Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.


Cementing of casing in the permafrost on the Alaskan North Slope presents new problems to many operators. Primarily, the cement system must be kept from freezing until after the setting reaction is complete. Different types of systems have been suggested and used to solve this problem. High alumina cement systems, however, appear to be the most satisfactory at this time.

This paper presents data of several systems proposed for permafrost cementing and attempts to point out the merits and disadvantages of each.


Cementing of pipe set through the permafrost in Alaskan North Slope wells introduces permafrost in Alaskan North Slope wells introduces new problems. The permafrost section is reported to vary from unconsolidated sands and gravels with ice lenses to some areas of icefree, consolidated rock. A broad definition of permafrost is that formation from surface to a depth where the temperature is at 32 degrees F or below. This depth may vary from 500 feet to 2000 feet. The permafrost temperature may range from 15 degrees F up to 32 degrees F. Conventional cement systems, commonly used in oil well cementing are not satisfactory under these conditions. Conventional cement slurries will freeze, preventing the development of set cement when placed in the low-temperature environment.

Operators on the North Slope requested a cement system that could be mixed, pumped and conventionally placed behind the pipe set through the permafrost. The cement should set to adequate compressive and bond strengths, sufficient to support the pipe and prevent the circulation of drilling fluids up the annulus as drilling is continued. It was further requested that the cement system and placement technique be kept as simple as possible due to the adverse working conditions present on the North Slope.

Conventional laboratory methods commonly used for designing and testing cement systems were not adequate to develop reliable cement systems for permafrost cementing. A test method more closely resembling permafrost conditions and one that could be readily reproduced was needed. A model was developed which met these requirements.

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