Evaluate the Effect of pH on the Mixed Brine and Chemical Solutions

The purpose of this study is to observe the effects of a superabsorbent polymer (SAP) when it is introduced to brine solutions containing Calcium ions at varying pH values. When injected into an oil well, a superabsorbent polymer will swell, blocking high permeability zones. The swelled polymer will decrease reservoir heterogeneity, diverting injected water to oil rich zones/areas of the formation. Understanding the kinetics of an SAP is crucial to its proper employment. However, when the polymer is introduced to brine solutions containing calcium, reactions involving the ionization of the sodium crosslinker of the polymers result in the destruction of the polymers and the formation of a precipitate. In an attempt to solve this problem, pH values of various concentrations of Calcium Chloride and Sodium Chloride in deionized water solutions will be varied and introduced to polymer samples to determine if lowering the pH can prevent precipitation. The procedure includes first introducing hydrochloric acid to brine mixtures, mixing and agitating the polymer with the brine solution, and lastly recording the results. The measurements to be recorded will include the volume of the polymers before, during, and after the swelling process. From this data, the swelling ratios of the polymer samples will be calculated, graphed, and contrasted appropriately according to time intervals and the pH of each sample. By following this procedure, the data shows that a very low pH can significantly inhibit the extent to which the polymer precipitates out with Calcium ions. Temperature tends to decrease polymer volume in brines with pH values above the 1–2 pH range, while pH values in or below said range increase in volume substantially.