Experimental Study on Simulation of Formation Water Scaling Under High Temperature and High Pressure Conditions

With the advancement of the global oil and gas resources exploitation process, the water production of oil and gas fields increases year by year, and the temperature and pressure of the reservoir and wellbore change dramatically, which makes the formation water scaling problem especially serious. The scale generated in oil and gas fields will block the wellbore, reduce the area of oil and gas circulation in the wellbore, and the oil and gas transportation efficiency will decrease, and the scaling in the near-well zone will lead to the decline of formation permeability, and in more serious cases, it will even lead to the scrapping of oil and gas wells, increase the maintenance cost of wells, and reduce the economic benefits of oil and gas fields. In this paper, we investigated the scaling law of formation water through high temperature and high pressure scaling experimental device, and determined the consumption of calcium ion concentration through EDTA titration experiment to derive the influence of temperature, pressure, pH to investigate the influence of environmental changes on the generation rate of calcium carbonate scale. The experimental results show that as the temperature increases, the scaling rate of formation water gradually becomes larger, but the effect of changing the pressure on the scaling rate of formation water is not obvious, and the increase of pH value will increase the scaling tendency of calcium carbonate scale in formation water. Therefore, it is possible to change the scaling tendency of formation water by changing the environmental conditions around the formation water in the production site, which provides a theoretical basis for the formulation of the scaling prevention and control program for oil and gas wells.