Petroleum Engineering

Evaluation of Polymers and Polymergels for Water Shutoff in Oil and Gas Wells - Literature Study

The aim of this project is compilation and consolidation of knowledge about polymer technologies for water control of defined zones in wells. The first part of this review is the presentation of the best available technology together with summary and evaluation of published field test data. About 200 references of the last 20 years were included in this report. The selected references describe 80 different polymer treatments, mainly in oil wells.

In this study the basic chemistry of published polymers and polymergels is described and the results of laboratory investigations are presented. The dominating systems use polyacrylamid compounds, whose properties are modified by selection of copolymers and cross-linkers. Investigations of resistance of the polymers and gels to low pH-value and high salinity are seldom published.

The cited references contain almost fragmentary data that describe the geological structure, the main chemical composition and details of the handling procedure. Nevertheless viscosity and temperature behaviour of polymers are adjustable over a wide range. So the composition of the polymer system can be varied in order to fit the requirements of the field conditions. The success rate of polymer treatments correlates with the knowledge of geological and geochemical field conditions as well as the extent of preliminary investigations. It was about 75 % in the considered literature.