Low-permeability reservoirs, including the Haynesville, Utica and Montney, have become the focus of many major | oil and gas producers. At over 10 million acres, the Montney is Canada's largest oil- and gas-producing field. -With multiple producing intervals, which combined are up to 1,000-feet thick, it's no surprise the Montney is also Canada's most productive play. The Montney is overpressured, self-sourced and productive across all fluid windows. This case study analyzes a multidisciplinary data set of geological and engineering data, including digital wireline logs, core and completion data, to determine the key drivers of production in the play.
In 2016, the Montney's daily output of 5.2 Bcf/d accounted for 30% of Canada's gas production. In comparison, the Haynesville and Utica produced 5.8 and 3.6 Bcf/d, respectively. The variability in the Montney's fringe areas must be understood to determine what factors can drive these areas to further success. The Gold Creek development area has less than 100 horizontal wells that primarily target the liquids-rich Middle Montney zone (4,000- to 6,000-feet deep). The North Montney fringe development is targeting a relatively shallow (~4,600 feet), overpressured Upper Montney zone, with the Middle and Lower Montney as additional targets. Liquids percentages in the Northern Fringe area are ~ 11 %, lower than Gold Creek at 20%. Potential for higher liquids yields make these fringe areas prospective areas of interest.
The Montney is a quartz-rich, siltstone-dominated, tight Triassic reservoir deposited in an arid environment along a passive margin slope setting with intrabasinal tectonics; it is found at depths of 4,000 to 10,000 feet. Areas of interest are the new developments along the fringes of the play in northeast British Columbia (NEBC), north of Fort St. John (Attachie), and southeast of Grande Prairie (Gold Creek) in Alberta. To perform the analysis, a regional stratigraphic and petrophysical model of the Montney divided the play into three zones into which all horizontal wells were allocated. The multidisciplinary data set was then put through a multivariable analysis to determine the most influential factors in low-permeability conditions.
The study analyzed 2,000 wells with digital logs that formed the geological model delineating where horizontal wells were drilled. In addition, completion and production data from ~10,000 wells were used to create type curves based on operator, year and region to account for geological differences. Results of this study identify the parameters that make the Montney successful, especially in new areas of development, and highlight the benefits of a multidisciplinary analytical approach to characterize low-permeability rocks. The ideal geological and engineering parameters targeted in the basin for each stratigraphic horizon will be discussed.
