

A second FPSO vessel is forthcoming. Shell will use an FPSO vessel in the Stones ultra-deepwater field.

“The FPSO [vessel] will also contain a turret with a detachable buoy that allows the vessel to turn in place during normal weather conditions,” Shell said on its website. “If a heavy storm or hurricane approaches, it can disconnect its mooring lines and risers from the well system and sail to safe areas. Stones will be the first time a turret and disconnectable buoy is configured with lazy wave risers in order to unlock oil production in ultra-deepwaters.”

Other large deepwater projects are utilizing spar platforms. Shell said its Perdido spar moves up and down only a few meters with the ocean’s swell during storms and is designed to stay upright even if it disconnects from its moorings. However, Hurricane Katrina was too strong for its Mars tension-leg platform, which toppled and required more than 1 million working hours to repair.

While operators seek suitable platforms with the weather in mind, researchers are looking for ways to help the industry better prepare for storms. Such information could be considered in the design of offshore facilities.

During OTC 2014, the Center for Atmospheric Research and North West University in South Africa presented a paper that examined methods to stimulate and predict future changes in hurricane impacts on the offshore energy industry. Using a simulation of Hurricane Katrina as a case study, researchers explored the ability of fully coupled atmosphere-ocean dynamical simulations to capture metocean hurricane conditions.

“The value of direct impact assessments was explored through the development and application of a cyclone damage potential [CDP] index. Application of the CDP to the current climate indicated a hotspot of damage potential in the Gulf of Mexico that, according to one future climate scenario, dissipates over the coming decades,” the paper said. “We caution that this is one of many plausible future scenarios, and ongoing work is aimed at establishing confidence levels in the future change.”

Contact the author, Velda Addison, at vaddison@hartenergy.com.

Offshore