Baroid Fluid Services
Wellbore Stress Management™ Service
There most likely is no segment of drilling non-productive
HAL15549
HAL18406
time in which it is more difficult to make an economic
decision than lost circulation. Estimations of economic
impact in this area vary widely, but are on common ground
in their very large magnitude. Slight improvements in
technology that reduce drilling non-productive time can
translate into millions of dollars of operating cost savings.
Wellbore Stress Management™ service is Halliburton's
engineered solutions which are designed to improve
wellbore strength and help reduce drilling non-productive
time due to lost circulation. This fully engineered approach
requires both unique planning software and materials.
Planning includes means to prevent lost circulation as well
as stop losses. Prevention of lost circulation by improving
the wellbore strength is accomplished by designing and
applying WellSET™ treatments that increase the hoop stress
around the wellbore.
D50 Values of STEELSEAL and
BARACARB Products
HAL14916
The goal of WellSET treatments is to increase the "hoop
stress" (and thus the wellbore pressure containment ability)
in the near wellbore region. This is accomplished by placing
a plugging material in an induced fracture that prevents
further pressure and fluid transmission to the fracture tip,
while at the same time widening and propping the fracture.
Chemical lost circulation treatments that form a
deformable, viscous and cohesive material (e.g., FlexPlug®
sealant) also may have the ability to improve the wellbore
pressure containment as long as they can increase
compressive stress at the fracture face.
The Halliburton DFG™ software with DrillAhead®
hydraulics module can predict the equivalent circulating
density (ECD) over an interval in one module, calculate the
width of a fracture that may be initiated, and select and
design a proper material and particle size distribution that
can efficiently prop and plug that fracture in a second
module. The matchless WellSET treatment materials are
selected from sized resilient graphitic carbon (eg.,
STEELSEAL lost circulation material) and ground marble
(eg. BARACARB 600 bridging agent).
BDF 392
1330
BDF 391
1150
BDF 393
665
BARACARB 600
600
STEELSEAL
340
BARACARB 150
150
STEELSEAL Fine
80
BDF 398
55
BARACARB 50
50
BARACARB SF
35
BARACARB 25
35
BARACARB 5
5
A third module then predicts the change in rheology
resulting from the addition of the specialized lost circulation
materials, which then is cycled back to update the ECD
calculations. The engineering model was able to adequately
predict rheology for LCM additions in non-aqueous
drilling fluids with sufficient accuracy to minimize error
on ECD predictions.
HALLIBURTON
The model is demonstrated using three products: 20 lb/bbl
BARACARB 25 bridging agent, 16 lb/bbl BDF-398
resilient graphitic carbon and 10 lb/bbl BAROFIBRE SF
seepage loss additive. Very good agreement was observed
between the measured and tested data as shown in the
accompanying figure.
This combination of unmatched planning and application
tools can allow the operator to make decisions ahead of time
during the "drilling the well on paper" phase as to which
approach is the most economic - prevention (pay now) or
remediation (pay later). Regardless of the choice, the
resulting cost can be reduced by knowing and choosing
the proper approach and materials ahead of time. The
learning process can improve future decisions as experience
is gained, resulting in a continued reduction in cost related
to lost circulation.
Productsversus
Viscosity Prediction
vs Measured
Data
MeasuredMixed
Rheology
Predicted
- after
LCM Addition
90
12 ppg
ppg
SBM;
12.0
Base
SBM, base rheology
80
46lb/bbl
lb/bbl
LCM:16measured
rheology
20
BAROCARB,
BDF 398, 10 BAROFIBRE
70
Predicted
20 lb/bbl
BAROCARB,
16 BDFRheology
398, 10 BAROFIBRE
46 lb/bbl
LCM:
Predicted
60
50
40
30
20 lb/bbl BARACARB 25
16 lb/bbl BDF 398
10 lb/bbl BAROFIBRE SF
20
10
0
0
100
200
300
400
500
RPM
600
HAL18409
Dial Reading
100
HAL18407
HAL18408
HAL18542
HAL18541
Contingency chemical sealant treatment applications are
designed using the DrillAhead® platform software package
that models long fractures. Capabilities include the ability
to model lost circulation fracture length and width vs. ECD
to plan chemical sealant treatments for lost circulation
mitigation. Our unrivaled chemical sealant systems are
designed to react with the drilling fluid itself to create highly
viscous and cohesive sealants in the wellbore that are
displaced into the lost circulation fractures. FUSE-IT™ lost
circulation treatment reacts over a wide range of waterbased fluid mixing ratios while FlexPlug® OBM slurry
reacts with oil-based fluids. FUSE-IT treatment also is
capable of reacting within an oil-based fluid if a water pill is
provided. These drilling-fluid-reactive systems are not
dependent on temperature or pressure, thus removing a
significant amount of placement uncertainty present with
competitive systems.
FUSE-IT treatment reacted
with a water-based fluid
HAL18543
FUSE-IT treatment reacted
within a non-aqueous fluid
www.halliburton.com
SDS-053 09/06
© 2006 Halliburton
All Rights Reserved
Printed in U.S.A.
Sales of Halliburton products and services will
be in accord solely with the terms and conditions
contained in the contract between Halliburton and
the customer that is applicable to the sale.