bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design Techniques for Reducing Toughness Related Cutter Issues in Carbonate Formations
Authors: Weeden Ryan W. , Whipple Justin 
Published: February 2010

Abstract
Carbonate formation drilling with PDC drill bits often leads to accelerated catastrophic diamond table loss of the PDC cutter. Historically, PDC toughness related failures have been blamed on the bit/formation interaction producing destructive drilling dysfunctions such as; axial, lateral, and torsional vibrations.
A number of design techniques have been applied to cutting structure/bit body design in an attempt to reduce the intensity and frequency of bit/formation interaction related drilling dysfunctions. These techniques were successful in reducing bit/formation interaction instigated drilling dysfunctions, however accelerated catastrophic diamond table failures were still observed at historical rates. This has led to the hypothesis that the accelerated catastrophic diamond table loss observed in carbonate formations is not exclusively related to drilling dysfunctions. The aforementioned hypothesis initiated a detailed study focusing on the relationship between cutting structure design and the damage observed from drilling carbonate formations. The results of this study clearly identified a relationship between hydraulic configuration, the relative magnitude and orientation of individual cutter’s impact force, and observed catastrophic diamond table failure.
Several experimental PDC drill bit designs were constructed using different hydraulic and cutting structure design techniques. These techniques were aimed at reducing the hydraulic erosion potential of cutter substrates and normalizing forces across the majority of the cutting structure. The product of these experimental bit runs has been incredibly positive. In every case, the optimized hydraulic configuration and impact force normalized cutting structure design has outperformed the control designs while drilling carbonate intervals.
This paper will focus on the performance differences between several control and experimental fixed cutter designs operating in the Anadarko Basin. The salient differences between these designs are the hydraulic configurations and the orientations of individual cutters on the control and experimental cutting structures. The slight modification of hydraulic configuration and individual cutter orientations (from control to experimental) has produced remarkable improvements in efficiency and durability. Several 7 7/8" diameter bit designs will provide the technical basis for this paper.
Comprehensive Studies of Aluminum Drillpipe
Authors: Tikhonov V. S. , Gelfgat M. Ya. , Cheatham Curis , Adelman Alex 
Published: February 2010

Abstract
Low weight, reduced bending stiffness and superior corrosion resistance combined with sufficiently high strength properties allow aluminum alloy drill pipe (ADP) to be used more extensively in drilling ultra-deep and extended-reach wells where corrosive environment may also be encountered.
This paper presents results of comprehensive studies of the most widely used LADP (Light Alloy Drill Pipe) 147×13 mm made from 1953T1 series aluminum alloy (Russian Grade). The studies involve the results of mechanical testing of small- scale specimens, corrosion testing in different media, fatigue testing of full-scale tool joint specimens, as well as finite- element analysis (FEA) of the "aluminum pipe – steel tool-joint" thread connection.
The results of the studies provide further evidence that use of LADP is entirely appropriate for drilling in many challenging environments.
Salinity-Based Pump & Dump Strategy for Drilling Salt with Supersaturated Fluids
Authors: Akers T. J. 
Published: February 2010

Abstract
Riserless drilling with weighted mud systems, commonly referred to as a "Pump & Dump" drilling strategy, is an established drilling technique used on deepwater wells with shallow hazards. Large holes and high flow rates result in very large volumes of fluid being required to drill to total depth (TD), circulate the well clean and cement the conductor casing string. Fluids management becomes a major issue in the riserless hole section. In the Gulf of Mexico, mud is often densified in excess of well requirements and then blended with seawater in a "Cut-Back" operation to reach the desired density to pump downhole.
When riserless drilling into salt, a Pump & Dump strategy is often used. Dilution with seawater, however, results in an undersaturated fluid. This fluid leaches the salt resulting in substantial hole enlargement. The hole enlargement can result in poor cementing jobs that require remediation or even an additional string of casing. A unique operation has been employed in the Santos Basin of Brazil where a supersaturated brine fluid was used to conduct a pump & dump operation with the goal of drilling with a saturated brine fluid and minimizing hole enlargement. This paper details the planning of the operation, fluid design, and pilot testing. Fluids management, equipment rig up, and results are discussed in detail. The operation has been successfully executed twice with both operations achieving the set objectives for the wells. Unforeseen complications that were encountered are discussed along with lessons learned that have been applied to subsequent operations.
Evaluation of Alternative Initial Responses to Kicks Taken during Managed Pressure Drilling
Authors: Davoudi Majid , Smith John Rogers , Patel Bhavin M. , Chirinos Jose E. 
Published: February 2010

Abstract
An industry-supported research project has completed its evaluation of alternative initial responses to kicks taken during the constant bottom hole pressure (CBHP) method of managed pressure drilling (MPD) operations. The evaluation is the first phase of a study that is intended to provide a basis for comprehensive, reliable well control procedures for MPD operations. The evaluation was based primarily on computer simulations of multiple alternative initial responses to several causes and severities of kicks in different well geometries. Three responses were concluded to have general application: increasing casing pressure until flow out equals flow in, shutting the well in, and using an adaptation of an MPD pump shut down schedule to detect and shut in low rate kicks.
A simple shut-in was concluded to be the most generally applicable response because it stops formation flow without requiring any special equipment. However, it also causes an increased risk of exceeding the formation fracture pressure for most situations versus a response that maintains continuous circulation. Increasing casing pressure while maintaining a constant pump rate until flow out equals flow in was concluded to be the most applicable response that avoids the disadvantages of shutting in the well. However, it requires accurate metering of return flow as a basis for determining whether formation flow has stopped. The adaptation of an MPD pump shut down schedule can be used to determine whether questionable kick indications are caused by a kick more conclusively than the other responses. It ends with the well being shut-in. A fourth response, increasing the pump rate, also has important but very limited application. The selection of which response is the most practical is shown to depend on well conditions and the equipment being used. Potential advantages of and constraints on the use of these responses are also explained.
Anchor Handling and Rig Move for Short Weather Windows During Exploration Drilling
Authors: Saasen Arild , Simpson Michael , Ribesen Bjørn Thore , Høj Jóanes 
Published: February 2010

Abstract
The paper describes field experience with a method for efficient anchor handling and rig move during North Sea exploration drilling campaigns with a semi submersible drilling rig requiring anchors for positional fix. A conventional anchor handling operation including a rig move operation is presented, followed by a detailed presentation of an innovative field operation including a method for combining anchor pick up, rig move and pre-setting. Four anchor handling boats were used to pick up anchors at an abandoned well. Thereafter the anchors and ground chains were sent off to next drilling location with three of the boats. These boats pre-set the anchors. The anchor pre-setting sequence was selected such that one boat was released after only a short period at the new location.
The last anchor handling vessel, the smallest one, was used in the rig move operation as a tug. When the rig arrived at the new drilling location, the three remaining boats were involved in connecting the anchors. As a result of the pre-set anchors, the mooring operation could be performed in a weather window, being roughly one half of the weather window needed for normal mooring operations. The anchor handling boats were released sequentially as early as possible reducing the cost of the entire operation significantly. As will be described a traditional anchor handling operation would have resulted in two days waiting on weather in addition to the extra time spent on anchor handling because the weather conditions deteriorated. The paper also describes the challenges of retrieving pre-laid anchors tensioned to the anticipated maximum 100 years load.
Large-Volume Cement Squeezes as Cost-Effective Solutions for Severe-Loss Zones
Authors: Algu Devendra , Galey Loran , Barrett Myles , Humphries Mike 
Published: February 2010

Abstract
Loss circulation is commonly induced while drilling wells through depleted intervals. The combination of narrow margin between formation pore pressure and fracture pressure makes loss circulation inevitable in many wells. Pretreatment of the drilling fluid with loss-circulation material while drilling and wellbore strengthening techniques have successfully reduced instances of high-rate, large-volume (&gt;1000 bbl) losses.
Fracture width and volume created by high-rate, large-volume losses often limit the effectiveness of conventional loss- circulation treatments for two reasons. First, the size and concentration of bridging materials that will effectively bridge the fracture opening can plug the bottomhole drilling assembly. A trip may be required to remove the bit and other components of the bottomhole drilling assembly. If losses are severe, this trip may not be possible without risk to well control. Second, it is difficult to restore and maintain wellbore strength to a level equivalent to the integrity prior to losses, especially if substantial openhole drilling time is required to reach the next casing point.
This paper presents the design strategy, formulations and testing requirements, placement techniques and procedure, and other practices utilized in successful large-volume cement squeezes to remediate severe, high-rate, large-volume losses. Results from two deepwater case studies will be presented to illustrate successful application of this treatment approach. Cement squeezes can be performed through many bottomhole drilling assemblies, where conditions require, and eliminate the dependence of success on correct sizing of bridging particles. Large-volume, specially designed cement squeezes have proven effective methods to restore wellbore integrity after loss rates as high as 320 to 480 bbl/hr and total volume of losses to the formation of up to 4000 bbl prior to treatment.
Pressure Transmission in Gelled Drilling Fluids in Deepwater Environments
Authors: Negrão C. O. , Franco A. T. , Oliveira G. M. , Martins A. L. , Gandelman R. A. , Rocha L. L. 
Published: February 2010

Abstract
Deep water drilling is normally associated to narrow operational windows where gains and losses are frequent. drilling fluids are designed to gel when it is not submitted to shear stress. This is necessary to avoid cuttings to settle during circulation stops. When circulation is resumed, the pump pressure rises above the circulation pressure in order overcome the gel strength. Due to its thyxotropic effect, the gel viscosity remains high for a while after the circulation restart. The gelation may have significant importance, specially, in deep waters where high pressures and low temperatures take place. Gel effects can both generate excessive pressures (inducing losses) and cause delays in pressure transmission which can directly affect gain detection devices. The current work presents a compressible transient flow model of the restart of drilling fluid circulation, in order to predict pressures at the borehole. The model comprises the conservation equations of mass and momentum which are solved by the finite volume method. A constitutive equation is employed to model the time dependent rheology of gel breaking. Case studies are conducted to evaluate the effect of fluid properties, well geometry and pumping pressure on the bottomhole pressures. Major effects on pressure propagations delay in deepwater drilling are highlighted.
Total System Optimization Delivered Significant Performance Improvement and Cost Savings in GoM Challenging Salt Section
Authors: Voss W. , Aslakson J. , Thomson I. , Radford S. , Thomson C. , Buxton B. 
Published: February 2010

Abstract
It is well known in the oil industry that there are many drilling challenges associated with salt drilling in the Gulf of Mexico continental shelf. Although many wells have already been drilled through salt, hazard prediction is still not very accurate, which makes extensive planning a critical requirement. While drilling a prior well through a thick salt body in the shallow waters of the Gulf of Mexico Ship Shoal area, the operator experienced many drilling-related problems, including numerous downhole tool failures, leading to considerable non-productive time (NPT) and additional costs. This paper will focus on the planning and execution of a sidetrack to this problematic well, again drilled through and exiting the salt. This paper highlights the problems encountered and the substantial cost savings realized by the operator.
During the planning phase, a thorough offset analysis was conducted using an engineered optimization process, which allowed the identification of the root causes for the downhole tool failures and mapping of the main drilling hazards. The main drilling challenge in this project was to drill and underream efficiently through anhydrite layers imbedded in the thick salt body. In the offset well, most of the drilling problems were associated with these anhydrite layers, which induced significant vibration and premature cutting structure damage. Location and thickness of the anhydrite layers were difficult to predict, therefore pre-established drilling procedures and best practices were key to help identify the anhydrite layer promptly and successfully overcome it.
The implementation of a multi-discipline total system approach to select the ideal combination of an application-specific rotary steerable system, real-time downhole drilling dynamics tool, drill bit and underreamer, in combination with appropriate planning, recommendations, drilling procedures, and best practices was crucial to deliver significant performance improvement by drilling the sidetrack salt section six days ahead of AFE, which represented US $2.1 million in savings for the operator.
Electromagnetic MWD Technology Improves Drilling Performance in Fayetteville Shale of North America
Authors: Janwadkar S. , Klotz C. , Welch B. , Finegan S. 
Published: February 2010

Abstract
The Fayetteville Shale is one of the newest and fastest-growing shale gas plays gaining significant prominence in North America. This unconventional reservoir is located in the Arkoma basin of Arkansas. Drilling horizontal wells coupled with hydraulic fracturing makes this reservoir highly prolific and comparable to the Barnett Shale. However, the area presents numerous challenges including loss of circulation, wellbore instability, and significant connection times reducing efficiency while drilling the curve and lateral sections.
To address these challenges, a detailed engineering analysis was performed using a proven drilling optimization procedure. As a result of the study, engineers determined that surface pressure limitations with high rates of penetration (ROP), together with pumping of loss circulation material (LCM) to control fluid losses negatively affected the performance of downhole measurement while drilling (MWD) equipment. Existing standard mudpulse technology could not operate efficiently while drilling with loss circulation, no fluid returns or high LCM concentrations. Wired-pipe technology is typically cost- prohibitive in this application.
An electromagnetic (EM) MWD system was used and the transmission of real-time data was done via EM signals through the formation instead of fluid pressure pulses through the inner bore of the pipe. The system was designed to provide accurate real-time MWD data and reliable directional control and was not hindered by the presence of multi-phase fluids, high-density solids, or LCM in the wellbore.
The results achieved are 33% to 36% increase in the average ROP and 13% reduction in drilling time to reach target depths. The authors will describe the significance of applying principles of EM technology to improve drilling performance.
An Experimental Study to Define Operational Parameters Governing Hole Enlargement While Drilling Offshore Heavy-Oil Reservoirs
Authors: da Costa F. G. , Ferreira M. V. , Campos E. F. , Macedo F. S. , Aragão A. F. , Martins A. L. 
Published: February 2010

Abstract
The development of heavy oil fields imposes several challenges for well construction: in order to guarantee minimum flow rates, long horizontals intervals are often required. Long horizontals are associated to long reservoir exposure times which can affect final open hole quality. Rock fluid interaction issues and BHA design directly affect the drilling of sensitive formations, such as non consolidated heavy oil reservoirs.
This article presents initially a comprehensive data analysis of caliper logs in offshore heavy oil wells drilled in Brazil. The analysis correlates hole enlargement with relevant parameters such as fluid type, flow regime and BHA composition. Data sources considered were real time monitoring equipment, logging data and drilling reports. Results indicate that water based fluids and turbulence proved to stimulate hole enlargement and should be avoided.
The study is also supported by a unique experimental work where fluid flow conditions were simulated in a pilot unit where the wellbore was represented by a non consolidated synthetic core saturated with high viscosity oil. For a given flow rate, hole enlargement is monitored with time by a real time CT scanning technique. Experimental results are in agreement with field observations. The role of drillstring composition was not contemplated in the experimental study.
An Intelligent System to Detect Drilling Problems Through Drilled Cuttings Return Analysis
Authors: Marana A. N. , Guilherme I. R. , Papa J. P. , Ferreira M. V. , Miura K. , Torres F. A. 
Published: February 2010

Abstract
Cuttings return analysis is an important tool to detect and prevent problems during the petroleum well drilling process. Several measurements and tools have been developed for drilling problems detection, including mud logging, PWD and downhole torque information. Cuttings flow meters were developed in the past to provide information regarding cuttings return at the shale shakers. Their use, however, significantly impact the operation including rig space issues, interferences in geological analysis besides, additional personel required.
This article proposes a non intrusive system to analyze the cuttings concentration at the shale shakers, which can indicate problems during drilling process, such as landslide, the collapse of the well borehole walls. Cuttings images are acquired by a high definition camera installed above the shakers and sent to a computer coupled with a data analysis system which aims the quantification and closure of a cuttings material balance in the well surface system domain. No additional people at the rigsite are required to operate the system.
Modern Artificial intelligence techniques are used for pattern recognition and data analysis. Techniques include the Optimum-Path Forest (OPF), Artificial Neural Network using Multilayer Perceptrons (ANN-MLP), Support Vector Machines (SVM) and a Bayesian Classifier (BC). Field test results conducted on offshore floating vessels are presented. Results show the robustness of the proposed system, which can be also integrated with other data to improve the efficiency of drilling problems detection.
Mesophase Spacer Designs Raise the Bar for Casing and Riser Clean-up in Deepwater Applications
Authors: Quintero Lirio , Christian Chad , Jones Thomas A. 
Published: February 2010

Abstract
When displacing and completing oil and gas wells in deepwater, contaminants, such as oil-base drilling fluids, drilled solids, pipe dope and other debris found in casing and risers, should be removed quickly and efficiently to avoid excessive operating costs and to minimize formation damage during the completion phase. Synthetic-based invert emulsion drilling fluid debris is considered the most difficult to remove and typically requires excessive rig time to filter brine to appropriate levels of clarity using conventional spacer systems. These unscheduled costs and delays can be avoided if the displacement and clean-up spacers are properly designed.
A properly designed displacement spacer system should remove all foreign debris, completely water-wet all metal surfaces in a single pass of the spacer train and require no more than a single circulation of completion brine. The spacers should also be formulated to (1) have superior detergency at cold seabed and downhole temperatures, (2) prevent viscous emulsions or sludge, and (3) be compatible with the drilling fluid to prevent channeling.
Using mesophase technology which is a surface-active additive package (SAAP), a new spacer system has been developed and tested that does not require the use of common organic solvents or terpenes. Additionally, the new system is simple to apply and reduces non-productive time (NPT). This novel two-spacer system has been successful in several deepwater applications, demonstrating its ability to efficiently clean the riser, casing, and wellbore clean-up tools. The displacement spacer system has been successfully applied during direct and indirect displacements of synthetic-based drilling fluids.
This paper will discuss the challenges and successes of displacing synthetic-based mud in deepwater applications and the lessons learned.
A new species of Mathevotaenia (Cestoda, Anoplocephalidae, Linstowiinae) from the lizard Sceloporus malachiticus (Squamata, Phrynosomatidae) from Panama
Authors: Bursey Charles , Goldberg Stephen , Telford Sam 
Published: February 2010

AbstractMathevotaenia panamaensis sp. nov. (Cestoda, Anoplocephalidae, Linstowiinae) from a green spiny lizard, Sceloporus malachiticus, collected in Panama is described. This is the first species of Mathevotaenia reported from a lizard host. The new species is most similar to Mathevotaenia bivittata in that mature eggs are concentrated along the lateral margins of the proglottids. Major differences between the two species include oval cirrus sac in M. bivittata, a spherical cirrus sac in M. panamaensis; ovary compact consisting of 10–15 short lobules in M. bivittata, ovary bilobed with each lobe consisting of 3–4 lobules in M. panamaensis.