bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrating Quantitative and Qualitative Rock Strength Data in Sanding Prediction Studies: An Application of the Schmidt Hammer Method
Authors: Taylor P. G. , Appleby R. R. 
Published: December 2007

Abstract
Despite continued advances in sand production prediction software, numerical modelling does not always agree with observed sandface behaviour once a well is flowing. Where core is available, computer models should be calibrated to laboratory determined rock strengths, measured on plugs cut from the core. The number of core plugs is often restricted due to time limitations and availability of good quality core. These may not be fully representative of the entire reservoir section due to complex variations in rock composition.
Sandstone failure and the onset of sand production can be more accurately predicted by integrating log derived rock strength, calibrated to rock mechanics laboratory test data, with petrographic observations made on the core; i.e. combining quantitative and qualitative methodologies. Such observations typically include mineralogy, rock texture, structure and reservoir quality. Laboratory numerical data are discrete, whereas log and observational data are continuous, and these do not always readily relate. This can make the integration of laboratory-to-field data a difficult process.
In an attempt to more closely relate quantitative and qualitative core data, a Schmidt impact testing hammer has been used to make hardness measurements along an entire core. The Schmidt hammer was originally designed for the non-destructive testing of concrete hardness in the civil engineering industry and was later adopted to estimate rock strength in mining, quarrying and tunnelling applications. The Schmidt hammer allows very rapid (and inexpensive) core testing, and has the added advantage of being non-destructive. Rock mechanics parameters can be determined in dense arrays that reflect the real inherent heterogeneity of the core.
Use of the Schmidt hammer has enabled extrapolation of laboratory determined rock strength across the entire core and has facilitated direct correlation of mineralogy and grain texture to sandstone failure and yield. Characterisation of overlying claystones has also provided essential data for the determination of stress shadowing effects. Further development and refinement of this technique should provide an additional useful tool in reservoir and overburden characterisation and predicting sand production.
The technique does not require specialist rock mechanics knowledge and can be applied at the well site or core viewing room. Useful data can be obtained from core material ranging from fresh state to old archived material. The speed and practicality of the Schmidt hammer as a rock strength characterisation tool is seen to have great potential.
Field Experiences With History Matching an Offshore Turbiditic Reservoir Using Inverse Modeling
Authors: Hohl D. , Jimenez E. A. , Datta-Gupta A. 
Published: December 2007

Abstract
Reconciling high-resolution geologic models with pressure and multiphase production history is one of the most time-consuming aspects of the workflow for geoscientists and engineers. Although significant advancements have been made in this area over the last decade, current industry practice largely involves iterative trial and error methods and often utilizes arbitrary permeability multipliers that lead to loss of geologic realism and consequently poor performance predictions.
In this paper, we demonstrate the application of an efficient inverse modeling scheme for history matching a waterflooded, structurally complex and faulted offshore turbiditic oil reservoir. The field has an estimated 500 MMSTB and is located in a prolific offshore hydrocarbon basin. Permeability and fault transmissibilities are the main uncertainties. More than 10 years of production data from up to 8 producing wells are available for history matching. Our approach combines the efficiency of the streamline-based sensitivity computations with the versatility and accuracy of finite difference models for matching the water cut at the producers.
Specifically, a finite-difference model is used for flow simulation and to generate velocity fields based on which we compute streamlines and sensitivities for updating reservoir permeability via fast inverse modeling. These sensitivities relate the reservoir properties to production data and can be obtained using a single flow simulation resulting in an efficient inverse algorithm for history matching. A unique aspect of the field study here is the novel approach used for streamline tracing and sensitivity calculations across faults and non-neighbor connections in the geologic models via local grid refinement.
A Management Technique That Integrates And Glues Cost And Environmental Performance Targets In E&P Drilling
Authors: Paulsen J. E. , Jensen B. , Pettersen J. , Svensen T. 
Published: December 2007

Abstract
This paper presents an integrated management technique that has been employed with success over the last 8 years in Statoil operations offshore Norway. The technique has been applied in integrated management of drilling fluids and drilling waste and is particularly suited for this purpose. It is argued that the attractive feature of the technique; the successful linking of tailor made technology employment and cost efficient environmental performance criteria have a much wider application potential. The fundamentals of the management concept are presented and data and examples are provided to highlight the structural constrains to be solved and the effect of the management technique applied.
The technique involves the supplier chain from procurement and through the life cycle of the operations. Performance criteria are linked to the concept of using best available techniques (BAT) to deliver the service. The responsibility of fluid providers is extended to include waste minimization; to be accountable for waste accrued by use of their products.
Experience and results since implementation show dramatic improvements in both cost savings and environmental performance for both operator and the fluid providers.
The effect of the management technique can be impressive as presented in this case where recycling of drilling fluids was increased by several orders of magnitude, drilling waste was significantly reduced and cost savings of several hundred MNOK (1US $ = 6.2 NOK) over a period of 8 years were measured. A change in attitude and awareness among the suppliers has been apparent, advances in technology that support sustainable industry practice in drilling has now become an important competitive edge. The management technique is argued to be superior to previous management techniques with respect to capacity to integrate and resolve multi criteria challenges.
Frontier HP/HT Exploration Drilling in the Krishna Godavari Basin, India
Authors: Kumar Suresh , Klimentos Theodore , Affes Sami 
Published: December 2007

AbstractThis paper describes a holistic approach to drilling engineering employed to design and drill the deepest offshore well in India. The paper covers the well construction methodology in conjunction with the contracting strategy and Service Quality Management processes. Moreover, the paper presents an innovative formation evaluation technique using wireline logs at HPHT conditions to optimize the perforation strategy and perforation depth interval selection in the absence of resistivity log data. Furthermore, borehole stability related problems were evaluated and a Mechanical Earth Model developed to improve the drilling performance in this area. The paper describes the application of the model in the exploration wildcat environment. The material presented will facilitate other well construction teams facing challenging drilling objectives in such a hostile remote environment. The paper also highlights the data acquisition challenges in the HTHP environment (410 deg F BHST and 12,000 psi BHP).
Innovative Advanced Technologies Overcome Directional Drilling Challenges of S and J Type Wells in N. America and Canada
Authors: Janwadkar Sandeep , Belavadi Mukund , Fortenberry David , Dawkins Brett , Kramer Mark , Privott Steve , Rogers Tom 
Published: December 2007

Abstract
The Barnett Shale field presents numerous drilling challenges. Meeting the increasing demands of natural gas requires economical development by efficient drilling of directional and horizontal wells. The standard technique for drilling S and J type directional wells was by utilizing steerable motors. This technique has several drawbacks: frequent trips to change angle of the AKO for the build/tangent/drop sections, poor hole quality due to string rotation, drillstring/BHA/casing wear, excessive cement volumes due to hole enlargements and high torque and drag due to wellbore tortuosity. Frequently the wells drilled in this field are closely spaced which require precise control of the well path to prevent collision. Steerable motors generate high wellbore tortuosity as corrections to the well path are made after every survey. Automated rib steering systems with rotating drill strings are cost prohibitive for this application.
To overcome these drilling challenges a strategy was outlined that comprised of the new non-rotating automated rib-steering system for low inclined 3-D wellbores. Research, field tests and application of innovative and sophisticated technologies has resulted in the development of this state of the art directional drilling system.
Since the introduction of the new technology many wells have been drilled in various fields of N. Texas and Canada with a build/drop rate up to 3°/100 ft. All sections of the wellbore (vertical, build, turn, tangent and drop) were performed without having to trip. Inclination of the tangent sections was maintained within +/- 0.2° of the target. Azimuth corrections were made without interrupting the drilling process and all directional operations were carried out by the system's automatic closed loop control. The new system has minimized hole enlargements, reduced torque/drag helping deliver a smooth, high quality wellbore and increased efficiency and quality of cementing operations. This has allowed the operator to log and set tubulars without incident and maximize the productivity from this field.
This innovative directional drilling system can be utilized to drill ‘S’ and ‘J’ type directional wells without string rotation, low-inclination convoluted well profiles can be drilled with precision due to constant control over inclination and azimuth. Different sections of the well are drilled without tripping by the systems closed loop control.
Cementing Under Pressure in Well Kill Operations: A Case History From the Eastern Mediterranean Sea
Authors: Johnstone Kristian , Conlon Tom , Gill Alex , Bahr Mahdy , Waheed Arshad 
Published: December 2007

Abstract
Well control can be an unpleasant experience. In its initial stages the problem often appears unconquerable and weeks can pass without progress.
This paper is about the successful abandonment of such an episode of well control, in deepwater (i.e. greater than 300 m water depth), that was initially suspended with a closed-in subsea BOP. The BOP held in place a sheared 5-in. drillpipe that had been intermittently blowing dry gas and formation cuttings to the rig floor for 20 days.
The objective of the well-recovery operations was to re-enter the well and properly abandon it without creating another uncontrolled situation. All operations were to be conducted in compliance with HSE protocols.
It was paramount to have total control of the well at all times necessitating two BOP stacks. This contingency resulted in the suspension of a heavy load on the seabed, subject to excessive bending moments during bad weather. The well head arrangement was essential but the time loss caused by weather conditions was becoming intolerable. New and innovative plans made during the well-control operations cut 3 to 4 weeks of uninterrupted operation down to 5 days of operation. Cementing under pressure was the key abandoning solution. Several scenarios were drawn up for this eventuality and this paper elaborates on the decisions, choices, and solutions made during the final abandonment operation.
A New Analytical Model for the SAGD Production Phase
Authors: Nukhaev M. , Pimenov V. , Shandrygin A. , Tertychnyi V. 
Published: December 2007

Abstract
Steam chamber (SC) control during steam-assisted gravity drainage (SAGD) has a great impact on the efficiency of heavy oil and natural bitumen recovery. An optimal production rate and corresponding bottomhole temperature and pressure should be maintained to improve SAGD cumulative oil recovery and the steam-oil ratio.
SAGD optimization work includes simulation results and real-time data monitoring. Existing analytical models1,2 are mainly dedicated to describing the ability of a reservoir to drain heated oil and do not depict all details of real SAGD processes.
In the present work a new analytical model of the SAGD production regime is described. The initial stage of oil production is considered before SC reaches the production well. The model accounts for mass and heat transfer during the process of heavy oil recovery and establishes a significant correlation between production rate and the dynamic of SC evolution. The model that was developed was compared with simulation done by commercial reservoir simulation software.
Improved BHA Sag Correction and Uncertainty Evaluation Brings Value to Wellbore Placement
Authors: Studer R. , Macresy L. 
Published: December 2007

Abstract
Recent well positioning uncertainties evaluation per SPE published ISCWSA model for MWD survey tools suggests that 80% of the inclination measurement error budget is a consequence of BHA sag.
BHA sag is the misalignment of the directional sensor with the borehole direction due to deflection of the MWD drill collar under gravity and borehole curvature. The magnitude of the error depends on BHA type and geometry, sensor spacing, hole size and several other factors.
This paper presents a new methodology based on modern 3D BHA/Hole interacting modeling for BHA sag corrections and residual error evaluation at each MWD survey stations.
11 different typical 17½" and 12¼" rotary and steerable motor BHA's with variable gauge stabilizers were computed in multiple configurations (borehole geometry, BHA settings, friction…) following a Monte Carlo process which involved more than a million simulations. Results of this study show that the residual BHA sag uncertainty as proposed by the ISCWSA model can be further reduced by as much as 50%.
A simplified software automated process was developed in order that Operations Support Centres can easily integrate the proposed methodology as part of near real time Survey Management advanced processing routines.
A sound BHA sag correction method along with a thoroughly analysed residual sag error, readily fit for use within the ISCWSA MWD well positioning uncertainty model (today's industry standard), appears essential in a wide variety of directional drilling applications including extended reach and horizontal drilling.
The proposed process contributes to significantly improve wellbore placement through the pay zone while drilling. Reduced trajectory positional uncertainties contribute to the construction of sound geological models for rational well target design, positioning and development pattern fine tuning during the drilling campaign. In turn reservoir management including mature fields shall benefit from improved Wellbore Placement as a multidisciplinary task by locating more accurately layer tops and contacts.
Raising Employee Awareness of HSE Risk: Using Hazard Observation Programs in Russia—Lessons Learned
Authors: Jumagaliev Marat , Knode Tom , Samoylova Olga 
Published: December 2007

Abstract
A hazard observation program is a core element of a proactive health and safety risk management approach. Early identification and robust communication of the hazards in the workplace accompanied by a timely follow-up on safety concerns play an essential role in mitigating the occupational risks and improving health, safety, and environmental performance.
The information coming directly from the people immediately exposed to the worksite environment brings unique value to the scope of health and safety risk awareness and risk reduction programs maintained by organizations. Another important benefit of the program is engaging every single person in the company in the process of identifying and eliminating risks they encounter in their daily job. Employees watching out for the hazards ultimately embrace a responsibility for their own safety and for the safety of the peers working next to them. This can be considered a first step toward making a difference in safety on behavioral and attitudinal levels.
While the concepts described above are well known to the oil and gas industry globally and should be easy to grasp, most companies in Russia have not implemented them. This paper describes how a hazard observation program was launched throughout company locations in the region and how it works today. Sharing the history of the initiative in Russia, common challenges and success stories may help to encourage local companies to employ the hazard observation tool for raising employees' awareness of the existing health and safety risks and for mitigating those risks to make a Russian oil field a safer place to work.
Russian Mature Fields Redevelopment
Authors: Cimic Miljenko 
Published: December 2007

Abstract
Redevelopment of mature oil fields is becoming increasingly important in Russia and worldwide. An extensive application of new ideas, coupling reservoir management and production enhancement of mature oil fields, is outlined in this paper. Discrepancies in the pressures, production and injection data can create significant errors in reservoir simulation models. Uncertainty should be acknowledged and accounted for during the history matching and reservoir simulation process. In many cases large amounts of historical data were collected but much is either inaccurate or critical types of data have not been gathered. Lots of Russian fields have great potential using modern techniques but each project has great uncertainty due to data constraints.
A strategic goal for Oil Company is mature fields redevelopment using new technology and approaches, in order to enhance oil production. Brown fields are suffering from serious reservoir management problems and field redevelopment strategies are based on significant improvement of the reservoir management and water flooding, development of new water injection patterns, which means idle producers/injectors recovery and production enhancement work on existing wells. The conclusions and recommendations of the paper include suggestions for ways to solve these problems. An understanding of historical data errors is not enough to guarantee reliable simulation models; reservoir description uncertainties and errors will always be an important driver of the model results.
The Physics of Steam Injection in Fractured Carbonate Reservoirs: Engineering Development Options that Minimize Risk
Authors: Shahin G. T. , Moosa R. , Kharusi B. , Chilek G. 
Published: December 2007

Abstract
Naturally fractured carbonate reservoirs hold well over 100 billion barrels of heavy oil worldwide. Thermally Assisted Gas Oil Gravity Drainage (TAGOGD) is a new and novel thermal EOR technique, which has applicability in selected reservoirs. In conventional isothermal GOGD, vertical fractures cause the gas-oil contact in the fracture system to advance ahead of the gas-oil contact within the matrix blocks, causing the oil in these blocks to become mobile. The addition of heat in the fractures generates additional hydrocarbon gas cap, lowers the viscosity of the oil, and accelerates conventional GOGD, as seen in the 220 cp heavy-oil Qarn Alam field in Oman. Pilot results in the Qarn Alam field support the commerciality of this process, and a first-of-it's-kind steam injection project is being implemented. The economic success of the Qarn Alam project depends on the ability to credibly predict steam requirements and oil production. Two key oil production mechanisms are heat transport through the fractures and into the matrix, and subsequent gas cap generation due to thermal volatilization of the oil. The process mechanisms involved in TAGOGD were validated through laboratory experiments, while the field forecast model results were validated by history matching pilot performance data. A fully integrated workflow of fracture characterization, integrated reservoir physics, and static and dynamic modeling has enabled uncertainties and risks involved in developing the Qarn Alam field to be managed in a scenario based design approach.
Application of Integrated Reservoir Studies and Probabilistic Techniques To Estimate Oil Volumes and Recovery, Tengiz Field, Republic of Kazakhstan
Authors: Dehghani K. , Jenkins S. , Fischer D. J. , Skalinski M. 
Published: December 2007

Abstract
Probabilistic methodologies have yielded new insights into oil volume and recovery for Tengiz Field, Republic of Kazakhstan. Tengiz is one of the deepest super-giant oil fields in the world, and is located on the shore of the Caspian Sea. Knowledge of the uncertainties inherent in oil recovery is a key to proper reservoir management of Tengiz Field.
Both structured Monte-Carlo and Experimental Design techniques have been used to investigate the interaction of key uncertainties for this deep, super-giant oil field. Probabilistic approaches have provided information about the most likely oil volume and production and give insights into the probable ranges of oil volume and production. This paper describes the methodology and technical studies conducted in support of the 2005 reservoir model for Tengiz Field.
A structured Monte-Carlo Technique has been used to construct several thousand static models of Tengiz Field. Construction of Monte-Carlo models is very fast and allows the impact of key uncertainties to be explored. Key reservoir uncertainties include structural elevation, geostatistical parameters (such as variogram length), the Bulk Volume Water (BVW) constants for each stratigrahic interval, the location of the boundary between facies intervals, and the extent of porous facies and altered (dolomitized) zones, etc.
Investigating the uncertainty in the dynamic performance of the model is much more computationally intensive. Experimental Design techniques minimize the number of computationally expensive simulation runs. Dynamic variables investigated include: oil in place, permeability enhancements, vertical to horizontal permeability ratio, well productivity, the water oil contact depth, and production capacity.
At Tengiz, uncertainties in variables which are "random" or vary spatially across the field have much less impact than uncertainties which can have systematic uncertainty. Examples of systematic uncertainty include wire-line to core calibration of porosity and saturation. This study also showed that for a specific development scenario the oil in place, gasoil relative permeability, and ratio of vertical to horizontal permeability, had the most impact on the estimated oil recoveries.