This is the 25th anniversary issue of SPE Drilling & Completion
(SPEDC). So many changes have occurred since SPEDC Volume 1
Number 1 was published in February 1986. Technology that we take for granted
today either did not exist then or was just emerging.
Major advances in communication and information technology have played a key
role in our industry. Imagine what it was like in 1986 when wells were drilled
and completed without the Internet, mobile phones, personal computers, email,
search engines, texting, broadband, webinars, and smart phones. True, some of
these technologies may be merely nice to have, but others are essential
cornerstones of well construction.
Significant improvements have also occurred in drilling and completion
technology--such as horizontal wells, 3D/4D seismic,
polycrystalline-diamond-compact bits, measuring-while drilling/logging-while
drilling, rotary steerable systems, top drives, real-time operations centers,
expandable pipe, multilateral wells, intelligent wells, underbalanced drilling,
managed-pressure drilling, casing drilling, synthetic-based fluids, hydraulic
fracturing, rig mechanization and automation, and many more.
As we mark this anniversary, it seemed appropriate to examine changes in
SPEDC over the years. To this end, Chris Carpenter, SPE Managing Editor
of Journals, supplied the table of contents for every issue from 1986 to the
present. These TOCs are available at http://www.spe.org/go/spedc and provide
the basis for the following reflections.
1986—SPE Drilling Engineering Is Born
When it was established in 1986, the journal was called SPE Drilling
Engineering. During this inaugural year, 47 papers were published in six
bimonthly issues. Domestic subscriptions for SPE members cost USD 17.50. Volume
1 Number 1 contained seven papers on the following topics: reducing cost per
foot in drilling deep, hard rock; clear brine drilling fluids; polymer drilling
fluids for improved shale stability; cuttings transport experiments in
directional wells; air drilling in the Black Warrior Basin to address lost
circulation; casing wear; and drilling using foam/mist combination. It
surprised me to realize that the topics themselves are still relevant today. Of
course, the specific technology discussed today would be quite different.
Nevertheless, it is noteworthy that the same general categories of problems
still exist 25 years later. In 1986, the first discussion of papers by readers
appeared in Volume 1 Number 5; it contained four discussions and one reply by
2010—SPE Drilling & Completion Is 25 Years Old
In 2010, 56 papers were published in four quarterly issues in SPE
Drilling & Completion. (The journal format changed to quarterly in
1987, and the journal name changed in March 1993.) Subscriptions for SPE
members cost USD 70 for print + online and USD 45 for online only.
Unfortunately, there are no discussions of any papers published in 2010. In
fact, such discussion is rare in recent years. Why is this? Debate of important
and controversial issues in a public forum can accelerate progress. At a
minimum, such debates can stimulate interest. Do readers today use other means
to discuss papers? Or is everyone simply too busy? A convenient method already
exists online at the SPEDC website to submit a discussion for each
paper. If readers began submitting online discussions in sufficient quantity,
then SPE would look into a type of notification system that would update
subscribers on new discussions. Write to let me know your thoughts on
discussions of papers.
Some Noteworthy Papers from 1986 to 2004 in My Humble Opinion
From 1986 to 2010, approximately 1,000 papers were published in
SPEDC. Starting with the March 2005 issue, all papers are available to
subscribers in online archives, so you can access them for free. However,
papers published from 1986 to 2004 are available only through OnePetro and are
not free. Therefore, to get a sense of when SPEDC first published papers
on important technologies, I scanned through the tables of contents from 1986
to 2004 that Chris provided. The following 35 papers seem especially noteworthy
in relation to industry firsts:
- First paper with deepwater in the title--August 1986.
- First paper on top drives--December 1986.
- "Wellsite Information Transfer Specifications (WITS) for Digital Rig-Site
- "Hydraulic Fracturing Slurry Transport in Horizontal Pipes--September
- "Bit Whirl--A New Theory of PDC Bit Failure"--December 1990.
- First paper on bottomhole-assembly whirl--also in December 1990.
- "Instrument Performance Models and Their Application to Directional
Surveying Operations"--again in December 1990--that was quite an issue!
- First paper on traveling-cylinder method for well-collision
- First paper on extended-reach drilling--June 1991.
- "Development of Lightweight Steel Drillpipe With a 165-ksi Yield
- First horizontal well in Gulf of Mexico--June 1992.
- "The Genesis of Torsional Drillstring Vibrations"--September 1992.
- "Dynamic Stability of Drillstrings Under Fluctuating Weight on Bit"--June
- "The Influence of Chemical Potential on Wellbore Stability"--September
- "Coiled Tubing Drilling"--also September 1993.
- "Casing Design for Trapped Annular Pressure Buildup"--June 1994.
- "Strategies and Structures for Drilling and Service Contracts in the
- "Case Histories and Application of a New Slimhole MWD
Multiple-Depth-of-Investigation Resistivity Sensor"--December 1996.
- "Drillstring Component Mass Imbalance: A Major Source of Downhole
Vibrations"--also December 1996.
- "Gravel Placement in Horizontal Wells"--June 1997.
- "Downhole Measurements of Synthetic-Based Drilling Fluids in an Offshore
Well Quantify Dynamic Pressure and Temperature Distributions"--September
- "Evaluation and Selection of Drill-In-Fluid Candidates To Minimize
Formation Damage"--also September 1997.
- "Field Experience with Multilaterals in the Idd El Shargi North Dome Field,
- "Pressure-While-Drilling Data Improve Reservoir Drilling Performance"--also
- First rotary-steerable system paper--June 1998.
- First paper on mixed-metal oxide drilling fluids--September 1999.
- First paper on casing drilling--March 2002.
- First paper on dual-gradient drilling--December 2002.
- First intelligent completion in Gulf of Mexico--March 2003.
- "Real-time Specific Energy Monitoring Enhances the Understanding of When to
Pull Worn PDC Bits"--also March 2003.
- "Otter: A 21-Kilometer Subsea Tieback with Dual Electric Submersible
- "Selective Floatation of Casing from a Floating Vessel"--June 2004.
- "Imaging Unstable Wellbores While Drilling"--December 2004.
- "A Method for Isolating Pressure Depleted Zones with Solid Expandable
Tubulars"--also December 2004.
- "Real-time Monitoring and Control of Water Influx to a Horizontal Well
Using Advanced Completion Equipped with Permanent Sensors"--again December
Clearly this highly unscientific selection is biased towards my own
experiences and interests. I would be interested in reading your list if you
care to share it.
People Make the Difference
The marking of our journals 25th anniversary represents a major achievement.
Many people have contributed over the last quarter century, including authors,
subscribers, reviewers, and SPE staff.
Currently, SPEDC has over 150 technical editors (TEs) who review
papers submitted for peer review. (Since 2009, the SPE peer-review system
allows all seven peer-reviewed journals to use each other’s TEs. While this is
a good thing, it does make it difficult to obtain a precise count of TEs for
SPEDC.) We salute their devotion and service. Each year, associate
editors (AEs) select the Outstanding TEs based on quality, timeliness, and
number of reviews. Our Outstanding TEs for 2010 are recognized elsewhere in
In the November 2010 issue of Journal of Petroleum Technology, SPE
President Labastie discussed peer review in his article titled "En Route." He
noted the significant improvement for all SPE journals in average time to
return an initial decision to authors--from 225 days in 2006 to 98 days
currently. SPEDC has achieved a similar improvement over this period.
Presently, our average time for returning an initial decision to authors is 86
The primary reason for the improved decision time is the hard work and
commitment by our reviewers. Special recognition goes to our ten AEs, who are
all experts in their field. Each AE is responsible for specific subjects as
shown below, with some overlap to accommodate potential conflicts of interest
and work load (after all, each one is a volunteer!): Carl
Thaemlitz--drilling fluids, completion fluids, and chemistry; Christoph
Zerbst--completions planning, design, and installation, sand control,
hydraulic fracturing, gravel packing, cuttings re-injection, safety in design
and engineering, intelligent completions, and multiphase flow in wells; John
Thorogood--directional drilling and surveying, drilling project management,
wellbore design/construction, human factors in health, safety, security,
environment and social responsibility, deep water, harsh environment, and
Arctic operations; Max Medina--hydraulic fracturing, advanced
tubing/casing design, completion design and planning, sand control,
perforating, thermal completion design, steam-assisted gravity-drainage
production and well construction, and intelligent completions; Fionn
Iversen--real-time drilling applications, drilling automation, drilling
process control and modeling, flow modeling, information systems and data use,
measurement and control, well control, and multiphase flow in wells; Kaibin
Qiu--wellbore stability, geomechanics, sanding, compaction and subsidence,
and pore pressure; Shilin Chen--drill bits, drilling dynamics, downhole
tools and equipment, and directional drilling; David Kulakofsky--cement,
cementing, and zonal isolation; John Mason--completion equipment,
planning, design and installation, perforating, hydraulic fracturing,
intelligent completions, and completion and intervention operations; and
Deepak Gala--managed-pressure drilling, underbalanced drilling, air
drilling, casing and liner drilling, well control, blowout preventers, and
Equally essential to SPEDC is the SPE staff, whose skills and
commitment are first class. On behalf of the TEs, AEs, and our readers, we
express our heartfelt thanks to each of them. Special thanks go to Stacie
Hughes, Mattie Tanner, Glenda Smith, Chris Carpenter,
and Victoria Preston.
Next 25 Years and Beyond
Carl Sagan famously said, "We live in a society exquisitely dependent on
science and technology, in which hardly anyone knows anything about science and
technology." The truth of this statement is worth pondering. How can our
society improve our collective ability to understand the ever-changing
technology that underpins not only our daily existence but also our industrial
Journals such as ours that use peer review are a key tool in this quest for
understanding technology. These journals provide a level of quality control
while ensuring that an industry’s technology is written, disseminated, shared,
and preserved for future generations. We are grateful to our predecessors for
having started SPEDC to publish the best papers on drilling and
completing oil and gas wells. We humbly carry on their hard work, noble vision,
and dedication to excellence so that future generations will continue to enjoy
the same benefits we derived from the first 25 years of SPEDC.
What does the next twenty-five years and beyond hold for SPEDC?
Again, we quote President Labastie from his "En Route" article in the November
2010 J. Pet Tech: "In closing, I would say that peer-reviewed journals
are one strong element of the distinctive character of SPE. They have done a
lot in the past for the prestige of our Society. They will do a lot in the
future, as our industry will certainly become more technology intensive and
will need more efficient ways to exchange high-quality technical
Now to the papers. This issue contains fourteen papers on the following
topics: general drilling--six papers, wellbore stability, geomechanics, and
drilling fluids--five papers, hydraulic fracturing--one paper, and
managed-pressure drilling--two papers.
Automation has had enormous impact on safety, efficiency, and risk reduction
in other industries such as aviation. Similar opportunity exists today for
drilling automation. Recently both SPE and IADC formed technical sections on
drilling automation. How are these two industry committees different in their
objectives, goals, and activities? Our first paper answers these questions and
more. Drilling Automation: Technologies, Terminology, and Parallels With
Other Industries describes concepts for drilling automation that are
already in operation or under development. It also proposes a classification
scheme for key categories. Automation in the aviation industry is described in
relation to drilling automation. Potential pitfalls are discussed that relate
to ergonomics, human factors, and avoiding "overautomation" ("Dave? … Just what
are you doing, Dave?" from HAL in 2001: A Space Odyssey). The paper
concludes that early adoption of standardization is critical for rapid
development of drilling automation. This paper comes at a crucial time because
such standards are currently under development for terminology, data, and
interfaces. The authors invite all interested companies and individuals to join
Cementing across salt zones was done as early as the late 1940s around salt
domes in the Gulf of Mexico. More recently, subsalt reservoirs have been
discovered in basins around the world, such as the Gulf of Mexico, the North
Sea, West Africa, eastern Canada, and Brazil. Field development in these
subsalt reservoirs requires successful cementation of casing strings that
contact thousands of feet of salt. Cementing Casing Strings Across Salt
Zones: An Overview of Global Best Practices explores the issues and
solutions associated with cementing casing strings across extensive salt
sections. Key concerns are salt movement (creep and flow), salt dissolution and
its impact on cement strength, and determination of safe mud weight when
drilling through and immediately below salt. This paper is essential reading
for anyone interested in the state of the art on this topic.
High-Integrity Wellbore Surveying proposes a new set of minimum
requirements for survey validation. It is a product of collaborative work by
the SPE Wellbore Positioning Technical Section. The paper documents weaknesses
in conventional directional-surveying quality control (QC) procedures.
Theoretical considerations, statistical analyses of real survey data, and
actual examples of failed surveys that passed conventional QC procedures
without detection are presented. The need for survey QC tests that validate
survey accuracy claims has been previously described by several authors, but
this paper provides the first comprehensive study of the contribution that such
tests make to directional-survey reliability. This paper systematically
evaluates each of the QC tests and tabulates which error terms are controlled
by which tests. The results point out weaknesses in current common practice and
demonstrate the significant effort required to achieve appropriate control.
This paper also deals with error-model validation. Error models are usually
based initially on manufacturing tolerances and estimates of reference
tolerances and environmental effects. QC tests derived from models may under-
or overestimate actual system performance. As statistically significant
quantities of field survey data are accumulated, it is possible to reverse the
QC process and test the model's compliance with the data. This practice has
also been previously proposed, but it is not commonplace and rarely extended to
the global applicability of tool-error models. This paper describes two methods
of validating error models using cumulated QC data.
Multiwell thermal interaction will alter the wellbore temperatures as well
as formation temperatures in the interwell zones and also farther out from the
well template. The change in temperature profile relative to a single well can
be significant. Multiwell Thermal Interaction: Predicting Wellbore and
Formation Temperatures for Closely Spaced Wells presents a methodology
based on standard industry thermal/hydraulic-modeling software and a
finite-element model (FEM) in a loosely coupled, iterative analysis that
assumes steady-state conditions. A case study for
high-pressure/high-temperature offshore field development is presented. The
multiwell disturbance on formation and wellbore temperatures affects well
design, facilities planning, and operations. Annular pressure buildup, wellhead
movement, tubular-stress design, cement-slurry design, subsidence/compaction
effects, and facilities health and safety issues can all be affected. If
multiwell thermal interaction is not taken into account, then load events, such
as annular pressure buildup, wellhead movement, and thermal-induced stresses
may be underestimated. In developing this model of multiwell thermal
interaction, the objective was to provide a practical, robust method that
incorporates standard industry tools and established analytical models. The
proposed method can be used to predict both the wellbore temperatures and
surrounding formation temperatures.
Managing Drilling Vibrations Through BHA Design Optimization employs
a bottomhole assembly (BHA) design evaluation process based on a
frequency-domain lateral-dynamic model in both predrill and post-drill hindcast
modes. The method conducts a comparative analysis of several specific BHA
designs. BHA lateral vibrations are characterized such that alternative BHA
configurations may be developed and compared directly with a proposed baseline
assembly. In the hindcast mode, the BHA model can be operated at the recorded
weight on bit and rotary speed to generate corresponding model results in time
or depth, and these values can be compared with the measured performance data.
A case study of a BHA with a motor and roller reamer is described, with
corresponding field date for four original BHAs and four redesigned assemblies.
A second case study shows model and field results for two rotary steerable
assemblies. The model employs two vibration modes for each candidate
BHA--lateral bending and "twirl," or BHA whirl. In the lateral bending mode, a
constant reference side bit force is applied, and the magnitudes of the
response are compared along each BHA. In the twirl mode, a reference mass
eccentricity is applied. Index values have been developed to summarize dynamic
performance to indicate which BHA design is preferred and identify operating
sweet spots. The authors have found that the relative performance assessment
based on use of this model is a good predictor of field results.
Probabilistic estimation of well duration has been common practice for more
than a decade. This paper asserts that it is not possible to use these previous
state-of-the-art methods to obtain sufficiently accurate predictions. In
Probabilistic Well-Time Estimation Revisited, a database of 118 central
North Sea wells was analyzed for nonproductive time (NPT) from the original
daily drilling reports. Results showed the data actually underestimated NPT by
19.7% on average. Train wrecks (mechanical NPT more than 2.5 days long) were
only 4% by number but represented 50% by duration. It was found that "ordinary"
mechanical NPT, train wrecks, waiting on weather in open water, and waiting on
weather with riser connected are all statistically distinct, with very
different occurrence frequencies and probability distribution functions.
Earlier models did not observe this important distinction. The authors claim
their analysis technique is accurate and that it may be applied as a template
to other areas after proper local calibration. They have published their entire
data set and the full technical basis of their method because they believe lack
of such information has held back progress in this area by hindering the debate
essential to bring the subject to a mature level. Publishing full details of
all steps in the analysis makes the paper a little long, but we agree with the
authors that it is essential to stimulate debate.
Wellbore Stability, Geomechanics, and Drilling Fluids
Wellbore strengthening has been a hot topic in recent years. Case
History: Successful Wellbore Strengthening Approach in a Depleted and Highly
Unconsolidated Sand in Deepwater Gulf of Mexico discusses drilling through
the depleted formations at Total's Matterhorn tension-leg platform in deepwater
Gulf of Mexico using a flat-rheology synthetic-based fluid engineered with a
high concentration of bridging particles to impart a strengthening effect on
the formation. A drill-ahead method of applying the treatment to the formation
was used (rather than a pill spotting method) because the risk of fracturing
the reservoir existed with the mud weight needed to control the caprock. The
paper describes the laboratory approach to fluid design and the operational
practices to apply the treatment on location. A post mortem analysis compares
formation breakdown pressures taken from fracturing operations to actual
wellbore pressures experienced while drilling and cementing to demonstrate that
a strengthening effect was realized. The results imply that using such a
designer fluid can have a strengthening effect on depleted/unconsolidated
formations, in which some operators have had limited success in applying
wellbore strengthening techniques.
Significant fluid loss while drilling through fractured formations is a
major problem. A common method of dealing with massive losses is to apply lost
circulation material (LCM). The authors are convinced that use of LCMs is not
the only way of reducing mud losses. In some cases, LCMs may result in
permanent damage of productive fractured zones. Field experience shows that
type and rheological parameters of the drilling fluid have a strong impact of
the rate and volume of losses while drilling through fractured formations. This
observation led to the work that is documented in Quantitative Analysis of
Mud Losses in Naturally Fractured Reservoirs: The Effect of Rheology, which
develops a mathematical model for Herschel-Bulkley (yield-power law) drilling
fluid losses in naturally fractured formations. It investigates effects of
rheological properties such as yield stress and flow behavior index on mud
losses. Results indicate that yield stress can control the ultimate volume of
losses while the shear-thinning effect can tremendously affect the rate of
losses. Therefore, mud losses in fractures can be minimized by optimizing the
rheology of the drilling fluid. The model allows for quantitative analysis of
losses that take into account fluid rheology to characterize the fractures.
Hydraulic aperture of conductive fractures can be obtained by continuously
monitoring mud losses and fitting field records of mud losses to the model.
Estimates of fracture width is valuable for designing sealing treatments and
other potential cures for lost circulation. The proposed model is useful for
drilling and completion design. A practical application of the proposed
technique is demonstrated through a field example of mud loss measurements in a
fractured well in the Gulf of Mexico. The paper concludes that use of LCM in
conjunction with rheology adjustment is recommended as a better way of
mitigating fluid losses than the use of LCM alone.
Previously the theory of rock failure based on planes of weakness has been
applied primarily for layered rocks. Here it is extended to significantly
weaker mudstones showing strength anisotropy. Wellbore-Instability
Predictions Within the Cretaceous Mudstones, Clair Field, West of Shetlands
describes a study conducted to address problems in earlier high-inclination
wells that experienced unstable wellbores in Cretaceous mudstones overlying the
Clair oilfield. Results of this study were used to plan an ERD well, which was
successfully drilled, cased, and brought on stream using the plane of weakness
modeling of wellbore instability. Although the magnitude of the mechanical
anisotropy in mildly compacted mudstones is small compared to that in the hard,
brittle rocks such as slates and schists for which the weak-plane model was
developed, the inherent weakness of these mudstones means that even a small
additional weakening can have a critical impact on wellbore stability and
drilling success. The characteristic signature of the weak plane failure mode
is a pronounced increase in the mud weight required for wellbore stability at
medium inclinations and a small additional increase in the mud weight required
for stability at high inclinations. Indications of unexpected instability at
(say) 20 to 40° should be closely investigated and not dismissed as a
consequence of drilling practices. They may be an early indicator of trouble at
moderate to high inclinations; conversely, trouble at moderate inclinations
need not imply that there is no drilling window at high inclinations. A similar
failure mechanism may occur in other parts of the world. Therefore, the method
developed here for the Clair field may also be useful elsewhere.
Numerous casing and production-liner deformation/failure problems have been
reported in high-porosity chalk formations in both the overburden and the
reservoir sections, causing costly operations problems that prevent workovers
and recompletions. A Comprehensive Modeling Analysis of Borehole Stability
and Production-Liner Deformation for Inclined/Horizontal Wells Completed in a
Highly Compacting Chalk Formation presents the results of studies performed
to investigate stability of an openhole, cemented liner, and uncemented-liner
completions in a highly compacting chalk formation. The effects of critical
cavity dimensions caused by various acid stimulation techniques were also
investigated. Analytical and numerical models were developed for evaluating
cavity-induced axial compression collapse of production liners. Model results
indicate that the risk of the cavity-induced axial compression collapse
substantially increases for short perforated intervals stimulated with large
acid treatments. Increasing the perforation-interval lengths along the entire
liner axis results in more uniform acid distribution and will greatly reduced
the chance of axial compression collapse caused by localized cavity
deformation. Key completion design criteria and stimulation strategies were
developed for wells completed in highly compacting chalk reservoirs to reduce
risk of casing and liner mechanical problems.
Drilling in depleted and compacted fields can cause costly problems. The
Valhall field in the Norwegian sector of the North Sea has experienced
significant reservoir compaction in weak chalks, exceeding 10 m in some places.
Sixty Days Ahead of Schedule: Reducing Drilling Risk at Valhall Using
Computational Geomechanics presents a novel approach for predicting local
stress changes in the overburden induced by reservoir compaction and
subsidence, whereas previous work has often focused on depletion-induced
fracture gradient changes in the reservoir itself. The new technology is based
on a history-matched full-field FEM geomechanics model to calculate stresses,
strains, and displacements. Results are exported from the FEM to geological
modeling software to perform wellbore stability calculations. In this
environment, users can incorporate 4D seismic from the permanent life-of-field
seismic array at Valhall. By calculating the operational mud weight window over
a high-risk interval in the overburden, a good correlation to historical NPT
was found. The method is used in detailed well planning where moving the well
50 m in one direction can be the difference between problem-free drilling and
huge drilling challenges. The paper presents application of the technology on a
new water injector delivered 60 days ahead of schedule with reduced costs of
approximately USD 20 million. The application potential for this technology is
significant even in reservoirs with less compaction than Valhall, as in
high-pressure/high-temperature fields and highly deforming reservoirs.
A Crosslinkable Synthetic-Polymer System for High-Temperature
Hydraulic-Fracturing Applications describes a new hydraulic fracturing
fluid capable of service temperature up to 232°C. The fluid uses a synthetic
polymer that is crosslinkable to metal ions to generate high viscosity. The
synthetic polymer fracturing gel overcomes thermal limitations of traditional
guar and derivatized guar-based fracturing fluids. Several advancements have
been made in the development of this technology to maximize the efficiency of
crosslinking and to give an effective breaking profile, resulting in good
laboratory gel cleanup in proppant pack. Research efforts have yielded a
fracturing fluid with good fluid stability at high temperatures to create
better proppant transport and placement. The crosslinking system can be tuned
for crosslinking onset as a function of temperature, thereby allowing
optimization to specific wellbore conditions. The system has been applied in
south Texas at temperatures approaching 232°C.
Solid case histories are highly useful instruments to transfer knowledge
from one area to another. Managed-Pressure Drilling Using a Parasite
Aerating String is such a case history that chronicles drilling in Piceance
basin in western United States. The basin presents significant challenges for
lost circulation and stuck pipe. This paper describes a new technique for this
basin that involves acquiring real-time equivalent-circulating-density data and
control of annulus mud weight through air injection in a parasite string. The
method was successful in achieving the desired major reduction in fluid losses
during drilling by controlling equivalent-circulating density.
Pressure maintenance within safe bounds and minimization of influx of fluids
from the formation during a kick are basic concerns of well control.
Managed-pressure drilling (MPD) offers improved capabilities over conventional
well-control methods to address these concerns. Improved Kick Management
During MPD by Real-Time Pore-Pressure Estimation asserts that the issue of
developing an appropriate process to control flow during MPD operations has not
been thoroughly addressed yet. By definition, MPD does not encourage influx
into the wellbore. Nevertheless, in some cases an influx will occur. When a
kick is taken, obtaining an accurate estimate of the pore pressure at the
influx zone as quickly as possible will assist regaining control of the well.
The proposed method estimates formation pore pressure automatically on basis of
real-time measurements when a gas kick is taken during MPD. It relies on
characteristics of the pressure-buildup curve. A North Sea well is used as test
case geometry, and an advanced hydraulics model is used in a virtual well in
computer simulations for presented results. The method is demonstrated to
maintain pressure within desired bounds and reduce formation fluid influx,
thereby reducing the risk of hole-stability problems and the cost associated
That wraps up this issue. On behalf of your entire Editorial Review
Committee, thank you for your continued support of SPE Drilling &