Proppants and their effect on the production of wells are not thoroughly understood. When selecting a proppant, operators deliberate: “Do I purchase a low-cost proppant to reduce completion costs or do I spend more for higher conductivity to increase long-term production and greater return on my investment?” Good well data can be difficult to obtain and completion designs can vary. Hence, only a few existing case histories provide apples-to-apples comparisons of long-term production performance based on the use of different proppant types.
Continuing our prior research (SPE Paper 169544), we present data that will help operators make informed decisions when selecting proppants for optimizing Bakken wells. To investigate effectiveness of different proppants, researchers tracked long-term production rates of several comparable well sets. For example, in the first study, three wells on the same pad in the Haystack Butte Field in McKenzie County, North Dakota were completed by one operator. A second study included 11 Bakken wells fractured by another operator in the Grail Field in McKenzie County.
All three wells in Haystack Butte Field were hydraulically fractured with similar completion methods. The only significant difference was the proppant type. One well used 100% uncoated sand, another well combined 45% uncoated sand with 55% resin-coated sand, and the third well used 45% uncoated sand and 55% ceramic proppant. The well completed with sand and ceramic proppant did not have the highest initial production rate (IPR), but had, on average, 20% higher production over a 365 day period. The well where sand was combined with resin-coated sand produced a higher IPR. However, over 365 days, that well's production was outpaced by the other two wells with the sand/ceramic well delivering the best long-term production of all three. Similar findings were confirmed among the wells in the Grail Field. This study focused on 11 Bakken wells that used sand with a tail in of 30% to 40% ceramic proppant, sand with a tail in of 30% resin-coated sand, and sand with 50% higher volume. It also indicated that using a high percentage and high volume of ceramic proppant delivers superior long-term economic benefits in Bakken wells.
These findings, in addition to others outlined in the paper, challenge the preconception that wells completed using ceramic proppant should deliver higher initial production rates. Time and again, the findings demonstrated that the long-term production of Bakken wells completed with ceramic proppant significantly outperforms wells completed exclusively with other proppant types. Moreover, data demonstrates that compared to sand-only completions, resin-coated sand helped improve initial production but did nothing to improve long-term production, especially in deeper wells.