Abstract
An investigation of the performance of a group of 38 Bakken, Montana and North Dakota, horizontal wells was conducted for the purpose of assessing the relative benefit of premium ceramic proppants compared to 20/40 white sand and other ceramic proppants. The observed production histories of the wells, normalized for reservoir quality, severity of pressure drawdown and treatment type and size, were used as the basis for the comparison. The primary performance metrics employed were: apparent or effective fracture half-length normalized for the amount of placed proppant, sustainability of the reservoir/wellbore connectivity, impact of artificial lift installation, incremental oil equivalent recovery at various points in the production histories and impact of rate of pressure drawdown. The premium proppants had similar benefit, while the third ceramic proppant actually performed more poorly than the 20/40 white sand.
Sensitivity to the various damage mechanisms, such as rapid reduction in surface flowing pressure, the impact of shut-ins and delay to artificial lift installation are discussed in the paper. Based on equivalent oil recovery, there is clear evidence of a completions related point of diminishing returns. All of these observations call into question the "minimum cost" well management strategy. Benefits are derived not only from significantly better hydrocarbon recovery and longer apparent fracture length, but less damage during shut-ins and artificial lift installation, along with less sensitivity to pressure drawdown.
