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Overview

We are building on what we have learned from our very first platform in Cook Inlet in 1964, to the gravel islands and steel drilling structures used off of the North Slope in the 1980s and, most recently, the integrated platforms off Russia’s Sakhalin Island.

Offshore Operations

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Platform Design


Platforms for developing hydrocarbons in Alaskan waters will be engineered to withstand ice forces, including rapidly moving multi-year ice and ice ridges.  Understanding the strength of sea ice and how it might interact with a structure is critical to safe platform design.

Ice scientists and material engineers will conduct many tests to ensure safe platform design including:

  • Field experiments on ice floes
  • Measurements/analysis on ice breaking against icebreakers
  • Measurements from full-scale ice interactions with structures
  • Simulations of the interactions of waves, currents and ice with an offshore arctic structure and
  • Laboratory scale model tests and simulations.

Directional Drilling

Once the platform is in place, Shell would drill production wells.  Today’s drilling technique, named "directional drilling," allows us to tap into multiple reservoirs located a distance from a platform.  Because the drill bit can be guided in different directions, wells no longer have to be drilled straight down into the reservoir.  This optimizes production and reduces the impact on the environment by requiring fewer platforms.

Prevention of Blowouts

Production wells have barriers in place, similar to exploration wells, to prevent the loss of control, including the use of drilling mud, casing, early detection and response technologies, and blowout preventers.

Accidents during production drilling are even more unlikely than in exploration operations because the well designs are based on the additional information obtained during exploratory drilling.  In fact, only 1% of oil discharges in North American waters are related to oil production, and only a fraction of those few incidents involve drilling.  The main source of oil in the ocean is naturally occurring oil seeps. 

In the unlikely event that uncontrolled hydrocarbons threaten to reach the surface, the well may be capped or, in extremely rare situations, a relief well would be drilled.

Discharge

Shell is working on initial platform designs for production operations that will meet with the standards of “no harmful discharge to the environment.”  Preliminary engineering work on potential Alaska Arctic offshore developments shows promising results regarding disposal of wastes into the subsurface.   Shell will meet all federal standards for waste discharge in the offshore and anticipates:

  • Discharge of mud and cuttings into the subsurface
  • Disposing of treated gray and black water into subsurface
  • Disposing of produced water back into the producing reservoirs.

The reason why discharges are handled differently between exploration and production wells is that during exploration operations, there is usually one well drilled from a location with no water produced.  Production operations, however, involve many wells from a single location that can produce a larger amount of cuttings and produced water from the oil-bearing formations.

Processing and Transportation

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Processing

For platform operations, processing facilities are used to separate the oil, gas and produced water from the wells.  The oil and/or gas is prepared for shipment while the produced water is treated and cleaned for disposal.  In some operations, the water is re-injected to maintain pressure in the reservoir.

Transportation

Once the offshore facility has separated the oil and gas, it sends them to refineries and processing plants on land.  Most offshore produced oil and gas is transported to shore using pipelines.  Shell’s preferred method for transporting oil and gas from offshore production facilities is via pipeline.

Pipeline Planning

Much research must go into the process of planning, routing and building a pipeline for the transportation of oil and gas.  In parts of the arctic, pipelines must be buried beneath the seafloor for protection from natural elements.  Ice gouge and strudel scour surveys are two methods used in the arctic to map the impact solid and melting ice can have on the seafloor. 

When large ice keels move with wind and ocean currents, they gouge the seafloor.  Ice gouge surveys are compiled year after year to gain knowledge into the average depth of the gouges, which then helps determine how deep the pipe must be buried to avoid damage from the moving ice.