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The widespread use of chemicals on oil and gas reservoirs composed of limestones has attracted the attention of engineers and geologists to the many wells producing from sands. The early attempts to treat wells producing from sands were not uniformly successful. During the past several years the authors have been collecting cores from various producing horizons; most of them have been studied in the laboratory. In certain areas chemicals have been used on sands with good results. This paper discusses the results of the laboratory work and contains a compilation of well treating data. Of the more than 300 cores studied, over 80% showed an increase in permeability when acidized in the laboratory. The average permeability increase was over 500%. The average acid solubilities of the more han 80 different oil-producing sands was 8.5%.

The authors have also included data on compressive strength of the cores before and after acidizing and chemical and x-ray analyses of typical sands.

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