Permafrost

The Industry Challenge:

Certain oilfields and recovery methods are sensitive to thermal gradients between the formation and injected/produced fluids. Examples include:

  • Permafrost Zones (i.e. thaw-induced subsidence)
  • Cyclic Steam and SAGD Operations (i.e. injected steam quality)
  • Deepwater Completions (i.e. to prevent hydrates)
  • Geothermal Applications

To reduce unwanted heat transfer, Operators may install Vacuum Insulated Tubulars (VIT); however, VIT technology poses several challenges that are...

The pdf file of this paper is in Russian. To purchase the paper in English, order SPE-149740-MS.

Abstract

Over the past decade, petroleum operators have shown increased interest in exploring and developing oil and gas reservoirs in both onshore and offshore Arctic areas. In many cases, the reservoirs are known to be overlain by massive permafrost layers on the order of 50 to 700 m thick. These conditions create unique design and operation challenges for production and injection wells from the...

Abstract

Over the past decade, petroleum operators have shown increased interest in exploring and developing oil and gas reservoirs in both onshore and offshore Arctic areas. In many cases, the reservoirs are known to be overlain by massive permafrost layers on the order of 50 to 700 m thick. These conditions create unique design and operation challenges for production and injection wells from the perspective of ensuring that well integrity will not be compromised by the inevitable thaw...

Abstract

Oil and gas producers have shown renewed interest in developing reservoirslocated both onshore and offshore within the Arctic regions of Alaska, Canadaand Russia. In many cases, the hydrocarbon reservoirs are known to be overlainby a massive permafrost interval that extends over depths of up to 700 m belowthe surface active layer. These conditions create unique design and operationalchallenges for production and injection wells from the perspective of ensuringthat well integrity will...

The Industry Challenge:

Gas pipelines in Arctic regions pass through areas of continuous and discontinuous permafrost. The segments where the pipeline is buried in discontinuous permafrost are subject to freeze-thaw cycles that can cause uplift on the pipeline.

Where the ground transitions from discontinuous to permanently frozen ground, the uplift forces can cause severe bending loads that can exceed the yield strength of the pipe, resulting in permanent deformations.

If the pipe yields, the...

The Industry Challenge:

Operations in the Arctic and cold weather regions are challenging due to embrittlement of components, and generation of significant thermal stress loads, which can lead to structural cracking and failures under otherwise normal loading conditions.

Temperature variations also change the elasticity and dimensions of sealing components leading to reduce performance and leaks.   For example bladder accumulators stiffen at cold temperatures, limiting their performance in...

The Industry Challenge:

Wells that penetrate permafrost are prone to subsidence caused by thawing of the soils that surround the well as the warm produced fluid is pumped to surface. Subsidence can damage the well casing, leading to hydrocarbon liquid leaks into the surrounding formations.

Furthermore, it can cause damage to the surface facilities and flow lines connected to the wells. Understanding the factors contributing to the rate of thawing and subsidence are necessary to design wellbores...