bluuebunny/crossref_metadata_2025_split huggingface dataset:
Attic Thin Oil Columns Horizontal Wells Optimization Through Advance Application of ICDs and Well Placement Technologies in South China
Authors: Tran T. , Huang Y. S. , TigerLian J. H. , Yu G. D. , Zhang H. , Partono Y. , GordonGoh K. F. , Lee J. S. , Kok J. , Lui Y. , Parlindungan M. H. 
Published: February 2010

Abstract
The horizontal wells side-track campaign at CACT’s H fields in South China Sea has been very successful and challenging over the last two years. Horizontal wells are well-recognized in developing thin-oil column within multi-stacked reservoir by exposing wellbore to maximum reservoir contact and drainage area. The lateral targets and remaining oil reserves are in attic thin oil columns in clean sands and shaly sands. Since the oil column is thin at the top of a clean sandstone reservoir with strong bottom water drive, early water break through can occur even when the lateral is well placed on the top of the reservoir.
To further optimize the reserves recovery, horizontal trajectories are placed near the top of the reservoir, and the well is completed with stand-alone screen combines with downhole inflow control devices (ICD’s). This combination provides the horizontal well optimum completion for draining and further prolongs the life of the well. The application of the field-adjustable nozzles based on real-time Logging-while-Drilling (LWD) data updates into ICD’s predrilled model, together with the precise well placement have enabled horizontal wells to be economically developed in a thin oil-bearing layer.
In this paper, some of the technical assessment and collaboration workflow between the multi disciplinary team of technology users and service providers, enrooting to the successful implementation of the first nozzle-type ICD’s installation and Distance-to-Boundary Well Placement technology in China will be highlighted. The success of the first ICD’s well completions installation was proven with better Productivity Index (PI) based on initial well performance. The first ICD’s well produced ~100% oil for almost two months since early Mar 2009. Meanwhile, a second ICD’s well with thinner net oil pay produced 100% oil for 20 days clearly showed the benefit of ICD later when water break through and increased to 85%.
The mentioned integrated Nozzle-ICD’s design with precise Distance-To-Boundary Well Placement solution have shifted the conventional application of ICD’s, which is hardware-orientated, from being dictated one-way by hardware supplier, towards a holistic reservoir-centric design. It has become an operation that keeps all-party informed and always in communication. The "real-time" add-value of LWD and well placement data in updating the predrilled ICD’s well model has benefitted horizontal wells inflow control design. This integrated and reservoir-centric solution has optimized horizontal well application successfully in one well, but facing some reservoir and structural challenges in another well; which has provided valuable lesson-learned for future drilling.
MWD Failure Rates Due to Drilling Dynamics
Authors: Reckmann Hanno , Jogi Pushkar , Kpetehoto Franck , Chandrasekaran Sridharan , Macpherson John 
Published: February 2010

Abstract
Rig downtime due to MWD tool failure is expensive, particularly on offshore rigs with extremely high operating costs. There are different reasons for tool failures, one being the high vibration loads on MWD tools under extreme drilling conditions. MWD and LWD tools are usually equipped with sensors to measure and record vibrations for drilling efficiency and optimization. The goal of the study described in this paper is to establish the link between MWD or LWD tool failure, and drilling dynamics. With this knowledge, it is possible to reduce failure rates and costs with real-time monitoring of downhole drilling dynamics.
To analyze the effect of drilling dynamics on MWD tool failures, a unique database of MWD runs in challenging environments was created. This database includes vibration data recorded at 5-second intervals from more than 12,000 drilling and reaming hours, over a total footage of 425,000 feet. In addition to unique dynamics data such as weight, torque, bending moments and axial, lateral and tangential RMS and peak accelerations, the database included detailed run and failure reports, and environmental information such as well profiles and drilling operations.
A statistical study using the logistic regression indicates the types of dynamic behavior most statistically significant in MWD/LWD tool failures. These are cumulative lateral vibrations and backward whirl. Cumulative axial or tangential acceleration appears not to be significant in current MWD/LWD tool failures.
A study on the correlation between recorded MWD tool dynamics and tool failure rates established the link between time spent operating above a level of vibration and the probability of tool failure. This paper contains charts describing this relationship between dynamics, operating hours, and MWD/LWD tool failure rates. These charts are valuable in operational risk management and in developing procedures for optimal drilling practices that reduce the dynamic loads on the MWD system, resulting in prolonged tool life and reduced cost.
Improvements in Multistage Fracturing of Horizontal Wells Using a Newly Introduced Single Trip Coiled Tubing Conveyed Annular Perforating and Fracturing Tool - Benefits, Savings, and Case Histories
Authors: Hari Rob , Laun Lyle 
Published: February 2010

Abstract
Multi stage fracturing of horizontal wells is quickly creating the same "step change" as when vertical wells first went horizontal. As improved advances are made in drilling and completing horizontal wells, new solutions are required to address the limitations of today’s multi-stage fracturing methods.
A new process, conceived and licensed from ExxonMobil Upstream Research Company, offers an alternative to existing multi-stage fracturing methods. This paper will discuss the benefits, cost savings and case histories of a newly released single trip coiled tubing conveyed annular fracturing & perforating assembly.
Riserless Drilling With Casing: Deepwater Casing Seat Optimization
Authors: Kotow Kenneth J. , Pritchard David M. 
Published: February 2010

AbstractThis technical submission on Deepwater Casing Seat Optimization is a follow up to the submission of Riserless Drilling with Casing: A New Paradigm for Deepwater Well Design OTC-19914, presented in May 2009. This paper had discussed the need for a deepwater well design change for GOM due to the well documented poor performance of drilling complex wells in the GOM, and subsequently proposed a well design concept based upon setting the first two casing strings significantly deeper than the current practice. This submission continues the discussion the rational for setting the riserless casing strings deeper than current practices and reviews the feasibility and challenges of a well design to implement such a significant change in the current deepwater well design.Riserless Casing Seating Optimization is a design method for the installation of riserless casing strings in deepwater drilling environments. The conventional deepwater well design model fails to take advantage of the early and progressive growth of the subsurface fracture gradient immediately below the mud line, due to perceived requirement to set an another casing string above anticipated shallow drilling hazards. This results in the inability to supply sufficient and safe "leak-off" for the drilling of subsequent holes and casing installations, adequately mitigate shallow hazards, and avoid "wasting" casing diameters in the riserless hole sections and thus subsequent sections to total vertical well depth. This method provides for the installation of at the minimum two riserless casing strings, beginning with the structural conductor, which is conventionally installed by "jetting" operations. The proposal is for the dual purpose use of the structural conductor in that it is installed at deeper depth so that it takes advantage of the early growth of the fracture gradient, and then becomes a true structural casing being able to support the axial loads of the BOP’s and subsequent casing strings. Furthermore this ensures sufficient leak-off protection for next string and the safe drilling of subsequent shallow hazards.This technical presentation suggests that drilling with casing could be the mitigating technology that will allow the hole sections depths to be drilled to depths corresponding to the pore pressure / fracture gradient environment. Drilling with casing, actually liner drilling due to the water depth, improves the near wellbore shallow fracture gradient while providing better dynamic ECD control of potential shallow water or gas flows. Furthermore there is a discussion on some of the key well design issues that pertain to this proposal.
Friction Factors: What are They for Torque, Drag, Vibration, Bottom Hole Assembly and Transient Surge/Swab Analyses?
Authors: Samuel Robello 
Published: February 2010

AbstractThe term "friction factor," conventionally defined for fluid flow engineering calculations, is also used for solid mechanics calculations in the drilling industry. At first glance, it may seem to be a misnomer, but there are underlying facts and reasons for the adoption of the term "mechanical friction factor" that is unique to the industry. This term is used as a proxy for the coefficient of friction (COF) or the Coulomb friction, a dimensionless scalar value, in the estimation of torque, drag, side forces for the directional tendancies prediction, static displacement of string for vibration analysis, and moving pipe elastic force for transient swab/surge pressure estimation. Because of larger uncertainties in the modeling of a long drillstring, including cuttings bed, tortuosity, mud properties, fluid viscous effects, wellbore temperature, pressure, and non-uniform geometrical interferences between the drillstring and wellbore, the COF is termed as a friction factor by including the uncertainties involved without defying the mechanics involved. Another important parameter used during the planning stage in combination with the friction factors is the tortuosity factor to provide artificial undulation to the wellbore. The tortuosity factor causes an additional problem, which requires a different friction factor for the analysis, even though the COF between the drillstring and the wellbore has not changed. Because there is no industry standard for quantifying these parameters, a great deal of confusion exists between these parameters and results in the overestimation or underestimation of the frictional drag. This paper describes the details, clear definition, calibration, pitfalls, and context in which they can be used. It presents the simple guidelines and several example calculations. This paper also provides methods for evaluating these parameters with real-time data.
A Gulf of Mexico Case History: Benefits of Foamed Cementing to Combat a SWF
Authors: Fuller George A. , Bolado David , Hardy Fred , Spath John 
Published: February 2010

Abstract
Cementing a deepwater riserless casing string in areas where shallow water flows (SWF) are encountered can be difficult and very costly if not successful on the first attempt. One of the practices commonly used by much of the industry for these jobs is foamed cementing. Foamed cementing has provided many benefits over specialized lightweight blends such as comparable heat of hydration properties, fluid compressibility for maximum hydrostatic transmission, improved elastic properties, and rapid density changes possible due to unforeseen well conditions.
Because of the surface features on the seafloor and the location of geological objectives, wells are routinely drilled in areas of potential SWF. These hazards are typically categorized as high flow potential, moderate flow potential, or minimal flow potential. Although the potential risk of encountering SWF hazards can be identified, the actual pressure of these hazards are not known until they are drilled. Preplanning is crucial to combat these flows before they are encountered.
This paper will discuss the planning that took place to prepare for cementing if SWF was encountered. These include: how preplanning was prepared for the event that the well began to flow, how weaker zones above the hazard were managed with lighter density foamed, how the density of foamed cement throughout the hole was planned without knowing the hole size, and how foamed cement helped with displacement in a very large annulus.
Sonic While Drilling: Multipole Acoustic Tools for Multiple Answers
Authors: Degrange Jean-Marie , Hawthorn Andy , Nakajima Hiroshi , Fujihara Takeo , Mochida Manabu 
Published: February 2010

Abstract
Acquiring good downhole sonic-while-drilling measurements is challenging and complex. However, because of the multiple applications of acoustic data it has been a major goal of the industry to develop tools that achieve this objective.
Applications for sonic-while-drilling data cover a wide spectrum, including real-time determination of pore pressure and overburden gradients, seismic calibration, complex lithology identification, gas detection, fracture evaluation, and estimation of mechanical properties. These are used by a broad spectrum of disciplines including drillers, geophysicists, geologists, petrophysicists, and reservoir and completion engineers.
Recent developments in multipole sonic measurements provide robust compressional and shear data irrespective of mud speed, as well as Stoneley information, that can be used for advanced sonic applications.
A novel hardware design, coupled with a reassessment of data handling and processing in parallel with extensive modeling now allows advanced answers to be acquired and delivered while drilling.
There are numerous examples in the literature that demonstrate the importance of multipole acoustic data for real-time pore pressure, wellbore stability and seismic correlation. This paper will look at some other applications of great benefit to the drilling and completion community, including top-of-cement identification, rock mechanics, gas detection and other sonic uses that can potentially be an aid in the overall goal of drilling optimization. Data will be shown from deviated, highly deviated and horizontal wells and other challenging logging environments.
Mono Diameter Expandable Drilling Liner Applications in Deepwater Drilling
Authors: Kumar Nitesh , Marker Roy , Corneliussen Rune , Kirkemo Erik G , Rønneberg Erik 
Published: February 2010

Abstract
Claims can be found in technical literature for using Mono Diameter Expandable Liners in deepwater applications. In a technical review of the existing Mono Diameter Expandable Liner systems by various vendors, it is concluded that Mono Diameter Expandable Liner can be considered for using as a drilling liner if certain prerequisites as discussed in this paper are met. Further, the product can be used in a brown field development scenario, where no pore pressure surprises are expected. In any case, once drilling to target has been achieved, the product must be covered by a conventional casing. Proper risk evaluation before running in the hole is recommended, given the high per day costs associated with the deepwater wells. On the other hand, if the product has to be used for deepwater pre planning and casing design purposes, substantial increase in strength (collapse & burst of the pipe) will be required, without which the product will not qualify industry standard casing design criteria’s at the basis of design level. From design perspective, one time or multiple mono diameter expandable liner extension are the same and the key issue to address in using this product is meeting the collapse pressure requirements.
Improved Accuracy of Borehole Positioning in Horizontal Wells
Authors: Lawrence Brett , Mojsin Tanja , Strachan Michael 
Published: February 2010

Abstract
Accurate measurement of the true vertical depth (TVD) and reduction in the error uncertainty of the TVD measurement has become an increasingly important element in field development and well placement. A field on the North West Shelf of Australia required precise positioning of the wellbore within the reservoir. The trajectory within the horizontal production section depended completely on accurate geometric measurements to achieve the goal of keeping the well within +/-1 m of the target TVD for the entire length of the horizontal section – typically 1600m to 2300m. With great attention to detail, this is possible; however, the uncertainties associated with determining the actual wellbore inclination would normally overwhelm the required accuracy.
The main sources of error while drilling horizontally result from misalignment (SAG) of the bottomhole assembly (BHA) within the wellbore, sensor axial misalignment, and axial accelerometer bias. To combat these sources of error, a multiple sensor system was designed with improved accelerometer bias (attained by using extreme calibration techniques). Compounded software programs for advanced BHA analysis and multistation analysis of the survey data were used. The data from the primary sensor determined the directional parameters used while drilling. The second directional sensor was positioned in the BHA to confirm the accuracy of the SAG correction applied to the primary sensor and to confirm any bias. Proprietary software was used in real time and post-drilling to perform multistation analyses of the accelerometer and magnetometer data from both sensors.
This paper describes the methods used to reduce the TVD uncertainty while drilling long horizontal sections. Improvements were made to standard Industry Steering Committee for Wellbore Surveying Accuracy (ISCWSA) MWD+SAG error model to simulate the increased level of accuracy generated as a result of the multiple sensor system. Using data from the two directional sensors and a continuous at-bit accelerometer assembly, the ellipse of uncertainty was estimated throughout the section and remained with a +/-1.5 m (1 sigma) limit. TVD uncertainty was set to zero at the gas/oil contact (GOC); it was not necessary to model the total error from surface.
Successful Application of RSS in a Highly Nitrified Mud System
Authors: Chase Clint , Zafar Syed Hammad 
Published: February 2010

Abstract
The presence of high nitrogen injection rates through the drillstring represents a challenge for modeling hydraulics inside the BHA, in particular rotary steerable systems (RSS). An algorithm was developed to simulate the downhole pressure across the desired bottom hole assembly (BHA) components for nitrified drilling fluids. This paper captures the main features of the model and its validation process.
First Year Performance Review for 6th-Generation Drillship
Authors: Davis Mike , Banks John , Rainnie Barry 
Published: February 2010

Abstract
The challenges of bringing an enhanced deepwater drilling vessel design to market and then into operations successfully in a high-activity market are immense. Using a project based approach with close co-operation between the rig owners, shipyard, customer, 3rd party equipment suppliers, classification society, a 6th generation drillship was successfully engineered, built, commissioned and delivered on time. The drilling contractor teamed up with their client and effectively completed it’s first two deepwater sub salt wells ahead of target time, and more importantly without causing harm to personnel or the environment.
The drillship was delivered to the operator on January 1, 2008 in Korea commencing a 4 year contract.
The paper will be a case study of the drillship’s excellent HSE and operational performance on her first two ultra deep water sub salt wells in Brazil and GOM. The paper details the progress of the project through the shipyard, acceptance programs and tracks both operational and HSE performance though it’s first year of operations.
Addressed in the paper are the factors that contributed to the success of this project i.e. conceptual, construction and timely delivery, along with a top quartile drilling performance. The project based approach to operations and planning that led to exceptionally low rig non-productive time on start-up and excellent HSE performance throughout the first year of operations.
The following issues are dealt with in the discussion: The operators rig selection process and criteriaBackground to selection, design and project execution for the construction of the drillshipProject management and acceptance testing including general approach to QA/QCWell planning strategy, personnel requirements and long lead time issuesMobilization and performance on the Deepwater project in GOMReview of well planning and execution strategy to maximize efficiency and HSE benefit to project stakeholders during delivery and first year of operation
Evaluation of Precision Drilling Super Single Performance
Authors: Griffin Harold Gordon 
Published: February 2010

Abstract
Drilling Rigs that lead the industry in performance and safety is what drilling owner/operators strive to have because these rigs will work in many different markets. The Precision Drilling Super Single Rig will be evaluated as a case study using data from wells drilled on performance and safety. As of November 2009 Precision Drilling has 53 Super Single Rigs in 5 different models (38 Slant, 6 Light,
5 Electric, 3 Stretch, and 1 Mobile) and has drilled over 16,750 wells.
Precision Drilling keeps detailed history records of its own rigs. The Super Single Rig data will be compared to industry. Individual well cases will be examined where it is known that a conventional rig and Super Single completed similar wells in a similar location.
Effect of Bicenter Bit-BHA Design on BHA Behavior
Authors: Taylor Jennifer , Bouska Reisha R. , McKenty Mike , Silva Roger , Prochaska Ernest 
Published: February 2010

Abstract
The petroleum industry is continually pushing to safely drill deeper, longer, and faster sections. The use of bicenter drill bits has been a popular option since the mid 1990s for borehole enlargement while drilling. Borehole enlargement offers significant benefits allowing multi-diameter casing strings, additional contingent hole sections and reduced equivalent circulating density with a narrow mud-weight situations, allowing longer well profiles and larger hole diameters to reach deeper reservoir sections.
Bicenter bits are unique because of their eccentric design and the rules of use below a smaller diameter drift. Those with a pilot bit and reamer combination are different than a conventional full-hole concentric bit. Generally, the bicenter bits are longer and have cutting force challenges not shared by concentric full-hole bits. The ability of a bicenter bit to drill a larger hole below a smaller drift diameter requires slightly different BHA configurations to maintain consistent directional control. There are currently no published reference tables or programs to accurately predict the directional behavior of bicenter-bit bottom-hole assemblies (BHAs).
This paper presents a study of bicenter bit and BHA runs in the Gulf of Mexico (GOM) that evaluates and analyzes operating parameters, stabilizer placement and BHA type [positive displacement motor and point-the-bit rotary steerable system (RSS)]. Also included are documented results, techniques, and references for establishing guidelines for successful use of bicenter-bit BHAs in directional drilling applications.