Curtis Cheatham, Weatherford International
Each year SPE surveys readers of its journals. In this issue, we will discuss results from the most recent survey for SPE Drilling &Completion.
When the survey was conducted last summer, we had 4,432 subscribers. Roughly9% of all subscribers responded to the survey--a total of 382 respondents. Of those who responded, 75% were print and online subscribers, and 25% were online only subscribers. The survey comprised 22 questions designed to assess how well the Editorial Review Committee is performing and help determine changes that would benefit our readers.
The primary mission of our journal is to provide the best technical content possible. Consequently, the question and data in Fig. 1 are supremely important.
Overall the results are encouraging--note that 62% rated technical content as very good or excellent while only 3% said it is fair or poor. Nevertheless,there is room for improvement. (Note: all 382 respondents did not answer this question.)
Over the last several years, several changes were made to try to improve the technical quality and reduce review cycle time. From the perspective of our Editorial Review Committee, there have been three substantive changes. First,SPE switched peer-review systems, which greatly improved process efficiency. Second, we increased the number of technical editors (currently at 160 compared to 108 in 2009). Finally, two more associate editors were added (currently 10)and each associate editor has been assigned primary responsibility for specific subject areas. The following questions helped assess the effects of these (and other) changes: "How would you compare SPE Drilling & Completion now with one year ago?" 36% said SPE Drilling & Completion either improved or significantly improved. 48% said it is about the same. Less than 1% said it is worse or significantly worse. (The remaining 15% said they did not subscribe last year.) Again the results are encouraging and tend to confirm we are headed in the right direction.
As I mentioned in the last issue, there has not been a single discussion submitted since (at least) October 2009 in SPE Drilling &Completion. The lack of paper discussion is a serious concern because expression of express diverse views is an essential component of any technical journal. Such debate can elucidate pros and cons of important and controversial subjects. Consequently, several survey questions focused on this subject. The following comments by respondents highlight the value of discussion of papers:
Why is there so little discussion? One theory is that changes in information sharing brought about by the Internet have changed the ways engineers choose to communicate with each other in discussing technical papers. Whatever the cause,we will continue to study ways to help readers re-engage in paper discussion.As always, we are keenly interested in your thoughts--that is, if you would care to discuss them. Here are a few relevant comments by respondents:
For those interested in submitting a discussion for a paper, the current process is described at
Fifty-one readers provided suggestions for improving SPE Drilling &Completion. The most frequent suggestion was submitted by nine readers who want more papers on specific--but various--topics such as drill bits, drilling and completion fluids, completions, and so on. Other readers made suggestions that can be grouped into common themes. Four themes are described below with a few responses under each theme to provide a flavor of the suggestions. The total number of times each theme was mentioned is also given.
Shorten time to publication in our journal--4 mentions:
More practical papers and case histories--6 mentions but with one mention(the last bullet) disagreeing with the others:
Keep up the good work--12 mentions:
New ideas--6 mentions:
The first theme--shortening review cycle time--is a primary focus of our Editorial Review Committee not only because of the numerous complaints received about it in the past (as noted in the comments above) but also because we realized we must do better. Significant progress has been made, but we believe that further improvement is possible. The key metric we use is average days from submission to first decision. Presently, the average is 81 days--down from86 days three months ago--and considerably better than in 2009 when it averaged between 137 and 273 days.
The second theme--more papers on practical application and case histories--is not something we focus on. It is up to authors to choose their subjects. The Editorial Review Committee applies its best efforts in reaching an impartial decision on each paper. We do not set quotas for specific categories of paper. In fact, case histories, or field case studies, is already one of the four general categories of papers for which SPE provides review guidelines to editorial review committees. The other three categories are theoretical manuscripts, experimental studies, and review papers. It is worth noting that five of our fourteen papers in this issue are case histories.
The third theme--what a great job we are doing!--is no doubt self serving on my part. But there were enough positive comments on the theme that it seemed appropriate to include them. The key point here is best put by the final comment: "it is already very good, so don’t mess with it too much."
The last theme--new ideas--has several intriguing suggestions. I will address the suggestion to devote an entire issue to a specific topic such as fluids. That is an idea we have previously considered but never done. We publish four issues each year with each issue containing 12 to 14 papers.Accumulating enough papers on a particular topic to fill an entire issue could take up to a year simply because there are not papers on any specific subject.And if we waited till we had a complete issue on a given topic, then we would delay publication of some papers by six months or longer. Given our commitment to publish papers as quickly as possible, such delay would be counterproductive. So, while we like the idea, there does not seem to be a good way to implement it. One recent change to address this concern is grouping papers in each issue under themes that we hope are useful to readers (which was also one of the suggestions above). However, even this approach has occasionally proved difficult because of the wide variety of subjects and the relatively small number of papers in each issue.
Your Editorial Review Committee recognizes the importance of our maintaining close contact with our readers. Several avenues exist for such communication.The readers’ survey is one of the most important methods we use to gauge how well our journal is perceived by readers. Frankly, it is disappointing that we cannot draw more significant conclusions from last year's survey because fewer than 9% of our readers responded to it. We are grateful to readers who responded to the survey--your voice is being heard. To all our readers, I urge you to take a few minutes to complete the next readers’ survey you receive for SPE Drilling & Completion. It will be worth your time and effort.
Now to the papers. This issue contains fourteen papers on the following topics: zonal isolation, data quality, drilling systems automation,completions, drill bits, drilling equipment and operations, drilling project management, and drilling fluids. Case histories are provided from Malaysia,Kuwait, the North Sea, deepwater Gulf of Mexico, and deepwater Brazil.
Our first paper analyzes creation of microannuli at cement-sheath interfaces. Microannuli at the well cement-sheath's interfaces (either with casing or formation) may result in loss of zonal isolation, which can cause significant problems. Common explanations for the phenomenon are change in cement volume because of cement hydration or casing contraction caused by temperature changes. How To Prevent Loss of Zonal Isolation Through a Comprehensive Analysis of Microannulus Formation shows other modes of failure also occur. Both theoretical and experimental evidence demonstrates current theoretical models used to simulate cement-sheath behavior do not fully predict what is observed in laboratory experiments.
The Influence of Data Quality on Workflows and Decision Making in Well Delivery delivers outstanding insight into a fundamental challenge facing the industry in real-time applications--data quality. The authors discuss critical data issues for drilling work processes in both a collaborative environment and further automation of the drilling process. They conclude data quality must be significantly improved to implement more complex but more efficient workflows or to achieve more automated workflows. A key factor limiting progress is the lack of a single party that controls all aspects of data quality. The authors conclude that operators, as the owners of the data,must take the lead. They also state that a standard means of measuring data quality of all data streams is needed and propose the best way to do this is to extend the WITSML standard.
Drilling systems automation is an emerging focus area for our industry and SPE. To help advance this effort, members of SPE have formed the Drilling Systems Automation Technical Section (DSATS). Any SPE member can join any technical section. To learn more about DSATS, go to
What are genetic algorithms? That was my first question when I read thetitle for Partition Perforation Optimization for Horizontal Wells Based onGenetic Algorithms. The problem being addressed is early water breakthroughand rapid water-cut increase in uniformly perforated horizontal wells caused by heterogeneity in permeability. This paper presents a new method to optimize perforation parameters along horizontal intervals to help homogenize inflow-velocity profile. Genetic algorithms are computational models that simulate the biologic evolution process of Darwin's genetic choice and natural selection. This novel mathematical approach is explained in detail and references for genetic algorithms are provided.
Cased-hole gravel packing is commonly used to control sand production.Effective Perforating and Gravel Placement: Key to Low-Skin, Sand-Free Production in Gravel Packs presents a fine case history using dynamic underbalanced perforating (DUP) for removal of perforation damage, effective gravel pack placement, and packing of the perforation tunnels. DUP was applied in west Malaysia to improve connectivity to the high-permeability reservoir by effectively removing perforation and drilling damage near the wellbore.
"An excellent paper blending geomechanics, material behavior, and reservoir behavior in a convincing manner." That is what one of our Technical Editors wrote in reviewing Modeling Horizontal-Completion Deformations in aDeepwater Unconsolidated-Sand Reservoir. This paper presents development and results of geomechanical models and analyses used to assess the risks of compaction-induced deformation and potential failure of horizontal gravel-pack completions in a field located in deepwater but at shallow depth below the seafloor. Both open hole and cased-hole gravel pack completions were analyzed.Model results presented in the paper include deformations of the completion and stresses in the screens as a function of reservoir-depletion pressure.
Standalone screens in openhole can provide highly reliable sand control in certain situations. A key question though is how are appropriate situations determined? A Review of Screen Selection for Standalone Applications and a New Methodology discusses various laboratory testing procedures used in the industry for evaluation of screen performance. It concludes that current practices can bias the choice toward a particular type of screen, such as wire wrapped and premium screens, and unduly limit the possible selection of standalone screens. Well, this sounds like a "must read" to anyone involved in selecting sand control techniques. Perhaps even a bit of controversy here? Anew testing and interpretation method is proposed that the authors claim eliminates the ambiguities associated with current practice.
Early concepts of hybrid bits go back to the 1930s. Gosh, that makes them even older than I am! Hybrid Bits Offer Distinct Advantages in Selected Roller-Cone and PDC-Bit Applications describes a new generation of hybrid bits that combine PDC-bit designs with rolling cutters on the periphery of the bit. Laboratory and field tests show improvements in drilling mechanics and dynamic stability. The new design is well suited for drilling heterogeneous and interbedded formations where roller-cone bits are too slow and PDC bits are subject to premature damage because of harmful vibrations. Other guidelines for application of this new type of hybrid bits are offered in the paper.
Breakthrough in 22-in.-Hole Drilling in Kuwait Deep Wells is another excellent case history. It describes efforts to drill larger-than-usual hole ata depth of 6,000 to 9,500 ft so that large surface casing can be run, thereby enabling reaching total depth with the appropriate hole size. A new PDC-bit design and a more-powerful 12¾-in. motor were developed and improved over the project, which resulted in achieving the goal of drilling this hole section inone bit run. This paper should be particularly interesting to readers involved in drilling large hole size in interbedded formations using PDC bits.
Design Methodology and Operational Practices Eliminate Differential Sticking presents fresh insights into causes and prevention of differentially stuck pipe. Most readers will find some new concepts to challenge their own thinking. The explanations and logic underlying the authors' proposed methods are clear, even if all readers may not agree with allof them. The review and perspective of the literature is exceptionally useful.Years of field application of the proposed method across the operator's global operations are convincing validation of their practices. There are some instances where the authors are uncertain of cause and effect, but the paper clearly notes where assumptions are made. This paper is highly recommended regardless of your knowledge level about differential sticking.
Slot-limited platforms have been a problem for some time. As described inthis next paper, dual conductors in a single slot is an existing solution. So you may ask, what is new? The authors of Magnus: Utilization of Conductor Sharing Wellhead Technology To Access Additional Hydrocarbons With a Slot-Constrained Platform encountered a new problem for which they developed novel twists on the dual-conductor solution, including a new "gamma wipe" surveying technique. The paper details an excellent case history that clearly explains what was done and why.
For multiple-well drilling and completion campaigns, cost and schedule performance tend to improve over time. This trend in improvement is referred to as a "learning curve." The pioneering work on learning curves applied to well construction is the classic SPE 15362 by Ford Brett and Keith Millheim in 1986.Today many operators consider the use of learning curves to be a best practice.Integrating Learning Curves in Probabilistic Well-Construction Estimates describes prior work in logical terms that relates their contributions,including several papers on probabilistic well-time estimation and of course the classic SPE 15362. The proposed method is a novel and logical extension to existing methods. In cases where the sample of comparison projects is small,there may be significant uncertainty in the rate and magnitude of learning. A general method and specific procedures for integrating learning curves inprobabilistic estimates are given in detail. Hopefully, the authors of SPE15362 will submit a discussion on this paper because we would really like to hear their thoughts on this subject.
Drilling fluid containing colloidal gas apron (CGA) microbubbles can bridge the pores of reservoir rock in the near-wellbore region and reduce risks of lost circulation and formation damage. Although there has been work performed on flow of the microbubbles through porous media, little is known about optimal conditions for blocking the pores. A Study of the Effects of Colloidal Gas Aphron Composition on Pore Blocking examines the effect of reservoir fluids on the pore-blocking ability of CGAs. Increasing resistance to fluid flow was observed as more CGA fluid was injected, indicating that microbubbles could effectively block the pores. The authors conclude aphrons will mitigate the fluid invasion into the rock and hence will reduce formation damage. The blockage was removed successfully by water after injection, indicating the pore blocking is reversible.
Riserless drilling with weighted-drilling-fluid systems, commonly known as"pump and dump" is an established technique for deepwater wells with shallow hazards. Large holes and high flow rates result in large volumes and major logistical issues. Because most deepwater operations are conducted far fromtheir resupply point, all fluid for the operation must be at the wellsite in advance. As described in Salinity-Based Pump-and-Dump Strategy for Drilling Salt With Supersaturated Fluids, one widely accepted practice has been to blend premixed pump and dump fluid with seawater to augment the volume. This technique allows more fluid to be pumped in the riserless operation than can be stored on location. This works except when drilling through salt because the salinity of the resultant fluid is the key drilling-fluid property. When salt is drilled with an undersaturated water-based fluid, the salt is leached into the fluid, which can result in hole enlargement and potentially lead to a poor cement job. Hence, fluid management becomes a major issue, which is the topic of our final paper. This paper is a case history of using supersaturated drilling fluid in Santos Basin of Brazil to minimize hole enlargement and help ensure good cement jobs. The excellent hole conditions while running casing and casing shoe integrities that exceed expectations indicate the strategy was a success.
Congratulations to Dr. John Thorogood who recently received the 2011 SPE Drilling Engineering Award that recognizes outstanding achievements and contributions to the advancement of the drilling engineering discipline for our society. John’s vision and leadership have been, and continue to be, truly remarkable. I would be remiss if I did not take the opportunity for one final plug for SPE Drilling & Completion by pointing out that Dr.Thorogood is also an Associate Editor for this journal.
That wraps up this issue. On behalf of your entire Editorial Review Committee, thank you for your continued support of SPE Drilling &Completion.
|Fig. 1—2010 SPE Drilling &Completion Reader Survey, Question 2 Responses|