![]() ![]() The true vertical depth of the Utica/Point Pleasant can range from 10,000 to 13,500 feet, and pore pressures are as high as 0.95 psi/foot in the deeper parts of the play in southwestern Pennsylvania. In addition, economic sensitivity analysis was run to estimate the incremental increase in EURs needed to justify delaying production by controlling pressure drawdown. ![]() Production performance was investigated using multiple reservoir techniques, including superposition plots, diagnostic plots, history matching, and decline curve analysis. In the overpressured Utica/Point Pleasant play, West Virginia University undertook a study to analyze the productivity of CONSOL Energy-operated wells that use both managed and unmanaged pressure drawdown production practices. In the Haynesville, Chevron coupled a geomechanical reservoir simulation model with a large dataset to show that effective stress on fractures was influenced by operational changes, and that a managed drawdown schedule improved EURs by up to 15 percent, mainly by reducing the effective stress on unpropped fracture regions. In this case, Devon implemented flowback operating procedures and rate transient analysis to significantly increase value and drive operational efficiencies while minimizing the potential risk of damaging completions through uncontrolled drawdown. In the Eagle Ford, for instance, a Devon Energy project found that aggressive pressure drawdown damaged well performance, while conservative pressure drawdown enhanced near-term economic value. Finding the optimal daily rate that balances production with drawdown can have significant positive economic impacts by avoiding reservoir damage and recovering more hydrocarbons over a well’s life cycle.įield examples from shale plays demonstrate the importance of pressure management. There is a balance between the rate at which a well is produced and its economic feasibility over time. In ultralow-permeability reservoirs, the impact of pressure drawdown management on well performance and reserves recovery is mostly related to pressure-dependent permeability. Unmanaged pressure drawdown also can create geomechanical issues in high-pressured reservoirs, and lead to a rapid transition from transient flow to boundary-dominated flow in unconventional gas reservoirs. An example is hydraulic fracture conductivity impairment caused by proppant crushing, embedment and fines migration. Studies in shale reservoirs indicate that aggressive or unmanaged pressure drawdown can have a number of detrimental consequences on flow capacity, EURs and well economics. The industry’s experience in unconventional plays such as the Eagle Ford, Haynesville and Utica shales underscores the importance of balancing high initial production rates with pressure drawdown considerations to potentially increase well productivity, profitability and estimated ultimate recovery. MORGANTOWN, W.V.–The ultimate goal in shale reservoirs is to produce wells at the highest economic rate while maintaining the integrity of the reservoir and completion, ensuring the maximum value of each producing asset over time.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |