It is with great pleasure that I welcome you to the March 2013 edition of
SPE Drilling & Completion. As I begin my term as Executive Editor, I
am fortunate to have assumed the role at a time when our journal’s circulation
is ever-growing and our review process operates in a timely manner. Over the
past 10 years, I have watched the Executive Editors Curtis Cheatham of
Weatherford, Rob Mitchell of Halliburton, John Mason of BP, and David Curry of
Baker Hughes make significant contributions in the quality of the journal’s
contents while simultaneously attending to big changes behind the scenes in
publishing and review processes. I thank them for all they have given to make
this journal what it is today.
I am very pleased to introduce our newest Associate Editors with
responsibilities for drilling and completion fluids, and chemistry: Richard
Jachnik and Barkim Demirdal. Their editorial and complimentary technical
skillsets provide the journal with a well-rounded base of expertise in regard
to fluids. I am also glad to announce that Curtis Cheatham has agreed to accept
the role of Associate Editor for responsibilities related to health, safety,
and environment topics. These new assignments bring our number of skilled
Associate Editors to 12:
- Cheatham, Curtis, Weatherford International Limited
- Chen, Shilin, Halliburton
- Demirdal, Barkim, C-FER Technologies
- Iversen, Fionn, International Research Institute of Stavanger
- Jachnik, Richard, Baker Hughes Drilling Fluids
- Mason, John, BP Exploration Operating Company
- Nas, Steve, SPT Group Incorporate
- Piot, Bernard, Schlumberger
- Qiu, Kaibin, Schlumberger
- Thorogood, John, Consultant
- Zerbst, Christoph, Petroleum Development Oman
- Zhou, (Joe) Yunxu, National Oilwell Varco
Now, on to the papers.
An informative study of dynamic underbalance perforating is presented in
Perforation Cleanup by Means of Dynamic Underbalance: New Understanding.
Dynamic-underbalance (DUB) perforating is a completion technique that uses a
perforating system engineered to create a rapid underbalance immediately upon
formation. Improvements in well deliverability are achieved by effectively
cleaning the newly created perforation tunnels, regardless of initial static
pressure conditions. Improved well productivity is attributed to enlargement of
tunnel diameter, a reduction in crushed-zone thickness and an increase in the
effective tunnel length.
Deviations between skin factors calculated using
computational-fluid-dynamics software and the Karakas-Tariq's model for
vertical perforated completions are addressed in Comparison of Skin Factors
for Perforated Completions Calculated With Computational-Fluid-Dynamics
Software and the Karakas-Tariq Semianalytical Model. The effects of
drilling damage, perforation, and permeability anisotropy are addressed.
Drilling Operations and Optimization
In our next paper, the authors present the view that today’s manual and
low-frequency procedures for measuring the properties of drilling fluids may be
inadequate for automated solutions because manual data input increases the risk
for operational errors. Simultaneous Continuous Monitoring of the
Drilling-Fluid Friction Factor and Density proposes a solution in the form
of an instrumented standpipe system that is capable of enabling continuous
automatic online updates of the density and frictional effects of drilling
fluids during drilling operations.
Although one of the main objectives of automation is to reduce human error,
several studies suggest that the introduction of automated decision aids does
not necessarily lead to a reduction in human error, but instead may create
opportunities for a different class of errors. Drilling Automation:
Potential for Human Error addresses the concerns of mode confusion, which
is when a technical system can behave differently from the user’s expectation
and, consequentially, lead to inappropriate use of the system. A virtual
testing environment and test cases are described along with discussion of the
results. Elements of key importance for development of good drilling automation
systems are proposed.
Cost reduction for drilling unconventional resources is a driving factor of
our next paper, The Optimal Range of the Nitrogen-Injection Rate in
Shale-Gas Well Drilling. The authors present an analytical method for
predicting the optimal range of the nitrogen gas injection rate required to
balance the issues of borehole cleaning and borehole integrity, which can
result in significant drilled footage increases through the application of
nitrogen gas percussion drilling.
The proving of injection as a technically feasible option for drilling waste
disposal in the Piceance is addressed in Colorado Drill-Cuttings-Injection
Pilot Results. A methodical approach to understanding the formation
response to injection along with the challenging logistical requirements, which
lead to a successful outcome, is presented.
The collision avoidance and closest approach calculations are two common
methods of representing 3D-wellbore separations in 2D. Explicit Calculation
of Expansion Factors for Collision Avoidance Between Two Coplanar Survey-Error
Ellipses presents a new, computationally efficient method for the exact
determination of the osculating condition of two survey error ellipses. The
positional uncertainty about a point on a wellbore is commonly represented as
an ellipsoid. This new method enables effective use of available interwell
space while satisfying the geometrical and probabilistic constraints associated
with collision risk, and is offered as a like-for-like replacement for the
existing pedal curve method.
Within the hostile environments of ultrahigh temperatures and pressures, the
chemistries of drilling fluid additives can face significant stability issues.
Meeting the Ultrahigh-Temperature/Ultrahigh-Pressure Fluid Challenge
addresses the development of invert emulsion drilling fluids specific to such
well conditions. Concerns around emulsion instability, filtration control, and
rheological properties control are discussed. Comparisons of the chemistries
and physical properties of these new fluids with those of more conventional
invert emulsions are given, including the application of a treated, ultrafine
barite weighting material.
In our final paper, the authors bring to our attention the importance of a
sound engineering basis for selecting tubular configuration for thermal EOR
applications in Burst and Collapse Responses of Production Casing in Thermal
Applications. The analysis results described in this paper demonstrate
thermal production casing has a substantially different set of burst and
collapse performance dependencies than those readily derived from existing API
equations and the prior literature.
Carl Thaemlitz is Intellectual Asset Manager for the Baroid
Product Service Line of Halliburton. His 22 years of drilling and completion
fluids experience include roles in technical services and operations
management, business development, and chemical research. Thaemlitz holds a BSc
degree in chemistry from Missouri State University and an MSc degree in
chemistry from Texas State University--San Marcos.