Effects of proppant selection on well productivity are demonstrated in a large case study covering 6,000 square kilometers (2,300 square miles) in Alberta, Canada. In 9 of 11 cases studied, wells fractured with ceramic proppant provided significantly higher gas production rates compared to wells propped with sand or other materials. The most frequently stimulated formation in the Western Canadian Sedimentary Basin is the Cardium formation of the Late Cretaceous period. Records indicate that across the basin the Cardium formation has received over 12,500 fracture stimulations during the last 50 years.
This study includes a review of 1,600 wells currently operated by 96 companies. On average, 156 new wells have been drilled annually since 2000. Record numbers of new wells were completed in 2004, and the number of Cardium wells completed in the last four years exceeds the total from the preceding two decades. A detailed database containing available fracture treatment and production data was compiled from government records and service industry sources. This paper summarizes a study of over 750 well stimulations.
Various stimulation strategies have been employed in the Cardium development. This paper examines productivity of hydraulic fractures propped with various materials and placed with a variety of fluid systems. Wells in this study were stimulated with as low as one tonne (2,200 lbm) to nearly 185 tonnes (407,000 lbm) of proppant per well in one to five stages.
Analyses suggest that significantly greater economic return can be achieved when fracture designs are optimized. In this study, the most common design was 60 tonnes (132,000 lbm) of proppant placed with a hydrocarbon-based fluid. For this treatment design, the average first year production for wells receiving 60 tonnes of sandwas 8.5(106) m3 (302 MMscf) of gas. Wells stimulated with 60 tonnes of ceramic proppant averaged 11.9(106) m3 (420 MMscf) production during the first year. Benefits vary with job size, fluid type, and other factors. The incremental cost of ceramic proppant is usually recovered within 30 days, generating a significant increase in profitability. At current gas prices, average return on investment achieved by optimizing proppant selection greatly exceeds 100%. Additional information is provided to assist fracture optimization strategy in the Cardium development.
Hydraulic fracturing is required to achieve economic production rates from most Cardium gas wells; in fact, records indicate over 12,500 stimulation treatments have been performed within this formation throughout the Western Canadian Sedimentary Basin (WCSB). Despite this extensive experience, no clear consensus has emerged from the various operators on fracture design optimization. The purpose of this paper is to evaluate the productivity achieved with various treatments. A detailed database was compiled from government and service industry records. Stimulation treatments are classified by fracturing fluid type, proppant type, and proppant quantity placed.
Description of Well Population The study area includes 1,600 wells located between 52– 18W5 and 56–23W5. This area encompasses portions of the Ansell, Cecelia, Dalehurst, Edson, Lambert, Medicine Lodge, Nosehill, Obed, Oldman, Peppers, Pine Creek, Sundance and Wild River fields.
