bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decline Curve Analysis for Double-Porosity Systems
Authors: Sageev A. , Da Prat G. , Ramey H. J. 
Published: December 2007

ABSTRACT
A type curve matching method for analyzing constant pressure testing in a double-porosity system is presented. Both infinite systems and closed outer boundary systems are considered. Rate responses of constant pressure wells with and without wellbore skin are described.
Five type curves are presented for the rate response of the constant pressure active well. The first four curves describe: (1) An infinite system without wellbore skin, (2) a closed outer boundary system without wellbore skin, (3) an infinite system with wellbore skin, and (4) a closed outer boundary system with wellbore skin. In the fifth type curve, the first four type curves are assembled into one.
A log-log type curve matching method is presented, where the parameters λ, ω, reD, and S are estimated. The parameters λ and ω describe interporosity flow and relative fracture storativity respectively, and τeD and S are the dimensionless size of the system and the wellbore skin respectively. This paper considers only the estimation of these four parameters. The estimations of permeabilities and storativities have been described in the past, hence, are not described in this paper.
It is observed that the presence of wellbore skin has an important effect on the rate response of the double-porosity system. It is essential for the success of the analysis, especially in the determination of λ and reD, to include wellbore skin. The presented analysis method is valid for transient interporosity flow with fracture skin greater than 0.33, with slab-shaped matrix.
Three type curve matching examples are presented along with a discussion of the applicability and practicality of the analysis method.
Computerized Monitoring of Compliance with Environmental Regulations and Permits
Authors: Lyons C. E. , Svoboda L. , Harbert J. M. 
Published: December 2007

ABSTRACT
The steady increase in the number and complexity of government regulations requires that oil and gas production companies find more efficient means to comply with environmental laws while maintaining profitable operations. One major production company has developed a comprehensive computer program to automate compliance with government environmental regulations. The highlights and advantages of this new computer system are described in the following paper.
Steam Quality Measurement in Flow Lines
Authors: Sinclair J. W. , Startzman R. A. 
Published: December 2007

ABSTRACT
This paper presents the results of a small scale experimental program undertaken to investigate critical and subcritical flow correlations between steam quality and pressure. Subcritical flow tests indicate only a general trend exists between steam quality and pressure drop through a venturi. However, for the critical flow of a steam-water mixture in the pressure range of 26 to 69 psia, results indicate a suitable correlation exists between steam quality and upstream pressure. Unlike existing methods for measuring quality, this method is independent of mass flow rate, is insensitive to flow splitting and avoids problems associated with sampling.
Procedural Design Considerations Associated with Tubing-Conveyed Underbalanced Perforating
Authors: Young W. S. , Zaleski T. E. 
Published: December 2007

Abstract
Thirty-two tubing conveyed underbalanced perforating jobs conducted in the Gulf of Mexico between May, 1980, and May, 1982, have been carefully reviewed in order to draw correlations between procedural variations and trouble prone jobs. General procedural guidelines designed to avoid past problems were formulated and are presented. The procedures are designed for the generalized case where the perforating guns will be pulled out of the well in order to gravel pack and not for those run as part of a permanent completion. Careful application of these procedural guidelines has resulted in reducing rig time requirements by an average of 35% on 33 additional tubing conveyed underbalanced perforating jobs conducted subsequent to the establishment of the guidelines contained in this paper.
Design of an Effective Gravel Pack for Sand Control: A Numerical Approach
Authors: Peden J. M. , Russell J. , Oyeneyin M. B. 
Published: December 2007

Abstract
The production of sand associated with oil and gas developments has been a considerable problem in production operations in the recent past. Early investigative work on the subject concentrated upon the mechanisms by which sand production is initiated and in addition how the sand might be restrained from flow into the wellbore by a concentric lining of gravel in the wellbore across the production zone. This research has provided useful guidelines for the selection of gravel for the prevention of sand migration(1,2,3).
Continuous Fracture Probability Determination as Applied to the Monterey Formation
Authors: Grove G. P. , Whittaker J. L. 
Published: December 2007

Abstract
Most openhole logs can be used for fracture detection. Each petrophysical measurement responds to fractures in a different way, and there is a large amount of literature describing the effects of fractures on tool responses. Most fracture detection programs written to date have either used only one or two logs or displayed many fracture indicators, but made little attempt to tie them together.
Since fracture systems appear to provide nearly all the permeability for production in the Monterey formation, fracture analysis is essential throughout the well. A new program has been written to give a continuous output of fracture probability using data from well logs. This method makes use of all the fracture information available from wireline logs, mud logs, and drilling data. Each indicator is used to give an individual probability of fracturing. The program then computes a Continuous Fracture Probability (CFP) log using all the available fracture indicators, where the probability of fracturing is a value between zero and one. It is easily adaptable to specific local conditions (particularly the Monterey formation) through log analyst input. Computed outputs illustrating the use of this method in the Monterey formation are shown, and parameters and data used for input into the program are discussed.
New Core Analysis Techniques for Naturally Fractured Reservoirs
Authors: Bergosh J. L. , Marks T. R. , Mitkus A. F. 
Published: December 2007

Abstract
This paper reviews existing core analysis technology and discusses its limitations when used for the evaluation of naturally fractured reservoirs like the Monterey Formation. New core analysis techniques and equipment are presented which can improve the quality of core analysis data and the results of a core study using these methods are reported.
Some New Techniques in Flow Metering of Steam Injection Rate and Quality in Thermal Recovery Processes
Authors: Pascal H. 
Published: December 2007

ABSTRACT
This paper is a theoretical investigation of two new techniques to be used in metering the steam quality and flow rate in two phase flows of steam and water mixtures in pipelines of steam injection. The first technique is two orifices in series. The performance of this flow system as a possible flow meter in two phase flow is graphically illustrated with regard to the determination of steam quality and flow rate. The second technique is the two-phase critical flow in a convergent-divergent nozzle. The possibility of using a single device, i.e. a convergent-divergent nozzle operating in the critical flow, in determining both the steam quality and flow rate is theoretically demonstrated. The illustration of the critical flow performance, as a possible flow meter in two phase flows of compressible mixtures, steam and water, is shown and discussed. A comparison with experimental data is also shown.
Application of Computers in the Analysis of Well Tests From Fractured Reservoirs
Authors: Barua J. , Kucuk F. , Gomez-Angulo J. 
Published: December 2007

ABSTRACT
Naturally fractured reservoirs have proved to be important in the petroleum industry because of their prolific production behavior. Over the years, considerable effort has gone into evaluating these reservoirs by well tests.
Well tests are particularly important in this case because the reservoir parameters are otherwise difficult or impossible to obtain.
Well tests on naturally fractured reservoirs are not very easy to analyze. However, in the rare case when two or three clear semilog straight lines are present, analysis is straightforward. More often, because of the wellbore storage, the first semilog or possibly all semilog straight lines are obscured. Under these circumstances, the common way to analyze the test at present is by log-log (type-curve) analysis. Log-log analysis always compares poorly with semilog analysis because the logarithm of the pressure drop varies very little as time increases. There are other disadvantages in log-log analysis; e.g., the limited number of curves available on a type-curve and the difficulty of matching buildups.
The pressure-derivative curves enhance the definition of early time data but only provide a limited means of estimating two-porosity reservoir parameters. Clearly, there is room for enhancement in the quality of parameter estimates. Especially now, with the simultaneous use of pressure and pressure-derivative, the need for a general improvement in estimation procedures is felt even more.
This study was directed towards the application of computers to semi-automatically matched field data with the appropriate mathematical models. It shows that even though the computer is a powerful tool, it is also necessary to put in a great deal of human effort in order to obtain good matches.
One published field case is analyzed semi-automatically using computers in the study.
Single-Well and Multiwell Pressure Interference Analysis
Authors: Economides M. J. , Ogbe D. O. 
Published: December 2007

ABSTRACT
The purpose of an interference test analysis is to provide reservoir characteristics such as permeability, porosity and areal extent. Reservoir anisotropy may be identified and measured. A drawback of interference testing is that it requires one or more potentially productive wells to be shut-in. However, this well test is superior to single-well drawdown or buildup because it often supplies results that reflect the characteristics of a much larger region of the reservoir. This paper presents a comprehensive review of the available analytical models and is supplemented by several real field problems and the associated interpretations. Guidelines are provided for the selection of the appropriate model, and criteria for interference well test design are outlined.
Prediction of Liquid Hydrocarbon Recovery from a Gas Condensate Reservoir
Authors: Almarry J. A. , Al-Saadoon F. T. 
Published: December 2007

ABSTRACT
A compositional model consisting of material balance (M-B) ‘equations and the Peng-Robinson (P-R) Equation of State (EOS), was developed starting with the work of Bergman, Tek, and Katz. The model simulates constant volume expansion (CVE) as obtained from experimental analyses of gas condensates.
The contributions of this paper include the following: (1) evaluation of the phase behavior and fluid properties for an arbitrary mixture of components (2) development of the material balance equations to compute depletion performance, (3) investigation of P-R EOS as a tool for reproducing measured PVT data, and (4) analysis of the effect of component property estimation on EOS predictions.
The North Field Khaff reservoir, which is situated offshore northwest of the northern top of Qatar, and the specific K-4 reservoir description was used as the example in this work.
Laboratory measurements for constant volume depletion and phase separations of a condensate fluid sample were obtained from well No. NWD 5 in the K-4 reservoir of the North Field in Qatar. This experimental data was used as a basis for comparing results from the proposed compositional model. The data analysis was carried out up to C20+ group hydrocarbons.
The experimental data used for comparison with the calculated results were volume percent liquid (retrograde condensation), cumulative produced volume, molecular weight of heavy components (C7+) produced, and compressibility factor. In addition to the values calculated above constant composition expansion at different temperatures, a partial phase diagram for K-4 gas condensate, and viscosity were calculated by the model.
Role Of Gas In Global Energy Balance
Authors: Clegg M.W. , Middleton A.R. 
Published: December 2007

1. Some Observations on the World Energy Scene
The difficulties of forecasting the behaviour of world energy and economic systems have led to persistent major revisions of energy forecasts during the last decade. However in the energy business where projects are highly capital intensive and lead times are long it is necessary to take a view of the future. The starting point for any energy forecast must be the economic environment and the structural changes in the world economy that may occur over the period considered - in the USA, for example, over the last decade they have led to a fall of 20% in the amount of primary energy needed to produce a unit of real income.
The consequences of these structural changes are exemplified by the growth in levels of conservation arising from the increase in absolute energy prices over the last decade. This trend towards greater efficiency can be prices over the last decade. This trend towards greater efficiency can be expected to continue. In Europe the increase in fuel prices led to significant falls in the amount of energy used for space heating; in Denmark energy use per dwelling fell by a third during the decade. A similarly large fall occurred in the US. All this took place through the installation of better insulation, double glazing and the reduction of waste; but the living standards and levels of comfort improved.
The forecast of higher prices in the long run coupled with an expected high level of technological advance suggests that structural change will continue, energy use will be less intensive and the ratio of energy to GDP will continue to fall. But there will be regional variations. As energy intensive industries are switched to the less developed countries where low cost hydrocarbon reserves exist the fall in the energy/GDP ratio will be more pronounced in the industrialized countries particularly the USA. The ratio for the less developed countries, by contrast, will not fall (Figure 1).
Saudi Arabian Computerized Log Analysis System
Authors: Asar H. K. , Saner S. , Amri T. S. 
Published: December 2007

ABSTRACT
Saudi Arabian Well Log Analysis System (SARLOG) is a computerized open hole well log interpretation system developed locally for the Ministry of Petroleum and Minerals. This system consists of a total of forty subprograms. These subprograms will digitize and prepare data, perform chartbook environmental corrections and do level by level main calculations. Cross plotting subprograms are included for verification of log calibration, identification of lithology, differentiation of gas and oil and determination of all formation parameters.
As the equations and methods used in well logging depend on lithology type, shaliness and available log combination, optional methods have been included in SARLOG to allow the log analysts to put his own judgement when it becomes required. Six shale indicators are used to approach a more precise shale value, and seven water saturation methods are optional for shaly sandstones and complex carbonate lithologies.
Surface and Downhole Production Safety Systems for Sour Oil and Gas Wells
Authors: Morsi K. M. 
Published: December 2007

ABSTRACT
The work on sour gas and oil wells by its nature is dangerous. Highly flamable and toxic sour gas and fluids under high pressure need to be handled by special equipment in a hostile environment.
Within ADCO, safety systems have been developed to protect the large investment, the environment and safety of operating personnel.
As a result of the high pressure and sour production involved, it is necessary to incorporate high – strength tubular materials and safety features such as surface controlled sub-surface safety valves, kill/dump valves, downhole packers and chemical injection systems into the completion design.
Several types of surface and sub-surface systems have been reviewed and tested for use in our onshore sour gas and oil wells in Abu Dhabi.
An Evaluation of Acid Frac/Matrix Stimulation of a Tight Limestone Formation in Exploratory Wells in Kuwait
Authors: Singh J. R. 
Published: December 2007

ABSTRACT
With the advent of Kuwait's intensive exploratory activities to locate and test deeper geologic structures, tighter and very low porosity limestone formations were progressively encountered. Most of these hydrocarbon bearing formations initially appeared to be very stubborn and hardly indicated any fluid influx into the well-bore. In certain cases the hydrostatic head was nearly completely removed by unloading the well practically down to perforations, thereby creating optimum draw-down but it either resulted in poor inflow or none at all. In the absence of currently available chemicals, equipment, job design engineering and better understanding of tight carbonate formations and their responses to various acid formulations, some of these could have slipped into unattractive categories. With the implementation of specially designed matrix and acid-frac treatments, these formation have, however, been unmasked and turned out to be highly potential finds now. This paper basically outlines the salient features of theoretical and operational aspects of stimulating and testing some of the very low porosity hard limestone formations in Kuwait recently.
A Novel Approach for Risk Assessment in Chemical EOR Projects
Authors: Gittler W. E. , Krumrine P. H. 
Published: December 2007

ABSTRACT
In today's volatile economic climate, comprehensive evaluation of the technical and financial uncertainties associated with all phases of tertiary or Enhanced Oil Recovery (EOR) projects is essential. In the portfolio approach used by major and independent oil producers, various EOR methods are in competition with exploration, drilling and continued secondary operations for limited funds.
A micro-computer-based, Chemical EOR Economics Simulator, (CEES) Model was developed to aid in the evaluations of various chemicals either used individually, or in combination for chemical EOR flooding. Chemicals such as alkalis, polymers, surfactants, sacrificial agents, etc., can be utilized in different chemical slug compositions. The model uses an oil recovery simulator with the option of utilizing a unique Monte Carlo technique to financially quantify the uncertainties associated with various chemical EOR alternatives. Parameters such as: Oil pricingCapital and expense escalationOil production and decline curvesTotal incremental oil production
are allowed to vary in the model. A user, by choice, can select a standard deviation for chosen parameters and allow them to vary randomly along a standard normal distribution. By varying any of these parameters, a project's sensitivity to that key factor can be determined. A cash flow analysis for each year is completed over the duration of the project and is used to produce an internal rate of return. In addition, an incremental internal rate of return is determined when the revenues and expenses attributable to the continued water flood are subtracted from the tertiary project. A single case can be completed or, through the use of multiple runs (1,000+), confidence bands can be established to determine the impact of each key uncertainty factor on the profitability of a proposed chemical flood.
Examples are given to demonstrate the advantages provided by using this tool for initial screening of proposed projects and in evaluating the financial and technical risks associated with close alternatives.
Internal Rate of Return: Friend or Foe?
Authors: Terry R. E. , Ehman M. P. 
Published: December 2007

Abstract
Results of a recent survey of over 100 exploration, production, and transmission companies operating in the Rocky Mountain Region indicate that the internal rate of return (IRR) is extremely popular as an economic evaluation criterion. However, there still remains, in the views of many authors and evaluators, a question concerning the validity of the IRR calculation. The validity question involves the calculation procedure and whether a rate of reinvestment of incomes is implied or not. Some feel that inherent in the calculation procedure is a reinvestment of incomes at the computed IRR, while others argue that there is no reinvestment implied and that it doesn't matter what is done with the incomes. Because of the reinvestment question and other complications of the IRR calculation, some individuals have suggested that other evaluation criteria be used.
This paper contains two parts. The first part presents a review of a few of the evaluation criteria used in the industry and the results of a recent survey concerning those criteria. The second part of the paper will address the reinvestment question and attempt to prove that the IRR calculation procedure does indeed imply reinvestment of incomes at the IRR.
Acoustic Static Bottomhole Pressures
Authors: McCoy J. N. , Podio A. L. , Huddleston K. L. , Drake B. 
Published: December 2007

ABSTRACT
Acoustic instruments have been used routinely for many years as an aid in analyzing well performance of normal-pressure oil producers.1
Recent developments in equipment and techniques now permit more-accurate calculations of acoustic static bottomhole pressures at surface pressures up to 15,000 psi in corrosive (CO2 and H2S) environments. Equations and charts are presented herein for determining static bottomhole pressures from acoustic and well data. Also, a special technique is recommended for shutting-in a well which in most cases will yield more-accurate results.
This method has been programmed for an inexpensive, portable notebook-size computer which can be used in the field to easily perform these calculations.
Hydraulic Fracture Evaluation in a Geopressured Reservoir
Authors: Sookprasong P. A. , Elbel J. L. 
Published: December 2007

ABSTRACT
Frequently, it is seen that production rate and flowing tubing pressure decline rapidly on abnormally pressured wells following a hydraulic fracture stimulation. It is often thought that rapid decline in production rate is due to inadequate fracture characteristics. However, the rate of decline depends on many factors, such as formation permeability, fracture half-length, fracture conductivity, reservoir pressure and reservoir size. Also on deep, low-permeability, high-pressure wells, closure stress can play an important role on the rate of decline in production when large rapid pressure drawdown is required for economic production rates.
This paper utilizes pressure transient test data and production data to evaluate a hydraulically fractured well in a geopressured reservoir. A prefracture buildup test, type-curve techniques for fractured wells with boundary effect, and a two-dimensional, single-phase simulation program with closure stress on proppant are used to arrive at an explanation for the performance of a well. It was found that a small reservoir drainage area and a loss of fracture conductivity were major factors of rapid decline in productivity.
Projections on future well performance were made and compared with subsequent actual well performance.