Tengiz Oil Production Plant, Kazakhstan

The oil processing plant in Tengiz is a project undertaken by the TengizChevroil (TCO) partnership. TCO acquired the Tengiz oil field in the western part of Kazakhstan in 1993. Since that date, it has undertaken a number of capital investment programmes. These have allowed a continuing rise in crude oil production from 1.5 million tons per year in 1993 to 9.6 million tonnes per year (220,000 barrels of oil equivalent per day). The most recent project is intended to increase production at the oil processing plant to 370,000 barrels per day by 2004. It is estimated that this will cost nearly $3 billion. Current work on the oil processing plant includes debottlenecking and the installation of a new train.

THE TENGIZ OIL FIELD INFRASTRUCTURE

The Tengiz oil field is one of the biggest in the world. It contains 24 billion barrels of high quality oil and six to nine billion barrels of recoverable oil. It is deep, having a target depth of 4,500 metres. It also contains significant gas reserves (18,000 billion cubic metres).

The field required a great deal of infrastructure investment to develop. Most of this was designed and implemented by the Russian Technical Design Institutes, but a consortium of western contractors built the processing plant. The consortium included Lurgi, Litwin and Lavalin.

The processing plant is made up of building blocks. Each building block is called a KTL (coming from the Russian for Complex Technology Line) and contains two trains of gas-oil separation, including oil-water separation and stabilization and sour-gas compression, two trains of amine-based acid-gas removal, two trains of Claus sulfur plant and tail-gas treating, one common gas-processing plant, one shared on-plot utility block, and one shared control room.

CURRENT TENGIZ PROJECT (FIFTH TRAIN)

The current Tengiz project builds on the existing infrastructure. De-bottlenecking in past expansion has led to the situation that the sulfur plant capacity exceeds requirements because H2S levels have in practice been not only lower than expected but also lower than the plant was designed to handle. It was decided that there was sufficient margin to handle existing sour gas flows and the flow from a new train.

The new fifth train now being constructed as a result will have utilities, a plant-wide control room and a gas-processing plant that can handle excess gas from KTL 1 and 2 as well as the new train.

FIFTH TRAIN OPTIONS

An in depth study was carried out to decide what the best use of the extracted oil. There were three main options under consideration.

The first option considered for the plant was converting the LPG to fuel. The most significant advantages of this would be: a significant reduction in flaring sales gas, a reduced risk to market LPG and reduced logistics and safety problems due to lower export volumes. Disadvantages include a high necessary capital expenditure due to the need to construct a gas export line, a low net present value, the cost of converting gas turbines, the requirement to operate the demethaniser colder and the necessity of burning excess non-sales gas.

The second option considered was to sell the LPG direct to the market. The advantages would be that there is a broad market for the products, it would minimise flaring, have a good net present value, use conventional processes and use available fractionation equipment. Disadvantages include having to store, load and export large quantities of LPG, the transportation logistics of LPG, uncertainty in the LPG market and a relatively high cost.

The third option considered was converting the LPG to liquids. There are several advantages to this approach. It would retain the focus on the core business objective of exporting oil by increasing crude production by 2,500 tons per day. As no flaring would be necessary, this option would be relatively environmentally friendly. There would be a potentially higher value of the product gasoline under a liquids scheme. The scheme would also have the advantage of exploiting a diversity of export outlets. The disadvantages include a high necessary capital expenditure, the use of technologies new to TCO, higher operational complexity and additional utility requirements.

The LPG to market option was the one recommended and approved.

TENGIZCHEVROIL PARTNERSHIP (TCO)

The TengizChevroil partnership has Chevron as its major partner (with 50% ownership of the joint venture). Mobil holds a further 25%. Kazakhstan owns a 20% share, and the smallest share belongs to the Russian Lukarco, which holds 5%.

Click here for printable version