bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Oil and Gas Companies
Authors: Choudhary Bijoy K. 
Published: December 2007

Abstract
Acquisition plays an important part for most companies in their continued growth, expansion and diversification. Oil and gas companies are no exception. There are numerous methods and yardsticks for evaluation of oil and gas properties and/or companies. The aim, in each case, is to arrive at a fair market value of the properties based on the information available.
A systematic approach is presented here for a quick, easy and accurate evaluation of an oil and gas company. The criteria of profitable acquisitions lie in understanding the basic concepts of discounted cash flow, rate of return, etc. Two computer programs are described - one to evaluate oil and gas properties and the other to analyze financial state of the company. Income tax, write-offs, cost of money, etc., should also be considered before reaching a final value.

Introduction
Very few papers have been published on the evaluation of oil and gas companies from the engineer's point of view. The papers cover only a general outline of the procedure to be followed. The details are not spelled out.
This paper presents a brief discussion into all aspects of engineering and financial evaluations of oil and gas companies. One does not have to have a strong financial background to understand, to interpret and to make intelligent use of the financial data available on a company. The subject matter is described in three parts, namely, engineering evaluation of the properties, financial analysis of the company and consideration of some of the other factors.
PROPERTY EVALUATION This is the first step of any evaluation of an oil and gas company. To arrive at a fair market value of its properties, the reserves of oil and gas are estimated and a reasonable production forecast is made. The geological production forecast is made. The geological and engineering considerations take into account location of the field, type of structure, net pay, type of formation, past performance, pay, type of formation, past performance, productive capacity of the wells, recovery productive capacity of the wells, recovery schemes, e.g., waterflood, gas injection, different types of solvent flood, thermal recovery methods, etc. The future production forecast depends on domestic demand, exports, etc. For example, in Alberta, Canada, the Energy Resources Conservation Board sets the allowable based on demand for oil in Canada and exports to the U. S.
Risk Analysis - An Aid in Evaluating Reservoir Development Alternatives
Authors: Goodknight R.C. , Thachuk A.R. 
Published: December 2007

Abstract
In this paper we present an exposition of Risk Analysis as it is applied to a reservoir development problem, mention the statistical notions involved, compare the work required to obtain a Risk Analysis versus a Conventional Cash Flow Analysis, and compare results for a reservoir development application.
The vehicle for the presentation is a reservoir development decision couched in terms familiar to the audience. The problem at hand is to decide whether or not to invest in a waterflood. We determine those additional data that are available to the decision maker using Risk Analysis to quantify the profitability of his alternatives as compared to results available using Conventional Cash Flow Analysis.
With the aid of a reasonably flexible computer program, the benefit of a Risk Analysis applied to a reservoir development decision can be obtained at practically no additional cost for analysis. Considering that significant cost is usually involved in the gathering of data and the definition of the relationships among the factors influencing a reservoir development decision, the additional quantification due to Risk Analysis has a very high return on the work involved.

Introduction
The thesis of this paper is that Risk Analysis is a simple extension of conventional profitability analysis, that the incremental profitability analysis, that the incremental cost of Risk Analysis is relatively small and that the rewards are relatively large. Our approach will be to define conventional profitability analysis and Risk Analysis for profitability analysis and Risk Analysis for the purposes of this paper, to present the one concept required in order to extend a conventional profitability analysis into a Risk Analysis, and to present an example application.
Optimizing Mature Oil Fields Through the Utilization of Alternative Artificial Lift Systems
Authors: Eson Rod 
Published: December 2007

Abstract
As producing oil and gas properties mature, the nature of the produced fluids change. Water cuts often increase, gas volumes and gas quality change, reservoir pressures decline and mechanical problems generally increase due to the advancing age of the wells. As a result, the artificial lift system initially selected for a well, lease and/or field may not be the most efficient as a field matures. However, once an operator has paid the capital to install artificial lift, many times the lift system in place is simply adjusted in an attempt to meet the changing well production characteristics. The following describes the effort of a progressive thinking, independent oil and gas producer in the re-evaluation of an artificial lift system in a field developed by an urban drillsite. The producing environment of the drillsite requires that special attention be given to the size, electric consumption and potential noise generated by the artificial lift systems being evaluated.
Not only is the process of evaluating specific artificial lift methods to be utilized for a given well described herein, but also how each wells production can effect the operation of an urban drillsite. As properties mature, and especially if they change ownership, operators tend to make changes to existing lift systems and process facilities. As a result, often times a property is inefficiently operated, which can lead to premature abandonment. It is demonstrated herein, that a superior approach to maintaining the status quo is to consider the best method of lift and fluid processing for current, and anticipated future production trends. In this way, the unit cost of producing the two urban drillsite described herein was reduced by nearly 75% which increased reserves by more than 2000%. The urban drillsite described is located in the Rideout Heights area of the Whittier field.
Origin and Maintenance of Abnormal Pressures
Authors: Louden Lester R. 
Published: December 2007

Abstract
A review of the origins of pressures and a restatement of the definition of abnormal pressures is presented. Geologic interactions are presented as supporting evidence for the basic origins. A discussion of the various geologic maintenance theories are presented with supporting evidence.

Text
The term "abnormal pressure" through general usage has come to mean higher-than-normal pressure encountered in the earth's crust while drilling. Some have defined these pressures as geopressures.
Normal is defined as the lithology gradient for a salt water basin. If so, we must accept any deviation from 0.465 psi/ft of depth as abnormal. Therefore, any fresh water or brackish water deposition must be called abnormal. There exists a normal for every geological setting, but since we drill far more wells in sediments associated with sea water deposition, 0.465 psi/ft of depth will be used as normal in this discussion.
Enhancing Frac-Pack Evaluations With Directional and Spectral Gamma Ray Measurements
Authors: Gadeken L. L. , Fox P. A. , Brumley J. L. , Wehunt C. D. , Thurston F. K. , Nasution R. D. 
Published: December 2007

Abstract
The effectiveness of frac-pack operations can be easily monitored by using radioactive tracers. The fluid and solid components of materials placed downhole can be tagged with different gamma-ray-emitting isotopes. After the pumping operations have been completed, specialized gamma ray logging sondes can be run in the well to establish the precise locations of the tagged materials. Directional gamma ray measurements determine the azimuthal placement distributions. Gamma ray spectral energy measurements allow the contributions of individual isotopes to be separated so that the vertical extent and radial displacement efficiency of the individual components pumped can be established.
This technology can be used to evaluate frac-packs and most other downhole placement operations. The knowledge of where materials are actually placed during downhole pumping operations provides unique diagnostic information. This allows subsequent operations to be improved and made more effective as necessary.
This paper reports on frac-pack operations in the shallow, unconsolidated sands of the Duri field in Indonesia. Gamma ray spectroscopy and directional gamma ray logs were run in several wells as part of a study to determine frac-pack performance.
The gamma ray directional logs show a number of significant asymmetries where sand was apparently placed on one side of the wellbore. There was some evidence of "ballooning" in several zones where the frac-pack pushed the formation sand away from the borehole. The gamma ray spectroscopy logs offered supporting evidence which was confirmed by additional laboratory analysis. The interpretation of all the gamma ray log results confirmed the frac-pack operations. The log results also provided evidence regarding the detailed manner in which the frac-pack was placed and gave rise to some adjustments to enhance frac-pack procedures.
This project demonstrated that frac-pack technology resulted in increased oil production and utilization of frac-pack operations will continue. However, maintenance requirements were not reduced as much as desired because of proppant flowback. Methods for further reducing costs are being investigated.
Applying NMR Total and Effective Porosity to Formation Evaluation
Authors: Coates George R. , Menger Stefan , Prammer Manfred , Miller Miller 
Published: December 2007

Abstract
The porosity of a reservoir and its water saturation fraction have long been at the heart of wireline and MWD log based formation evaluation. In many formations, however, the complexity of the mineralogy and the properties of the formation's conductivity have only permitted qualitative answers. This has even been true with evaluations based on multi-log data suites.
At the 1996 SPE Conference a new NMR logging process, the MRIL®* C/TP system, was introduced. C/TP provides a measure of total porosity independent of mineralogy and dependent only on the hydrogen density of the fluids themselves.
This represents a significant advantage over the conventional density, neutron, and acoustic ‘porosity’ logs, which mostly respond to rock properties. Furthermore, the C/TP amplitude can be subdivided into pore size groups associated with clay mineral bound water, capillary bound water and pores free to accumulate hydrocarbon (FFI).
Usage of the MRIL has proven the benefit of a borehole-centralized log, a feature that makes it largely independent of borehole size and shape. It has also become recognized as the first porosity log that truly measures the pore system and not some inference of porosity based on the rock matrix.
Thus the log analyst is provided with a wireline log that is truly a porosity log which provides a quantitative measure of total and effective porosity.
To investigate the accuracy and reliability of these methods and ideas, well bore data are assembled and compared to conventional log and core results. A full description of these comparisons and processes are included to show the benefit of a true porosity measurement that is insensitive to matrix mineralogy and only depend on pore size and fluid contents,the advantage of a porosity measurement largely independent of borehole condition.
Paraffin Deposition from Crude Oils: Comparison of Laboratory Results to Field Data
Authors: Hammami Ahmed , Raines Michael A. 
Published: December 2007

Abstract
In this study, we evaluate the characteristics of four reservoir fluids sampled from two offshore fields in the Gulf of Mexico as well as their propensities towards paraffins deposition due to temperature and/or pressure variations. State-of-the-art techniques, namely a cross polarized microscopy (CPM) and a laser-based solids detection system (SDS), have been used to measure the onsets of paraffin crystallization temperatures, also known as wax appearance temperatures (WAT) and/or cloud points. The results are presented, discussed and compared to reported field data. Explanations for the observed differences and/or similarities between laboratory and field WAT are proposed.
Effect of Water Breakthrough on Sand Production: Experimental and Field Evidence
Authors: Skjærstein Anne , Tronvoll Johan , Santarelli Frederic J. , Jøranson Håvard 
Published: December 2007

Abstract
It has been reported from different field operators that the onset of sand production in a particular field coincided with water breakthrough at the production wells. Several mechanisms have been proposed to explain these observations such as pore pressure gradient increase near perforations due to relative permeability effects, reduced capillary bond due to increased water saturation, and loss of rock cohesion because of chemical incompatibility between produced water and the reservoir rock.
Yet, there does not seem to exist any systematic study of such a phenomenon on a large scale, neither capable of supporting any of the proposed mechanisms nor the statement that the onset of water breakthrough may trigger the onset of sand production.
As a consequence, a vast campaign of physical model experiments of perforation cavities using field and outcrop material was undertaken to observe directly the effect of water breakthrough upon the onset of sand production. The experiments, have convincingly demonstrated that the two phenomena could not be linked directly, but that once sand production has initiated, water production could accelerate the sand influx thus making it more noticeable and problematic for daily operations.
Finally, the problem of the coincidence of water breakthrough and onset of sand production has been analysed on a series of more than 40 oil and gas wells in weak sand reservoirs. This analysis of field data further confirms the laboratory and theoretical findings described in the paper.
Hello, This is Your Gas Well Calling
Authors: Maloney D. R. , Haley J. W. 
Published: December 2007

Abstract
Imagine being able to survey production from gas wells while at home, the office, or even while traveling. Think of the advantages of a system that automatically calls soon after an alarm condition is detected at a site. A measurement and communication system that provides these services is already in operation in New Mexico, Oklahoma, Texas, and a portion of Kansas.
This paper describes GPM Gas Corporation's innovative electronic gas flow measurement, telemetry, and telecommunications system. It can provide hourly measurements from over 17,000 electronic flow measurement (EFM) meters, which track the delivery of over 1.9 billion cubic feet of gas each day through more than 26,000 miles of gathering lines. Users have many options for obtaining gas rate, pressure, and temperature data, including automated voice reports over the phone, fax services, and data downloads from the database and network. The system simplifies many functions such as gas rate measurements, custody transfers, compensation, and scheduling of field services, allowing producers and GPM to take advantage of near real-time information for optimizing operations and reducing costs.
The system serves as an excellent example of how telecommunications can improve operations through integrating data collection and information management.
Thermodynamic Micellization Model for Asphaltene Precipitation from Reservoir Crudes at High Pressures and Temperatures
Authors: Pan Huanquan , Firoozabadi Abbas 
Published: December 2007

Abstract
Asphaltene precipitation from reservoir crudes has been modeled using liquid-liquid equilibrium; the precipitated heavy phase is assumed to be in the liquid state and to consist of only asphaltene and resin. The light liquid phase is assumed to consist of the monomers of all the components and the micelles. A thermodynamic micellization model and the Peng-Robinson equation of state (EOS) description of all monomers fully specify the thermodynamic equilibrium state. From the direct minimization of the Gibbs free energy of the liquid-liquid system, the composition and the amount of each of the phases are calculated.
The above model is used to calculate precipitation from three different reservoir crudes. Once vapor-liquid equilibrium parameters are obtained, there is no further adjustment of the parameters of the EOS for precipitation calculations. The predictions from the thermodynamic micellization model are in good agreement with data. The effect of pressure, temperature and composition on precipitation is properly predicted by the model.
Coupling Fluid-Flow and Geomechanics in Dual-Porosity Modeling of Naturally Fractured Reservoirs
Authors: Chen Her-Yuan , Teufel Lawrence W. 
Published: December 2007

Abstract
The purpose of this study is to formulate a coupled fluid-flow/geomechanics model of a naturally fractured reservoir. Fluid flow is modeled within the context of dual-porosity (more generally, overlapping-continuum) concept while geomechanics is modeled following Biot's isothermal, linear poroelastic theory. The development follows along the line of the conventional and existing porous fluid-flow modeling. The commonly used systematic fluid-flow modeling is therefore preserved. We show how the conventional fluid-flow dual-porosity formulations are extended to a coupled fluid-flow/geomechanics model. Interpretation of the pore volumetric changes of the dual continua, fractures and matrix-blocks, and the associated effective stress laws are the most difficult and critical coupling considerations. New relations describing the dual rock volumetric changes are presented. These relations allow a smooth and consistent transition between single-porosity and dual-porosity concepts and are in terms of measurable quantities. Reduction to the single-porosity is presented to demonstrate the conceptual consistency of the proposed model.
Inflow Performance and Transient Pressure Behavior of Selectively Completed Vertical Wells
Authors: Yildiz T. , Cinar Y. 
Published: December 2007

Abstract
This paper presents new methods to estimate the inflow performance and transient pressure behavior of selectively completed vertical wells. In the first part, inflow performance of wells perforated at several intervals along the producing formation is investigated experimentally and theoretically. Theoretical investigation is based on an analytical solution. An arbitrary number and pattern of open intervals with different skin values are considered in the analytical model. An electrical analog was constructed to verify the productivity model. The productivity model compared very well with the experimental data obtained from the electrical analog apparatus. The parameters controlling well productivity are identified through a sensitivity study. Well completion strategies to achieve optimum well productivity are discussed. It is observed that formation anisotropy, total perforated length/formation thickness ratio, and mechanical skin distribution due to formation damage are the parameters controlling the well productivity.
In the second part, transient pressure and pressure-derivative response of selectively perforated wells are modeled and examined. The wellbore storage effect and non-uniform skin effect are included. A new interpretation technique which combines the conventional semilog straightline analysis and type-curve matching method is presented to determine reservoir parameters. It has been observed that the effective mechanical skin is a time-dependent parameter. In case of selectively completed vertical wells, pseudoskin is interrelated to mechanical skin distribution due to formation damage around the wellbore. If rate distribution along the wellbore is available from production logging, horizontal and vertical permeabilities, total skin factor and its components, effective mechanical skin and pseudoskin, can be determined uniquely. The proposed interpretation technique is used to analyze the well test data.
Huff-n-Puff Technologies for Water Production Control: Analytical Reservour Modelling
Authors: Holleben Carlos , Bedrikovetsky Pavel 
Published: December 2007

Abstract
The injection stage of huff-n-puff polymer process is described by the traditional model for polymer flooding. During the production stage, the irreversibly adsorbed polymer is trapped by the reservoir oil, and the amount of polymer trapped by oil is an additional unknown for the mathematical model of the process. So, the traditional model is not applicable any more. Laboratory tests performed show that the trapped polymer can significantly reduce the permeability for oil. A new mathematical model for the polymer huff-n-puff process honouring the adsorbed polymer trapped by the reservoir oil, is developed. 1-D models for huff-n-puff processes have been developed for cases of the use of oil and of polymer as displaced fluids.
Short Radius Directional Drilling, when Combined with Project Planning, Drilling Efficiency and Geosteering, is a Valuable Production Enhancement Tool
Authors: Nitis Ike , Askew Warren 
Published: December 2007

Abstract
Short radius drilling has not yet reached its full potential in the global market. To prepare for the perceived increase in activity for this technique, systems have been developed to adapt to a variety of hole conditions and target requirements. The systems, designed around positive displacement mud motors and a flexible MWD, have been successfully deployed in many areas of the world.
Drilling the short radius well efficiently is only one aspect of an integrated series of events, all of which must be orchestrated and performed correctly to guarantee the financial success of the project. Particularly in areas where short radius and re-entry drilling is a new experience, the directional driller, as the technical driver, is involved in aspects of the planning and operation which traditionally are not in his domain.
This paper reviews the development and status of the short radius drilling systems, and discusses related operations which affect the outcome of the project.
Using Concrete Technology to Improve the Performance of Lightweight Cements
Authors: Moulin Eric , Revil Philippe , Jain Bipin 
Published: December 2007

Abstract
To successfully cement across and isolate formations with low fracture gradients requires the use of lightweight cement slurries. Conventional lightweight slurries usually have a high water-to-solid ratio, which results in long waiting-on-cement times, limited compressive strength development, and a relatively permeable cement sheath subject to acid and brine attack. A new approach to designing cement slurries effectively decouples the physical properties of set cement from the slurry properties and density, resulting in high performance lightweight cement slurries that reduce rig time and the logistics and costs associated with using conventional slurry designs. This has been clearly demonstrated in the cases of completing in reservoirs with a low fracture gradient (eliminating the risk of block squeeze), replacement of two-stage cement jobs by a single stage, and the use of a single slurry to replace lead/tail cement and side-track plugs. Results are described from various field applications where the technology has been used.