Abstract
A new methodology to obtain the optimum fracture treatment design for a wide range of reservoir conditions has been developed and successfully implemented. The approach discussed here significantly reduces the time required to evaluate an optimum design and limits the materials considered to only those that are appropriate for the reservoir conditions. These improvements make it an ideal methodology for real-time re-design of fracture treatments after feedback from minifrac data has been implemented.
This innovative fracture design methodology has capability to determine appropriate fracture conductivity and an economic optimum fracture length while reconciling these with actual fracture growth behavior in the reservoir. The technique incorporates the following simple, automated steps:
Selects the most cost-effective fluid that will meet a minimum apparent viscosity requirement at a specified shear rate and temperature condition from a large industry fluid library to ensure that the proppant will be placed within the pay zone.
Selects a proppant that will provide the required fracture conductivity at the cheapest cost from a large industry library.
Determines the proppant concentration that is required at the wellbore to achieve a user-specified dimensionless conductivity criterion for a range of fracture lengths.
Evaluates economic criteria such as net present value (NPV) and return on investment (ROI) for different fracture lengths by comparing fracture treatment cost and revenues from production response.
Determines the optimum fracture conductivity profile that will have a uniform pressure drop down the fracture. The conductivity is adjusted for potential losses from non-Darcy and multi-phase flow, gel damage, embedment, and other proppant damage effects.
Iterates a fracture treatment schedule that will result in the best fit of the optimum conductivity profile.
The methodology can help optimize fracture treatments in any type of environment. The technique is simple and can be run quickly in a real-time environment after a minifrac is conducted to make changes to the propped fracture treatment. The procedure has been implemented in a commercially available fracture design program.
