Paper: West Texas San Andres San Fracs

The San Andres formation in the North Permian Basin in West Te.xas typically requires stimulation to be economically productive. Acid fracs are effective at increasing production but require frequent repetition due to steep declines. In the past, a comparatively small number of wells were sand-fraced and had limited success. The nature and degree of stresses in and bounding the productive zone typically result in frac treatments growing vertically into high mobility water zones. Techniques such as plugging back existing perforations and controlled fluid viscosity and pump rates combined with DataFR4Cs allowed the 35 wells covered in this paper to be fraced with controlled dimensions. This prevented the fracs from growing into adjacent water zones. The subject wells which were sand-faced since 1993 increased from an average production rate of 12.7 bopd to 35 bopd with an average 28.8% decline. The average water production increased from 25 to 50 bwpd which represents only a 2-fold increase in water compared to a 3-fold increase in oil production.