Details of what will be the world’s longest heated crude oil pipeline, carrying oil from Uganda to the Indian Ocean coast of Tanzania, have been revealed showing how a cocoon of electrical and fibre-optic cables along its entire 1443 km length will provide heat and real-time satellite surveillance to prevent leaks.
The East Africa Crude Oil Pipeline (EACOP), due to cost around US$4 billion, is the keystone of Uganda’s booming oil and gas sector development, scheduled to pump its first crude oil in 2025.
“With its extensive fibre-optic network allowing online connectivity, EACOP promises to be one of the world’s smartest and safest bulk pipelines with real-time monitoring along its entire length via satellite,” said Dozith Abeinomugisha, Director in-charge of Midstream developments at the Petroleum Authority of Uganda (PAU).
Safety staff will be able to detect any pressure change indicative of a leak, sabotage or pilfering within seconds and isolate the relevant section of pipe to keep environmental damage and commercial loss to a minimum.
Both the PAU and EACOP’s holding company will have real-time monitoring centres at their respective offices to receive immediate updates via satellite uplink. This means that monitoring is not dependent on local mobile phone or radio networks, guaranteeing greater reliability.
The remote data monitoring and transmission technology known SCADA (Supervisory Control and Data Acquisition) works even though the pipe will be buried between 1 and 3 metres underground, providing safety staff with a complete, live picture of the entire pipeline.
With EACOP planners aware of the importance of mitigating climate change, renewable energy will be used as much as possible for all pumping, heating, monitoring, and storing. The Ugandan section will be entirely carbon neutral with 80MW of solar and hydro providing all the power needed while work is continuing on the Tanzanian side to develop similar levels of renewable capacity.
The design and construction of EACOP, which began in 2018, has been one of the greatest challenges of African infrastructure engineering in recent history.
First, engineers had the challenge of how to pump crude oil that at surface temperature is not in liquid form and therefore resistant to flow, but more in a waxy state reminiscent of shoe polish.
Not uncommon in the oil sector, where so called `sweet’ crude of a fine quality such as Uganda’s solidifies after being pumped up from high-pressure, high-temperature reserves deep underground, the normal solution is to heat pumping infrastructure to ensure it remains liquid.
But the colossal 1443 km length of the EACOP route, more than twice that of the current longest heated crude oil pipeline, which stretches 660 km across Gujarat state in India, posed an additional headache.
In order for flow to be maintained, the EACOP has to be kept at a temperature of at least 50 °C. Testing showed that if the crude oil is flowing at high rates under high pressure initial heating at the pipe head to 80 °C will be enough to keep it moving, as the rate of cooling is so slow it remains above the 50 °C threshold along its entire 1443km.
But if flow rates and pressure come down it will cool more as it moves, threatening to solidify and block the flow. To get round this, two heating stations have been added to the design, capable of boosting the crude oil temperature back towards 80 °C to ensure strong flow.
To keep it above 50 °C heating cables will run the entire length of the pipe using a technology known as Long Line Heat Tracing (LLHT) which works on a similar principle as a kettle element, using resistance to generate heat when an electric current passes through a specially chosen high resistance filament.
With temperature so critical, EACOP’s conventional 24 in. wide carbon steel pipe had to be carefully redesigned for heat and monitoring.
Uganda’s crude oil being sweet (with no corrosive impurities such as sulphur) means that the pipeline does not have to be lined on the inside as such high-grade crude oil has minimum corrosion effect on steel. So, for protection the pipe need only be lined on the outside.
In addition to a standard Fusion Bonded Epoxy (FBE) resin protective coating 400-600 µm thick on the outside, engineers have added a much thicker 70 mm `smart’ layer of insulation made from polyurethane, with special channels down which electrical heating element LLHT cables and fibre-optic lines needed for SCADA will be fitted.
The entire pipe will then be covered with an outer, hard, protective coat of 5-7 mm protective High-Density Polyethylene (HDPE), meaning EACOP will effectively have four layers: inner steel, epoxy resin, polyurethane and finally polyethylene.
So sophisticated is this layering that a coating factory is currently being built in Tanzania so that each 18 m length of pipe, already being manufactured in China, is sheathed correctly before it is sent out to be laid in the ground.
With safety a top priority for EACOP, high grade steel and welding between each 18 m length, tested at the time of laying and rejected if any faults are found, means the risk of internal leakage across the 25 year life of the pipe is reduced to almost nothing.
But to make sure, the SCADA system, constantly monitored by both safety officers and computer tracking algorithms finetuned through the latest machine learning technology, will pick up the slightest change in pressure indicative of a leak. The sensors can also detect seismic activity in case of earthquakes and warn operators to turn off the flow if there is a risk of a dangerous tremor.
Block valves are placed every few kilometres along the pipeline meaning that if a leak is spotted, the affected section can be isolated immediately and only a short section of pipe risks being drained.
In other African oil producing nations, pilfering and sabotage have a history of causing leaks. The plan to bury EACOP mitigates this risk considerably, according to planners. In addition, SCADA can detect any surface interference along the right of way should anyone try to dig down to the pipe.
For most of the route, burying is possible as the terrain was chosen so as not to be too rocky. This means that a 30 m wide corridor above the pipe will be demarcated and kept clear of any digging, quarrying or other activities that disturb the ground.
Livestock will still be able to graze as normal and some crops planted so the disruption to rural communities will be kept to a minimum.
Scouting for the EACOP route began in 2018, and after two years of consultation and surveying, it was decided the pipeline would arc for 296 km southeast through Uganda from the collection and pumping station at Kabaale in Hoima district, before crossing 1147 km in Tanzania to its Indian Ocean coast at Chongoleani village near the port of Tanga.
The route was chosen to minimise disruption to the local population and the environment, but this met a challenge close to the coastline where a steep slope in the terrain could potentially cause surges in pressure as the crude oil flows downhill at high angles. Two pressure reduction stations were added to the design to maintain the pressure for the project’s high safety standards.
“Local farmers and residents were consulted in both Uganda and Tanzania where the pipeline cuts across their land. Public information campaigns were launched to offer compensation to legitimate claimants for loss of land, assets such as buildings and grazing rights”, adds Mr. Ali Ssekatawa, Director for Legal and Corporate Affairs at PAU.
In Uganda the number of people affected is 3660 and in Tanzania, 9513. To date 90% in Uganda have accepted compensation packages, including 177 who have opted for new homes resettling them away from the pipeline rather than cash.
Negotiations continue but in the case of a failure to agree between EACOP planners and residents, both countries have a legal regimes under which land can be acquired by government through a transparent process of compulsory acquisition and compensation.
With the two already-licensed production areas covering the Tilenga and Kingfisher projects, both located in western Uganda around Lake Albert, scheduled to peak at 230 000 bpd production, an export pipeline is essential to maximise earnings for Uganda’s hydrocarbon assets.
The country is planning to build its own refinery to deal with local demand for petrol and other consumer products, one that will use up 60 000 bpd, meaning at the current planned peak EACOP will pump 170 000 bpd.
To allow for new production capacity from yet to be developed exploration areas in Uganda and changes in the levels of refinery consumption, EACOP has been designed with a maximum flow rate of 246 000 bpd.
This allows Uganda to build in added capacity over the next few years confident that the longest, heated, smart crude oil pipeline in the world can keep revenues coming in to finance economic upliftment and progress in the African nation.
“Uganda can be proud of its place at the cutting edge of pipeline technology with EACOP showing how committed the country is to develop its oil and gas assets responsibly, openly and profitably. Uganda will not only benefit through earnings from the sale of crude oil, but from the engineering and technical skills transfer driven by the EACOP project,” says Mr. Abeinomugisha.
Work is already advanced on the pumping stations, work camps and storage facilities along the EACOP route as well as the coating plant. The first 100 km of pipe (5600 sections each 18 m in length, all loaded onto a single bulk carrier) has been manufactured in China and is expected to arrive by ship in the Tanzanian hub port of Dar es Salaam within weeks. After coating and welding the first sections of pipe are due to be laid midway through next year.
Read the article online at: https://www.worldpipelines.com/business-news/21112023/details-of-worlds-longest-heated-crude-oil-pipeline-revealed/