Why Does OCTG Pipe Scale?

The main reasons for OCTG pipe scaling include the following aspects:

1. Water quality problems

Calcium, magnesium and other ions in the water adhere to the inside of the pipe to form scale. As time goes by, the scale gradually increases, seriously affecting the flow and heat dissipation performance of the pipe.

2. Operation status problems

The operation status of the pipeline will also affect the formation of scale. For example, if the pipeline speed is too slow, the temperature is too low, the flow is too small, etc., scale minerals will be deposited on the inner wall of the pipe to form scale.

3. Pipeline material problems

The material of the pipeline will also affect the scaling. For example, if there are defects, wear, oxidation and other manifestations on the inner surface of the steel pipeline, it is easy to produce scale.

4. High mineralization of produced water

Highly mineralized produced water contains high concentrations of ions, which are deposited on the inner wall of the pipe to form scale.

5. Changes in temperature, pressure, and pH value

During the mining process, changes in temperature, pressure and pH value will also lead to the formation of scale. For example, the main reason for scaling in Daqing Toutai Oilfield is that the injection water contains a large amount of scaling ions. At the same time, changes in temperature, pressure, and pH value during the production process lead to the formation of calcium carbonate and iron compound scale.

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The hazards of scaling in OCTG pipes:

‌1. Affecting oil production efficiency

Scaling will cause the inner diameter of the pipeline to decrease, the flow of oil products to be blocked, and the transportation efficiency to decrease.

‌2. Increase operating costs

Scaling will increase the resistance loss of the pipeline, leading to increased energy consumption, and require frequent cleaning and maintenance, which increases operating costs.

‌3. Safety hazards

Severe scaling may cause pipeline blockage and cause safety accidents such as high-pressure explosions.

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The methods for preventing and solving scaling in OCTG pipes include:

‌1. Regular cleaning: Use professional cleaning agents and equipment to clean the oil pipe regularly to reduce the risk of pipeline damage.

‌2. Improve the operating status: Increase the speed, flow and temperature of the pipeline to reduce the incidence of scaling.

‌3. Choose the right pipe material: Use plastic or fiberglass pipes with smooth inner surfaces to reduce the possibility of scaling.

‌4. Strengthen water quality treatment: Control the concentration of ions in water, lower the pH value, etc. to reduce scaling.

‌5. Use anti-corrosion and anti-scaling agents: Through screening and compounding experiments, the best anti-corrosion and anti-scaling agent formula is obtained to reduce the occurrence of corrosion and scaling.

Article source: https://article-realm.com/article/Business/70073-Why-Does-OCTG-Pipe-Scale.html