Executive Summary

Robert Mitchell, Halliburton Company

A Progress Report

In the March 2008 edition of the SPE Drilling & Completion Journal, wedescribed the problems with the journal-review process and how we hoped toresolve them. While we have not yet met the goals we set, there has beensignificant progress. The first problem was the backlog of papers accepted forpublication. In the March 2008 issue, a total of 9 papers were published, inthe current issue there are 20 papers. The second problem was to exercise morecontrol on the papers submitted from conferences. In 2007, there were 509manuscripts submitted for review, and in 2008, there were 295 manuscriptssubmitted. The third problem was papers that had been in the system for morethan 12 months. In 2007, there were 88 papers that were in review for more than12 months, and in 2008, there were 5 (though our goal is zero). We haveincreased the size of the editorial review committee--associate editors from 5to 6, and reviewers from 71 to 104. Expect further improvement for 2009.

This month there are twelve drilling papers and eight completion papers fora total of twenty papers.

Drilling Papers

Human-Factors Implications of Remote Drilling Operations: A Case StudyFrom the North Sea. Real-time data transfer has given rise to remotemonitoring, reducing personnel on board and cost. The real challenge lies notwith the technical feasibility, but with the impact on work processes, which ispoorly understood. For example, onshore teams generally approved of theconcept, but the offshore response was mixed, with both strong support for itsinnovative potential and critical voices about system reliability, contractualconcerns and the impact on work-life balance. This is an important and highlyrecommended paper. Drilling and Completing High-Angle Wells in High DensityCesium Formate Brine--The Kvitebjørn Experience, 2004–2006. Drilling andcompletion fluids based on cesium formate brines were selected by Statoil forthe high-pressure/high-temperature (HP/HT) Kvitebjørn field. Cesium formatebrine was selected primarily to minimize well-control problems and maximizewell productivity, but the use of the same fluid system for both drilling andcompletion also gave the benefits of simplified operations, reduced waste, andelimination of fluid-incompatibility problems. Optimization of Deep-DrillingPerformance--Benchmark Testing Drives ROP Improvements for Bits and DrillingFluids. This paper describes benchmark testing of advanced diamond bits andHP/HT drilling fluids at high pressures. PDC bits and drilling-fluidcompositions with properties that promote invasion, without causing formationdamage, both showed promise for improving drilling efficiency in hard rock athigh bottomhole pressures. Hydraulic Predictions of Polymer-Thickened FoamFlow in Horizontal and Directional Wells. Foam has proven to be effectiveand economical in underbalanced operations, and it is gaining widerapplications in many areas. This paper summarizes the significant effects ofpolymer on foam rheology and presents a hydraulic model that simulates aqueous-and polymer-based foam flow in directional and horizontal wellbores. A NovelApproach for Determining, Evaluating, and Applying Stress-Concentration Factorsfor Rotary-Shouldered Connections. In recent years, drilling programs havebecome significantly more aggressive, and as a result, rotary-shoulderedconnections often experience exceptionally elevated stress conditions. Thispaper presents a series of evaluations to find a logical and conservativeapproach to evaluate the maximum peak-stress behavior in rotary-shoulderedconnections in response to operation loads. How Good Is the Torque/DragModel? The torque/drag model is a simplified drillstring analysis that hasbeen almost universally adopted by the industry. In general, this model hasagreed well with field experience, but occasionally it has failed. This paperreviews the torque/drag-model assumptions in depth, with many surprisingdiscoveries. Both strong and weak points of the model are discussed, withsuggestions for model improvement and tests to evaluate model performance forspecific cases. Defining the Limits of Tubular-Handling Equipment at ExtremeTension Loadings. While landing string designs have progressed, the designof the handling equipment, until recently, has been based upon conventionalslip technology. Because of the increasing loads being placed on landingstrings and the associated handling equipment, an array of tests were performedto better understand the handling equipment currently in use for landing heavyloads. Five different sets of handling equipment were tested, including fourconventional slips and an unconventional slipless system. This paper givescomplete details of the experimental procedures and the results of the tests.Special Issues in the Stress Analysis of Casing Strings in Steam-InjectionWells: Mathematical Development and Design. The design of tubulars forsteam-injection wells is complex. Because the tubulars in these wellsinvariably experience inelastic loading, issues such as the effects oftemperature on the static and cyclic (fatigue) material properties becomeimportant. This paper presents a mathematical model of casing strings subjectedto thermal loads in steam-injection wells. The model includes the effects oftemperature on material properties and the effects of wellbore curvature andprestress during the heating cycle. Sealing Capacity of APIConnections--Theoretical and Experimental Results. Hydraulic fracturing hasbecome a state-of-the-art stimulation technique. However, the high pressuresthat are achieved during the pumping phase require the understanding of leakresistance of API connections. This paper presents the experimental results ofthe tests carried out on four different thread compounds using the improved"grooved-plate" method. From these tests, a chart is presented thatgives the real connection resistance based on its initial makeup torque.Cement-Shrinkage Measurement in Oilwell Cementing--A Comparative Study ofLaboratory Methods and Procedures. The main purpose of a primary cementingjob is to provide effective zonal isolation for the life of the well. A pathfor fluid migration could be created if the cement sheath fails either becauseof shrinkage and/or because of loss of structural integrity from its lack ofcapacity to withstand stresses from well operations. This paper focuses on thecontribution to near-term cement-sheath failure from shrinkage. The resultspresented in this work can be used to test shrinkage characteristics of cementslurries in the laboratory, under downhole conditions, and, by using theseresults, select the right cement system. Evaluation of the Potential for Gasand CO2 Leakage Along Wellbores. CO2 storage in geological media requires aproper assessment of the risk of CO2 leakage. In this paper, the importantfactors for predicting which wellbores are most likely to leak were determined.The analysis was based on a survey of data from more than 315,000 wells drilledup to the end of 2004 in the province of Alberta, Canada. Finite-ElementStudies of Near-Wellbore Region During Cementing Operations: Part I. Asstated before, a wellbore cement sheath is expected to provide zonal isolationand borehole integrity during well construction and well life. Cement sheathsmechanically interact with other elements in the wellbore region to stressesfrom geological processes and operational activities. Quantifying theseinteracting physical components and processes has technical, economic, andenvironmental significance. A staged finite-element approach is proposed thatallows one to follow the development of stress and strain state during allstages of the well life.

Completion Papers

Evaluation of Sand-Control Completions in the Duri Steamflood, Sumatra,Indonesia. One of the biggest problems associated with the production ofthe crude oil in the Duri field in Sumatra, Indonesia was the production ofmassive amounts of solids. The results of an evaluation program showed thecompletion designs and sand-control screens were up to industry standards;however, several operational aspects were identified as opportunities forimprovement. Lessons Learned on Sand-Control Failure and Subsequent Workoverat Magnolia Deepwater Development. Because of the long lengths of theproducing reservoirs and large variations in sand-grain sizes in the Magnoliafield, premium screens with shunt tubes in conjunction with cased-hole fracpacks have been used to complete the wells. The third well failed duringinitial unloading, allowing unacceptable rates of sand production. A detailedexamination was conducted in conjunction with laboratory collapse and erosiontesting of the premium screens. Revised operational procedures were used in sixsubsequent frac packs without any additional failures and zero-to-negativecompletion skins. Sand Exclusion and Management in the Okwori Subsea OilField, Nigeria. Several downhole sand-control failures in Okwori subsea oilproducers resulted in a significant overhaul of the downhole sand-controlmethod and a review of topside-sand management. A revised openhole sand controlwas designed, together with changes in drilling practices, reservoir drill-influid, and filter-cake cleanup techniques. Magnolia DeepwaterExperience--Frac Packing Long, Perforated Intervals in Unconsolidated SiltReservoirs. ConocoPhillips is developing the Magnolia field with wellsproducing primarily from massive, fine-grained, Pleistocene reservoirs thatrequire sand control to prevent sand production. This paper discusses screenselection in silt/very-fine-sand reservoirs, carrier-fluid selection,perforation strategy, the ability to frac across shale intervals, and theeffectiveness of achieving a frac pack with premium screens with shunt tubes.Challenges, Lessons Learned, and Successful Implementations of MultilateralCompletion Technology Offshore Abu Dhabi. An integrated approach for thetrial planning and implementation, and lessons learned, from a predesign trialled to reaching the final goals of independent coiled-tubing access to theupper and lower laterals, for performing effective stimulation and reservoirmonitoring. Delivering a Fully Qualified HP/HT Production Packer FollowingField Failure. The failure of a primary barrier on a completed HP/HT wellresulted in a significant pressure increase in the production annulus,requiring a complex well-kill operation to resolve. The failure investigationfound no clear cause, but a test demonstrated that very small irregularities inthe internal-casing profile would cause the packer casing-seal to fail. Apacker-seal system was successfully developed that could withstand thespecified degree of casing irregularity. Quantification ofOverbalance-Induced Invasive Damage and the Estimation of Equivalent-SkinEffect on Production. An important premise of underbalanced drilling (UBD)is the productivity improvement it delivers through mitigation of invasivedamage. Characterization and quantification of such damage, therefore, becomesnecessary for assessing the value delivered by UBD. This paper details a novelapproach that combines dynamic microscale-reservoir simulations, calibrated tospecial core tests to model the extent of invasive damage, and its impact onflowback during production. Two field cases are discussed in detail.Qualifying Proppant Performance. To qualify proppant performance,specific quality-control procedures must be rigidly followed, consisting ofrepresentative sampling from a flowing stream, standardized testing withcalibrated equipment, and sample retention for follow up evaluation. This paperaddresses how to apply these principles to evaluate the performancecharacteristics of delivered proppant.