American Oil and Gas Reporter - May 2019 - 46

SpecialReport: Pad Production Optimization
Moreover, the model translates the effects of frac hits on short- and long-term
production forecasts to enable operators
to evaluate the success of treatment designs, improve the production performance
of stimulated wells and optimize field
development strategies. The workflow is
capable of modeling complicated well

and completion design scenarios, and
easily can be applied to various field development plans to evaluate economics
and improve the production optimization
decision making process.
The permeability of the reservoir model
is derived from microseismic events and
recorded rock breakages, accurately de-

FIGURE 1A
Eleven-Arm Microseismic Monitoring Array (Three-Well Pad)

FIGURE 1B
Microseismic Event Distribution Recorded During Stimulation

46 THE AMERICAN OIL & GAS REPORTER

scribing the location of hydraulic fractures
and permeable zones, and indicating potential communicating regions. Once the
model is prepared and calibrated using
collected field data, it can be used to
forecast the production of every well on
a pad. In addition to reservoir simulation
and production forecasting, decline curve
analysis (DCA) is performed to assess
the behavior of individual wells under
current production conditions.
The technology was applied to a pad
in the Appalachian Basin where three
dry gas wells were drilled and completed:
one in the Geneseo, and the other two in
the underlying Marcellus Shale. Microseismic data collected while fracturing
the three wells was analyzed, and the
event locations, magnitudes and fracture
plane characteristics were used to construct
a discrete fracture network (DFN). The
permeability of a numerical reservoir
model was calculated from the generated
DFN, and the model was further integrated
with available reservoir data.
History matching was then carried out
using three years of production data to
calibrate the reservoir model, which also
was used to predict water and gas production for 30 years. Finally, DCA examined reservoir production behavior.
The microseismic data showed the
presence of communication between the
pad wells, with frac hits established as
more events were recorded in the offset
wells, indicating the extent of hydraulic
fractures. In addition, the pressure perturbation in offset wells confirmed the
presence of a pathway connecting the
wells during stimulation. Furthermore,
the reservoir model built in the numerical
reservoir simulator showed an overlap of
drainage volumes. In the reservoir model,
the depleted region expands across multilayer formations both laterally and vertically. An analysis of the production behavior of the wells using DCA suggests
an almost logarithmic trend, which is expected for these types of reservoirs.
Surprisingly, a detailed analysis of the
results reveals no significant deviation in
overall well performance associated with
interference, especially in the early years
of production. At greater than 10 years
of production, the expansion of the de-

American Oil and Gas Reporter - May 2019

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