The Value of Research
I don’t believe I need to convince the readers of SPEDC of the value ofresearch. Otherwise, you wouldn't be writing papers and reading this journal.However, I saw a poster that I think outlines the problem neatly.
We have all seen the inspirational posters with uplifting messages like"fly with the eagles, etc.," and some of you may have seen some of themock-inspirational posters created in response. The poster I saw stated,"The simplest solutions are often the cleverest. They are also usuallywrong."
Therefore, the subject of today's executive summary is the effective force.To account for the effects of fluid forces, the actual force in a pipe isreplaced with the effective force in the equilibrium equations. Why must we dothis? Consider a metal bar. I test the metal bar and find that it collapsesunder an axial load of 100 lbs. I then submerge the bar to a depth where thewater pressure on the ends of the bar equal 100 lbs. Does the bar collapse?Most engineers would say no, but skeptics can easily perform the experiment tofind out. The normal expectation is that the effective load on the bar would bezero in this case, and, indeed, the effective force is zero. Fluid pressuresinteract with the pipe in several distinct ways. A resultant load appears whenwe have a tapered pipe or a curved pipe. A resultant load appears when the pipeinclination changes or when the pressure changes with position. If we pose asimple problem where these effects are zero, then we might be persuaded thatthe effective force is an invalid concept. We would be wrong.
What should we do? The simple answer is to read what others have done toinvent the concept. The original papers by Klinkenberg and Lubinski, forinstance, go to great lengths to understand and explain the effects of fluidpressure. Studying the history of a subject is often a useful way to learnabout a subject and to add depth to your understanding. This simple concept isnot wrong--it's called research.
In this issue, we have a variety of Drilling and Completion topics. Includedin the completion topics are: Guidelines For Shale Inhibition DuringOpenhole Gravel Packing With Water-Based Fluids. The drilling community iswell aware of problems with shale swelling and sloughing caused by water-baseddrilling muds. The problems with shale reactivity during gravel packing remainlargely unexplored. This paper provides guidelines on selection methodology ofshale inhibitors for gravel-packing applications. Standard hot roll dispersiontests were found useful, but the authors have determined that a dynamic flowthrough test should be used for assurance of a successful water packingtreatment. Improved Prediction of Shallow Sediment Fracturing For OffshoreApplications. Shallow sediments in deep-water wells have proventroublesome. Among problems associated with these formations are low fracturestrength, borehole collapse, water influx, poor cement jobs, and shallow gasflows. In this paper, a generalized fracture model is developed for shallowsediments in relaxed depositional environments. The model was tested for fivedeepwater cases and one shallow-water well, and the correlations to measuredfrac gradients were found to be excellent. First Laboratory PerforatingTests in Coal Show Lower-Than-Expected Penetration. In an era of increasingenergy costs, the huge coal bed methane resources begin to look moreattractive. Because of the low production rate, however, completionfundamentals are critical and have received little attention. This paperrepresents the first testing program to investigate the perforatingcharacteristics of coal. Both penetration and tunnel diameter were found to besignificantly less for coal than would be predicted by current weak rockmodels. This means impaired flow and communication to the wellbore. Clearly,further research in perforating coal, perhaps providing improved gas flow,could yield large dividends. Rapid Planning and Execution of the FirstMultilateral Well in the Gulf of Thailand: Results and Lessons Learned.Routine drilling in the Kaphong field discovered unexpectedly two newproduction horizons. This paper chronicles the rapid process that planned andexecuted the multilateral well needed to tap this reservoir. The authors sharethe lessons learned and the unintended consequences of executing this projectso quickly. Tubing Buckling--The Rest of the Story. The first study oftubing buckling characterized the buckling as independent of boundary effects,and examination of the formulation clearly shows that the solution is notconsistent with typical packers. The conventional wisdom is that the bucklingsolution applies "far from the packer." In this paper, the effect ofthe packer on the buckling solution is explicitly determined, so that thecompletion engineer can now determine the "near packer" tubing stressesand bending moments for his tubing design.
For drilling topics this issue includes: Universal Process ForBenchmarking Drilling Fluid Performance. Benchmarking drilling performanceis not easy. Most commonly, drilling costs have been correlated to keyperformance indicators and individual drilling metrics, with varying degrees ofsuccess. The benchmarking of drilling fluid costs is even more problematic. Inthis paper, the approach is to compare mud cost to a corresponding technicallimit. The authors have offered to share their techniques with the industry,and have supplied full implementation details. Correlations and Analysis ofCuttings Transport With Aerated Fluids in Deviated Wells. The use ofunderbalanced drilling techniques has been successful in improving recovery inmature fields and in developing low-pressure, low-permeability reservoirs.Cuttings transport is a major factor in the cost of wells, but theunderstanding of cuttings transport with multiphase fluids is very limited.This paper helps fill this void with data and empirical correlations for holecleaning with aerated fluids at intermediate inclinations with pipe rotation.Measuring and Predicting Dynamic Sag. Sag is the variation in density ofa drilling fluid as a result of the settling of suspended particles orweighting material in a wellbore. Sag is a concern, because it can cause costlyand hazardous situations while drilling or cementing. This paper presents a newtesting apparatus for static and dynamic settling rate measurements. Thediscovery that there is a lack of correlation between sag and traditionalviscometer measurements is significant. The new testing device provides notonly better understanding of the sag phenomena, but also provides a bettermeans to characterize fluid performance. Factors Controlling The MembraneEfficiency of Shales When Interacting With Water-Based and Oil-Based Muds.At first glance, this paper seems to be too esoteric for a drilling andcompletions journal. However, this paper has direct impact on the formulationof drilling fluids to prevent shale swelling and subsequent wellbore collapse.Applications such as design of water-based muds and the importance of stableemulsions of oil-based muds make this paper must reading for drilling fluidresearchers. Underbalanced Drilling of a Horizontal Well in DepletedReservoir: A Wellbore-Stability Perspective. Underbalanced drilling hasbeen shown to reduce formation damage and differential sticking. Highlydepleted reservoirs have extremely low pore pressures, thus requiring a verylow ECD to achieve underbalanced conditions. The result is that the wellborehas limited support from the mud pressure, increasing the risk of wellboreinstability. This paper presents a practical wellbore stability technique forevaluating underbalanced drilling for a horizontal well. Best Practice inUnderstanding and Managing Lost Circulation Challenges. Lost circulation isdefined as the loss of whole mud into the formation, as opposed to simple fluidloss. Natural lost circulation occurs when drilling operations penetrate aformation with large pores and leaky faults and fractures. Artificial lostcirculation occurs when hydraulic fractures are created. This paper provides acomprehensive review of the emerging technologies for controlling lostcirculation, and evaluates where they are most applicable. Cementing UnderPressure in Well-Kill Operations: A Case History From the Eastern MediterraneanSea. Cementing in an unbalanced wellbore in an active gas flow has itsdifficulties. The gas flow can cause channels that compromise the integrity ofthe cement plug. These problems were dealt with by careful contingencyplanning, special cement formulation, and the use of a hydraulic simulator toplan the operation. Connection Performance Evaluation For Casing-DrillingApplication. Casing drilling technology combines drilling problems withcasing concerns. As a result, the performance of connectors under theseconditions is receiving increased scrutiny. This paper describes a testingprogram to simulate actual working conditions for a casing drilling connection.The test program has four phases: design selection, fatigue to failure, staticcapacity, and post fatigue testing. The results of testing 9 5/8, 53.3 lb P-110drilling with casing connectors are presented in detail. Ultradeep DrillingPushes Drillstring Technology Innovations. This paper presents acomprehensive review of the technical challenges posed by ultradeep drilling,25,000 ft TVD or greater. Tensile load limits require high strength drillpipeand nonsteel alternatives, double-shoulder connectors, and new pipe handlingtechnologies. BOP shearing capacity and pressure integrity upon drill pipecollapse may need increases in performance limits. Finally, improved BHAconnection technology is needed to minimize downhole failures.
Progress on the Big Backlog
There are several good things to report. John Thorogood has completed thereview process for all the papers over 2 years old. John deserves a big thankyou. If you see him, buy him a drink. He probably needs it. Please notice thatthis issue of SPEDC has 15 papers, which is an increase over the 9 papers inthe last issue. Therefore, we are making progress.
Conflict of Interest
You may have noticed that one of my papers is in the current issue ofSPEDC. Because most SPE journal editors also write papers, SPE provides forthis case. Curtis Cheatham acts as the executive editor for all of my papers,and I don't get to say a thing about it.