bluuebunny/crossref_metadata_2025_split huggingface dataset:
BHA and Drill String Fundamentals: Technology Training for Beginners
Authors: Wakefield Sarah , Pigusch Katrina 
Published: February 2011

Abstract
In the industry, there is an abundance of highly technical engineer-based training available on drill string design, but a different approach is required for employees that simply need a basic understanding of drill string principles. Some trainees and shop-hands have a need for a basic understanding of bottom hole assembly (BHA) fundamentals and drill string design in order to build a foundation for future training courses as well as eventually make informed choices on the job.
To meet this need during our training course, we chose five basic topics that covered BHA fundamentals and drill string design, and we covered each of the five topics using current adult learning fundamentals. The content we chose was: BHA components and assemblies, drill pipe anatomy and identification, connection science, failure mechanisms and basic drill string design. Exercises designed specifically for the content required students to label the critical pin and box area of a connection, create posters on failure mechanisms and calculate the maximum overpull for drill pipe, among other things. Our objective was to provide training that not only addressed the necessary technical information, but also presented the content in a way that was geared towards learning and retention.
Pre and post test results, along with course evaluations, offered evidence this introductory level course provided the students with an effective foundation of knowledge. Most students left the course with a better understanding of BHA fundamentals and were able to describe specific ways that the course would help them do their jobs better. Information provided in the paper can benefit trainees or shop-hands seeking a basic understanding of drill-string principles. The information is also applicable to training departments industry-wide looking to develop introductory technical training.
Finding the Best Alternative for Plugging Problem in MEG Regeneration Unit Using AHP Method
Authors: Khorrami Z. , Karimkhani B. , Farhadi F.A. 
Published: February 2011

Abstract
MEG regeneration and injection unit regenerates aqueous MEG. The main goal of this unit is approaching desired MEG concentration whereas MEG loss via removed water is a big issue. Circulating glycol is polluted with Ca++ and Mg++ which forms carbonate scale and causes plugging of pipe lines, filters, lean/rich exchanger, still column packings and reboiler tube bundle and decreases their efficiency, consequently increases MEG loss via top product. Different alternatives exist according to similar experiences around the world. Using specific criteria and AHP (Analytical Hierarchy Process) method priority of these alternatives has been found. Results are as following:Increasing number of filtersUsing parallel filtration systemReplacing charcoal filters in short periodsIncreasing flow rate in case of no operational problem
Considering all constrains, final recommendation includes improvement of operational conditions, regular cleaning of equipments and enhancing filtration system.
Effective Well and Reservoir Management Reverses Production Decline in a Brownfield Cluster in South Oman – A Case Study
Authors: Mirza M. , Al Saadi Hassan , Effendi Andryas , Hafidz Fidi Abdul , Anwar Zul 
Published: February 2011

Abstract
A complex brown-field cluster in South Oman showed decline in production despite aggressive level of development and infill drilling over the last few years. This cluster has more than 18 fields, with 10 of them are producing. Different major reservoirs distributed across several stratigraphic horizons and contains moderate to highly viscous oil (10 to 400 cP). The reservoirs comprise unconsolidated fluvial, fluvial deltaic and glacial sandstones of Palaezoic age. The geologically complex field due to large number of faults and fractures has been on production of more than 15 years and has been developed using vertical and horizontal wells during different phases of development. One water injection well is in operation in one major field for more than 5 years.
Reservoir surveillance and management in this cluster poses a formidable challenge due to:
- Significant well-stock (more than 150 wells) of different types (vertical, deviated, horizontal, multi-lateral) - Problem associated with data acquisition as all the wells are completed with pumps (beam pump, progressive cavity pump and electrical submersible pump) and most of them are completed with some sand-control devices - Un-efficient water injection management - Logistically problems associated with large distance between the Well and Reservoir Surveillance and Production team at company office and the operational team at field location.
The case study presented in this paper describes how a sustained well and reservoir surveillance and management strategy implemented across the entire value chain starting from the planning to operation stage in this cluster could not only arrest but literally reverse the well and field production decline trend using the existing well stock. The paper clearly illustrates that success of reservoir surveillance and management rests not only on the application of right technology but more on close integration among various disciplines in a cohesive work environment.
A Reservoir Simulation Model for Ground Freezing Process
Authors: Shen Chonghui , Mckinzie Bill , Arbabi Sepehr 
Published: February 2011

Abstract
Ground freezing technology has been applied in Colorado oil shale formation to control ground-water flow for Shell's In-situ Conversion Process (ICP). The circulation of coolant through subsurface pipes causes the formation water to freeze and plug off permeable channels, and results in an impermeable flow barrier (also known as a freeze wall). The freeze wall will be used to isolate the developing area from the undeveloped area for ground-water protection and product containment. Because the ground freezing in our application is intended to be operated in conjunction with ICP, there is a need to develop an integrated reservoir simulation model with the capabilities for both freezing and in-situ conversion processes. This paper describes the development of a reservoir simulation model for ground freezing process. It also discusses some of the simulation challenges of ground freezing process in a reservoir simulator. The developed model has been calibrated with data from a 2003 field test and used to assess the sensitivity of freeze wall closure time with respect to freeze-hole spacing, initial formation temperature, ground water flow strength (hydraulic conductivity and gradient), and water salinity etc. The simulation results revealed that the freeze-wall closure time depends strongly on freeze-hole spacing, water seepage rate and formation temperature.
A Practical Approach for Calculating EOS Coefficients
Authors: Ahmed Tarek , Meehan D. Nathan 
Published: February 2011

Abstract
Cubic equations-of-state (EOS) mathematically relate pressure, volume, and temperature. These equations describe the volumetric and phase behavior of single components and mixtures requiring only the critical properties and acentric factor of each component including the plus-fraction. For pure compounds, the required properties are well defined; however, nearly all naturally occurring gas and crude oil fluids contain heavy fractions that are not well defined. These heavy plus-fractions are mixtures of hundreds of paraffinic, naphthenic, aromatic, and other organic compounds that cannot be discretely identified and described. These heavy fractions are often lumped together and called the "plus-fraction" (e.g. C7+ fractions). Adequately characterizing these undefined plus fractions in terms of their critical properties and acentric factors has been long recognized as a challenge in compositional analysis using EOS models. Changing the characterization of the plus fraction can have a significant impact on the volumetric and phase behavior of a hydrocarbon mixture predicted by EOS models. In applying EOS in compositional modeling and PVT analysis, empirical correlations are used to estimate critical properties and acentric factors of the plus-fractions. Coefficients for these empirical expressions were generated by matching critical properties of pure components; however, the applications of these empirical relationships are extended to estimate the critical properties the plus-fractions.
This paper presents a practical approach for calculating EOS parameters "a, b, and α" of the plus-fraction from its readily available measured physical properties, i.e., molecular weight "M" and specific gravity "γ". Our objective is to improve the predictive capability of EOS models. A new model was developed based on the Peng-Robinson Equation of State "PR EOS" and with the modification as outlined in this paper. The predictive capability of the modified PR EOS is displayed by matching a set of laboratory data on several crude oil and gas-condensate systems. Performance of the proposed method was also compared with predictive PVT results generated by two commercial compositional simulation models. Additional validations were made by comparing results from applying the proposed approach with those of Coats and Smart4 regression methodology with PR EOS.
An Investigation of Heavy-Foam Properties for Offshore Drilling
Authors: Liu Chunlei , Zhang Nan , Guo Boyun , Ghalambor Ali 
Published: February 2011

Abstract
A unique problem in drilling oil and gas wells offshore is the narrow window between the formation pore pressure and fracture pressure. The current drilling practice with constant-density drilling fluids requires excessive casing programs and larger, more expensive rigs to drill offshore wells. Although different techniques, such as dual-gradient drilling, have been used to ease the problem, they are limited to certain geological conditions. This study investigated the properties of heavy foams that may be used in offshore drilling to solve the problem.
In this study we performed a systematic investigation of heavy foams which are defined as the foams generated using weighted water and brine. Our study focused on rheological modeling, polymer selection, and foam properties. This paper presents our experimental results from 5 heavy foam systems namely water-barite-nitrogen system, water-hematite-nitrogen system, water- KCl-nitrogen system, water-CaBr2-nitrogen system, and water-CaBr2-barite-nitrogen system. We conclude that all of the investigated heavy foams behave as Bingham-Plastic fluids with an exception that the heavy foams from the water-barite-nitrogen system show Power-Law behavior. The best heavy foams from the water-CaBr2-nitrogen system were generated using Guar Gum as viscosifier. Foams from the water-CaBr2-nitrogen system have better stability and quality than those from the water-KCl- nitrogen system. Data from this study may serve as a base for selecting heavy foams in drilling offshore oil and gas wells.
New Method to Deconvolve Well-Test Data Under Changing Well Conditions
Authors: Houzé Olivier , Tauzin Eric , Allain Olivier 
Published: February 2011

Abstract
Recent work on deconvolution allows well test interpretation engineers to combine several shut-in periods into a single, much longer deconvolved response, allowing identification of boundaries overlooked in the analysis of these individual shut-ins.
Initial algorithms by von Schroeter et al (2004)1 require the individual shut-in responses to be consistent in terms of wellbore storage and skin. An alternate method by Levitan (2005)2 allows inconsistent early time responses to be combined, but requires multiple deconvolutions and an iterative search of the reservoir initial pressure.
The new suggested algorithms waive the von Schroeter et al limitation without the drawbacks of the Levitan method. These algorithms are illustrated with real data coming from permanent gauges. This paper also points out the remaining limitations of the deconvolution process.
This paper was written as a technical communication. It was made a short as possible in order to complement past publications1-2 on the subject. Readers are invited to use these publications for the details of the equations and a more exhaustive list of references.
High Resolution Reservoir Monitoring using Crosswell Seismic
Authors: Nalonnil Ajay , Marion Bruce 
Published: February 2011

Abstract
Crosswell seismic is an emerging technology which provides highly detailed images of the subsurface at the reservoir scale. The technology has the potential not only to delineate complex structure but also to monitor the effectiveness of hydrocarbon recovery and CO2 sequestration strategies.The technique employs tomographic surveying, whereby a transmitter and receiver are deployed in separate wells. With this setup, interwell velocity profiling and structure can be obtained from direct wave and reflection processing respectively.
With hydrocarbon recovery and CO2 sequestration becoming more prominent in the oil and gas industry, the ability to monitor the efficiency of these strategies is paramount. In this paper, two case studies of crosswell seismic surveying are discussed with the focus on high resolution imaging and monitoring during CO2 injection for improved oil recovery and sequestration respectively. A brief description of the measurement theory and its capabilities is provided, followed by a description of the processing workflow and finally a discussion of the acquired results.
These two cases discussed demonstrate that crosswell seismic was able to successfully monitor the injection through velocity profiling in time lapse and provide answers as to why and how the flow has occurred through interpretation of the crosswell reflection seismic section. The results clearly show that crosswell seismic could significantly reduce the uncertainty and risk associated with injection processes for both improved recovery and sequestration.
A Decision Support System for Cost-effective Assessment of Sand Production Risk and Selection of Completion
Authors: Rahman Khalil , Khaksar Abbas , Kayes Toby 
Published: February 2011

Abstract
An early study of sand production prediction and management is increasingly becoming an important part of an overall field development study. This is because the petroleum industry is expanding its production operations in more challenging unconsolidated rocks and depleted reservoirs. Complex well completion architectures that are sand prone are also increasingly used. This requires a reliable sand production prediction method that can model the sand production risk over life of the field. Reliable sand production assessment methods are essentially based on geomechanical approaches that integrate in-situ stresses, reservoir pressure and its depletion trend, rock strength, well trajectory, completion type and planned drawdown. Use of grossly empirical, often unreliable, methods to infer sand production risk could result in either unnecessary an upfront sand control cost or sand management cost during production due to unpredicted sanding.
This paper demonstrates by application to a field case in South East Asia how to develop and use a decision support system for credible sand production assessment and completion selection. Once a geomechanical model is built and sand production assessments have been carried out for a few wells by a robust sand production prediction model, the knowledge and information can be converted into a decision support system for new wells in the field. Provided the field Earth stresses and the reservoir pressure are applicable, the system then needs only a log-derived rock strength profile for sanding evaluation and decision making for new well trajectory and completion configuration. Using the existing geomechanical model, calibrated og-derived rock strength profiling and field supported sanding prediction, a simple flow chart is developed to assist well engineers to decide the completion type by taking into account the risk of sand production and hole collapse during production. The availability of such a decision support system assists the well and production engineers to follow a quick, cost-effective, simplified but sound approach for sand production assessment and completion selection as opposed to being grossly empirical, or too rigorous.
Integrated PoF and CBM Strategies for Improving Electronics Reliability Performance of Downhole MWD and LWD Tools
Authors: Zhan Sheng , Ahmad Izhar , Heuermann-Kuehn Ludger , Baumann Joerg 
Published: February 2011

Abstract
Electronics that operate under downhole drilling conditions, such as printed circuit board assemblies (PCBAs) in measurement-while-drilling (MWD)/logging-while-drilling (LWD) tools, can experience a significant amount of extremely high temperatures and vibration stresses over their lifetimes, which may induce failures during deployment. This study demonstrates the methodologies on integrated physics of failure (PoF) for improving the reliability performance of MWD/LWD tools.
PoF discussed in this study is for identifying and understanding failure modes, failure mechanisms, and failure sites of drilling electronics for their particular life-cycle loading conditions. This PoF study is a systematic methodology, integrated with data acquisition technologies, conditional-based maintenance (CBM) and failure analysis techniques to actualize the real-time life management on improving maintenance decisions, and providing guidance to incorporate reliability into the well-planning and operation processes, thus enabling monetary savings for the oil company and the MWD/LWD service provider.
Through data acquisition technologies, the drilling environmental profile is captured by the sensor and recorded in the memories of the MWD/LWD tool. Based on the drilling environmental profiles, the drilling stress and loading conditions are retrieved and calculated for estimating the remaining life of the drilling electronics. With CBM strategy, electronic units assessed with high risk results are excluded from being deployed to the field to avoid potential failure in the field. PoF is followed up to investigate the failure mechanism of units returned from field. Real-case studies on MWD/LWD tools operated onshore the U.S. and in the Asia Pacific region are presented.
The objective of this study is to enable real-time electronics reliability assessment on MWD/LWD tools under their actual application conditions. When combined with PoF models, CBM strategy is capable of making continuously updated predictions on the remaining life of electronics based on the in-situ drilling environmental and operational conditions.
Elliptical Geometry Model for Sand Production during Depletion
Authors: Aadnoy B.S. , Kaarstad E. 
Published: February 2011

Abstract
Sand production is a key issue when selecting completion solutions. Not only the immediate choice of technical solution is affected, but also the long term plans for workover operations and the choice of Intelligent Well Systems (IWS) for mitigating the sand production problems.
In this paper we investigate the effects of in-situ stresses and rock properties combined with the optimal well geometry. The well is initially circular, but the collapsed state should be modelled with elliptical geometry. The volume of sand produced in a depletion phase is then computed from the equilibrium state of the borehole. The models are explicit analytical and simple to use.
Laboratory Development and Field Application of Novel Cement System for Cementing High-temperature Oil Wells
Authors: Wan X. , Zhang H. , Li Y. , Yang Y. , Shan H. , Xiao Z. 
Published: February 2011

Abstract
Cementing high temperature exploration wells present a number of challenges to well construction engineers. High bottom hole static temperature (above 100°C), very low pump rates and excessively long job times due to the constraints imposed by tight annular clearances and the use of heavy, viscous drilling muds and cement slurries, and formation complexities (salt layer, high leakoff, unstable formations) all contribute to the operational risks not only during placement of the cement slurry in the wellbore, but also later to the set cement sheath during the life of the well. Various cement systems have been applied with unsuccessful results.
A new cement formulation developed has helped to resolve the problems encountered in cementing these exploration wells and eight jobs have been completed in the field with great success. Synergistic effect between the new retarder and fluid loss control additive improve the system performance significantly such as low fluid loss rate, minimal free water, proper rheology, predictable thickening time, high resistance to salt contaminations, and no adverse effect on set cement strength. An effective laminar flow spacer was also developed and used to displace drilling muds effectively to enhance its placement and improve the cementing bond.
This paper will describe details of thorough and systematic laboratory development of the new cement system and present case histories to document its effectiveness for cementing high temperature exploration wells.
A Practical Approach to Evaluating Drilling Projects
Authors: Nkwocha Chimerebere 
Published: February 2011

Abstract
In the past estimating drilling performance or project performance for well engineering projects has been carried out in a combination of ways such as accounting for time based events that eventually result in costs or financial relationships. It is rather unfortunate, but the requirement within the industry still remains the quantification of projects and project costs as a function of cost or financial exposure. In most cases the situation is one of which inherent peculiarities within the project, though not man-made, are somewhat relegated to the background during project evaluation. Frequently this is due to the inability of project teams to quantify the parameters required to adequately establish key contributory factors responsible for overall project performance. In this paper I have tried to postulate a rather straight-forward method of establishing performance metrics without so much as deriving complex equations an engineer may find highly impossible or cumbersome to fully regularize to provide any meaningful relationship from one well to the other. The relationship model developed tries to relate both operational and financial efficiencies as a project/well specific performance factor referred to as TPI, i.e. the "Technical Performance Index". The TPI is specific to each well and a regional average provides an indication for overall performance. This paper does not consider completion operations or any operation related to well testing or workover operations at this moment but focuses primarilly on dry-hole operations up until the well is programmed for completions.