bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation of Immiscible CO2 Injection in a Fractured Carbonate Reservoir, Bati Raman Field, Turkey
Authors: Spivak A. , Karaoguz D. , Issever K. , Nolen J. S. 
Published: December 2007

ABSTRACT
This paper describes the use of a dualporosity, fractured reservoir simulator to investigate the application of the immiscible CO2 injection process in Turkey's largest Oil Field. Injection of CO2 into the Bati Raman field for the purpose of enhanced recovery commenced in 1986. The source of the CO2 is the nearby Dodan gas field, approximately 89 km from Bati Raman. This project is currently the world's largest application of the immiscible CO2 injection process.
Theoretical studies of both cyclic stimulation of wells and the gas drive process (continuous gas injection) are described along with field results for the first two years of gas injection.
Flexible Sand Barrier (FSB): A Novel Sand Control System
Authors: Dickinson W. , Knoll R. G. , Nordlund R. , Dickinson W. 
Published: December 2007

ABSTRACT
A series of experiments were conducted to determine the utility of a Flexible Sand Barrier (FSB) (helically wound flexible metal tubing) as a permeable casing within horizontal boreholes. These experiments focused on its production capacity and filtering capability. A test cell was developed which allowed testing over a range of pressure drops with or without a gravel pack. Laboratory in flow tests indicated 0.10 to 0.21 m3/d per meter (0.2 to 0.4 bbl/d per foot) of FSB in a 30 psi (0.21 MPa) reservoir with 1.0 Pa s (1000 cp) oil. Several configurations of the product from various manufacturers were compared and a suitable candidate was chosen for field testing which is underway.
Directional Well Planning with Multiple Targets in Three Dimensions
Authors: Goldman W. A. 
Published: December 2007

ABSTRACT
The purpose of this paper is to extend the radius of curvature method to 3 dimensional design problems. The technique utilizes transformation of coordinates involving simultaneous translation and rotation. A reference coordinate system is anchored at the surface conductor location while a traveling coordinate system progresses from target to target with the bit.
Current directional planning techniques involve approximations in the calculation of tool face angle and require an estimate of the direction change. The technique presented in this paper provides a direct solution for both tool face angle and azimuth. The method is applicable in planning a build-and-hold or "slant" directional well, or a build-hold-and-drop or "S-shape" directional well with multiple targets in 3 dimensions. This paper also applies the radius of curvature method to designing the lead angle of a directional well to compensate for expected bit walking tendency. Also presented is a method of determining whether it is possible to reach a given target based on the minimum rate of angle change required. The technique is well suited to programmable hand calculators for use in the field.
The Evolution of Fracture Stimulation Design for the Red Oak Formation in the Arkoma Basin: A Case Study
Authors: Sizemore J. C. 
Published: December 2007

ABSTRACT
The evolution of fracture stimulation design for the Red Oak formation in the Arkoma Basin of Eastern Oklahoma has led to significant economic improvements manifested not only in greater production but in less expensive treatments. Over the past 32 months, over 48 stimulations have been performed ranging from 15,000 gallons to 290,000 gallons of fluid and from 10,000 pounds to 500,000 pounds of proppant. During this period, improvements in fracture fluid, fracture design and treatment implementation have all led to greater success.
An Analysis of Oil/Water Flow Phenomena in Horizontal Pipes
Authors: Arirachakaran S. , Oglesby K. D. , Malinowsky M. S. , Shoham O. , Brill J. P. 
Published: December 2007

ABSTRACT
Extensive experimental data were acquired for oil-water flow in horizontal pipes for a very wide range of oil viscosity. Pressure drop, flow rate, input water fraction, in-situ holdup, mixture temperature, and flow pattern data were obtained for 612 oil-water tests in 1.5-in. pipe, and 587 tests in 1-in. pipe. Oils with viscosities of 4.7, 58, 84, and 115 cp were used in the 1.5-in. runs, while the 1-in. tests used 237-cp and 2116-cp oils, all measured at 70 °F. Mixture velocities varied from 1.5 to 12 ft/s, while input water fractions ranged from 0.05 to 0.90, and mixture temperatures were between 50 and 98 °F.
A new correlation is proposed for the prediction of the inversion point of an oil-water dispersion. It was found that the input water fraction required to invert the dispersion decreases with increasing oil viscosity. Pressure drop due to friction was also found to increase abruptly when the flowing oil-water mixture reached the inversion point where the external phase inverted from water to oil.
Two pressure-gradient prediction models are presented; one for stratified, and the other for homogeneously dispersed oil-water flows. Comparison between model predictions and experimental data shows satisfactory agreement.
Experimental oil-water flow pattern maps were developed. The existing flow pattern in an oil-water mixture depends primarily on mixture velocity, input water fraction, and oil viscosity (only when oil is the external phase).
Use of an Automatic History-Matching Technique to Analyze Pressure Buildup Data Affected by Wellbore Phase Segregation: Case Histories
Authors: Rushing J. A. , Lee W. J. 
Published: December 2007

ABSTRACT
An automatic history-matching technique has been developed for analyzing pressure buildup data affected by wellbore phase segregation. This automated type-curve analysis method uses a Gauss-Newton least-squares procedure to match observed field pressures and pressures simulated with Fair's1 phase segregation model. From this analysis we determine not only estimates of wellbore skin factor and formation permeability but also indications of the magnitude of the phase segregation effects.
The basis of conventional semilog analysis techniques for buildup tests is the presence and correct identification of a middle-time line whose slope is related to formation permeability. However, wellbore phase segregation may delay or completely suppress the development of this line, so semilog analysis methods often cannot be used. Fair1 has developed type curves for analyzing buildup data distorted by wellbore phase segregation, but unique solutions are difficult to obtain from manual type-curve matching. Since our automatic history-matching technique does not rely upon the presence of a middle-time line, this new method becomes especially useful when conventional semilog analysis techniques cannot be applied. In addition, comparisons of results from our automatic history-matching and Fair's1 manual type-curve fitting suggest that more reliable solutions can be achieved with this new automated procedure.
We present analyses of pressure buildup data taken from the petroleum literature and a previously unpublished field test. Comparisons of the results from our automatic history-matching, Fair's1 manual type-curve fitting, and the Horner2 semilog plotting method illustrate the applicability of this new method for analyzing field buildup tests distorted by wellbore phase segregation.
Field Calibration of Wedge Meter for Natural Gas Flow Measurement
Authors: Shen J. J. S. 
Published: December 2007

ABSTRACT
This paper presents the methodology and results of calibrating a commercial 4" (102 mm) segmental wedge meter in a field environment using a high-gravity natural gas. By comparing the segmental wedge meter flow rates with the sonic nozzles and orifice meters installed in the system, it was determined that use of the factory-supplied flow coefficients would cause the segmental wedge meter to undermeasure the gas flow rate. Based on the sonic nozzle reference, new sets of flow coefficients were derived for the wafer-style wedge meter tested with an uncertainty of ±0.38%. It was concluded that the the nozzle-calibrated flow coefficients obtained in this field test should improve the measurement accuracy of the 4" (102 mm) segmental wedge meter for natural gas flow measurement.
Case Histories: Plunger Lift Boosts Production in Deep Appalachian Gas Wells
Authors: Schwall G. H. 
Published: December 2007

ABSTRACT
Production increases of 50 to 100% and more have been obtained with plunger lift installations on gas wells in the South Burns Chapel Field in northern West Virginia. At the present time, 14 wells out of 35 are being produced with plunger lift. Pre-installation analysis showed that gas/liquid ratios (GLR) were high indicating potential success, but significant downtime was recorded during the initial phases of production. An operations guideline for plunger lift installation and startup has been developed to reduce downtime on future installations.
Asphaltene Deposition: A Comprehensive Description of Problem Manifestations and Modeling Approaches
Authors: Leontaritis K. J. 
Published: December 2007

ABSTRACT
The so-called "asphaltene problem" manifests itself in almost all the facets of production, processing, and transportation of petroleum. Due to the multiplicity of the engineering disciplines involved in the above processes an interdisciplinary approach is best suited for seeking fundamental understanding of and solutions to the problem.
This paper gives a detailed description of how the asphaltene problem manifests itself in the field. It discusses in-situ formation damage deep in the reservoir matrix and near the wellbore, subsurface and surface production facilities problems, and refining, blending, and transportation problems due to asphaltene flocculation and deposition. The molecular and colloidal asphaltene models are described and recommendations are made as to the preferred physical model. Existing, published analytical asphaltene models based on either molecular or colloidal nature of asphaltenes are presented and analyzed. A preferred modeling approach based on the colloidal physical model is recommended. The colloidal model permits and supports calculations based on both reversible equilibrium thermodynamics and irreversible colloidal flocculation as well.
Water Blasting for Scale Removal in the Rangely Weber Sand Unit
Authors: Buell R. S. 
Published: December 2007

Abstract
Barium sulfate scale deposition is a serious operational problem in the Rangely Weber Sand Unit (RWSU), often resulting in lost oil production. The historical method in the RWSU to restore production was to mechanically scrape the scale from the wellbore and then hydraulically break through any scale remaining in and around perforations. An alternative mechanical method of scale removal was recently used on a trial basis in the RWSU. Water blasting was used which directs high pressure jets of water with polymer additive at the perforations and casing wall. Water blasting was used on four wells and the results indicate that while water blasting does remove some scale, it is not an attractive option for stimulating production where barium sulfate scale has caused reduced production.
Design and Evaluation of Acid Fracturing Treatments
Authors: Ben-Naceur Kamel , Economides Michael J. 
Published: December 2007

ABSTRACT
During acid fracturing, different fluids, including a reactive one, are injected. As a result certain complex phenomena are evident. The determination of the performance of the treating fluids from injectivity tests departs from techniques that are applicable in propped fracturing because of the drastic change in rheological and leak-off properties between the viscous pad and the acid. Also, the simulation of the treatments includes the mechanism of diffusion of the reactive fluid to the fracture walls, and the injection of fluids with a large contrast in viscosities. Mechanical instabilities such as wormhole growth and viscous fingering have been shown to develop during the injection.
A design model coupling the fracture geometry to the diffusion mechanisms, such as heat and mass transfer, is presented. The model allows the simulation of both multi-stage injection treatments, with alternating stages of pad and acid, and gelled acid treatments.
A comparison between the two types of stimulation is performed. The implications on fracture conductivity after closure are analyzed based on different models of closure on etched channels in elastic and elastoplastic media. Guidelines for designing treatments in those formations are given, as well as a comparison with proppant injection.
An important aspect of the design is the estimation of fluid leakoff. Current pressure decline analysis techniques typically assume that a single fluid is injected. A method is offered to interpret injectivity tests with fluids having large contrasts in rheological and leakoff properties. Predicted pressures are finally compared with observed treatment pressures in the case of large viscosity contrasts.
Multi-Mechanistic Approach to the Reservoir Analysis of Tight Blanket Sands
Authors: Bezilla M. , Ertekin T. , Adewumi M. A. , Frohne K-H. 
Published: December 2007

ABSTRACT
Tight sand formations, because of their peculiar characteristics, do not conform to the well established behavioral patterns normally associated with conventional natural gas reservoirs. These attributes of tight sands render the conventional reservoir models inadequate when applied to tight sands. It is widely projected that gas resources available in these tight formations, which in the Western United States alone stands at about 5,703 Trillion Cubic Feet, may be the cornerstone of the future energy sufficiency of this country. It is also believed that the major bottleneck in the development of these resources is the lack of understanding of the fluid dynamics in these formations. It is therefore imperative to evolve a good model based on a fundamental understanding of the rather unique physics of flow in this media. A very important unconventional characteristic of tight formations is its dual-porosity nature in the form of micro/macropore structure and the pressure-field, concentration-field driven flow potentials imposed on the system. This physics calls for the use of dual-porosity, multi-mechanistic approach for the description of the transport of natural gas in these formations. Such a model is presented here. Both synthetic and actual field examples are used to illustrate the predictive capability of the model. Results show that the conventional single-mechanistic approach tends to under-predict recovery. They also demonstrate that the dual-mechanistic approach is of the essence.
Direct Type-Curve Synthesis of Pressure Transient Tests
Authors: Tiab D. 
Published: December 2007

ABSTRACT
"Direct Type Curve Synthesis" is a novel, direct, quick and accurate approach for interpreting pressure transient tests. This approach uses loglog plots of the pressure derivative versus time to calculate reservoir parameters such as permeability, porosity, skin, wellbore storage, half-fracture length, and distance to boundaries, without type curve matching. The method consists of obtaining characteristic points of intersection of straight line portions of the curves and their slope from a loglog plot of the pressure derivative as a function of time. These points and slopes are then used with special equations obtained from type-curve plots (i.e. loglog plots) of the dimensionless pressure derivative as a function of the dimensionless time for the appropriate reservoir system.
The new technique is illustrated in this paper for the case of pressure drawdown of vertically fractured wells. For the infinite-conductivity fracture case, pressure derivative plots reveal a dominant flow regime, called here the "bi-radial" flow. This flow regime, which corresponds to the transient period between the infinite acting radial flow and linear flow regimes, is described by a straight line of slope −2/π. Several simple equations, using the time of intersection of the three straight lines of slope −0.5 (linear flow), −2/π (bi-radial flow), and −1 (finite acting radial flow), and the pressure derivative values at test time of one hour have been derived. These equations can be used to calculate the half-fracture length independently of the permeability. The straight line portion of the bi-radial flow regime can be used to calculate k and xf even if the early-time pressure points, which describe the linear flow regime, were not recorded or discarded because of mechanical problems or too few to draw with confidence the half-slope straight line.
Prefracture Analysis of Red Mountain Sands: An Integrated Analysis of Openhole and Cased Hole Logs
Authors: Streeter R. W. , Hunt E. R. 
Published: December 2007

Abstract
Both gas permeability and in situ closure stresses computed from log analysis are confirmed by pre-fracture well tests and analysis of fracture stimulation operations on the No. 3 Deep Seam 30-4 in Mesa County, Colorado, one of three wells in a Red Mountain tight gas sands project funded by the Gas Research Institute. The log analysis provides porosity, water saturation, permeability, moduli, and in situ closure stress from an integration of open hole and cased hole geophysical well logs. Log analysis in the completed interval indicates an average gas permeability of 44 microdarcies as compared to 31 microdarcies from subsequent well test analysis. The in situ stress profile from log analysis indicates only moderately weak barriers above and below the completed zone, and this was later confirmed by the fracture modeling performed using the pressure versus time results of the well stimulation, which indicated no apparent constraints on vertical growth.
Permeabilities and in situ stresses needed for reservoir characterization and for hydraulic fracture design can be determined from the analysis of a combination of available open hole and appropriate cased hole logs. The available open hole data included resistivity, gamma ray, density, and compensated neutron logs. Acoustic velocities (Vp and Vs) are also needed for moduli and stress calculations, and cased hole full wave acoustic logs were recommended to provide these data. Prior to the full wave acoustic logs, cement bond logs were run on all three wells in the Red Mountain project to determine if good cement bond existed across the zones of interest. Presence of a microannulus, which was found in one well, causes strong casing acoustic signals that mask the compressional signals. In this well, good full wave acoustic log data were obtained by logging with the casing pressured up to 1500 psi. To obtain the necessary accuracy for pre-fracture analysis, quality control is a must.
Image Analysis of Pore Geometry: Relationship to Reservoir Engineering and Modeling
Authors: Ehrlich R. , Davies D. K. 
Published: December 2007

ABSTRACT
Image analysis of thin section and SEM samples from core plugs, sidewall cores and cuttings samples provides rapid, quantitative data concerning the size and geometric complexity of reservoir pore systems. Several distinct classes of porosity (Pore Types) co-exist in many reservoirs. This is particularly true in reservoirs which are shaly or have under-gone diagenesis (sandstones with less than 25% porosity, and all carbonates). Each pore type has 1) a unique size distribution that is independent of other pore types in the same reservoir, and 2) a unique relationship between pore body and pore throat size. Reservoirs with similar values for porosity and permeability can have different production efficiencies due to variations in pore geometry.
Regression procedures provide a first order model between measured capillary pressure and image-derived pore types. This relates pore types to measured pore throat size and allows for the direct calculation of permeability and capillary pressure from small samples (sidewall cores). Three dimensionless variables (Tau, Epsilon and Sigma) are calculated from image analysis of pore geometry. These provide quantitative information regarding the relative efficiencies of individual sands within a reservoir and between various reservoirs. Comparisons of efficiency based on Tau and Epsilon, allow for a numerical ranking of reservoir quality based on a uniform, quantitative system of analysis.
The Study of Alternate and Unstable Gas/Water Displacements Using a Small-Scale Model
Authors: Amiell P. , Billiotte J. , Meunier G. , Arnould M. 
Published: December 2007

Abstract
The operation of an aquifer gas storage can be distinguished from the production of a classical gas field by two fondamental points:–the flow rates in an aquifer storage are much more important, with gas/water displacement sometimes becoming instable–the alternating movement of fluids brings about variations in petrophysical properties despite apparently identical conditions
These two principal problems need to be carefully treated to correctly forecast and strictly monitor the development and operation of an aquifer storage.
This paper presents the results of a study which was conducted on a small scale model of metric size, allowing the visualization and quantification of the different phenomena observed. The effect of different parameters (inclination angle, gas flow-rate, number of cycles, etc.) on stability, geometric characteristics of the gas bubble, the allowable quantity of gas injected, and the Trapped Gas Ratio were investigated. Results were enhanced by the use of video-taping as interpreted by image processing.
Measurement of Relative Permeability and Flow Properties of a Gas Condensate System During Pressure Depletion and Pressure Maintenance
Authors: Munkerud P. K. 
Published: December 2007

Abstract
The objectives of the work presented in this paper, were development and testing of techniques for measurement of relative permeability of gas condensate fluid systems by pressure depletion and dynamic displacement of retrograde liquid at different interfacial tensions. The experiments employed a six component model system and were based on measurements of basic core and fluid properties, preliminary compositional simulation of fluid behaviour, slim tube tests and displacement in long Berea core1-4.
The measurements showed that the relative permeability curves to the gas condensate model system in a depletion process, are similar to curves of ordinary gas/oil systems, and that gravitational segregation of condensate is pronounced even at liquid saturations below the critical saturation for flow. During dynamic displacement of retrograde liquid by gas in equilibrium with the liquid, the relative permeability to gas and liquid showed strong dependence on interfacial tension between the two phases.
NGL Treating With Zinc Oxide
Authors: Auld R. G. , Latimer T. R. , Ciancio D. J. 
Published: December 2007

Abstract
Minor quantities of certain sulphur compounds can cause natural gas liquids (NGL) to fail the copper strip corrosivity test. At Esso Resources Canada Limited's Quirk Creek Gas Plant, it was found that there were periods, during high plant throughput, when NGL quality excursions were experienced. To gain control of the NGL quality and to ensure that the product could be shipped by pipeline, a program was undertaken to test various ways of treating the NGL product. In this paper, the experimental work involving slip stream testing and analysis of sulphur compound removal capacity at ambient temperatures is discussed. The resulting design of a full stream catalized zinc oxide treating unit installed to assure the NGL product meets the copper strip corrosivity test specification is described.