Methods to Maximize Completion Efficiency in the Eagle Ford Reservoir

摘要

Unconventional reservoirs depend on an effective system of completion to achieve good production. The rock is less rigid than conventional formations and, in some circumstances, will display a plastic nature. Portions of the rock could demonstrate a flow capacity that could complicate flow paths created by fracture stimulation. The Eagle Ford exhibits some of these potentially troublesome characteristics. Dipole sonic logs have been used to establish Young’s modulus and Poisson’s ratio for the frac design. These same measurements are useful in unconventional reservoirs, but more complex data are necessary. Traditional two-dimensional (2-D) models of these values do not necessarily maintain their relationship in the horizontal portions of the well. The determination of vertical and horizontal components of Young’s modulus and Poisson’s ratio from the dipole sonic can be incorporated into the treatment design. The ability of the reservoir fluids to migrate through the fractures created by the treatment also requires some additional attention. If the fluids will not release into the created fractures, this portion of the reservoir will be unproductive. Just as in traditional reservoirs, permeability must be defined as an important reservoir parameter. Permeability established by nuclear magnetic resonance (NMR) determines the most efficient treatment area of the reservoir. These considered together help provide the best potential completion in unconventional reservoirs, including the Eagle Ford. This paper includes examples of the NMR determination of apparent permeability, along with examples of dipole-sonic vertical and horizontal calculations from the Eagle Ford. These calculations are used to determine the best landing horizon for the horizontal well and the best completion sections in the horizontal wellbore.