Kashagan: Pushing Technological Frontiers
Petroleum interviews NCOC'S External Relations Director Pierre Delpont
– Mr.Delpont, I understand tha the Kashagan oilfield is one of th largest and most complex industria projects being undertaken anywher in the world and, as such, require new and innovative approaches and technologies. What innovative ap proaches are you adopting to adap to the environment and the climate o North Caspian?
– Indeed, it is. Located in the northern part of the Caspian Sea Kazakhstan’s first offshore oil and gas project, Kashagan is one o the world’s largest and technically most challenging projects current ly being developed. And some o the challenges that the Consor tium has to deal with on a daily basis are quite unprecedented among those are:
- Kashagan is located some 4,200 meters below the seabed and is highly pressured (770 bar of ini tial pressure). The crude oil it con tains has high ‘sour gas’ content Although exploration of high pres sure, high sour gas reservoirs is no new, when compared to other sou gas fields around the world, Kasha gan can be considered to be push ing industry frontiers when seen in the context of the harsh operating environment of the northern part o the Caspian Sea.
- The shallow northern part where the consortium operates, cov ers a quarter of its total surface but accounts for only around half a percent of its total volume. While the maximum depth in the south ern part of the Caspian Sea is 1,025 meters, it is only three to four meter deep near the Kashagan field.
- Low salinity, due to the in-flow of fresh water from the Volga River combined with shallow waters and winter temperatures below minu 30 degrees mean that the northern part of the Caspian Sea freeze for nearly five months of the year Ice drifts and ice scouring place heavy constraints on construction activities.
- The northern part of the Cas- pian Sea is a very sensitive envi- ronmental area with abundant and diverse fauna and flora, including a number of endemic species
- North Caspian is a difficult location to supply essential project equipment. Logistical challenges are amplified by limited access to waterways, such as the Volga Don Canal and Baltic Sea-Volga water- ways, which are only navigable for around six months of the year due to thick winter ice. The development of such a chal- lenging project in a frontier envi- ronment requires new and innova- tive approaches and technologies. Through NCOC, each of the world’s renowned partner companies in the Consortium brought in their strengths, expertise and innovative approaches to the project, to some of which I would like to draw your attention now:
- Due to the shallow water and cold winter, it is not possible to use conventional drilling and pro- duction technologies – such as concrete structures or jacket plat- forms. So to protect offshore facili- ties from harsh winters and pack ice movement, the Consortium decided to install them on artificial islands which are the most impres- sive innovation. The larger artifi- cial islands are hub islands, which are real off-shore towns that could accommodate thousands of work- ers, with a number of facilities such as oil and gas processing, com- pression and electric power units. Artificial islands are made of mln of tonnes of sand and lime extracted from quarries then conveyed to the required off-shore location using large barges.
- Another inventive concept is the concept of “pre-assembled barges” that are brought to the Caspian Sea through the Volga-Don canal from various parts of the world. Upon arrival, the barges, which house a range of equipment from raw gas injection compressors to emergen- cy generators, are completed using Kazakhstani fabrication yards. They are then mobilized offshore, jacked into place and secured on giant piles some 80 meters high. In the remote future, this will also make decom- missioning and removal of the facili- ties easier when production ceases.
- We also built a new genera- tion of an icebreaker vessel should an emergency situation occur. The Ice-Breaking Emergency and Evac- uation Vessel (IBEEV) will be able to take 330 offshore personnel to safety out of harm’s way, irrespec- tive of outside conditions. Sour gas compressors, created specifically for Kashagan, are among the high- est power (35 MW) and pressure (800 bars) combination in the indus- try. “Smart wells” drilling technol- ogy, innovative well design and special materials are being used to accommodate the high pressure, sour nature and huge size of the reservoir;
- Another thing that I would like to mention is state-of-the-art pipe laying technique which we use as this also demonstrates our commit- ment to environmental responsibil- ity. According to the development concept, there are hundreds of kilo- meters of large-diameter pipe that have to be laid between drilling islands and hub islands or between a hub island and an onshore process- ing plant. The technique allows for trenching, pipe laying and backfill- ing at the same time and minimizes impact on the environment, allow- ing it to recover within a range of a few weeks;