Abstract

During the productive life of a well, it is not uncommon to observe a noticeable increase in water production. This water production is often defined as the Water - Oil Ratio and is abbreviated as W.O.R.

Typically the increasing W.O.R. can be attributed to a natural rise of the water level, often accelerated by water coning. A second common cause may be from water fingering or an early breakthrough of the water in a high permeability streak in the reservoir during a secondary recovery operation, such as water flooding.

This paper deals with an effective method of reducing the W.O.R. of a well by placing a polymer into the matrix of the producing interval through a surface injection operation.

The polymer injected into the producing formation reacts with the rock surface of the reservoir, and changes its interaction with the producing fluids. As a result, there is a change in the relative permeability on the rock surface to water and oil. A presentation of successful case histories is included at the end of this paper.