Scale inhibitor qualification: evaluation for treatment in Brazilian pre-salt fields

Abstract

Inorganic scale deposition is one of the main challenges related to the ow assurance in the Oil & Gas Industry. The pre-salt oil elds has been becoming very important, especially for the Brazilian market. The operational conditions in these types of scenarios are extremely favorable for precipitation of salts. The main factors for this include high salinity, high temperature and considerable changes on the pH of the produced uid. For this work, it was possible to predict the scale indexes of some scenarios from Brazilian pre-salt elds throughout software simulations and then, a development of a suitable scale inhibitor. The chemistry showed great performance in avoiding scale precipitation for a long period of test as well as compatibility with high calcium brines. The analyzes carried out included projections on the Scale Soft Pitzer software to evaluate the thermodynamic conditions of the system, compatibility tests with brine, and tests on the DSL ("Dynamic Scale Loop") equipment, in order to verify the performance of inhibitors under dynamic conditions. The MIC, "minimum inhibition concentration", found for the PAPEMP based chemical evaluated, was a low one, resulting in a very economical solution for applications in Pre-Salt elds.