bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reservoir Engineering Aspects of Oil Recovery from Low Permeability Reservoirs by Air Injection
Authors: Turta A. T. , Singhal A. K. 
Published: December 2007

Abstract
This paper addresses the reservoir engineering aspects of air injection as an Enhanced Oil Recovery (EOR) technique for low permeability light oil reservoirs. In its most successful form, the process is currently known as High Pressure Air Injection (HPAI), and has been applied in deep, carbonate reservoirs. The development of this process in conjunction with an application of the in-situ combustion (ISC) process to light oil reservoirs, as well as the main mechanisms pertaining to ISC and to gas miscible flooding, are analyzed. It is seen that various air injection processes can be classified, depending on their spontaneous ignition potential and gas miscibility at reservoir conditions, into four different processes. Based on an in-depth literature review, the best reservoir conditions for application of each of these four processes are derived. The main differences in operational aspects (pollution, corrosion, safety) for these processes are also discussed. Air injection can be applied either as a horizontal flood or as a vertical flood. For reef reservoirs, only a vertical mode of displacement is contemplated, while for non-reef reservoirs both these forms may be feasible. The application of air injection to fractured carbonate reservoirs is evaluated, although so far, the reported successful projects have been only in non-fractured carbonate reservoirs. A preliminary analysis shows that for fractured reservoir applications, only the vertical flooding mode is feasible. Design considerations for pilot testing of the technique are discussed, and the differences in piloting for a horizontal flood are pointed out. The crucial point is the location of the pilot on the structure, which is a key element in a proper evaluation of the pilot, and its subsequent development to a commercial size operation.
Finally, specific recommendations on laboratory work in support of design and evaluation of a field pilot are presented.
History Matching Gas Injection Processes with In-Situ Saturation Measurements and Process Hysteresis
Authors: Yu S. Y. , Akervoll I. , Torsaeter O. , Stensen J. A. , Kleppe J. , Midtlyng S. H. 
Published: December 2007

Abstract
This paper describes experiments and simulation of gas injection processes with hysteresis. Two complete gas- and oil injection cycles have been performed at the reservoir conditions of 300 bar pressure and 100 °C temperature under X-ray Computer Tomography (CT) surveillance to obtain oil and gas in-situ saturation values at irreducible water saturation. The reservoir condition core flood experiments were performed on restored North Sea reservoir cores with use of live pre-equilibrated oil and gas phases at reservoir conditions by separator liquid samples and excess gas.
The core flood conditions were designed prior to the physical experimental program by using a reservoir simulator. The basis for the history matching was the CT in-situ saturation measurements of oil and gas in six cross sections along the length axis of the core versus pore volumes (PV) of equilibrium gas injected, oil and gas production volumes versus PV injected and the differential pressure recordings across the core during the injection experiments.
The experiments are history matched by use of the ECLIPSE reservoir simulation package. In this procedure the well completions are specified with an explicit transmissibility factor. Injection and production dummy grid blocks are connected to inlet and outlet end of the simulation grid. The production wells are controlled by either bottom hole pressure or the total reservoir fluid rate; the injection wells are rate controlled according to the physical rates. A systematic sensitivity study by isolating variables has been done in matching production history, in-situ saturation values of gas and oil, and differential pressure recorded in the displacement experiments. The analysis of the results has identified the most important dynamic reservoir parameters and characteristics that control the recovery mechanism during each displacement sequence of the gas and oil injection experiments. The hysteresis functions in the two-phase gas-oil injection sequences have been investigated.
Design and Execution of the Alison Horizontal Multilateral Project
Authors: Morgan D. R. 
Published: December 2007

Abstract
The Phillips operated Alison field in the UK North Sea produces gas from a low permeability layered Rotliegendes sand reservoir. The field was developed with a single subsea well producing out of three horizontal laterals. Four laterals were drilled. The first lateral encountered a fracture system and was abandoned to eliminate any risk of producing water through the fractures. The second lateral was completed with a slotted liner in layer C, the tightest but thickest layer in the reservoir. Following a production test of this lateral, the third and fourth laterals were drilled in layers B and D respectively and completed open hole.
Phis paper will discuss various aspects of the project, including drilling the horizontal section for each of the laterals, the tools and techniques used to abandon the first lateral, and the different methods used in establishing the junctions concentrating on the open hole junction used to establish the fourth lateral. The success of the open hole junction in this well has resulted in the use of this technique for wells in other developments, including one example where a lateral was drilled to TD, the junction established and drilling continued in the second lateral without a trip.
The Design Considerations of a Multilateral Well
Authors: Lim Ben , Xi Liang Ming , Quan Chen Xi , Chang Zhou Jun , Hua Zhong , Ping Qiu 
Published: December 2007

Abstract
This paper discusses the approach for a reservoir up design of a multilateral well. In the last two to three years, the industry has seen multilateral wells of varying complexities drilled and completed by operators in diverse areas. This paper presents one approach to the design of a multilateral well conducted by a team comprising of operator's and contractor's personnel. The intent of the authors of this paper is to discuss their approach to the selection of a candidate for a multilateral well, the drilling and the completion design of a multilateral well.
The case in point for this paper's discussion is a multilateral well in Beibu Gulf*. The methodology encompasses the full circuit of a well design, beginning with candidate selection, lithology considerations, well engineering, drilling and well profile optimization, fluid considerations, and the final well completion.
Consolidation for Screenless Completions and Proppant-Flowback Control in Hot Wells
Authors: Dewprashad B. T. , Nguyen P. D. , Kuhlman R. D. , Besler M. 
Published: December 2007

Abstract
This paper describes the evaluation and field application of a proppant-consolidation system [as aresin-coated proppant(RCP) is otherwise known] that was developed for treating high-temperature wells (i.e., ≥175°F). Proppant treated with the new high-temperature liquid coating will be called HTL-RCP for the purposes of this paper. The HTL-RCP system is unique in that it is a single-liquid treatment that is used to coat proppants on-the-fly during a treatment on location without the need for specialized metering equipment. The coating promotes adhesion between proppant grains to such an extent that even if the well is flowed back immediately after a treatment, it still cures to give a high-strength consolidation. This paper presents the results of field tests, the evaluation of treatments for proppant-flowback control in tight formations, the application of screenless completions in high-permeability formations, consolidation tests, and breaker-compatibility studies, all of which were conducted under simulated treatment and downhole conditions. The paper describes the development of rock-mechanical testing that was performed to help the prediction of long-term consolidation properties under production conditions of closure stress, cycling, and high bottomhole temperatures (BHTs).
Testing under simulated treatment and downhole conditions indicates that unlike other proppants that are precoated with phenolic resins (P-RCPs), consolidations using the HTL-RCP system do not lose strengths with extended onsets of formation closures. In addition, strengths several times those obtained with other RCPs (using the same amounts of resin) are produced. Rock-mechanical testing indicates that the material is very resistant to cycling and creep. A Mohr-Coulomb failure envelope obtained by rock-mechanical tests indicates that consolidations exceeding strengths required for screenless completions are obtainable under downhole conditions with the material. Treatment with the material does not require additional breaker, resulting in controlled fluid breaks and good cleanup without complicating the fracturing treatment. Effective proppant-flowback control and enhanced productivity were observed in all of the wells treated with the HTL-RCP system.
Evaluating Culture and Language Effects on Safety
Authors: Huang Chunlin , Fu Chengyu , Boben M. E. 
Published: December 2007

Abstract
During the fourth quarter of 1997, a safety perception survey was conducted on three offshore facilities operating by Phillips China Inc.(PCI) in the South China Sea. This survey evaluated the workforce, and their perceived EHS performance with emphasis concentrating on the influence of the different cultures and languages. Opportunities for improvement were identified and then an action plan was developed and implemented.
Nuclear Magnetic Resonance Logging Methods for Fluid Typing
Authors: Hou B. L. , Coates G. R. 
Published: December 2007

Abstract
This is a review paper on applying Magnetic Resonance Imaging Logging (MRIL) methods for detecting and quantitatively measuring volumes occupied by brine, gas, and oil. These methods include Differential Spectrum Method (DSM), Enhanced Diffusion Method (EDM), Shift Spectrum Method (SSM) in transverse relaxation time (T2) domain or in spin-echo time domain (i.e., Time Domain Analysis; TDA), Total Porosity Measurement (TPM), and Injecting Contrast Agent Method (ICAM). The principles, data acquisitions, and data processes of these methods and their applications are introduced and discussed.
Surface-Modification System for Fracture-Conductivity Enhancement
Authors: Nguyen Philip D. , Weaver Jimmie D. , Dewprashad Brahmadeo T. 
Published: December 2007

Abstract
The proppant grain, once coated with a surface modification material, interacts instantaneously with the surrounding particulate because of an increase in surface friction. Experiments show that when such materials are coated with proppants, the settling time of proppants from aqueous-based fracturing fluid is increased. Therefore, the coating results in a better vertical distribution within the fracture and an increase in pack porosity of as much as 30%. API conductivity measurements of proppant packs were found to support this observation, but indicated that closure stress plays an important role in final proppant-pack conductivity. Testing with complete fracturing-fluid systems indicates that improved fluid removal can be achieved under some conditions. Field testing has supported this conclusion by providing both faster and more effective well cleanup after water-based fracturing treatments. Extensive field testing has provided considerable evidence for increased and sustained fracture productivity. Since the surface modification is performed on-the-fly and requires no additional time, aggressive gel-break schedules and well-flowback rates are used. Since most treatments resulted in little or no back-production of proppants or fines, the high-friction surface-modification materials were shown to stabilize proppant packs.
Macroemulsion Rheology and Drop Capture Mechanism During Flow in Porous Media
Authors: Khambharatana F. , Thomas S. , Ali S. M. Farouq 
Published: December 2007

Abstract
Emulsions play more and more important role in the oil recovery as they are found to occur in most enhanced oil recovery processes and are involved in certain modes of crude oil transportation. Furthermore, they can also be used in secondary recovery as blocking agents to improve waterflooding performance in layered reservoirs or under bottom-water conditions. However, there is still a lack of detailed understanding of the mechanisms involved during the displacement process. Therefore, there is a need for understanding the physics controlling the flow of an emulsion in a porous medium.
However, very little research has been carried out in the area of the flow mechanics of emulsions in porous media. Additionally, emulsion rheology and drop capture were investigated separately for certain conditions. These conditions restrict the model to specific applications. This leads to the question of how emulsion transport occurs in a porous medium in the case where emulsion drop size and the pore size are comparable, which is often the case. Therefore, the present study was carried out to observe the physical mechanisms that occurred when a stable emulsion flows in a porous medium for the system of comparable drop and pore sizes. Particularly, emulsion rheologies and droplet captures for both caustic and surfactant emulsions flowing through Berea sandstone and Ottawa sand packs were investigated comprehensively.
The results show that the change in emulsion rheology in a porous medium has an overall trend similar to that in a viscometer for the shear rates of interest. Furthermore, the emulsion droplets were found to be captured according to a filtration process.
A New Multiband Generation of NMR Logging Tools
Authors: Prammer M. G. , Bouton J. , Chandler R. N. , Drack E. D. , Miller M. N. 
Published: December 2007

Abstract
The paper describes the hardware and operation of a new generation of nuclear magnetic resonance (NMR) logging tools. In the past, NMR required the logging engineer to consider the T1 relaxation times of the reservoir fluids likely to be encountered. Actual or simply assumed long T1's translated into slow logging speeds. The new tool generation overcomes this limitation. The key feature is that nine sensitive volumes are polarized in parallel and are read out in rapid sequence. A new sonde design speeds up the polarization process by a factor of 2. Each volume contributes equally to the result, and can support identical measurements for rapid stacking and fast logging, or can be used for individual, simultaneous measurements.
Laboratory data and field test results are presented to demonstrate both the relative simplicity of operation and the improvement in data quality. Logging speeds can be typically upgraded by a factor of 4, while data for total porosity determination and fluid typing are acquired in a single logging pass.
Cyclic Steam Injection on Parallel Horizontal Wells: Geostatistical Description, Thermal Simulation and Field Experience
Authors: Cosentino L. , Spotti G. , Gonzalez J.E. , Araujo Y. , Herrera J. 
Published: December 2007

Abstract
Recent development of Bachaquero 2 Field (Lake Maracaibo, Venezuela) has been based mainly on cyclic steam injection on horizontal wells. Initial oil deliverability of the heated wells proved to be up to 5 times greater with respect to the cold wells.
This paper presents the results of a multi-disciplinary project focussed on the drilling of a pair of horizontal wells for cyclic stearn injection. The project involved a reservoir characterization and a numerical simulation phase, the drilling, steam injection and production of these wells, a data acquisition project and eventually a fial detailed simulation stage.
Experimental and numerical results show that the presence and the thickness of interbedded shale has a severe impact on heat distribution. Very little interference has to be expected between parallel horizontal wells when the separating shale is continuous and its average thickness is greater than about 12 feet. A preliminary stochastic description of the reservoir can be very useful in assessing the presence and expected average thickness of the interbedded shale.
The experience allowed us to set the best production strategy for the 2-horizontal well system, in terms of sequence and duration of the cycles, steam rate, total injected steam, steam quality and soak time. It also helped in setting guidelines for the future development of the Bachaquero 2 Field.
P. 293
Modeling Transient Foam Flow in Porous Media Using a Bubble Population Correlation
Authors: Bertin H.J. , Quintard M.Y. , Castanier L.M. 
Published: December 2007

Abstract
Foam is used in many oil recovery operations (gas mobility control, profile improvement, acidizing etc.). To date, modeling foam flow, specially transient foam flow, is still difficult. Foam viscosity depends strongly on its microstructure (texture), hence, one of the modeling approaches for foam flow in porous media can be done by a population balance equation, giving the bubble density number, that in turn gets included in a classical black oil simulator. Although this type of model produces excellent agreement between theory and laboratory experiments, the degree of difficulty in determining various parameters needed is too high to implement it in commercial simulators,
This study shows a bubble population correlation based on experimental observations and theoretical results obtained at the pore scale (micromodels, network modeling) and at the core scale (transient foam flow in homogeneous and heterogeneous media). In this correlation, we express explicitly the evolution of the mobile bubble density, (the foam texture that governs foam viscosity) as a function of the physical properties of the porous medium (porosity, permeability and capillary pressure) and the evolution of the mobile gas saturation, This correlation has been rather easily implemented in a numerical simulator and the resulting set of data has been matched against results of transient experiments, performed under a CT scanner as well as experiments performed by two other research institutions. The match of the experimental data and the correlation result is excellent. The results have also been compared with a complete simulation using the population balance model. The agreement is excellent between the two types of models.
This simplified formulation allows decoupling the effect of the porous media parameters such as porosity, permeability and capillary pressure from the effects caused by the surfactant, It conserves most of the benefits of the physics of foam flow as seen in the literature and allows simulation of heterogeneous porous media.
P. 319
Sub-seismic Faults Can Seriously Affect Fluid Flow in the Njord Field off Western Norway - A Stochastic Fault Modeling Case Study
Authors: Damsleth Eivind , Sangolt Vegard , Aamodt Geir 
Published: December 2007

Abstract
The Njord Field is heavily faulted. A stochastic fault modeling study has been performed on a sector of the field to quantify the potential impact of sub-seismic faulting on the production. Emphasis was given to the sensitivity of the results to the number of sub-seismic faults, the fault orientation, and the fault sealing properties. The main conclusions are: - Sub-seismic faults have neglectable effect on recovery, nor on the shape of the production profile, unless they are almost completely sealing. - The distribution of strike directions had no effects on the production.–Recovery decreases with increasing number of sub-seismic faults.–A large number of sealing sub-seismic faults will on average reduce the sector production with 20–25 %, compared to a base case model without sub-seismic faults. In some cases the reduction is much worse.–The production from individual wells is much more sensitive than the sector total to sub-seismic faults. Reductions up to 80 % have been observed in the simulations.
The HAVANA software has been used for the sub-seismic faults modeling. Irap RMS has been used for visualization and quality control, and the effects of the sub-seismic faults on production have been investigated using the fluid flow simulator Eclipse. HAVANA has proved to be very useful for this kind of studies.
P. 295
Probabilistic Reserves Lead to More Accurate Assessments
Authors: Schuyler J.R. 
Published: December 2007

Abstract
Property evaluations are key inputs for decision-making. Reserve category definitions-guidelines to petroleum property evaluation practice-intentionally produce conservative reserve valuations. Additional biases, actually errors, are introduced inadvertently. Many evaluation engineers are unaware of fundamental statistical processes that apply.
This paper describes two issues arising with the application of probabilistic techniques in reserve estimations. The first is aggregation of properties. This topic is identified, though without guidance, in the new SPE/WPT reserve definitions. Can we obtain proved reserves from a portfolio of probable reserves? Does a property's acquisition affect its reserves? Can we get proved reserves by aggregating probable or possible reserves? Professionals asked about these issues have admitted mixed levels of understanding and had diverse opinions as to best practice.
A second, companion issue is that monetary values are more important for deeision-making than reserve volumes. Therefore, prices and other economic assumptions are critical. In probabilistic reserve assessments, probability distributions express judgments about uncertainties. Forecast calculated with probabilities lead to more complete and more accurate evaluations.
P. 179
Temperature Prediction for Deepwater Wells: A Field Validated Methodology
Authors: Romero J. , Touboul E. 
Published: December 2007

Abstract
A precise knowledge of downhole circulating temperature is necessary for the design of safe well construction operations. The reliability of existing correlation and models is sometimes reduced in deepwater wells. Indeed, the mechanism of heat exchange with the sea is more complex than for rock formation, requiring additional inputs such as sea current, riser geometry and insulation. This paper describes an advanced numerical simulator for the design and evaluation of downhole circulating temperatures during drilling and cementing operations in deepwater wells. The equations governing heat transfer between the wellbore and the sea are developed first.
Several methods for obtaining offshore temperature measurement are presented and recommendations are given to use measurement while drilling (MWD) data as part of the design and evaluation process for wellbore temperature. A field case is then presented to illustrate how such MWD data can provide meaningful information for determining circulating and static temperature on deepwater wells. The down-hole measurements were compared to simulated temperature to illustrate how the MWD temperature can be correlated to bottom-hole circulating temperature. Finally, a methodology is proposed to assess the effect of deep water on circulating temperature and cement design based on MWD temperature measurements.
P. 339
Pipeline's Progress - A North Slope Update
Authors: Henriksen Donald A. 
Published: December 2007

Abstract
The Prudhoe Bay oil field, discovered in 1968 on the North Slope of Alaska, is the largest oil field in North America. The Trans Alaska Pipeline System, designed to transport Prudhoe Bay crude oil to an ice-free port on Prudhoe Bay crude oil to an ice-free port on the south coast of Alaska, will be the largest and most expensive construction project financed and built by private enterprise. Prudhoe Bay and TAPS jointly will have a Prudhoe Bay and TAPS jointly will have a major impact on future West Coast energy supply.
The history of North Slope petroleum exploration leading to the Prudhoe Bay discovery is briefly reviewed. Plans for the development of the Prudhoe Bay field are outlined, together with a general description of the producing facilities. The history of the Trans Alaska Pipeline System is reviewed, and current construction plans are described.