bluuebunny/crossref_metadata_2025_split huggingface dataset:
Engineering Applications for Integrated Reservoir Characterization
Authors: Ehlig-Economides Christine A. 
Published: December 2007

ABSTRACT
With data acquisition at many scales, comprehensive databases, and integrated data visualizations, a much more realistic understanding of the implications of reservoir characterization on production is emerging. This paper provides a multidisciplinary overview of four tasks: reservoir delineation, reservoir modeling, production optimization, and uncertainty analysis. Each of these tasks highlights specific engineering applications. An overview is provided of geophysical, geological, and petrophysical approaches that engineers need to understand in order to communicate effectively with geoscientists. Flow units and compartments are the key elements used in this paper to relate the reservoir characterization provided by geoscientists to what is needed by engineers. These two concepts enable engineers and geoscientists to develop a common view of what various disciplines can reveal about a reservoir.
Applications for integrated reservoir characterization include improving drilling and completion locations, optimizing well productivity, and enhancing recoverable reserves. An integrated reservoir characterization focused on flow units and reservoir compartments amplifies considerably what can be understood from conventional engineering techniques, including reserves estimation, material balance, production data analysis, and fluid flow simulation.
Examples from field studies demonstrate results derived from integrated reservoir characterization that would not have been apparent from conventional engineering methods.
Quantitative Description for the Heterogeneity of Pore Structure by Using Mercury Capillary Pressure Curves
Authors: Pingping Shen , Kevin Li , Fenshu Jia 
Published: December 2007

ABSTRACT
Pore structure of reservoir rock is one of the most important factors to affect microscopic oil and water flowing in porous media and the development efficiency of an oil field developed by water injection. There are now many methods for describing pore structure. However, much attention is being paid to develop better and more efficient methods. Fractal dimension has been used to quantitatively describe the heterogeneity of pore structure in this paper. It has been showed that the larger the fractal dimension of pore structure, the more heterogeneous the pore structure for sandstones, sandstones with gravel and pinhole dolomite rocks. The fractal dimension of pore structure is calculated from the mercury-injection capillary pressure curve of the rock.
The typical two-section fractal behaviour of sandstone pore structure in Lamadian Oilfield, Daqing has been studied in this paper. It has been found that there is a good correlation between the fractal dimension of large pores with fractal behaviour and the oil recovery at water breakthrough while there is also a good relationship between the fractal dimension of the small pores with fractal behaviour and irreducible water saturation. This shows that the large fractal pores affect the amount of oil recovery at water breakthrough and the small fractal pores affect the amount of irreducible water saturation for this type of sandstones from Lamadian Oilfield. It has also been found that there is no relationship between the fractal dimension of pore structure and the oil recovery at water breakthrough if the pore structure of sandstone from Lamadian Oilfield was treated as one-section fractal structure.
Polytropic Flow Of Natural Gas In Vertical Pipes
Authors: Adair John K. , Power Harry H. 
Published: December 2007

A method is presented for calculating the flowing bottom hole pressure in natural gas wells using a polytropic equation of state. The polytropic equation is based on an empirical exponent and is determined by using the point functions of pressure P, temperature T and compressibility factor Z at the terminals of the vertical flow string.
A comparison of calculated and field measured results were made on gas well data presented in the literature. The average percent deviation between the calculated and observed flowing bottom hole pressures was 0.416.
The polytropic method may use any compressibility factor correlation applicable to the fluid under study, which is important when the amount of inerts is appreciable.
An example demonstrating the polytropic method is presented-using friction factor correlations which are based on an absolute pipe roughness of 0.0006 in.
New Analysis Method for the Vertical Fracture Well
Authors: Yue-wu Liu , Ci-qun Liu 
Published: December 2007

ABSTRACT
The pressure transient behavior of hydraulically fractured wells has been the subject of considerable study over the recent years. Several investigators have presented solutions of the fundamental equations, identified qualitative diagnostic trends and suggested integral techniques. This paper presents a new method to solve the problem of analysis of well test data of the hydraulically fractured well.
The new mathematical model for the vertically fractured well in the dual-porosity and homogeneous reservoirs was founded by using the elliptic flow model and the integral method of conservation mass. The solution for the new model was obtained in real space. The type curves for the vertically fractured well in both homogeneous and dual-porosity reservoirs with and without wellbore storage and skin effect were calculated. In order to consider the wellbore storage and skin effect, the techniques of Laplace numerical transformation and Laplace numeral inversion were used. The special results for homogeneous reservoir have been identified by compared with the results of other authors, such as the infinite conductivity solution of A.C. Gringarten, the finite conductivity solution of H. Cinco-ley and the finite conductivity solution of M.J.Economades which considered the wellbore storage. They all have the same identities. Two field examples are used to illustrate the use of the new method.
The characteristics of the type curves for both homogeneous and dual-porosity reservoir are described. For the dual-porosity reservoir, the type curve presents seven flow periods: the wellbore storage controlled period, the skin effect controlled period, the bilinear flow period, the first transient period, the dual-porosity characteristic flow period, the second transient flow period, and the radial or pseudo-radial flow period.
The solutions have the following advantages: The solution may be used for both homogenous and dual-porosity reservoirs, and for both infinite and finite conductivity vertical fracture. The range of the dimensionless conductivity is from 0.001 to 500. Even more, the type curve is quickly calculated by using this method than any others. The new sets of type curves can be directly used in the oil field.
Water-Oil Capillary Pressure and Wettability Measurements Using Micropore Membrane Technique
Authors: Longeron Daniel , Hammervold Wibeke L. , Skjaeveland Svein M. 
Published: December 2007

ABSTRACT
This paper describes a new technique to simultaneously measure the capillary pressure curves and wettability indices for an oil – brine – rock system. By improving the porous plate method, the full cycle of four capillary pressure curves, i.e. spontaneous and forced drainage and imbibition, is measured in days instead of months. This is achieved by the use of thin oil- and water-wet micropore membranes and short samples with large diameter.
Measurements have been done on sandstone and carbonate cores with wettabilities ranging from strongly water-wet to oil-wet. A reduction in experimental time by a factor of 10 or more is gained by the new method for a full cycle of the four capillary pressure curves.
In addition, a new measure of wettability is suggested as an improvement of the USBM test, incorporating all four areas between the capillary pressure curves and the saturation axis. The new wettability index may be conceived as an extension of the Amott test, with the four saturation intervals weighted by the corresponding areas under the capillary pressure curve and may better discriminate between mixed-wet and spotted-wet samples.
Prediction on the Reasonable Flow Rate and Productivity of Single Well in the Gasfield of Central Shan-Gan-Ning Basin
Authors: Keqiang Yu 
Published: December 2007

ABSTRACT
According to the productivity equation established by the modified isochronal test (MIT) in the Gasfield of Central Skan-Gan-Ning Basin, the gas well type curve can be generated and the reasonable flow rate of a gas well can be known from the curve. The correlation between reasonable flow rate and absolute open flow potential (qAOF) is also established. The statistic analyses of the correlation between qAOF and kh from the well test and between qAOF and the coefficient b in the binomial productivity equation have been done with this study and the correlations between them have therefore been set up. By using the correlations, the productivity of the new well can be forecasted.
Experimental Measurement of Coal Matrix Shrinkage Due to Gas Desorption and Implications for Cleat Permeability Increases
Authors: Seidle John P. , Huitt L. G. 
Published: December 2007

Abstract
Coal is not an inert reservoir rock and reacts to gas des-orbed from its surface. Coal matrix shrinks as gas is desorbed, increasing cleat width and, therefore, permeability. Very few coal matrix shrinkage data have been reported in the literature so a series of experiments was undertaken to measure such data at reservoir pressures, temperatures, and 100% relative humidity. Strain gages were affixed to the coal sample in the face and butt cleat directions as well as the vertical direction. This work reports measured deformations of a sample of high volatile C bituminous coal from the San Jan Basin during sorption and desorption of first methane then CO2. A pressure cycle was also run with helium, a nonsorbing gas, to determine mechanical compliance of the sample. Observed strain gage behaviors are discussed and shrinkage coefficients for both gases reported. Matrix shrinkage was found to correlate with gas content rather than pressure, confirming the work of a previous investigator. Shrinkage coefficients varied more among replicate gages aligned in the same direction than between gages in different directions. Anisotropic shrinkage effects are discussed. Using a matchstick geometry model, equations are derived for permeability change due to matrix shrinkage. Coefficients reported here are used in example calculations of absolute permeability and porosity increases during coalbed depletion.
Net Present Value Probability Distributions From Decline Curve Reserves Estimates
Authors: Simpson D.E. , Huffman C.H. , Thompson R.S. 
Published: December 2007

D. E. Simpson, C. H. Huffman, and R. S. Thompson
SPE Members

Abstract
This paper demonstrates how reserves probability distributions can be used to develop net present value (NPV) distributions. NPV probability distributions were developed from the rate and reserves distributions presented in SPE 28333. This real data study used practicing engineer's evaluations of production histories. Two approaches were examined to quantify portfolio risk. The first approach, the NPV Relative Risk Plot, compares the mean NPV with the NPV relative risk ratio for the portfolio. The relative risk ratio is the NPV standard deviation () divided the mean () NPV. The second approach, a Risk - Return Plot, is a plot of the discounted cash flow rate of return (DCFROR) versus the a for the DCFROR distribution. This plot provides a risk - return relationship for comparing various portfolios. These methods may help evaluate property acquisition and divestiture alternatives and assess the relative risk of a suite of wells or fields for bank loans.

Introduction
Reserves acquisition and divestiture decisions are based on many factors including corporate strategy, risk, the company's financial position and cash flow requirements. The value of a prospective acquisition or divestiture is uncertain since it depends on factors such as future oil prices, production rates, and discount rate that must be estimated. To quantify risk, NPV probability distributions were developed from the rate and reserves distributions presented in SPE 28333, "Probability Ranges for Reserves Estimates From Decline Curve Analysis."
Two approaches were examined to quantify portfolio risk. The first approach, the NPV Relative Risk Plot, compares the mean () NPV with the NPV relative risk ratio for the portfolio. The relative risk ratio is the NPV standard deviation (a) divided the NPV. The second approach, a Risk - Return Plot, is a plot of the discounted cash flow rate of return (DCFROR) versus the a for the DCFROR distribution. This plot provides a risk - return relationship for comparing various portfolios.
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A Method for Characterizing Costs and Benefits of Future Regulatory Requirements on the U.S. Natural Gas Industry
Authors: Godec M. L. , Becker A. B. , Smith G. E. , Pauling Gene 
Published: December 2007

Abstract
At the same time that natural gas is being promoted as an environmentally preferred fuel with expectations of rising use, future environmental requirements may constrain U.S. supplies. A desire to reconcile contradictory environmental objectives has led the U.S. natural gas exploration and production (E&P) industry to call for a better understanding (and better balancing) of the costs and benefits of environmental requirements that may confront it.
The use of systematic "cost/benefit analyses" is one approach that many claim can assist in characterizing explicitly and quantitatively (and ultimately balancing) the environmental and economic impacts of environmental initiatives. This paper presents a methodology, currently under development by the U.S. Department of Energy (DOE), that could allow the costs and benefits associated with alternative environmental compliance requirements affecting natural gas E&P operations to be more systematically and comprehensively analyzed within a total market context, while still accounting for the site-specific geological and engineering aspects affecting operator economic decision-making. Through presentation of this developing analytical capability, the authors hope to begin a dialogue on potential methods for considering the costs and benefits of proposed future environmental requirements on the U.S, gas industry.
An Analysis of Forecasts of Energy Supply, Demand, and Oil Prices
Authors: Skov Arlie M. 
Published: December 2007

Abstract
Throughout the history of the oil and gas industry, forecasts have been made of energy supply, future rates of production, energy demand and of oil prices. These forecasts are used for a wide variety of purposes including the oil industry itself, financial institutions, public policy planners, nations, and groups of nations (OPEC).
Most forecasts are incorrect after only a few years, but they are often updated without a fundamental under-standing of why the earlier predictions were in error. This leads to painful disruptions and redirections not only within the oil industry but also in public policy debates and decisions on a national and global scale.
This paper reviews some of the more significant forecasts of energy supply, demand, and oil prices made in the last 25 years, and identifies the basic premises used and why they led to incorrect forecasts. Usually the premises have been too narrowly based. A broader basis is proposed, which includes continuing changes in technology, national goals, public attitudes and environmental concerns. Extrapolation of past trends is a poor basis for forecasts. Hence, a broader understanding of the changing world is essential and must be incorporated meaningfully into forecasts.
Tax Credits Stimulate Gas Drilling Without Decreasing Federal Tax Revenue: A Win-Win Situation
Authors: Cline Scott B. , Stanley Brian J. 
Published: December 2007

Abstract
The long-term U.S. natural gas resource base (1300+ TCF) exists. The challenge is the timely conversion of that resource base to proved, deliverable reserves. Tax credits stimulate the transfer of the natural gas resource base to deliverable proved reserves by effective price enhancement and through the discovery, application, and dissemination of technology. Tax incentives act as net price increases to gas producers as long as all companies have roughly the same tax rate and all are able to utilize the credit. Tax incentives can thus be merged with gas price for statistical purposes. This paper demonstrates how the existence of the §29 credits stimulated drilling, increased relatively clean burning gas reserves, resulted in new technological advances and possibly increased federal tax receipts with no upward pressure on gas prices. New tax-stimulus mechanisms are introduced that will help ensure that tax credits both stimulate drilling and increase tax revenue.
Cost Functions For Oil Well Drilling, Lease Equipment And Well Operation In Texas
Authors: Beike Dieter , Holtz Mark H. 
Published: December 2007

Abstract
Regression modeling of Texas oil well drilling, equipment and operating costs was performed with the price of oil being the only independent variable. Cost functions were established for West Texas and South Texas for three different depth intervals. Cost comparisons were made possible on a regional and depth basis as well as on a process basis (primary vs. secondary recovery operations - the latter for West Texas only). Best results were achieved for mid-range and deeper West Texas oil drilling costs, West Texas secondary lease equipment costs and West Texas and South Texas operating costs.
The Cost of Not Using 3D Seismic Technology: A Case Study
Authors: Walsh P. R. , Borsato R. A. 
Published: December 2007

Abstract
After purchasing a producing gas field from a major Canadian utility, Lagasco completed a 3-D seismic program over the pool to explain discrepancies associated with gas-in-place determinations. Utilizing the Coveny pool as a model, the results confirmed the economic benefits of 3-D seismic technology.
Development and Management of Complex Dulang (E14) Reservoir, Offshore Malaysia: A Simulation Case Study
Authors: Sonrexa Kartikay , Aziz Azly , Bandal Malvinder 
Published: December 2007

ABSTRACT
The Dulang Unit Area covers the central part of the highly heterogeneous Dulang Field which is located offshore Peninsular Malaysia. The Unit Area consists of 19 stacked shaly sandstone reservoirs which are divided into about 90 fault blocks containing multiple fluid contacts. The estimated Original-Oil-In-Place (OOIP) is in the vicinity of 700 million stock tank barrels (MMSTB). Production commenced in March 1991 and is currently maintained at more than 50,000 barrels of oil per day (BOPD). Reservoir simulation is one of the vital tools which has been employed from the very beginning to develop as well as manage this challenging field. This paper documents a case history dealing with the construction of numerical models of two distinct fruit blocks in one of the major reservoirs (E14). The simulation studies led to the consolidation of the development plan as well as reservoir management strategies. They also greatly aided in improving the reservoir characterization.
Arun Field: Model for Successful Gas Development
Authors: Myers S. D. 
Published: December 2007

ABSTRACT
Economically and industrially, the Asia Pacific region is the fastest growing area in the world. Demand for energy to support this rapid expansion is expected to more than double over the next 15 years.
Natural gas, which can be found throughout the Pacific Rim, will play an important and growing role in the years ahead, both to fuel the development of local economies, and as a valuable product for export.
An excellent example of the value that can be achieved from developing and marketing natural gas resources is the Arun Field in North Sumatra, Indonesia. Arun is the largest producing gas field in Indonesia and accounts for nearly one-fourth of today's Pacific Rim LNG trade, together with substantial sales of condensate and LPG. Three local industrial facilites in northern Sumatra also depend on Arun fuel gas for plant operation.
This paper traces the history of Arun through field development, plant construction, and building of infrastructure in a remote and environmentally sensitive area. Focus is on the importance of technology to insure project success — reservoir management, drilling, well completions and highgrading of plant and field facilites to maximize gas sales.
Slim Hole Drilling Technology – Past, Present, Future
Authors: Millheim K. K. , Prohaska M. , Thompson B. 
Published: December 2007

ABSTRACT
Slimhole drilling in one form or another has been used by the mining and construction industry, and the oil and gas industry since the 1940's. Drilling a slimhole borehole is the standard way of drilling for the mining and construction industry. Whereas, the oil and gas industries, in spite of its potential major cost savings, rarely drilled slimhole wells; when they did it, was only because there was no other choice. However, since the late 1980's, the oil and gas industry has been experimenting on a continuous basis with the use of slimhole drilling technology to reduce drilling costs and improve exploration results.
The first part of the paper presents the evolution of slimhole drilling since 1989 from the oil and gas industry point of view. The next section of the paper covers the state of the art of slimhole detailing its technical accomplishments and remaning challenges.
The last part of the paper presents the slimhole drilling system and dynamics that are taking place. From this systems analysis, a view of the future of slimhole drilling is possible. Can slimhole drilling technology drastically reduce cost? Improve exploration? Be used offshore? Can the contracting, service, and manufacturing industries respond and provide slimhole drilling technologies? Will companies be able to change their thinking? All these questions will be discussed in this paper.