Team:CMUQ/HP/Gold Integrated
1. Job title, experience and nature of work:
Taher Alkilani, is an oil and gas professional with 21 years experience in process, production, corrosion & scale. Taher is an expert in corrosion control; in depth hands-on experience in Microbial Induced Corrosion (MIC) monitoring and control, pipelines integrity management, well completion integrity management, failure analysis and materials selection.
2. What is the process of oil extraction in Doha?
Oil is extracted from subsea wells. A process called oil seeping is used to exctract the remaining oil. This process involved pumpng sea water into the well from different direction, and based on the fact that water is denser than oil, the remainnig oil is ‘sweeped’ up into the pipeline and exctraceted to be putified later.
The oil and water separation happens at high temperatures, this is because low temperatures minizes separation based on different densities.
Pipelines are Subsurface and carry carry mixed fluids, therefore, to get crude (pure) oil:
○ Dewatering: this is the removal of water
○ Degasing: removal of gases, which can be used as gas lift to enhance production, export for sale, or used directly as fuel
Once the crude oil is obtained above sea level, it is carried to mainland in VLCC, very large crude carriers.
3. How many barrels are extracted everyday?
Approximately 350,000 barrels of unpurified oil per day
4. What is the diameter of underwater pipelines used in Qatar?
Range of pipe diameter: 6 to 48 inches
5. What is the temperature and pressure of the oil when it is extracted?
The oil temerature is very high, and it’s pumped at high pressures in the pipelines
6. What does Oxy currently do to combat MIC in the oil pipelines?
Corrosion happens in well-to-separator-tank pipes, because of the sea water that is pumped in order to sweep the oil. This is because sea water provides ideal environment fot SRB growth. There are 2 types corrosion that happens in these pipes:
o External corrosion, which can be solved by a method called cathodic protection and cement coating.
o Internal corrosion, which is the big challenge: Acid gases: CO2 , SRB produces H2S gives iron sulfide which is the film but it’s protective for the pipeline. De-aeration removes oxygen → Iron oxide causes corrosion
The current measure used are:
o Chemicals: biocides (Biodegradable chemicals are cheap and effective) → Biocides: weekly batch, high concentration for a short period of time, e.g Gluteraldehyde. Need to sample water before adding biocide, because different biocides require different conditions to work effectively, two types of water-oil mixtures:
o Sweet: does not contain H2S
o Sour: contains H2S, which casues the biocide Glutaraldehyde (Biocide) inactivation
o Process control: prevent the pipeline from being stagnant (Deadleg: related to bacteria, which is when there’s not enough flow in pipe: 1m/seconds flow considered slow and is suitable for bacteria to grow)
o Material renewal: localized
7. What are the current sampling protocols being utilized in the industry?
• MPN most probable number : inoculate in media but takes time, accurate (two weeks)
• ATP : instantaneous but will give count to all bacteria not just SRB
• NACE method to find bacterial population in oil systems: 102 - 104 bacteria is alarming: https://www.enes26.ru/forum/attachment.php?attachmentid=583&d=1409765851
• Sample both locations before pipes go into water and after they come out. Comparison of colony count is done; end of pipeline shouldn’t have more bacteria.
