OFM software, Petrel platform, and PIPESIM simulator yield more
reliable field forecast and reserve estimation
Working with AQP, Schlumberger developed a workflow by which the missing
reservoir parameters—reservoir pressure and the productivity indices of
the wells—could be estimated using the RTA technique in the Petrel
platform. These data could then be used to history match the reservoir
simulation model and provide a more reliable field forecast and reserve
As a first step, all existing measured data were gathered and input into
OFM well and reservoir analysis software to remove any inconsistencies and bad
data. The cleaned and prepared data were then imported directly into the Petrel
Well deliverability capabilities in the Petrel platform are powered by
the PIPESIM simulator, which calculates well hydraulics. Inputs to the model
include well geometry, PVT information, and wellhead pressure and rate
information. For wells with recent well test data, which includes wellhead and
bottomhole measurements, the model was tuned using flow correlation
matching—this adjusts the friction factors (FF) and holdup factors (HF).
For wells that did not have well test data, the average FF and HF were used in
each of these models to calculate the bottomhole flowing pressure.
In some cases, there were accurate downhole gauge measurements or
estimates of static reservoir pressure from well test analysis, so the PIPESIM
simulator was used to calculate the well productivity index. This could then be
used to history match each well.
In the majority of cases, there was no static reservoir pressure
information. For these, hydraulic vertical flow performance (VFP) tables were
created in the PIPESIM simulator and imported into the Petrel platform. By
using measured wellhead flow rate and pressure data in combination with the
VFP, the bottomhole flowing pressure could be estimated and used to analyze
flow rate history and compute bottomhole pressures for rate transient analysis.
Use of the obtained parameters improves certainty in the production
Conducting RTA in the Petrel platform provided estimates of the average
static reservoir pressure, skin, permeability, and productivity
parameters— data that were critical to the production optimization
project. The obtained parameters were used in the well history-matching process
to optimize production through simulation and obtain production forecasts based
on physics (rate and reservoir pressure), rather than the empirical estimates
of the past.