Thaemlitz

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.

Perforated Completions

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.

Drilling Fluids

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.

Tubulars

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
carl.thaemlitz@halliburton.com

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.