Inferring Injection Returns from Chloride Monitoring Data

Abstract

Reservoir chloride concentration and injection rate data have been used to identify injection return flow paths in the reservoir. General trends of chloride and injection rate with time were isolated from their respective short-term variations using the wavelet transformation approach. Multiple regression techniques were then used to correlate the isolated short-term variations in chloride with corresponding short-term fluctuations in injection rates and subsequently to quantify the degree of connectivity between injectors and producers. Data from Palinpinon-I field in the Philippines were analyzed using the outlined method and results were verified successfully against tracer test data and qualitative field observations. Results of analysis of chloride and injection rate data from Dixie Valley field in Nevada illustrated that multilinear modeling is not suitable for analyzing data sets that lack sufficient time variability or "texture".