PRESSURE TRANSIENT ANALYSIS
Pressure Transient Analysis and Interpretation is
instrumental in the evaluation of the well-reservoir
system potential to enhance its characterization and
enabling engineers and geoscientist to design
improved exploration and depletion strategies.   

By analyzing the measured high-resolution pressure
transient response from downhole pressure gauges
and resulting flow regimes, an analytical model can
be selected to fit the pressure and pressure
derivative signals by regression.

The analytical model is the combination of four
sub-models representing the wellbore, the well, the
reservoir and the limits or boundaries.  Finding the
right analytical model is finding a solution not
necessarily unique to the interpretation. The
following lists describe the optional analytical
sub-model types.
IWFS SERVICES
WELL MODEL
- Finite Radius
- Infinite Conductivity Fracture
- Finite Conductivity Fracture
- Limited Entry
- Horizontal
- Fractured Horizontal
- Fractured Horizontal + SRVB
- Fractured Horizontal + Trilinear
BOUNDARY MODEL
- Infinite
- Single fault
- Leaky Fault
- Intersecting faults
- Channel
- Closed Circle
- Rectangle (Centered)
- Rectangle
- Weak constant pressure
- Strong constant pressure
MAIN CALCULATED PARAMETERS:

The application and fitness of the analytical
model to the data provided, enables the
calculation of the following key well and
reservoir parameters including but not limited
to:

•        Wellbore Storage Coefficient
•        Skin Factor
•        Skin Pressure Drop
•        Permeability
•        Transmissibility
•        Extrapolated Reservoir Pressure
•        Average Reservoir Pressure
•        Distance to no-flow boundaries
•        Distance to constant pressure boundaries
•        Productivity Index
•        Flow Efficiency
CLIENT PROVIDED DATA:

Pressure transient test interpretation can be done with limited
data, however, the quality of the analysis and interpretation of
pressure transient tests from oil and gas wells highly depends
on the completeness and accuracy of the data provided by the
Client.  Not only high-resolution pressure and production test
data, but well, wellbore, reservoir properties (rock and fluid),
basic geological data and information on the production of
offset wells connected to the same reservoir by the time the
test was run are also very important. The following list shows
the data requirements from the Client. The first four items are
the minimum to carry out the analysis
METHODOLOGY:

To complete the analysis and interpretation of a pressure
transient test we follow this methodology:

1. Data loading and synchronization
2. Quality control
3. Data screening and preliminary diagnostics
4. Analytical Modelling
5. Sensitivity
6. Regression and Improvement
7. 2D & 3D Numerical Modelling
8. Inflow Performance
9. Calculations, Plots & Reporting

Pressure transient analysis and interpretation practices
enable operators to assess well potential, improve their
understanding of the reservoir and its boundaries,
understand near wellbore effects, evaluate the impact of
offset wells, and the ability to plan and forecast production
with a higher degree of accuracy.

Feel Free to contact us to assist you with your pressure
transient tests.
WELLBORE STORAGE
- Constant
- Variable
RESERVOIR MODEL
- Homogeneous
- Double porosity (PSS)
- Double porosity transient
- Double permeability
- Radial Composite

- Pressure Buildup
- Pressure Drawdown
- Injection/Falloff
- Interference
- Mini-frac
PRESSURE TRANSIENT TEST DATA FROM CLIENT:

1.  - Time – pressure test data in digital format
2.  - Production test data
3.  - Well & Completion Data
4.  - Reservoir properties
5.  - Offset wells production when test was run
6.  - Well production history
7.  - Structural map
TO OUR CLIENTS:

IWFS LLC has the expertise to assist its clients in the
analysis and interpretation of oil and gas pressure transient
tests from vertical, deviated and horizontal oil or gas
exploratory, appraisal and/or development wells in
conventional or unconventional reservoirs, using the latest
generation software technology. The list below shows the
test types IWFS LLC can perform for its Clients:
NUMERICAL GENERATED GRID:
LINKS TO PTA ARTICLES & PAPERS:
Clients: IWFS, LLC Contact Information:

Mario A. Salazar, Integrated Well Flow Solutions LLC
e-mail: mario.salazar@inwellflowsol.com
phone: 1-512-363-0822