bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiphase Flow: A Cost-Efficient Solution for Marginal Field Developments
Authors: Falcimaigne J. R. 
Published: December 2007

Abstract
Satellite developments are an attractive solution for producing oil from small marginal fields. However, their application is limited by the distance that the crude oil can travel with the natural pressure of the reservoir. To overcome this limitation the paper proposes to use multiphase pumping to provide energy to the fluid. To implement this technology at low technical risks, the pumping unit could be located at the surface, aboard a small floating support. The production would be exported by means of a reusable flexible pipe to a processing centre.
After presenting recent advances in multiphase production, the paper describes the proposed system, designed to produce fields with 20 to 60 millions bbl. of recoverable reserves and located from 10 to 60 km, or beyond, from existing facilities or the shore. The system is characterized by its mobility. After depletion of a Held, it can be easily retrieved and moved to another location. In addition to reduced capital expenditures and relocability, the proposed system may accelerate the oil recovery of a field and the produced gas can be processed on the host platform and exported in an existing pipeline system.
Development and Standardisation: Challenge or Contradiction?
Authors: Sandhaugen R. A. , Lindland H. J. 
Published: December 2007

Abstract
This paper reviews Statoil's experience with standardisation of its subsea field developments. Aspects of maintaining standard specifications in a rapidly developing technology are discussed, as well as the inherent disadvantages and advantages of this approach. Subsea standardisation applied at correct system design level and agreed with potential suppliers, will contribute to economical development of marginal fields.
Remobilisation of Trapped Hydrocarbons in Water-Invaded Zones of Gas Condensate Reservoirs
Authors: Henderson G. D. , Danesh Ali , Tehrani D. H. , Peden J. M. 
Published: December 2007

Abstract
During the production of gas condensate reservoirs which have underlying aquifers present, large areas of the reservoir can be invaded by water during pressure reduction, resulting in the entrapment of large quantities of hydrocarbons. In order to simulate this process in the laboratory, experiments were conducted using gas and condensate saturated cores which were initially flooded with water to simulate the entrapment of hydrocarbons. Pressure reduction of the cores was then initiated in order to allow the hydrocarbons to expand and reach a critical hydrocarbon saturation at which hydrocarbons remobilised.
It was found that the average critical hydrocarbon saturation required for remobilisation of hydrocarbons was approximately 0.56, which was about 0.12 higher than the initial hydrocarbon saturation. Pressure reduction was initiated at different stages in the phase behaviour of the gas condensate fluid in the cores. This appeared to have only a minor effect on the hydrocarbon expansion required for remobilisation when the initial hydrocarbon saturations were similar. The results highlighted significant differences between the hydrocarbon expansion required for remobilisation, the fluid production profiles after remobilisation, and the effect of pressure reduction rate on remobilisation, for the gas condensate compared to a single phase gas.
How to Rate Crude Oils for Alkaline Flooding Potential: A Study Based on 239 Crude Oils
Authors: Smith J. E. 
Published: December 2007

ABSTRACT
This paper presents an overview of results of 239 crude oils which have been tested over a 10-yaar period. The oils represent 83 different formations. Analysis data from the Department of Energy (DOE) was available for 103 of the oils. Alkaline reactivity was correlated with crude oil composition and properties. Oils that contained a high proportion of vacuum distillate and components that tend to concentrate in the vacuum distillate had a high probability of alkaline reactivity. High molecular weight aromatics positively influenced alkaline reactivity, while paraffinic components had the opposite effect. Chemical properties correlated with alkaline reactivity more strongly than physical properties. A rating system based on factors that influence reactivity was constructed and applied to groups of oils. The rating system should be used as an initial screening tool for alkaline flooding potential.
A Review of Retention Mechanisms of Ethoxylated Sulfonates in Reservoir Cores
Authors: Austad Tor 
Published: December 2007

ABSTRACT
The present paper reviews work done on the adsorption of ethoxylated sulfonates during the Norwegian state-supported program on IOR, termed SPOR.The objective of the project is to obtain fundamental understanding of the mechanisms involved concerning the loss of surfactants by chemical flooding of sandstone reservoirs in The North Sea. Special emphasis is made concerning the effects of clay minerals in reservoir cores.The first part deals shortly with ethoxylated surfactants in general, chemical analysis, chemical stability, and temperature and salt tolerance. Both static adsorption onto model core material and nonequilibrium dynamic adsorption in reservoir cores, chromatographic effects, and possible sacrificial agents are handled in greater detail.
Growth and Control of Sulfidogenic Bacteria in a Laboratory Model Seawater Flood Thermal Gradient
Authors: Salanitro J. P. , Williams M. P. , Langston G. C. 
Published: December 2007

ABSTRACT
A model laboratory oilfield reservoir system consisting of a packed sand thermal gradient under continuous seawater infiltration was constructed to study the migration, persistence and activity of sulfate-reducing bacteria (SRB). Nutrients (fatty acids and NH4+/PO4−3) or biocide (glutaraldehyde) were added to the injection water to determine optimum conditions for SRB growth and control of microbial H2S formation. Halotolerant SRB isolated from Gulf Coast seawater were injected into the packed sand to promote colonization. Data obtained from several experiments demonstrated that: 1) there is no apparent correlation between the numbers of viable SRB recovered in a waterflood and the presence of H2S levels, 2) SRB which grow optimally at 25 and 35°C are thermo-tolerant and could be recovered from higher temperatures of the gradient (55 and 75°C). 3)Microbial sulfide production in the seawater and formation water injection fluid occurred only when lactic acid substrate was present, 4)H2S levels generated in the packed sand varied from 50–150 mg/day (30–100 mg/1 column effluent), 5) SRB growth and activity in the seawater flood could be significantly eliminated by the addition of high biocide concentrations (&gt; 1000 mg/1 glutaraldehyde) and 6) SRB produced H2S that was depleted in δ34S from the seawater SO4−2 by 10–12 per mil (δ34S = +6 to +8). These results show that sulfidogenic bacteria injected into a reservoir with the flood water may survive higher temperatures in the formation and be recovered from producing well fluids. These organisms may colonize cooler zones and sustain growth by degrading fatty acids in formation waters. Furthermore, recent literature findings on the isolation of extremely thermophilic fatty acid-utilizing sulfate-reducers (grow at 70–90°C) and SRB capable of growing on saturated hydrocarbons (C12 – C16) from oilfield production systems and anaerobic sediments suggests that thermophilic oil degraders may also be responsible for the onset of sour gas production in initially sweet waterfloods.
Crosslinked Borate HPG Equilibria and Rheological Characterization
Authors: Kesavan Subramanian , Prud’homme R. K. , Parris M. D. 
Published: December 2007

Abstract
Viscoelastic properties of hydroxypropyl guar (HPG) crosslinked by borate ions were studied using steady shear and dynamic oscillatory shear experiments. Chemical equilibria involving boric acid, borate ions, and borate ions associated with cis-diol sites on the polysaccharide chains determine the number of crosslinks. These equilibria are functions of temperature and pH, and thus the rheology of the borate gels depend on temperature and pH. Dynamic oscillatory measurements on polymer solutions crosslinked by borax were performed over the temperature range from 10°C to 65°C, and the pH range from 6.35 to 9.5. The storage and loss moduli obey time-temperature superposition so that master curves can be constructed over 6 decades in frequency. Leibler, et al. have recently proposed a theory for the rheology of associating polymer systems. Following this theory, we have subtracted the solution moduli from the gel moduli and the resulting reduced moduli data follow a single time constant Maxwell model. Steady shear experiments were performed in capillary tubes at two different diameters to determine wall slip. The shear rates studied were such that the chains do not have sufficient time to relax completely. By analysing the data from the two tubes, the gel was found to slip at the wall. Three different regions were seen in the stress – shear rate behavior of these gels. At low rates, the stress increases rapidly with shear rate. At intermediate shear rates, the stress remains constant and at high shear rates, the stress increases slowly with rate and the gel is found to slip in this region. The actual stress – shear rate behavior after accounting for slip and slip velocities were determined.
Experimental Validation of Sandstone Acidization Models
Authors: Hsi C. D. , Bryant S. L. , Neira R. D. 
Published: December 2007

Abstract
Sandstone HCl/HF acid matrix stimulation is a complex process involving numerous minerals and reactions. Previous attempts to model these reactions employed a "lumping" procedure to classify sandstone minerals as either fast reacting or slow reacting depending on their reaction rates with hydrofluoric acid.
Bryant (1991)1 showed that the two-mineral dissolution model can not accurately account for the effect of flow velocity on HF consumption rates. Consequently, this model cannot reliably extrapolate laboratory data to field conditions which involve radial flow geometry. Bryant presented an improved model to include the secondary dissolution/precipitation reaction of fluosilicic acid (H2SiF6) with clays and amorphous silica. The improved model was previously tested only against limited published data from three laboratory acid core flood tests. To further validate the model, additional laboratory acid core flood tests were conducted using different sandstone cores and with different acid injection rates and concentrations. Test results show that the improved model not only predicts the HF effluent histories reasonably well but also predicts the dissolved Si and Al concentration profiles in the effluent acid. This suggests that the improved model provides a more reliable basis for extrapolating laboratory data and for simulating matrix acid treatments. The improved model also helps to understand the dissolution/precipitation reactions occurring during sandstone acidization processes.
Compositional Reservoir Simulation With a Predictive Model for Viscous Fingering
Authors: Rubin Barry , Barker J. W. , Blunt M. J. , Christie M. A. , Culverwell I. D. , Mansfield Mark 
Published: December 2007

Abstract
This paper describes how an empirical model of compositional viscous fingering can be implemented in a conventional compositional reservoir simulator without major changes to the code. The empirical model is used to calculate pseudo relative permeabilities, transport coefficients (‘α-factors’) and a new density coefficient (‘β-factor’) which are used as input to the modified simulator. The modified simulator predicts the average behaviour of a variety of unstable gas displacement processes. The results are shown to be in excellent agreement with those of conventional compositional simulations which resolve the fingering explicitly.
Scaling Up the Non-Newtonian Flow Characteristics of Polymers, Foams, and Emulsions
Authors: Coombe D. A. , Oballa Viera , Buchanan W. L. 
Published: December 2007

Abstract
A generalized compositional thermal simulator is used to analyze the impact of the non-Newtonian flow characteristics of polymers, foams, and emulsions at three length/time scales.
At the pore scale a novel use of a reservoir simulator is employed to create networks of varying topology in order to study the impact of porous media structure on rheological behavior. Aspects of non-Newtonian flow of polymers, foams, and emulsions at this scale are then compared and contrasted. In particular the suitability of viscometer power law parameters to porous media, and the role of pore constrictions in trapping and mobilization are considered.
Subsequently, the non-Newtonian behavior of these fluids at the core and field scales are examined. It is shown that the impact of heterogeneity, crossflow and radial flow patterns, and region dependent trapping have analogies with the more microscopic scale. Furthermore, the shear rate dependence of in situ foam and emulsion generation suggests different modelling approaches at the core and field scales, with core scale rate processes replaced by pseudo-equilibrium K values at the field scale.
Numerical aspects of non-Newtonian modelling (explicit versus implicit and block-centered versus face-centered velocity evaluation) are discussed briefly.
A New Limited Compositional Reservoir Simulator
Authors: Tang D. E. , Zick A. A. 
Published: December 2007

Abstract
A new, limited compositional reservoir simulator has been developed. The development of this simulator was motivated by the fact that there are fundamental flaws in the formulation of existing four-component simulators. The unique feature of this simulator is that its phase behavior model is based on the concepts of pseudoternary, equilibrium phase diagrams. Phase envelopes are composed of pressure-dependent, piecewise linear bubble-point and dew-point surfaces with tie lines provided by a generalized version of Hand's Rule. Equilibrium calculations are noniterative and very efficient. Densities and viscosities are modeled by an equation of state and the Lohrenz-Bray-Clark correlation. This new model captures the essential physics missing in conventional four-component simulators.
Other features of the simulator include the Todd-Longstaff mixing model and compositionally consistent relative permeabilities. A practical example application of this new simulator is provided.
A More Accurate Numerical Scheme for Locally Refined Meshes in Heterogeneous Reservoirs
Authors: Hermitte Thierry , Guerillot D. R. 
Published: December 2007

Abstract
During reservoir simulation, the process of inferring the behavior of a real reservoir from the performance of a mathematical model implies a coarse discretization of the region to be simulated. The use of large size grids (blocks of several hundred of meters) increase numerical dispersion, therefore masking the physical phenomena actually occuring. The simulation then does not take into account wellbore effects, fluid fronts, etc. In that case, results are not accurate and thus unreliable. Reduction of the grid block size improves results accuracy but increases the number of blocks. Running costs become then too high. In order to decrease the grid block sizes without significantly increasing their number, Adaptive Mesh Refinement Method can be succesfully applied whereby the grid is locally refined when certain physical phenomena are expected to occur and need a better precision at the local level.
For such a method to be succesful, a dynamic data structure is needed as well as a higher order numerical scheme for pressure and saturation. The main difficulties are to approximate the fluid fluxes at the interface of two blocks belonging to two regions having been refined differently. Indeed, in this situation the block nodes are not aligned anymore, thus requiring a higher order approximation. The problem is then to obtain a numerical scheme having excellent theoretical properties such as conservativity and convergence.
This paper presents a new numerical scheme (conservative and convergent) with a good accuracy through use of locally refined grids. Furthermore, this new Scheme for Local Refinement Technics, SLRT, takes into account reservoir heterogeneity.
A comparison was made between this new scheme (SLRT) and other schemes suited for locally refined grids both for homogeneous and heterogeneous media. We show that this new scheme gives a better approximation for pressure and saturation. It can be easily implemented on any available simulator.
Extension of the TVD Midpoint Scheme to Higher-Order Accuracy in Time
Authors: Rubin Barry , Edwards Michael 
Published: December 2007

Abstract
A new approach for increasing the space and time accuracy of numerical schemes employed in standard (commercial) reservoir simulators is presented in this paper.
We introduce a novel TVD fully second order flux approximation (Two Time Level Flux TTLF) extending the work previously done on applying TVD schemes [1] to general purpose Black Oil/EOS Compositional reservoir simulators (eg. VIP). The TVD TTLF scheme is a more fundamental application of flux limiters on the second order Taylor's series expansion of the inter-block flux. This enables commercial first order accurate simulators to achieve second order accuracy in both space and time without significantly increasing their complexity.
This paper presents the development of the improved temporal accuracy TVD scheme and the results of the scheme on linear and non-linear 1-D pulse propagation problems and 2-D finely gridded compositional problems.
A Fully Explicit Scheme in Reservoir Simulation on a Massively Parallel Computer
Authors: Piault Emmanuel , Ding Yu 
Published: December 2007

Abstract
A new approach to solving the equations governing oil reservoir simulation is described. The generalization of an explicit unconditionally stable scheme for the heat equation is presented. This sclreme is used to solve the pressure equation of a diphasic model. Massively parallel computer, which have shown their capacity in high speed computations for explicit finite difference scheme, is used.
TOPEX: An Expert System for Estimating and Analyzing the Operating Costs of Oil and Gas Production Facilities
Authors: Greffioz Jean , Olver A. J. , Schirmer Patrice 
Published: December 2007

Abstract
TOPEX is a new approach to operating cost estimation of oil and gas installations. It does not rely on knowledge of the capital cost of the installation and uses a computerized expert system (or knowledge base).
Estimates are generated from specific details of the equipment and systems and general databases of prices and manhours.
A novel methodology has been developed for quantifying the operational complexity of an installation which is then correlated with operations manpower.
The use of a computerized application allows rapid calculation of estimates so that what-if and sensitivity studies can be readily done.
The knowledge base provides a powerful tool to handle the large amounts of data involved and acts as a repository for the expertise used in its development.
A Cheap Method for the Load-Out and Installation of Tambora Central Production Unit
Authors: Poirier D. J. M. , Accart M. A. 
Published: December 2007

ABSTRACT
TAMBORA and TUNU gas fields are located in the delta of the Mahakam river in the province of East Kalimantan (Indonesia) in the vicinity of HANDIL and BEKAPAI oil fields currently operated by TOTAL INDONESIE, (fig. 1)
In 1988, TOTAL INDONESIE launched the initial phase of development of these two fields enabling the production of 300 MMSCFD of gas by end of the year 1990.
The new facilities installed at this time included a single level platform of 2,600 m tons weight (TAMBORA Central Production unit no. 1).
In order to minimize the construction cost, the platform was installed by ballasting in one single piece without using cranes for lifting parts of the structure into place.
Due to the nature of the structure of the platform, the construction involved three delicate operations requiring special care:
the pre-driving of 16 piles which required accurate positioning. the load-out of the deck with its possible harmful effect on the integrity of the structure. the installation of the deck to be performed within a limited period of time (tide window).
The operation was successfully achieved and the method proved to be workable, safe and economical.
Slim-Hole Drilling in the Gulf of Suez, Egypt
Authors: Ghazaly S. M. , Khalaf Fouad 
Published: December 2007

Abstract
This paper discusses the economical, operational and environmental aspects of the reduced hole size drilling now used in offshore operations in Gupco and other major petroleum companies operating in the Gulf of Suez Area Egypt. The results demonstrate that reduced hole size drilling saves cost: use of slim hole reduces time related intangible savings, fixed tangible savings, and tangible equipment savings.
The advantages of smaller hole size and the reduction in the volume and size of oil wet drilling cuttings help minimize the environmental impact associated with the use of oil base mud. The reduction in drilling fluid volume and treatment cost, higher rates of penetration, better hole cleaning capabilities, savings in consumables (such as bits, mud, cement and diesel oil), less tangible cost, and easier equipment mobilization are interacted to produce significant operational gains. This results in savings of 40 to 50 percent of well costs versus the cost of conventional wells drilled in the same area.
Although substantial saving were realized, there are elevated risks with the major one being the lack of a good contingency in the event unexpec-ted hole condition or geological condition require an extra casing to be run prior to reaching the total depth. Drilling 6″ hole size (or less) for long sections is difficult. Usually, very slow drilling R0P is associated with erratic directional responses, and can restrict use of MWD tools. Moreover, more drill string failures are likely to occur.
Effective preplanning between the drilling, exploration, and engineering to accurately define possible geologic targets and their potential drilling problems can minimize these risks associated with drilling slim holes and provide higher levels of success in meeting objectives.
In summary, slim hole drilling offers significant operational and environ-mental advantages. And cost savings relative to the conventional well design were realized in the Gulf of Suez – Egypt.
Factors Limiting the Quantitative Use of Mud-Logging Data
Authors: Kyllingstad Åge , Horpestad Jan L. , Klakegg Sigve , Kristiansen Ansgar , Aadnøy Bernt S. 
Published: December 2007

Abstract
This paper focuses on the quality of mud logging data and the need for improving the quality. Included examples clearly demonstrate that traditional mud logging data suffers from errors and poor quality which limits its quantitative use, for instance in drill bit optimisation or modelling work. Special concern is paid to the accuracy of the depth, the rate of penetration and the surface weight on bit. It is concluded that there is a significant potential for improving the accuracy of these variables.