Modeling of quantifying proppants for stimulation reservoir volume fracturing in a shale hydrocarbon reservoir

摘要

Massive hydraulic fracturing (MHF) technology is widely used to increase the stimulation reservoir volumes in the development of shale hydrocarbon reservoirs by pumping large amounts of fracturing fluids and proppants at a high injection rate. However, fresh water dissipation and the flowback fluid pollution created by this technology brings serious environmental problems. Moreover, the post-production of MHF is uncertain and some fractured wells keep a low production level all the time. It is therefore necessary to find an economical treatment size to satisfy the actual geology position of shale reservoirs, such as mountainous and water shortage regions. The amount of proppant for MHF are a key parameter of treatment size, which also effect the volume of fracturing fluids and injection rate directly. A proppant quantifying model for MHF in a shale hydrocarbon reservoir was developed. In this model, the complex fracture network was characterized as the enhanced permeability area (EPA), and then a correlation was built between the amount of proppants and the EPA based on the Warren-Root model. When the EPA parameters were optimized by a reservoir simulator according to the post-production and net present value, the optimum volume of proppants for a specific shale well can be obtained easily. The new model has been applied at the first horizontal well in Jianghan shale oil field and three horizontal and eighteen vertical wells in Western Sichuan shale gas field successfully. Compared with the results of the early empirical design method used in Western Sichuan, this approach shows a better post-production.