We released the 2016 Sustainability Report today. The publication gathers information on the company's operating, economic, social, and environmental performance. For the first time, the document correlates with the United Nations (UN) Sustainable Development Goals (ODS), a set of 17 goals that address issues such as climate change, the sustainable use of ocean and terrestrial ecosystems, economic growth, and sustainable consumption and production, among others. Another report novelty is the representation, through the business model, of our performance in sustainability and of the determining factors for its results and capacity to generate value.
Included in the data disclosed in the document is the progress we have made in our environmental management. We have invested in programs and actions for process optimization and emission mitigation, such as facility revamps, in the use of more efficient equipment, in the increased use of natural gas, in project and operating practice standardization, and in investments in research and technology. In 2016, there was a reduction of about 15 percent in the absolute greenhouse gas emissions compared to 2015.
Water reuse actions also yielded relevant results. In 2016, we reused 24.8 million cubic meters of water, which corresponds to 11.5 percent of our total demand for freshwater and sufficient to supply, for example, a city of approximately 600,000 inhabitants for a year.
The report also presents the research lines that we have developed together with partner institutions that contribute to the evolution of business and to the technological progress of the oil and gas sector. A total of R$1.8 billion was invested in research and development (R&D) projects in 2016. Of total investments, R$548.5 million were earmarked for collaborations with 90 universities and research institutes in Brazil and with 21 international institutions. In 2016, we applied for 24 patents in Brazil and 38 abroad.