Abstract

For the past several years, Texaco has been dealing with the control and prevention of scale and corrosion under extremely high temperature conditions. This paper will discuss the specifics of our efforts to treat for scale and corrosion in two rather extreme environments. The first situation involves a number of high temperature oil production wells plagued with both severe corrosion and scale deposition. The chemical treatment program has had to deal not only with the high bottomhole temperatures, but also with the high concentrations of calcium in the produced brines and with the occurrence of calcite, iron sulfide, and zinc sulfide scale deposits. To our knowledge, very few, if any, scale inhibitors have been developed for use in preventing iron or zinc sulfide scale. Although the success of our efforts at controlling these scale deposits is still under review, the initial results, to be reported herein, are encouraging. Details of the corrosion treatment activities will also be discussed.

The second situation of interest involves the control of silicate scale deposition in Texaco's California steam flood operations. Current efforts involving the treatment of produced brines for use in steam generators will be briefly reviewed. In addition, data pertaining to the concentration of silica in the feedwater to the steam generators will be presented, along with similar data from other steamflood operators within California, in an attempt to establish a very general guideline for determining an allowable limit for silica concentration in steam generator feedwater.