Inaugural SPWLA Appalachia Chapter "Lunch & Learn"
with Membership Drive
Who should attend: All Persons Interested in the Topic and/or Learning About Membership in the SPWLA and its new Appalachia Chapter
When: Wednesday- March 13, 2019
11:30am – 12:45pm ET
Questions: [email protected]
Where: Cefalo's Banquet and Event Center
428 Washington Ave. Carnegie, PA 15106
UNCONVENTIONAL RESERVOIR FRACTURE EVALUATION UTILIZING DEEP SHEAR-WAVE IMAGING
Presented By: Doug Patterson, BHGE,
SPWLA Regional Director for North America
shale reservoir evaluation and development are extremely challenging. One of
the most dominating aspects is permeability, which is measured in the
nano-darcy range. Although these wells are stimulated to enhance production,
the presence or absence of natural fractures can have a large impact on the
production results. In addition, the fracture variation across a reservoir can
be substantial, leading to large production variations, even in adjacent wells.
Gaining insight about the natural fracture system, both intersecting and around
the borehole, is crucial and can often help determine the economic success of a
well and/or reservoir.
standard means of fracture evaluation, such as borehole imaging, Stoneley
permeability analysis, and azimuthal shear-wave anisotropy evaluation from
cross-dipole, provide valuable information when evaluating fractures. These
standard methods, however, can only investigate a limited area around the
borehole—imaging looks at the borehole wall and the other borehole acoustic
methods rely on refracted and guided modes that respond to an area as large as
2 to 4 ft out into the formation. The flexural wave from the dipole is one of
the guided modes that generally reads the deepest and is used in the standard
cross-dipole analysis. In addition to flexural mode, the dipole source creates
shear body waves that radiate away from the borehole and into the formation.
When these shear waves impinge on a fracture their energy reflects back to the
borehole, enabling the facture to be imaged. The reflection strength is a
function of the shear-wave polarization and the nature of the fracture, with
the strongest response occurring from the shear waves intersecting a
fluid/gas-filled fracture and polarizing in the fracture’s strike direction.
important aspect is that these shear waves have azimuthal sensitivity,
providing a means to determine the fracture direction. These features enable
the evaluation of fractures over a much larger area around the well, often in
excess of 60 ft from the borehole, and even detecting major fractures that do
not intersect the well.
look at the application of this deep shear-wave imaging technology in several
unconventional reservoirs across North America. Our review includes
conventional methods and the deep shear-wave imaging analysis, showing its
value in gaining important insight about the natural fracture system around the
borehole, especially non-intersecting fractures. In addition, we will
look at its application in mapping geologic structures in horizontal wells,
demonstrating the ability to detect sub-seismic faults.