HBX-2 Appraisal Well Test

HBX-2 Appraisal Well Test

The subsurface team is preparing a well test (DST) for an appraisal well HBX-2 in an offshore oil reservoir. The well is slightly deviated with a drilled net reservoir section length L= 187 feet, as shown in the cross-section below.
Table 1 shows the PVT and static data for this well:

Fluid Volume-Factor :1.2000 vol/vol
Fluid Viscosity :0.500E+00 CP
Fluid Compressibility :0.170E-04 1/PSI
water compressibility :0.300E-05 1/PSI
porosity :22.1000 %
water saturation :25.7000 %
rock compressibility :0.400E-05 1/PSI
well-bore radius :0.354E+00 FEET

The pressure profiles from MDT is presented below:
(click on the plot to enlarge it)
The objectives of the test are to confirm productivity (KH, skin), flow the well at a sustained oil rate of 5,000 bbl/d and prove a connected volume of 10 million barrels of oil at surface.


The completion engineer suggests the following DST string along with a first draft of the test sequence. (click on the plot to enlarge it)

Well Test Design

get ready

Real-Time Well Testing Operations

The well HBX-2 has now been perforated and we start the clean-up period by gradually increasing the choke size and taking some routine fluid samples at surface.


At the end of the clean-up, the well is closed at the downhole tester valve. As you have access to the real-time data during the operations, the figure below shows the derivative of the first PBU.

get ready

Post-Operations Well Test Analysis

The reservoir engineer on the rig sent you the following interpretation.
(click on the plot to enlarge it)
[Mob. Ratio (1) = Mobility of the outer zone / Mobility of the inner zone]

get ready

Perforating and testing a new sand

At the end of the 2nd PBU, the team decides to run in hole some perforating guns and perforate a sand layer of net stratigraphic thickness H2=42 feet, above the pay zone.
Then they flow all the zones and perform a shut-in (PBU 3). The result is shown below on the log-log plot.
(Click on the plot to enlarge it).

get ready

well testing in an appraisal well is divided into 3 sections: well test design, real-time well testing during operations and post-ops well test interpretation

Fracture behavior