Rock Lithology-Based Laboratory Protocols and Best Practices for Polymer Screening for EOR Application in Conventional and Harsh Reservoirs

Abstract

EOR applications have seen a recent shift in focus from onshore use in sandstone formations to more complex environments, such as carbonates and reservoirs in offshore settings. This explains the attention given thus far to develop EOR screening criteria mainly for use in sandstone reservoirs, where significant success has been observed. Screening of chemical EOR applications is mostly centered on the evaluation and characterization of fluids and some formation properties without explicit consideration of the formation lithology in some cases. Standardized lithology-based laboratory protocols are required to avoid cost overruns on screening and the design of fluid formulations for specific use in a particular reservoir. Such is the case of carbonates, typically highly heterogenous formations often found in high salinity and temperature conditions, where most available chemicals have limited applicability, and where standard screening protocols are not reliable or lack proper detection limits. In this chapter, we present an integrated laboratory workflow for polymer screening with recommended protocols based on formation lithology. It was derived from successful polymer application in the O&G industry and our own experimental work over the last two decades. Its use results in better quality data with time savings, contributing to a better understanding of the field application.