The desired product is a type of fluid called packer fluid, which is used to complete oil and gas wells. Packer fluid is a clear fluid without solids that is made of water-soluble salts. This fluid looks exactly like water, but its weight is almost twice that of water. Packer fluid is a completely transparent fluid, without solids and with high density, which is also very economical from an economic point of view, In this fluid, an attempt has been made to eliminate all the problems and disadvantages of past packer fluids and to produce an optimal internal fluid. This fluid does not contain any formate, chlorine and bromide ions, which significantly reduces the corrosion rate. By removing bromide ion, many problems of this fluid such as incompatibility with the environment, unavailability and high price have been solved. This product has very low corrosion which will reduce well maintenance costs. The packer fluid offered with a density between 70 pcf and 114 pcf has formed a wide range of different weights, which can be used for all oil and gas wells. The stability of this fluid at high temperature and having a low crystallization point makes it ideal for use in oil and gas wells. The members of Petro Sayal Amirkabir team were able to design a heavy and optimal packer fluid for the first time by using available and high-quality raw materials inside the country in a completely new and engineered way. This fluid replaces calcium bromide, which is primarily sourced from abroad, Calcium bromide is a toxic liquid that is harmful to the environment, but this product is environmentally friendly. The technical knowledge of this product has been acquired through internal research and development. So that in order to make this product, the inventors did a lot of research and tests on about 100 materials and finally succeeded in making such a product.