Essentials of Polymer Flooding Technique

Chapter six Engineering

Polymer selection is a critical part of the design of a chemical enhanced oil recovery (EOR) project. Once the right chemistry and molecular weight have been selected, it is necessary to design injection facilities so the macromolecules experience as little modification as possible during the entire journey from the surface down to the reservoir. The previous chapters detailed the main factors affecting polymer stability. Obviously, when designing injection facilities, the main goal is to limit any chemical or mechanical degradation as much as possible. Specific guidelines have been developed, some of which are detailed in this chapter.

6.1. Preliminary Requirements

6.1.1. Water Quality

Field experience has shown that a well‐performing waterflood with clean water and good injectivity will generally translate into a well‐performing polymer flood. In any waterflood, the presence of oil carry‐over and suspended solids in the injection water can have a detrimental impact on long‐term injectivity. The fewer contaminants, the better. The polymer itself is not influenced by the presence of oil or solids, even though flocculation can occur with particles. Oxygen is more problematic both for the polymer (degradation) and the injection facilities (corrosion, bacterial development). Its concentration should therefore be decreased as much as possible. ...