200 wells completed in the Berea and Devonian shale formations were studied. Wells that were stimulated with nitrogen foam plus proppant outperformed treatments with nitrogen alone. Even if the cost of proppant doubled the treatment cost, it was a good investment. In lower perm areas (k<0.01 md) wells receiving proppant will recover 295 mmcf/well compared to 176 mmcf with N2 alone. This is a 67% increase in reserves.
This paper presents results of a production data comparison and an economic analysis of two stimulation methods (nitrogen foam with proppant versus nitrogen only) pumped in more than 200 wells owned and operated by Equitable Production Company. The wells, located in Pike County, Kentucky, were completed in the Berea and Devonian shale formations, and each formation was stimulated separately. About half the wells were stimulated with nitrogen foam containing proppant; the other treatments consisted of nitrogen only.
These wells were drilled in the 1990s and sufficient production data were available to make definitive comparisons. The results indicated that the wells treated with foam containing proppant significantly outperformed the wells treated with nitrogen only. Economic results also illustrated that it is more profitable to pump nitrogen foam with proppant even though the cost of the treatment is more than double.
In furtherance of this study, the operator is currently pumping foam with proppant in wells within the study area and is identifying additional acreage for use of this stimulation treatment. Existing wells are also being evaluated for restimulation potential. The results of this paper are noteworthy for the Appalachian Basin because many operators pump multiple stages of nitrogen-only treatments.
Author(s): Jr., R.J. MacDonald, J.H. Frantz, G.W. Merriam, Schlumberger; S.T. Schlotterbeck, Equitable Production Company
Paper Number: SPE 77464