Article Archive
Article Archive
- Introduction of Cement Slurry System (Part 1)
- Introduction of Cement Slurry System (Part 2)
- Introduction of Cement Slurry System (Part 3)
- Introduction of Cement Slurry System (Part 4)
- High Temperature and High Pressure Cementing Technology
- Low Density Cementing Slurry Technology
- Anti Gas Channeling Cementing Technology
- Drag Reducing Agents (DRA) or Drag Reducers (DR)
- Nitrogen Surfactant Compound Huff and Puff Technology
- Oil Washing Technology for Increasing Production
Known drag reducers are mainly olefin polymers, polyisobutylene, copolymers of butene and isoprene or their hydrogenated polymers, polyethylene, ethylene and propylene, or copolymers of them and other olefins, copolymers of butadiene and isoprene or styrene, etc. Some non hydrocarbon polymers, such as polysiloxane, polyacrylate or polymethacrylate or other olefinic carboxylates, copolymers of carboxylic ether and alcohol, were also tested. However, no matter what kind of polymer, as a drag reducer, it requires ultra-high molecular weight. Generally speaking, the molecular weight of drag reducers is 20, 3 million, or even more than 10 million. The larger the molecular weight and the longer the main chain, the better the drag reduction effect. The increase of molecular chain of drag reducer is beneficial to drag reduction, but it reduces the shear resistance. At present, the best solution to this problem has not been found.
Raw Materials of Drag Reducer
Many compounds can be used as drag reducers, but up to now, the most effective and widely used are poly (C 4-C 14 α 2-olefins), especially poly (octyl) and decane-21. The raw material of drag reducer can be either single olefin or two different olefins, block polymerization or copolymerization. The raw material composition affects the randomness, flexibility and elasticity of the polymer, which is finally reflected in the drag reduction performance. The polymerization of multi-component raw materials and the addition of non olefinic components such as alkenyl carboxylate and alkenylamide can have a great impact on the polymerization results and product performance.
Synthesis Method
Generally, Ziegler 2nata method is used to synthesize drag reducers. The characteristic of this method is that the requirement of equipment and pressure is not high, and the degree of polymerization dispersion and structure irregularity are high. The preparation of catalyst, crystal type, polymerization conditions and impurity content in raw materials can affect the product quality sensitively.
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