bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification and Distribution of Hydraulic Flow Units in a Heterogeneous Carbonate Reservoir: North Robertson Unit, West Texas
Authors: Davies D. K. , Vessell R. K. 
Published: December 2007

Abstract
A model is developed of a heterogeneous carbonate reservoir based fundamentally on measurement of pore geometrical parameters. Pore level reservoir modeling results in improved accuracy in the prediction of rock types, permeability and identification of flow units. Pore geometrical attributes are integrated with wireline log data to allow for I) log-based identification of intervals of rock with different capillary characteristics, and ii) field-wide, log-based prediction of permeability. Twelve hydraulic flow units are identified through integration of data concerning rock type distribution and depositional environments. Maps of permeability thickness (kH) for each flow unit reveal significant stratigraphic compart-mentalization. Future development drilling using uniform well spacing patterns is not appropriate. The location and design of infill drilling patterns should be geologically targeted for prudent, cost-effective field development.
Flow Units Vs Depositional Cycles In Field Development, Reeves San Andres Field, Yoakum County, TX
Authors: Danielli H. M. C. 
Published: December 2007

Abstract
Geological reservoir layering for simulation and development usually models depositional sequences. Another approach looks for flow units, i.e., rock units with uniform flow properties. The two are not always identical and should be distinguished. Numerical core descriptions show that porosity and permeability in Reeves Field are determined by both depositional and diagenetic parameters. Flow units defined in this way cut across depositional cycles and cannot be traced between wells with 40-acre spacing. High oil cuts are obtained from 20-acre infill wells despite a long-term waterflood. Reservoir behavior is controlled by the geometry of these flow units, not by depositional cycles.
A Case Study of the Development of the Sundown Slaughter Unit CO2 Flood Hockley County, Texas
Authors: Folger L. K. , Guillot S. N. 
Published: December 2007

Abstract
This paper describes the design of the miscible CO2 flood on the Sundown Slaughter Unit. The 8,700 acre unit was a mature waterflood in the San Andres formation surrounded by seven active CO2 floods. CO2 injection commenced on the Unit in January of 1994. The project benefited from the available technology on CO2 flooding and particularly information on other CO2 projects in the Slaughter field. The paper summarizes methods used in the geologic description, reservoir characterization, pattern selection, CO2 flood predictions, and field preparation. The CO2 injection plan and actual performance to date are also presented.
Dollarhide Devonian CO2 Flood: Project Performance Review 10 Years Later
Authors: Bellavance J. F. R. 
Published: December 2007

ABSTRACT
The Doilarhide Devonian CO2 miscible flood has demonstrated substantial production increases in Phases 1, 2, 3 and 4 of the 5 Phase project. To date, incremental recovery is estimated at 15.8 MMBBLS. The field has now produced 63.7 MMBO and is presently under a program of accelerated depletion. In view of the detrimental effects of the WAG cycles on injectivity, water injection has been limited to areas of severe breakthrough. Production currently averages 3080 bbls/d. A total of 66.5 BCF or a 11.2% HCPV of CO2 has been injected into the reservoir and less than 15% has been produced. CO2 breakthrough has not been a problem in the Devonian hence, a WAG process is not warranted at Doilarhide.
Pump-in/Shutdown Tests Key to Finding Near-WelIbore Restrictions
Authors: Hyden Ron E. , Stegent Neil A. 
Published: December 2007

Abstract
Hydraulic fracturing treatments are often significantly impacted by near-wellbore flow regimes that are not anticipated and usually unaccounted for. Identifying the existence of these unusual flow restrictions and quantifying their magnitude has been described in previous work done by Cleary et al.' This paper presents case histories showing the value of simple pump-in/shutdown tests before large-scale hydraulic fracture treat-ments to evaluate such near-wellbore formation restrictions as tortuosity, existence of multiple fractures, and perforation fric-tion, based on the previous work of Cleary et al. These case history evaluations have led to more predictable job outcomes. Testing includes step-down rate tests, water-hammer effects, and fluid efficiency test analysis. These tests are all conducted and analyzed before the treatment, on the day of the treatment.
Water and Gas Coning in the Oil Reservoirs With Steady State and Transient Flow (Part I: Vertical Wells)
Authors: Azar-Nejad F. , Tortike W. S. , Ali S.M. Farouq 
Published: December 2007

Abstract
This paper examines fluid flow mechanism in an infinite rectilinear reservoir with bottom water and/or gas cap. The water-oil contact (WOC) is treated as a no-flow moving boundary while the initial WOC is kept at a constant pressure. The potential distribution around the partially penetrating wellbore is a solution of Laplace or difiusivity equation with uniform potential inner boundary condition (1BC). A new dimensionless variable is introduced. Dimensionless Density, as a function of reservoir geometry, reservoir anisotropy, fluid properties, production rate and the difference of the densities of two fluids. This paper reports the existence of a Critical Dimensionless Density, CDD. above which cone is stable. The results of this study show that for large v alues of Dimensionless Density the cone height is very small and the well pressure response is almost identical to that of the reservoirs without bottom water or a gas cap. Therefore for reservoirs with a high Dimensionless Density a solution of no-flow boundary at the initial WOC level seems more accurate with respect to solution with constant potential boundary. CDD indicates that 1) in anisotropic reservoirs, smaller the vertical permeability the larger is the critical production rate or time of breakthrough. 2) Heavy oils, at equivalent conditions, have smaller critical production rate or time of the breakthrough due to higher viscosity. Thus thermal processes such as steam stimulation reduce the cone height and consequently increase the time of the breakthrough.
Development and Application of Unique Natural Solvents for Treating Paraffin and Asphaltene Related Problems
Authors: King S. R. , Cotney C. R. 
Published: December 2007

Abstract
Paraffin and asphaltene related problems including solid deposits, stabilization of emulsions and sludge production1,2,3continue to plaque the oil and gas industry. Condensates and refined aromatic solvents are popular treatments for dissolving and/or controlling paraffin and asphaltene related problems. These treating fluids are typically used as a quick fix with little regard for formation damage consequences and long term effectiveness.
Testing, blending and refining of unique condensate feedstocks has resulted in unique natural multi-component hydrocarbon solvents. These unique solvents will dissolve a broad carbon number spectrum of organic deposits and keep them in solution under extreme conditions. These natural solvents maximize solvency, demulsifying properties and natural wettibility tendencies without the addition of chemical additives. These natural solvents offer economic alternatives and enhancement to common treatment practices including condensate treatments, hot oiling, chemical treatments, stimulation and production treatments.
Studies on Fracturing in Carbonate Formations in Mexico
Authors: Porres A. , Samudio M. , Pacheco C. , Castrejón F. 
Published: December 2007

Abstract
The study of fracturing in carbonate formations has become a critical factor for the exploitation policies for the main oil and gas producing reservoirs in Mexico, since a great percentage of hydrocarbons production is associated with this kind of reservoirs.
In this paper a methodology that integrates diverse sources of information at different spatial scales is proposed, the range of spatial scales goes from the microscopic level study of thin section of rocks and cores to the megascopic level where fracturing is determined with seismic information.
To define reservoirs fracturing it has been utilized information derived from cuttings samples, cores, well logging, wellbore images, well testing and seismic interpretations.
Given that the fractures are not isolated phenomena in nature, the studies herein described, target to know their origin, in this way, fractures and their spatial relations are identified with the purpose of defining fracture system, principal stresses and their association with major tectonic features such as folds and faults; letting know the fracturing pattern and its association with the geologic model of the area.
Fracture parameters are estimated by means of core analysis and well log information using indices derived mainly from resistivity and porosity logs, on the other hand, fracture orientation is determined from dipmeter information, wellbore images and its correlation with cores.
The application of this method and its results in two fields of Mexico are shown, these results allowed to establish models at well and reservoir levels. Also from these it was possible to estimate preferential fracture orientations in areas not yet drilled, which is of great importance for the optimum field development.
Rock Cutting By Laser
Authors: Carstens Jeffrey P. , Brown Clyde O. 
Published: December 2007

Introduction
A recent study of laser-assisted mechanical rock tunneling, conducted at the United Aircraft Research Laboratories under Department of Transportation sponsorship, had as a goal the investigation of laser-assisted mechanical rock fracture for use in tunneling machines boring in extremely hard rock. The results of this study, which are reported in Ref. 1, indicate that the use of the laser in a low-power-density mode to preweaken the rock without causing malting of the rock surface is indeed a feasible mode of weakening hard rock, which does allow a reduction in the energy required for subsequent mechanical removal of the rock. However the system studies undertaken in Ref. 1 indicate that the amount of strength reduction achieved by the laser or any other type of heating system would not be sufficient to justify economically the addition of an expensive heating system to a hard rock tunneling machine.
One avenue toward employing concentrated heat energy which appears to have a potentially greater efficiency in reducing potentially greater efficiency in reducing the strength of hard rock was identified in the Ref. 1 study. This concept involves using highly concentrated thermal energy to form very narrow melt cuts in the rock. This mode of rock weakening has two advantages relative to the use of the low-power-density heating mode in which rock melting is not allowed to occur. For one thing, the use of an extremely high-power-density energy beam allows penetration of the heat into the rock at substantially higher speeds than the nonmelting case, in which penetration speeds are based on the speed of thermal diffusion into the solid rock. Secondly, there are indications that the deposition of heat at depth in the rock could allow removal of a much greater rock volume than the same amount of heat if it were allowed simply to heat-weaken an entire surface area. Careful use of a very highly concentrated heat tool could allow weakening of rock along specific planes, with subsequent removal of relatively large pieces of rock bounded by these planes.
Tailoring the TLP – Evolution and Adaptation of the Concept
Authors: Stokes Edward G. , Koon J. Ray , Thompson Dwight A. 
Published: December 2007

Abstract
A generic characteristic of the Tension Leg Platform (TLP) concept is the interdependencies between the elements of its design, Ref. 1. For example, a change in deck layout and/or weight can affect the center of gravity, which affects platform dynamics, tether tensions, and so on. An important attribute of the concept is its insensitivity to water depth while providing direct access to wells for maintenance.
TLPs can be configured in a variety of ways to achieve different objectives. Hutton1, Jolliet, and Heidrun are three unique applications of the concept, Ref. 2, Fig. 1. The authors' company has through the design evolution and operation of these units, and through studies of other similar TLP concepts, continued to focus on ways to improve its adaptability in different location, environments, water depths and reservoir sizes. Based on the best practices and lessons learned from the existing developments, the advances in related technologies, and knowledge gained from other studies, an even broader range of cost-effective TLP solutions will be possible in the future.
This paper discusses the similarities and differences in three TLPs and the factors that influenced their evolution and adaptation. The paper also reviews the history of the concept, TLP principles, project and operational learnings from each application, and other adaptations of the TLP concept.
Minimum Attractive Rates of Return Associated to Different Risk Levels: A Methodology Applied to Production Projects of The Brazilian Petroleum Industry
Authors: Asrilhant B. , Ensslin L. 
Published: December 2007

Abstract
The use of the maximization of net present value (NPV) associated to a single discount rate as a criterion of evaluation and selection of resources allocation projects tends to direct the investments portfolio up to a situation of high risk, and possible endangering economic position. This inappropriate situation may, however, be manageable through the use of the risk-return rule as assumed criterion. First of all, a compound factor which associates risk due to the market environment, obtained by the Capital Asset Pricing Model (CAPM), to risk related to the project liquidity, identified by the concept of securities duration is introduced. Finally, a factor, pointed out by the Prospect Theory, which carachterizes the losses aversion is incorporated. When the available information is difuse, the risk related to the cash flows estimation is added. Thus, one adjusts the minimum attractive rate of return of a project to its global risk, whose NPV adjusted to the global risk calculation allows a comparison among projects of different risk levels, through a single objective criterion, which incorporates the three risk factors judged significant. Finally, the methodology will be applied to production projects of the Brazilian petroleum industry.
On the Exploitation Conditions of the Akal Reservoir Considering Gas Cap Nitrogen Injection
Authors: Arévalo—V J. A. , Samaniego—V. F. , López—C. F. F. , Urquieta—S. E. 
Published: December 2007

Abstract
This paper presents the results of a study performed to evaluate nitrogen injection in the offshore Akal oil reservoir. It includes a geological description, measurement of physical properties, model development, mechanistic studies, and three dimensional compositional simulations. Nitrogen injection is being evaluated as a way to accelerate and increase oil recovery, through an improvement of the gravity drainage, main producing mechanism in this reservoir, and by pressure maintenance purposes.
Synthetic-Based Fluids Enhance Environmental and Drilling Performance in Deepwater Locations
Authors: Zevallos Manuel A. Legendre , Candler John , Wood J. Hooker , Reuter Larry M. 
Published: December 2007

Abstract
Deepwater drilling in the Gulf of Mexico is a challenging opportunity for drilling fluid performance. Synthetic-based muds (SBMs) applied in the Gulf of Mexico have overcome performance shortfalls of currently available water-based and oil-based muds. This paper will compare environmental, health, and drilling performance factors of polyalphaolefins (PAO) and internal olefins (10) SBMs with emphasis on rheological profiles, acute toxicity, benthic toxicity, bioaccumulation, and biodegradation rates. Field case histories of PAO and 10 SBMs used in deepwater projects are compared to water-based muds (WBM) and oil-based muds (OBM).
Prediction of Rheological Behavior of Ester-Based Drilling Fluids under Downhole Conditions
Authors: Hemphill Terry 
Published: December 2007

Abstract
The accurate prediction of drilling fluid rheological behavior under downhole conditions has become increasingly important, especially on highly-deviated and extended-reach wells drilled with invert emulsions. On these wells, hole cleaning and cuttings suspension parameters should be maintained within optimum ranges for best results, and firm control over unnecessary increases in annular pressure losses and Equivalent Circulating Densities (ECDs) must be exercised. Rather than calculate downhole hydraulics using surface data, more accurate simulation of fluid properties downhole should be used.
Rheological tests that simulated field conditions were run in the laboratory on an ester-based drilling fluid from the field. The rheological behavior of the fluid was tested under varying ranges of temperature, pressure, and ester/water ratios. A predictive downhole rheological model of the ester-based drilling fluid was constructed using over eight hundred (800) fluid viscosity measurements. Using the surface rheological measurements and downhole temperature and pressure, the computer algorithm rapidly calculates fluid properties under the specific downhole conditions.
Design and Application of Brine-Based Drilling Fluids
Authors: Swartwout R. , Pearcy R. 
Published: December 2007

Abstract
The oil & gas industry has evolved a new class of drilling systems designated for the drilling of the pay-zone sections of wells. In addition to high angle drilling operations, these fluids are now being utilized for underreaming and workover type operations where formation protection is of major concern. As compared to typical drilling fluids, these fluids are unique in that they are brine based and designed to not only fulfill requirements desired for drilling operations but are also essentially non-damaging to the production zone.
Brine based drilling fluids have become one of the most widely utilized systems for the drilling of the productive interval due to their ability to protect the formation while drilling.1 These fluids are formulated with a brine as the liquid phase, selected bridging solids and polymers. The brine liquid phase may be composed of NH4Cl, KCl, KBr, HCOOK, NaCl, HCOONa, NaBr, CaCl2, CaBr2 and ZnBr2 as single or multiple salt solutions. Bridging solids can be water soluble or acid soluble. Selected polymers are added to provide proper suspension and desired Theological properties.
Criteria used to properly design brine based fluid for specific drilling operations will be discussed. Proper formulation of a selected drilling fluid will take into consideration well hydraulics, formation compatibility and completion strategy. Proper selection of the base brine, bridging solids and polymers should result with an optimum drilling fluid that minimizes formation damage.
Downstream Gas Opportunities in Mexico
Authors: Flores Eduardo E. 
Published: December 2007

Abstract
Speaking for myself and on behalf of Mr. Ignacio Pichardo, the Secretary of Energy, I would like to extend to you a warm welcome to Mexico and to this beautiful and historical city of Villahermosa, Tabasco.
As you probably know, the natural gas industry in Mexico was managed and operated by the State with very limited access to the private sector. What this meant was that there was neither private ownership of pipelines nor distribution systems, very limited private investment and restrictions on free trade of the commodity.
As of June, 1995, we have new regulations regarding transportation, storage, and distribution of natural gas with private ownership of pipelines and distribution systems explicity allowed. There are no longer any restrictions on imports of natural gas, thus ending the Petroleos Mexicanos monopoly in this particular area.
Environmental Cost Criteria for Exploration and Production
Authors: Parums A. M. , O'Leary H. E. 
Published: December 2007

Abstract
The objective of this study is to assemble, in a rational, comparable format, typical costs per tonne for reducing E&P emissions and discharges to the environment.
The aim of the study was to provide a rationale for helping BP's upstream business to target spend most efficiently in response to environmental, concerns. Economic evaluation is only one of the factors in deciding whether to implement an environmental improvement – other considerations may include regulatory compliance, community concerns and operational benefits.
The environmental issues covered are (i) oil discharges to sea from produced water and drill cuttings (ii) hydrocarbon emissions to air – VOC's & Methane (iii) combustion emissions – NOx and CO2.
Optimizing Cuttings Circulation in Horizontal Well Drilling
Authors: Martins A. L. , Sá C. H. M. , Lourenço A. M. F. , Campos W. 
Published: December 2007

Abstract
The action of stopping drilling to circulate the cuttings out of the well is always a point of controversy among oilfield teams. The practice of circulating periodically the hole may avoid several operational problems during the drilling of a horizontal well. On the other hand, if hydraulic minimum requirements for the cuttings bed removal are not achieved, circulation can be ineffective, time consuming and, in some cases, detrimental to wellbore stability. This paper presents a series of large scale lab experiments which aimed at the investigation of the erosion of a cuttings bed deposited on the lower part of a horizontal annular section. A group of correlations, based on the experimental data, was developed to predict bed height and critical flow rate for bed removal as functions of several independent variables. The proposed methodology, coupled with a cuttings transport numerical simulator, is an useful tool for programming effective circulation of a cuttings bed.
A Method for Simplifying Field Application of ASP Flooding
Authors: French Troy R. 
Published: December 2007

Abstract
An injection strategy that should simplify field application of the ASP (alkali/surfactant/polymer) process was developed. Additionally, this procedure should be useful for increasing oil recovery from on going polymer floods. Process design was accomplished with computer simulations which were supported with laboratory experiments. Small slugs of concentrated alkali and surfactant, which were diluted by in situ mixing, produced suitable conditions for ultra-low IFT (interfacial tension) at the leading edge of a larger polymer slug.
Computer simulation was used to determine diffusion/dispersion parameters so that the degree of in situ reservoir mixing of small chemical slugs could be predicted. A three-dimensional, three-phase, reservoir simulator was used for simulation. The derived diffusion/dispersion coefficients were used for chemical flooding simulations, and the simulation predictions were verified with laboratory core floods. Coreflood effluent compositions matched computer simulation predictions.
When followed with polymer, injection of small, concentrated, slugs of alkali and surfactant mobilized as much oil as injection of larger, more dilute, slugs of alkali/surfactant. This procedure should simplify field application of ASP flooding because very small slugs of alkali and surfactant can be easily handled and injected in an oil field. It was also shown that injection of small slugs of alkali and surfactant during an on going polymer flood should improve oil recovery significantly. An additional 23% PV of oil was recovered when small alkali and surfactant slugs were injected during polymer flooding.