bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Implementation of a Microbially Enhanced Oil Recovery Field Pilot, Payne County, Oklahoma
Authors: Knapp R. M. , Mclnerney M. J. , Coates J. D. , Chisholm J. L. , Menzie D. E. , Bhupathiraju V. K. 
Published: December 2007

Abstract
A multi-well microbially enhanced waterflooding field pilot was conducted in the Southeast Vassar Vertz Sand Unit in Payne County, Oklahoma. Selective reductions in the interwell permeability between the injection well and the three production wells were observed after the microbial treatment. The permeability in the pilot area was more uniform after microbial treatment than before. More importantly, a major flow channel from the injection well to another portion of the reservoir was blocked. Changes in the alkalinity and sulfide concentrations indicated that the above observed alterations in flow paths and permeability were the result of in situ microbial growth and activity.
Fracture Measurement Using Hydraulic Impedance Testing
Authors: Paige R. W. , Roberts J. D. M. , Murray L. R. , Mellor D. W. 
Published: December 2007

ABSTRACT
Hydraulic Impedance Testing (HIT) is a technique which has been developed to measure formation fractures intersecting wellbores. Fracture dimensions are determined by introducing a pressure pulse into a well and interpreting the resulting pressure trace. The method only involves the use of wellhead equipment and is therefore a very cost effective method for obtaining information about fractures in the formation. This paper describes a method for interpreting HIT data and demonstrates its validity through laboratory and field measurements.
Direct comparisons between HIT field measurements and independent evidence for fracture dimensions are presented for a number of water injection wells. The most striking results are that HIT estimates of fracture height correlate well with the flowing intervals obtained from spinner logs, and HIT estimates of fracture length tend to agree with those obtained from PFO’s. HIT derived fracture dimensions are also comparable to those obtained from computer simulation of thermal fracturing.
More than 50 water injection wells have been tested with HIT and found to be intersected by formation fractures. Determination of fracture geometries in water injectors can be used for the optimisation of both areal and vertical waterflood sweep and increase understanding of the processes controlling injectivity. HIT may also provide a useful tool in hydraulic fracturing work.
Design and Installation of a Polyethylene Natural Gas Gathering System: A Case Study
Authors: Carlisle Todd 
Published: December 2007

Abstract
In certain applications, the use of polyethylene pipe in a natural gas gathering system offers substantial advantages over a conventional welded steel line. Polyethylene flowline is ideal for use in a natural gas gathering system where average field pressures are below 250 psig. A polyethylene line may be the only alternative when economics dictate the expense of a costlier steel une impractical, or when corrosion is a major concern.
This paper covers the design process and installation of a polyethylene natural gas gathering system in south Ohio. Methods used to calculate pressure drops in the system based on anticipated field conditions, including length, size and schedule of pipe, throughput, and compressor inlet pressure, are discussed. Procedures used to evaluate the pressure limitations of a polyethylene flowline are also examined. Other design factors such as state and federal regulations and line protection systems are presented. Project costs are compared and contrasted to a comparable conventional welded steel line. Installation techniques, equipment, and pitfalls are addressed. Post installation pressure drop data is analyzed to determine the accuracy of the pressure drop methodologies used to design the gathering system and those methodologies modified to more closely match field performance.
A Mechanistic Model of a Nitrogen-Charged, Pressure-Operated Gas Lift Valve
Authors: Sagar R. K. , Schmidt Zelimir , Doty D. R. , Weston K. C. 
Published: December 2007

Abstract
For any gas lift system installation it is important to know the dynamic opening and closing pressures and valve throughput to yield an efficient and optimized gas lift system installation. A comprehensive theoretical and experimental study was performed to develop an improved mechanistic model of a pressure operated nitrogen charged gas-lift valve.
Experiments are conducted on a Teledyne Merla N-15R, 1.5 inch, nitrogen charged, bellows operated gas-lift valve. A static probe tester is used to determine the load rates as a function of the initial dome pressure. Empirical equations quantifying bellows behavior are developed. Quasi-one dimensional flow theory for a convergent-divergent nozzle is used to model and describe the complex high velocity gas flow through the ball-seat configuration. The reduction of flow rate in the critical flow region of the throttling and transition flow regimes is achieved by the occurrence of a normal shock wave in the ball-seat configuration. A model incorporating compressible flow theory and the behavior of the bellows assembly is developed. Experimental and theoretical sensitivity studies indicate that a nitrogen charged pressure operated valve is very sensitive to performance parameters. Changes in pressures and temperatures by as little as 1% can change the maximum flow rate by as much as 30%.
The Field Application of a Surfactant for the Production of Heavy, Viscous Crude Oils
Authors: McCafferty J. F. , McClaflin G. G. 
Published: December 2007

ABSTRACT
A surfactant, water, hydrocarbon diluent system designed to produce heavy crude by forming an oil-in-water emulsion has been successfully field-tested. The new process significantly lowers the production costs for viscous crude by reducing the hydrocarbon diluent usage.
Compressibility Factors for Naturally Occurring Petroleum Gases
Authors: Corredor J. H. , Piper L. D. , McCain W. D. 
Published: December 2007

ABSTRACT
The Stewart, Burkhardt and Voo (SBV) equations, as modified by Sutton, give values of pseudocritical properties which, when used with the Dranchuk and Abou-Kassem (DAK) representation of the Standing and Katz (SK) chart, currently provide the most accurate estimates of compressibility factors for naturally occurring petroleum gases. However, other correlations must be used to account for the properties of the heptane plus fraction and the presence of acid gases. A modification of the SBV equations is presented which takes into account the effects of the heptane plus fraction, acid gases and nitrogen. The new correlation provides more accurate estimates of the compressibility factor than can be obtained by current methods and also eliminates the need for involving additional correlations for properties of the heptanes plus fraction and presence of acid gases and nitrogen. The modification was developed using a set of 896 data points, ranging in composition from lean, sweet to rich, acid gases, and was tested against representative gases from the literature.
Graphical System Analysis of Gasfield Production
Authors: Skarsholt L. T. , Asheim Harald 
Published: December 2007

Abstract
The graphical technique presented enables characterization of gas field production performance by 6 parameters. These can be estimated from production data, as shown for the Frigg field example. The parameters can be scaled to represent similar fields and to quantify the effect of design modifications. Among other applications, this allows optimization of the production system design.
Simulated Annealing for Interpreting Gas/Water Laboratory Corefloods
Authors: Ouenes Ahmed , Fasanino Guy , de France Gaz , Lee R. L. 
Published: December 2007

ABSTRACT
This paper presents a new approach for the simultaneous estimation of relative permeability and capillary pressure curves from two-phase laboratory corefloods. The new technique enables us to retrieve a discrete representation of the flow functions by using a discrete optimization method called simulated annealing. The number of discrete points for each flow curve can be very high and yet will not affect the convergence of the algorithm specially designed for multidimensional optimization problems. Moreover, the algorithm is totally independent from the forward model; therefore, changes in the objective function, boundary conditions, or numerical scheme do not affect the formulation of the optimization problem. Simulated annealing as a global optimization method does not require the evaluation of objective function gradients. Hence, costly gradient computations by finite differences or lengthy derivations of adjoint equations for the optimal control theory are not necessary. The flow functions are estimated after minimizing a least-squares objective function containing all available and reliable experimental data obtained from standard drainage or imbibition experiments. The automatic history-matching code is demonstrated with actual and synthetic experiments, and good matching is obtained for various cases tested. Since the convergence of the algorithm is no longer the major concern, other physical problems such as end effect and the dependence of relative permeability curves on the flow rate are addressed.
3-D Finite Difference Modeling of Wireline Formation Tests in Tight Gas Sands
Authors: Xu Hui , Bassiouni Zaki , Desbrandes Robert 
Published: December 2007

ABSTRACT
In tight gas sands, conventional models of wireline formation testers (WFT) yield non-representative estimates of formation permeability because several important conditions found in real well situations are neglected. These conditions include flowline storage, skin permeability, formation anisotropy, supercharging pressure, and test geometry.
The three-dimensional finite difference model presented in this paper incorporates all these conditions. The effect of these conditions on the WFT pressure response are discussed. The model was verified using the spherical model with boundary conditions set close to those prevailing in a spherical flow regime.
The 3-D model was used to interpret three field data sets obtained in low permeability formations. The formation permeabilities were determined by matching the data to theoretical curves computed from the 3-D model.
Development and Validation of a Modified Well Model Equation for Nonuniform Grids with Application to Horizontal Well and Coning Problems.
Authors: Sharpe H. N. , Ramesh B. A. 
Published: December 2007

Abstract
In this paper we demonstrate the important limitations of trie standard Peaceman well model equation when applied to non-uniform areal cartesian grids and when used in flow problems with a significant vertical flow component near the well. We present and validate simple modifications to the Peaceman well model which restore its validity for non-uniform areal grids and for problems which model vertical flow processes like gas and water coning.
An Experimental Study of Capillary and Gravity Crossflow in Fractured Porous Media
Authors: Firoozabadi Abbas , Markeset Tore 
Published: December 2007

Abstract
Physical phenomena such as capillary, gravity, and viscous cross flow at the interface of two different porous media or in the fracture space between matrix blocks are believed to affect the flow of multiphases. We have not found any reported work on capillary and gravity cross flow in fractured porous media.
An experimental and theoretical work has been initiated to understand cross flow in fractured porous media. In this paper, the results of our experimental effort on capillary and gravity crossflow in fractured porous media are presented. Drainage performance of a stack of 12 matrix slabs, three in each row, was measured. The angle between the stack and the vertical direction varied from 0° to 45°. Experiments on a stack of matrix blocks were also conducted to compare the results. The data show that capillary cross flow across side faces of a matrix block is an important flow mechanism. Capillary cross flow enhances drainage performance in fractured porous media.
Simulation of Carbon Dioxide Flooding Using Horizontal Wells
Authors: Lim M. T. , Khan S. A. , Sepehrnoori Kamy , Pope G. A. 
Published: December 2007

ABSTRACT
A compositional equation-of-state simulator has been used to make comparisons of CO2 process performance with several combinations of horizontal and vertical wells and various alternative reservoir descriptions. This is the first time that the performance of CO2 flooding using horizontal wells has been reported. We have used the reservoir and fluid properties of an actual West Texas carbonate reservoir that is currently being waterflooded. The phase behavior and properties of the CO2 used in these simulations are typical of those of multiple-contact- miscible field conditions of West Texas. A layered-type reservoir description was initially used to investigate the effect of water- altemating-gas (WAG) ratio with various combinations of well types. We then investigated the effect of vertical permeability, length, and position of the horizontal injector using the same reservoir description and a horizontal injector-vertical producer combination. Similar investigations using an unconditioned stochastic permeability field having a Dykstra Parsons coefficient (VDP) of 0.81 were made. Our final three-phase flow simulation was performed using a stochastic permeability field conditioned with core data. Since three nonaqueous phases can occur at low temperatures typical of West Texas floods resulting in up to four-phase flow with mobile water, we investigated the impact of four-phase flow in one of these simulations. This is the first time that three-dimensional, four-phase flow reservoir simulations have been reported with either vertical or horizontal wells.
Early Performance and Evaluation of the Kuparuk Hydrocarbon Miscible Flood
Authors: Reinbold E. W. , Bokhari S. W. , Enger S. R. , Ma T. D. , Renke S. M. 
Published: December 2007

ABSTRACT
A small-scale hydrocarbon miscible flood was initiated at the Kuparuk River Unit on the North Slope of Alaska in mid-1988, three years after the start-up of waterflooding. This Small Scale EOR (SSEOR) project, along with an infill drilling program, is improving recovery from a stratified and highly faulted sandstone reservoir.
The project design was aided by limited compositional reservoir simulation. The design calls for the injection of a 30% hydrocarbon pore volume (HCPV) slug of miscible injectant (MI) which is injected alternately with water at a 1:1 water-alternating-gas (WAG) ratio for mobility control.
An extensive laboratory program was conducted to understand the displacement process and to develop an equation of state (EOS) fluid characterization. The displacement process is characterized as a condensing/vaporizing gas-drive process, providing a high unit displacement efficiency.
A comprehensive surveillance program was implemented to quantify reservoir continuity and vertical conformance. A gas tracer program has helped in interpreting the influence of faulting on interwell continuity and regional fluid flux. Injection and production well surveys indicate that permeability stratification controls vertical conformance.
Preliminary evaluation of project performance indicates significant incremental recovery associated with both infill drilling and enriched gas injection. Typical EOR response includes a significant increase in the oil production rate, with an associated decreasing watercut and increasing gas-oil ratio.
Crossflow Mechanisms by Gas Drive in Heterogeneous Reservoirs
Authors: Fayers F. J. , Lee Sheng-Tai 
Published: December 2007

Abstract
In this paper a number of factors contributing to mass transfer by cross flow in gas displacement are examined. The mechanisms involved are diffusion, dispersive mixing, capillary pumping, interfacial tension variation, and relative permeability modification. The use of a modified Wilke-Chang correlation for bulk diffusion coefficients in multi-component systems is suggested. The performance of this correlation is tested against the limited experimental data available on diffusion coefficients. A general formulation of the terms needed to be included in compositional simulators for cross flow effects is reviewed, and thence some of the key aspects are analyzed using measurements from the IFP-diffusion experiment. The role of the gas phase tortuosity factor is investigated, but spatially varying capillary force is also found to be a dominating mechanism. An example reservoir application with a two-layer heterogeneous character is then studied to determine the relative magnitudes of cross flow, and how these compare between a nearly miscible displacement and a dry gas vaporizing process.
The Second Long-Term Horizontal Well Test in Troll: Successful Production From a 13-in. Oil Column With the Well Partly Completed in the Water Zone
Authors: Haug B. T. 
Published: December 2007

ABSTRACT
Inspired by the success of the first long-term test with a horizontal well on Troll1, a second long-term test was carried out in 1991. This 4 months long-term production test with an 800 m horizontal well was performed in a 13 m oil column sandwiched between a large gas cap and an active aquifer in the Troll West Gas Province. The horizontal section target depth was 1 m above the WOC, but approximately 25% of the well trajectory was actually below the WOC.
The observed production data from the test were history matched with a numerical simulator. The effects of various geological features on water cut and GOR development were studied, and several simulation models matching the production history were built. These models were used to evaluate the effects on oil recovery of various design parameters such as; length of the horizontal section, completion depth, liner diameter and liner roughness.
The production history indicated that inverse coning took place in the parts of the well situated below the initial WOC. The history matching confirmed the results from the first long-term test, but also demonstrated the strong sensitivity of history matching and long-term production predictions to small changes in geological interpretations and to frictional pressure loss in the horizontal section.
Large upside potential was found in the Troll West Gas Province for longer horizontal wells, deeper completions and super-critical production.
National Petroleum Regulatory Policy Options: A Review
Authors: Stultz-Karim S. P. 
Published: December 2007

ABSTRACT
This paper is intended to provide guidelines for petroleum legislation and regulation for developing, petroleum exporting nations and the transitional nations of the Commonwealth of Independent States and the petroleum producing nations of Eastern Europe. Included in this survey of methods of petroleum regulation and legislation are concepts of ownership of petroleum rights, contractual arrangements between host countries, and investing international petroleum companies, components of petroleum regulation, the differing perspectives of investing companies’ and host national governments of petroleum regulation, and an expected monetary value model of petroleum regulatory design which incorporates the consideration of exploration risk to enable national governments to maximize public revenue while encouraging exploration investment and the obtainment of domestic political economic policy objectives.
New Techniques for Solving Cementing Problems in a Field Laboratory
Authors: Moulin E. M. , Roy M. L. , Caddell S. E. , Vidick Benoit , Hughes T. L. 
Published: December 2007

Abstract
In recent years, the quality of oil well cements has become increasingly variable. Using a cement characterization program provides a highly reliable means of determining the relative quality of a proposed cement. Furthermore, results can be used to determine the origin of poor performances by some cements in the field. This paper briefly presents techniques such as calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, and pycnometry which provide useful tools for supplementing conventional testing methods. In addition, several case studies are presented which use these same techniques to solve field.
Predicting the Pressure Drop in a Cased-Hole Gravel Pack Completion
Authors: Pucknell J. K. , Mason J. N. E. 
Published: December 2007

Abstract
In sand-producing formations, a cased hole gravel pack is usually the preferred completion method. There are various reasons why the alternatives, an open hole gravel pack or a sand consolidation treatment, may not be suitable. However, the productivity of the cased hole gravel pack is much poorer than the alternatives because of high mechanical skins.
Despite the importance of this mechanical skin, the existing pressure drop prediction models are incomplete. Many papers deal with the region of linear flow in the casing/cement tunnels and the flow through the gravel between casing and screen. What happens just outside the casing is rarely mentioned, even though the pressure drops beyond the casing may be significant.
One complication is that perforation tunnels in the formation might either remain intact or they could collapse before gravel packing, creating a void behind the casing.
This paper presents new methods for predicting the pressure drops outside the casing and so allows the construction of a comprehensive model for cased hole gravel pack productivity. A newly-developed finite difference computer simulator was used to produce a general method for intact perforations packed with gravel. For collapsed perforations, an analytical method was developed which is based on the amount of gravel placed behind the casing.
Alwyn North Brent East Panel: Detailed Reservoir Analysis To Improve Reservoir Management and Recovery
Authors: Montmayeur Hugues , Rae S. F. , Coombes T. P. 
Published: December 2007

Abstract
The Brent East reservoir of the Alwyn North Field, with few producer wells and a relatively short production life, represents a challenge for data gathering and reservoir management. Accurate reservoir description had to be obtained rapidly to adjust to unexpected events in order to maximise recovery and prepare enhanced oil recovery programmes.
Real-Time Compression of Logging Data
Authors: Gardner W. R. , Sanstrom W. C. 
Published: December 2007

ABSTRACT
The high telemetry data rates required by state-of-the-art downhole imaging tools have made real-time tool data compression desirable. This increases the effective telemetry data rate and decrease data storage requirements. A variety of lossless and lossy data compression techniques are available for possible logging applications.
Lossless variable-length-coding techniques are applied to different classes of well log data (i.e. dipmeter, density, imaging tools …) to determine the achievable compression ratios and feasibility for real-time processing. Compression ratios of ranging from 1.2:1 to 22:1 are achieved depending on the type of log data.
Lossy image compression techniques developed by the telecommunications industry for the transmission of high definition images over reduced bandwidth channels are adapted to provide real-time compression of imaging logs. The modified image compression algorithms are used to compress log images from a circumferential acoustic scanning tool. Circumferential Acoustic Scanning Tool images compressed by a factor of 20- to-1 were barely distinguishable from the original uncompressed images. Most of the important geologic features are still preserved when the images are compressed at ratios exceeding 80-to-1.