The low-permeability Jurassic reservoir in Changqing Maling has been in the middle and high water cut stage after long-term development of water injection. In order to improve development efficiency and further explore a new way to enhance oil recovery of the reservoir. a significant development test and a polymer-surfactant flooding study were carried out in the Maling Beisan area in... https://www.megavitamines.shop/product-category/your-heart/