Abstract

This study reviewed and assessed some of the inhibition techniques used in the industry with regards to handling oilfield scales in general and silicates scales in particular. Conventional scale inhibitors used are facing restrictions world over, due to their ecotoxicity and non-biodegradability, which has led to the call for green scale inhibition in the oil and industry. Due to the inefficiency of the conventional primary and secondary recovery methods to yield above 20-40% OOIP, the need for Enhanced Oil Recovery (EOR) techniques to recover a higher proportion of the Oil Originally in Place (OOIP) has become vital. Alkaline/Surfactant/Polymer (ASP) is one of such techniques and has proven successful due to its ability to raise displacement and sweep efficiency. Despite its popularity as a potentially cost-effective chemical flooding method, it is not without (its) problems, one of which is the excessive formation of silicate scales. Silicate scale is a very serious problem in the oil and gas industry; which forms in perforation holes, casing surface, tubing and surface facilities. During an ASP flood, as the flood progresses into the production well, liquid produced from different layers intermingle, leading to a rapid decrease in the pH value of the mixed waters. Other factors such as temperature, pressure, divalent cations present also play some roles, but pH variation plays the major role. These among other factors facilitate precipitation of silicates and its deposition on tubing, surface pipeline, pumps and surface production facilities resulting in excessive production loss; increasing the average work over periods, which influences the production and causes low commercial effectiveness. Green scale inhibitors are considered as alternative scale inhibitors due to their value-added benefits to the environment with respect to the methods of treating oilfield scales. It is recommended that the industry should shift to the green technology as an alternative scale inhibition method so as to protect the environment.

Keywords:

ASP, green scale inhibitors, OOIP, silicate scale, scale inhibition, scale inhibitors,

References

Competing interests

The authors have no competing interests.

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The authors have no competing interests.