Accurate routine core porosity measurements are critically important in tight gas sands. Because of a growing concern that current routine core analysis may not be reliable at low porosity a study was conducted to verify and improve, as needed, the routine service laboratory procedures normally used.

Routine analysis of ambient porosity was performed by a service company laboratory on 242 core plugs from the Travis Peak formation of a well in Panola County, Texas. Twenty of the plugs were then analyzed by two additional service company laboratories for porosity. Each of the three laboratories had problems with their porosity results, which would normally have gone unnoticed. After reruns, agreement among the labs was excellent, with an average standard deviation of about 0.25 porosity units when comparing one lab against another.

In order to improve reliability of routine porosity analysis, recommended practices and quality control procedures are presented. In addition, basic methods of porosity measurement are reviewed along with accuracy to be expected from each method.

You can access this article if you purchase or spend a download.