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 writers have been collecting cores from various producing formations; 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, more than 80 per cent showed an increase in permeability when acidized in the laboratory. The average permeability increase was more than 300 per cent. The average acid solubilities of the more than 80 different oil-producing sands was 8.5 per cent.
The writers have also included data on compressive strength of the cores before and after acidizing and chemical and X-ray analyses of typical sands.