Development of a New Squeeze Scale Inhibitor for Mitigating Formation Damage for High TDS High Temperature Tight Carbonate Reservoir

摘要

The development of effective scale squeeze inhibitors in tight carbonate reservoirs with permeability less than 5md is still a big challenge, especially for high Total Dissolved Solids (TDS) and high temperature wells. The formation damage is one of the major considerations in high TDS, high temperature, and tight carbonate reservoirs as it can be caused due to fines mobilization, carbonate reservoir dissolution and collapse, and scale inhibitor compatibility issues. For the development of any scale inhibitor for squeeze application, the product must also demonstrate good inhibition performance, long squeeze life and accurate residual analysis at low concentrations. This paper will demonstrate a logical design procedure to develop a new scale inhibitor suitable for a challenging high TDS, high temperature tight carbonate reservoir through squeeze application. The new scale inhibitor has been shown to be non- damaging to tight carbonate reservoir material under high temperature high TDS conditions, along with excellent retention and release characteristics. The results of a comprehensive testing program, including compatibility, formation dissolution, dynamic tubing blockage and core flood tests will be presented that will highlight the development of a non-formation damage scale inhibitor suitable for the high TDS high temperature tight carbonate reservoir. In addition, the potential mechanisms of formation damage will be addressed. The impact of calcium tolerance, pH and molecular chemistry, carbonate reservoir dissolution and lab test procedure will be discussed compared to some traditional phosphonate and other polymeric scale inhibitors.