American Oil and Gas Reporter - February 2016 - 34

SpecialReport: Unconventional Resource Science
The AWP Field was discovered in the
early 1980s after fracture stimulation
technology was applied to the Olmos,
and Swift Energy's long operational
history in the field dates to a series of acquisitions in the late 1980s that secured
working interests in 67 producing gas
wells located on a 4,900-acre leasehold.
Infill drilling began immediately after
Swift acquired its initial acreage position,
followed by field extension drilling.
Through the years, Swift has enlarged
its interests gradually through both acquisitions and drilling. By the late 1990s,
it had grown the field to more than 40,000
net acres and had drilled and fracture
stimulated several hundred vertical wells.
However, as the limits of the field
were extended, the reduced rock and
reservoir quality, and resulting poor production results, made economic margins
very narrow. Consequently, the operating
focus was on cost reduction and enhanced
recovery through refined drilling and
completion practices, modified production
methods, and gathering and transportation
efficiencies.
Acquiring 3-D Seismic Data
About 10 years ago, Swift Energy began acquiring the first 3-D seismic data
over the majority of the AWP Field and
in an area extending north of the field.
The surveying was designed to image
deeper targets and find new areas for
field extension. Swift also took note of

FIGURE 2
Arbitrary Seismic Line Along Horizontal Olmos Well
With Fracture Trend Extracted from 'cFrac' Attribute Volume
Swift Well

the enhanced well performance that horizontal drilling and multistage fracturing
had on resource plays.
At the time, the company was building

FIGURE 1
Colored Acoustic Impedance Well Logs
And Acoustic Impedance Volume in Olmos Wells
Well 2
160 MBoe

Well 1
15 MBoe

Note: the quality of calibration between seismic and well log data and the low P
impedance anomaly present on Well 2

Sources: The seismic data displayed in the images accompanying this article are owned
or controlled by Global Geophysical Services Inc., Seitel Data Ltd. and/or Swift Energy
Company; interpretation is that of Swift Energy.

34 THE AMERICAN OIL & GAS REPORTER

an Eagle Ford acreage position and preparing to drill its first well in the play. As
Swift was designing horizontal exploratory
wells for the Eagle Ford source rock, it
decided to apply horizontal drilling and
multistage fracturing to enhance production rates, reserve recoveries and economics in the overlying Olmos.
The combination of horizontal drilling
and hydraulic fracturing allows each new
well to target eight to nine times the reserves of a typical vertical Olmos well at
only four to five times the cost. More
importantly, it provides access to reserves
that otherwise would be uneconomical
to produce, allowing Swift to continue
extending the field's known limits.
Although AWP Field drilling activity
has been reduced significantly over the
past year because of low commodity
prices, well performance has continued
to improve steadily since the first Olmos
horizontal well-the R Bracken 33H-was
placed on production, making 6.3 million
cubic feet a day seven years ago.
In total, multiple 3-D datasets from
more than a dozen surveys acquired by
Swift create a 700 square-mile proprietary
geoscientific database that also includes
American Oil and Gas Reporter - February 2016

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