American Oil and Gas Reporter - January 2017 - 76

Production Technology
Analyzing public monthly production
records involving multiple ownership
properties can identify high-productivity
areas where property values and reserves
recovery may be increased by well cleanouts, workovers, refracturing, new drilling
locations, etc. Perhaps just as importantly,
it also can delineate areas of no additional
interest.
In any case, a seemingly intractable
data problem can be reduced to a rather
straightforward procedure by studying
publicly available well records. Eventually,
cumulative production, remaining reserves,
or initial production rate estimates plotted
on available property maps can provide
meaningful insights and highlight areas
of opportunity for further review.
To illustrate the processes, public information was used to outline well behavior for productive trend modeling

within an area of the Eagle Ford Shale
play in South Texas. Each well within
the study area was identified and subjected
to the data mining process. The objective
of this work was to generate results that
could identify "mature" developed areas
as well as areas with additional upside
potential.
Transforming production data is only
the first step in the process; a comprehensive interpretation of the results must
follow. Data and maps obtained from
public records provide a basis for plotting
production trends for a particular well
set. Analyzing well tickets, coupled with
the oil, gas and water production histories,
supplies considerable insights for interpreting a well history, since erratic production changes can be numerous, especially in unconventional resource plays.
Recovery estimates can be determined

FIGURE 1
Aspect Ratio for Very Low Permeability Matrix
(Boundary in Y Direction and Wellbore Length along the X Axis)

0

4

1

AD

Xe/Ye

4

2

0.8
0.4
0.2

XwD

0.2
0.4
0.8

5
10
20
20
10
5

2

2

4

1

76 THE AMERICAN OIL & GAS REPORTER

XeD

only after the data are plotted and studied
to select the proper production segment
to analyze.
Selecting transient and boundary-dominated production segments is of paramount importance in interpreting Eagle
Ford wells. Smoothing techniques such
as material balance time and normalized
production can be applied, if necessary.
The "goodness" of the fracture system
can be estimated from the transient portion
of the curve, and reserves can be estimated
from the boundary side. Of course, the
process will not apply if discrete systems
cannot be identified. The results then are
plotted on property maps and interpreted.
Using a service provider to access
public information, one can map, query,
browse and export well and production
information common to designated properties. Records ranging from well location,
deviation surveys, stimulation treatments,
core analysis, and oil/gas/water production
volumes can be accessed for various
analyses.
Because not all data are presented in
usable form, analysis code must be written
to transform some of the data to a readable
format for analysis and mapping. A
Python-based program simplifies manipulation of the data to Microsoft Excel®
spreadsheets. An open-source application
for mapping allows lease, operator and
well locations to be mapped for comparison purposes.
Decline Curve Studies
For the Eagle Ford study, a method
was developed to apply basic decline
curve studies to scan large amounts of
data when reconnoitering mature producing areas. In the selected lease area,
Eagle Ford wells are drilled horizontally
with lateral lengths between 3,000 and
5,000 feet, and are stimulated with multistage fracturing to materially expand
communication between the low-permeability matrix face and wellbore.
The reservoir flow system consists of
two parts. First, production initially mi-
American Oil and Gas Reporter - January 2017

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