The Kashagan Oil Field is located under the sea approximately 80 km southeast of the town of Atyrau. Field development includes production of crude oil and associated sour gas (>15% h2s) from the reservoir by a combination of offshore processing facilities and pipeline systems to transport the crude oil and gas to the onshore processing facility (opf), 40 km east of Atyrau. Here oil and gas are treated, conditioned and the transferred via existing infrastructures.
The overall pipeline system from the D-Island offshore facilities to the onshore processing facility comprises two 28” sour oil and gas pipelines 95.7 km long, running in a northerly direction with an offshore length of 65 km long from the top of the riser to the landfall location (shoreline) on the north coast of the Caspian Sea. The pipelines continue onshore to the processing facility in a pipeline with a total length of 30.7 km, including 4.1 km in a swamp.
The project presents several peculiarities:
- In the winter, the air temperature drops to -30 °C and the climatic conditions are aggravated by a strong cold north-easterly wind, creating extreme blizzard conditions.
- The water depth is very shallow in the area of development (ranging from a depth of approximately 4 m at Kashagan Oil Field to 0 m near the shore); there are seasonal and annual changes in the water level of the Caspian Sea, and the sea becomes ice-bound in winter.
- The shallow water and swamp section crosses a special environmental region, referred to as a SER Zone, located between the progressives kp 52.3 and kp 67, with an overall length of 15 km. In this protected area, installation work is not allowed between 1 April and 15 July.
