March DC Executive Summary

Carl Thaemlitz, AramcoServices Company


Welcome to the 30th volume of SPE Drilling & Completion journal. With this first issue of the New Year, we introduce the new associate editors for SPEDC and we also thank those dedicated individuals whose terms as associate editor (AE) have been fulfilled. Also in this issue, the current state of the journal is presented in a mostly statistical form.

Editorial Staff Updates. We are indebted to Bernard Piot for hismany years of excellent service as AE for manuscripts related to cementing andzonal isolation issues. Assuming the AE title for the next 3-year terms of service are David Stiles and Simon James, both well-known experts in their specialties. We welcome David and Simon into their new roles as AEs and look forward to their contributions to the journal.

There is also a changing of the guard for the AE duties overseeing the manuscripts related to well control and managed-pressure drilling (MPD). Steve Nas has provided outstanding service as the AE supervising these areas of specialty, and his achievements during the term are most appreciated. Two new AEs are being welcomed into thisarea of specialty, Ramadan Ahmed and Alexander Crabtree. Their expertise in MPD and associated subjects ensure that the expertise of AEs for this topic remains at the highest level of quality.

Because of the increased volume of manuscripts being received by SPEDC,we are increasing our AE counts for certain topics.
  • Stephane Menand is assuming a role as AE for directional drilling, drill bits, and drillstring dynamics-related issues.
  • Claas van der Zwaag for a role as AE for completion planning,design, and installation; sand control, intelligent completions, and gravel packing.
Which leads us to the current composition of the AE team, by area of specialty:

MPD, Well Control, and Underbalanced Drilling
  • Ramadan Ahmed
  • Alexander Crabtree
Cement, Cementing, and Zonal Isolation
  • David Stiles
  • Simon James

Directional Drilling, Drill Bits, andDrillstring Dynamics

  • Shilin Chen
  • Curtis Cheatham
  • Stephane Menand

Completion Planning, Design, and Installation;Sand Control, Intelligent Completions, and Gravel Packing

  • Christoph Zerbst
  • Claas van der Zwaag

Real-Time Operations, Drilling Automation,Drilling Process Control and Modeling, and Well Control

  • Eric van Oort
  • John Thorogood

Completion and Intervention Operations,Well Design, and Construction

  • JohnMason

Geomechanics, Wellbore Stability, andPore Pressure

  • Kaibin Qiu

Hydraulics, Coiled Tubing, MultiphaseFlow, and Rheology

  • Yunxu (Joe) Zhou

Drilling Fluids, Fluids Handling, Processing,and Treatment; Rock/Fluid Interactions, and Cuttings Transport

  • Richard Jachnik
  • Barkim Demirdal

JournalPerformance Statistics. SPEDCcontinues to show generally favorable performances through increases inmanuscripts submitted and a wide readership. The following are highlights ofperformance statistics for the period July 2013 to June 2014:

  • 218 papers were submitted for review, 40% greater than duringthe previous year
  • 20% acceptance rate, slightly decreased from 24%
  • 189 technical reviewers participated, a 23% increase
  • 414 reviews submitted 39% greater than during the previousyear
  • 76 days average time to initial decision, a 17% improvement
  • 217 initial decisions, a 20% increase
  •  211 final dispositions, a 25% increase
  • Two author’s appeals, one the previous year
  • 43 manuscripts accepted for publication, a 19% improvement
  • 4,083 subscribers, a 13% decline that is expected to recoverwith adjustment to the new online-only format
  • Citation index is essentially unchanged at 0.25

And now, on to the papers…

Drilling

A new model for predicting the torque and drag behavior of drillstrings is presented in Drillstring Analysis With a Discrete Torque/Drag Model, which improves upon the evaluation of drillstring integrity through the provision of bending moments and shear forces. For simple trajectories, the new model gives similar results to those of the model by Dawson and Morehead; however, for complicated trajectories, the new model allows for better representation of the contact forces occurring within the wellbore. The improved contact force prediction allows for better friction factor predictions.

Combined Rate of Penetration and Pressure Regulation for Drilling Optimization by Use of High-Speed Telemetry makes use of wired-drillpipe technology to consider multiple variables when attempting to control complex processes (e.g, drilling in deepwater wells). A case is made for how the application of a comprehensive multivariate controller for both the rate of penetration and the well pressure is superior to that of the common method, where separate controllers are used, allowing for the shift to anticipatory decision-making responses rather than feedback-based responses.

The authors of our next paper, A New Approach To Estimate Invasion Radius of Water-Based-Drilling-Fluid Filtrate To Evaluate Formation Damage Caused by Overbalanced Drilling, propose a practical model to determine the depth of mud-filtrate invasion near the wellbore when drilled using a water-based mud. The model handles multiphase flow issues, which results in a better representation of the drilling-fluid filtrate and formation-fluid-displacement process, allowing for improved wellbore skin predictions.

Finite-Element Studies of Hoop-Stress Enhancement for Wellbore Strengthening discusses the mechanism of wellbore strengthening by focusing on hoop stresses at and near the wellbore through the application of the finite-element method. Wellbore and near-wellbore stresses are evaluated during the processes of fracture creation, propagation, and after plugging with lost circulation materials. This better understanding of the several interacting events local to the wellbore and near-wellbore regions can result in improved operational practices related to lost-circulation management.

Large accumulations of methane hydrates are known to exist in the deepwater Nankai Trough off the southern coast of Japan. Because of its enormous potential as an energy source, there is growing interest in the production of methane gas from these deposits. Well-Integrity Evaluation for Methane-Hydrate Production in the Deepwater Nankai Trough presents a study that provided critical information to assist in preparation for, and execution of, a work flow and methodology applicable to well-integrity evaluations for wells constructed within methane hydrate-bearing formations. As large amounts of compaction and subsidence may be anticipated for such wells, methods to mitigate reductions in well integrity are important to prevent losses of zonal isolation caused by overburden pressures.

Sustained casing pressure and gas migration problems caused by thermal and stress loading may occur as a result of temperature and pressure induced stresses, which can be created by well events such as hydraulic fracturing, cyclic steam injection, steam assisted gravity drainage (SAGD), production, completion, and other remedial treatments. Using Fatigue-Failure Envelope for Cement-Sheath-Integrity Evaluation presents a method for evaluation cement sheath integrity on the basis of the effects of fatigue on cement samples at simulated downhole conditions. The experimental process is discussed in detail.

Coalbed methane is one of the major clean-burning gas resources. The southern Qinshui basin of China is rich in coalbed methane and is the first area in China to show good commercial production. The Use of a Novel Spacer and Ultralow-Density Cement System To Control Lost Circulation in Coalbed-Methane Wells presents how the application of a spacer fluid containing a hydrophilic fiber, when used along with ultralow-density cement slurries, can be used to mitigate losses. Details are provided describing the slurry design, its field application, and the cement-bond evaluations that verify the conclusions.

Completion

The authors of our final paper introduce worst case discharge as a relatively new term given to a hypothetical event that is deemed to be of low probability but of high impact. Assessment of Fracture Containment and Broaching Resulting From Worst-Case-Discharge Events addresses the circumstances that lead to such events and the occurrences’ subsequent impacts upon the subsurface well structures. The paper reviews and discusses design changes targeted at mitigating and remediating potentially negative impacts for a variety of scenarios.