bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeting New Wells In A Mature Field
Authors: Javed Mohammad S. 
Published: December 2007

ABSTRACT
It has been estimated through a simulation study that about 20 million STB of oil can be recovered through infill drilling in the flank areas of one of the prolific, but depleting reservoirs (Arab C) in a Qatar offshore field. The area where this appreciable amount of oil (known as "Cellar Oil") exists, has been left unswept by the non-ideal location of the "Dumpflooders" - injection wells, for pressure maintenance, which gravitate water from a source formation directly into the producing reservoir.
This paper highlights the results of the simulation study of this mature reservoir, studied together with the underlying Arab D, where high oil concentrations are shown in the flank areas, between the OWC and the dumpflooders. Although, the existing flank production wells have been performing satisfactorily, it was found, from the study, that even prolonged production through these would not drain this trapped Cellar Oil; new wells must be drilled to recover it. The infill wells, proposed for this purpose, happen to be located in areas such that they can be completed dually in a horizontal mode with another underlying reservoir (Uwainat) having an oil rim, thus, further increasing the attractiveness of the project. The study also indicates the necessity of infill drilling in other parts of the Arab C and Arab D.
Case History: Relief Well Control of Underground Blowout In Bahrain
Authors: Flak Larry H. , Muhanna Ghassan A. , Al-Qassab Mohamed 
Published: December 2007

ABSTRACT
As producing wells in the Middle East mature, downhole corrosion problems are causing increased blowout risk. Well 159 was drilled in 1959 and was completed within the shallow "Ac" sandstone reservoir with perforations at 2029’ to 2062’. External casing corrosion and tubing failure lead to an underground blowout. Casings near surface had deteriorated to the point that wellbore access from surface was no longer possible to control the blowout. An estimated 8 MMscfpd gas containing 1000 PPM H2S and 6% CO2 was blowing into a shallow brackish water aquifer (150’ to 700’). Well 159 wellhead vibrated at surface from subsurface flow. Gas leaked out of the aquifer into cellars of Well 159 and surrounding wells. This complicated field operations and placed offset wells at increased risk. This paper describes a case history of the relief well used to successfully control the underground blowout of Well 159.
Core-Log Integration For A Saudi Arabian Sandstone Reservoir
Authors: Saha Souvick , Al-Kaabi Abdulaziz U. , Amabeoku Maclean O. , Al-Fossail Khalid 
Published: December 2007

ABSTRACT
For a detailed characterization of a reservoir, core-log integration is essential. In this paper, data integration from logs and cores of a Saudi Arabian sandstone reservoir is discussed with particular attention to effects of clay on resistivity logs and water saturation. There are four sources of data, namely, core resistivity measurement, clay study from cores (XRD, CEC), spectral core gamma ray, and well logs. In order to generate continuous cation exchange capacity (CEC) with depth, spectral gamma ray measurements (both from core and downhole log) and CEC from cores are correlated. Qv (CEC per unit pore volume) values are calculated utilizing only well logs by applying Waxman-Smits equation in water bearing zone. Log derived Qv values from water zone were then correlated with porosity to generate Qv values in the oil column and compared with core derived Qv. Finally, data from well logs (porosity, resistivity and qv) and cores (resistivity parameters m, n, and Qv) were integrated for more accurate water saturation calculation. The core-log correlation can be applied to other wells avoiding expensive core analysis, and the technique developed in this project can be used in other sandstone reservoirs.
Prediction of Three-phase Coning Behaviour for Horizontal Wells in Naturally Fractured Reservoirs
Authors: Verbruggen M. H. W. , Schulte A. M. 
Published: December 2007

ABSTRACT
A semi-analytical model has been developed that predicts the production behaviour of horizontal wells in a naturally fractured reservoir. A water zone is assumed to underly the reservoir, and the pressure is assumed to be maintained by gas injection at the reservoir’s crest. The model combines the recovery processes of gas/oil and water/oil gravity drainage in the matrix system with three-phase coning in the fracture system. The offtake rate is assumed to be subcriticai or critical with respect to gas coning, in order to avoid gas cycling. With respect to water coning, the offtake rate may be either subcriticai or supercritical. The validity of the new model is confirmed by numerical simulations of such fractured reservoirs.
The model allows a quick investigation of how, e.g., oil zone thickness, offtake rate, well spacing and well location affect the oil recovery. As such, it can be used as a fast and simple screening tool. On the basis of its results, more detailed numerical simulations that include the full geology and flow equations can then be used for further optimisation and economic evaluation.
Analysis of Well Tests From Naturally Fractured Reservoirs by Automated Type-Curve Matching
Authors: Menekse K. , Onur M. , Zeybek M. 
Published: December 2007

ABSTRACT
Due to the diversity of existing idealized naturally fractured reservoir models, e.g. double porosity models with transient or pseudo-steady interporosity flow, etc., and the large number of parameters needed to be estimated in these models, the analysis of well test data from naturally fractured reservoirs by the well-known conventional graphical techniques is often difficult if not impossible. In recent years, the computer-aided automated type curve matching techniques based on nonlinear regression methods (e.g. least-squares, least absolute value, etc.) have been increasingly popular in estimating well/reservoir parameters from transient well test data.
In this work, we explore in detail the applicability of nonlinear regression techniques to obtain the parameter estimates from well-test pressure data from naturally fractured reservoirs. We implement both the nonlinear regression technique based on L2 norm (least-squares) minimization and the nonlinear regression technique known as "robust" regression based on L1 norm (least absolute value) minimization. Important characteristics of these nonlinear regression methods are discussed. In modeling the pressure data, we consider the most commonly used double porosity models such as Warren and Root’s pseudo steady state interporosity flow model as well as transient interporosity flow models with slab and spherical matrix blocks (with or without interporosity skin effects) including wellbore and storage effects. The analysis of multi-rate tests by nonlinear regression techniques is also given. As model functions, pressure (or pressure change), conventional pressure derivative, pressure plus pressure derivative, pressure/pressure derivative ratio and integral pressure functions are considered in regression. The advantages and disadvantages associated with use of each function in the analysis are discussed. It is shown that the pressure/pressure derivative ratio increases the chances of obtaining a unique fit, that is, that it is not very sensitive to different initial guesses for parameter values unlike the other model functions. In addition, we show that the regression method using the integral functions yields more accurate estimates (with narrower confidence intervals) than the methods based on pressure derivative in cases where the pressure data is very noisy. Guidelines for the effective use of nonlinear regression techniques when analyzing well tests from dual porosity reservoirs are also provided. The applicability of the proposed methods is demonstrated by analyzing several sets of synthetic and field data.
Performance Prediction Using Geostatistics and Window Reservoir Simulation
Authors: Fontanilla J. P. , Al-Khalawi A. A. , Johnson S. G. 
Published: December 2007

ABSTRACT
This paper is the first window model study in the northern area of a large carbonate reservoir in Saudi Arabia. It describes window reservoir simulation with geostatistics to model uneven water encroachment in the southwest producing area of the northern portion of the reservoir. In addition, this paper describes performance predictions that investigate the sweep efficiency of the current peripheral waterflood.
A 50 × 50 × 549 (240 m. × 260 m. × 0.15 m. average grid block size) geological model was constructed with geostatistics software. Conditional simulation was used to obtain spatial distributions of porosity and volume of dolomite. Core data transforms were used to obtain horizontal and vertical permeability distributions.
Simple averaging techniques were used to convert the 549-layer geological model to a 50 × 50 × 10 (240 m. × 260 m. × 8 m. average grid block size) window reservoir simulation model. Flux injectors and flux producers were assigned to the outermost grid blocks. Historical boundary flux rates were obtained from a coarsely-gridded full-field model.
Pressure distribution, water cuts, GORs, and recent flowmeter data were history matched. Permeability correction factors and numerous parameter adjustments were required to obtain the final history match. The permeability correction factors were based on pressure transient permeability-thickness analyses.
The prediction phase of the study evaluated the effects of infill drilling, the use of artificial lifts, workovers, horizontal wells, producing rate constraints, and tight zone development to formulate depletion strategies for the development of this area. The window model will also be used to investigate day-to-day reservoir management problems in this area.
On the Theory of Polymer Solution Flooding Process
Authors: Sarem A.M. 
Published: December 2007

Abstract
Certain polymeric waterflood additives, such as partially hydrolyzed polyacrylamide, impart a useful but seemingly "abnormal" resistance to flow of flood water through porous rock. This "abnormal" resistance has resulted in a substantial increase in waterflood oil recovery—beyond what could normally be expected from the viscosity increase that the polymer causes in the flood water.
A theory has been formulated and qualitatively tested on laboratory data to explain this beneficial "abnormal" property in terms of interaction between molecular coulombic and ionic forces. The theory is used to show how the polymer can reduce the mobility of water but not that of oil. The application of the theory for tailor-making more effective polymers is also discussed.
In line with the above-mentioned theory, a study of the adsorption of polymer on the pore surface of porous media has shown that more polymer is adsorbed from salt-containing water than from fresh water. Also, the amount of polymer adsorption and the length of polymer retention time on low-surface-energy teflon beads was found to be considerably less than on a high-surface-energy fired sand.
Opportunities for Petroleum Company Leadership in Host Nations Sustainable Petroleum Economic Development Business
Authors: Stultz-Karim S. P. 
Published: December 2007

Abstract
This paper examines the dynamic international political economic environment in which petroleum exploration and production companies must operate when considering investments in the economically transitional nations of the former Soviet Union or developing nations. In this period of critical global changes low oil prices is only one factor with which petroleum companies must be concerned in their investment decisions Other factors include the transition from a Dipolar world to a multipolar world of free trade zones, the general malaise of the international economy, public and political recognition that nations and industries can no longer practice environmental "beggar-thy-neighbor" policies, and the rejection of aggregate national economic growth policies for sustainable economic development policies in both the developed and developing world This paper focuses on actions which investing petroleum exploration and production companies can take in order to gain a leadership role in the sustainable petroleum economic development business, to work with host countries’ regulations, and to develop a cooperative environment with host countries so that both the investing company and the host country can progress, not just survive.
Analysis of the Economic Benefits and Strategy of Exploration and Development of China's Oil and Gas
Authors: Sun Qirui , Lei Huanming 
Published: December 2007

Abstract
On one hand, the population of China accounts for one-fifth that of the world, whereas the proved oil reserve for an average person in China makes up less than one nineth that in the world. And the average natural gas reserve per person of China is only one twentieth that of the world. On the other hand, the yearly oil output of China has risen from 120,000 tons to 139,000,000 tons, which has made China one of the largest oil countries in the world, presenting a striking contrast with the former. This is a problem which is worth noticing. More and more oil and gas are needed for the continued economic development of China, but the oil industry of exploration and development is faced with such contradictions and difficulties as lack of reserve volume, imbalance of the ratio of reserves and production, shortage of funds, surplus of staffs, low labour productivity, and so on. For this reason it is necessary to analyse the economic benefit and strategy of China's oil and gas exploration and development. With a series of data and charts this paper analyses the economic benefit of the exploration and development of China's oil and gas and proceed to study the strategy of "Stabilising the Eastern Part and Developing the Western Part of Oil Zones " and "Starting the Second Oil Undertaking and Opening the Second Battlefield for Oil Production". And in this paper the author comes up with his own points of view.
Matrix Flow Evaluation Technique For Water Control Applications
Authors: Novotny Rudolf J. 
Published: December 2007

Rudolf J. Novotny*

Abstract
Production of unwanted water from oil and gas wells has consistently burdened the industry. Many chemical systems have been developed to selectively reduce the flow of water into the wellbore 1 but not appreciably affect the production of hydrocarbons. Although these systems work well in the laboratory, many field applications have proven less than successful. The limited success of these types of systems may not be due to product failure but to poor candidate selection. The functioning mechanism of the chemical systems limits their application to wells where the production of water moves through the formation matrix, not from a channel or fracture.
A methodology has been developed utilizing production data and Darcy's flow equations to evaluate well candidates for these and other matrix applications. This evaluation technique will assist the engineer in deciding the potential mechanism of excessive water influx. Once the source or conduit for water production is determined, the appropriate type of water control application can be designed and applied. Examples of candidate evaluations and field application results are presented.

Introduction
Many oil and gas wells also produce water. This water production can occur on initial completion or later in the life of the well. A small amount of water production does not create a problem and in some instances is beneficial; however, when water production becomes excessive, then consideration for reducing it should be made. Excessive water adds cost to the production of the well. More water means additional lifting, treatment, and separating cost. It can also reduce the hydrocarbon production, by increasing the head in the wellbore, reducing the drawdown, or in gas wells, higher density water in the production string can lead to early shut-in or the necessity to install artificial lift.
Fluid distribution vertically in a reservoir is important. The relative amounts of oil, water, and gas present at a particular level in the reservoir determine the fluids that will be produced by a well completed at that level, and also influence the relative rates of fluid production. In most "water wet" sandstone formations, the water saturation varies from 100% below the oil zone to progressively lower percentages at points higher in the oil zone. The zone from a point of 100% water saturation to some point above where water saturation is fairly constant is called the transition zone. Relative permeability relations permit both water and oil to be produced from the transition zone.
P. 161
Calculating The Distance To A Discontinuity From D.S.T. Data
Authors: Gibson J.A. , Campbell A.T. 
Published: December 2007

Abstract
Pressure build-ups from properly conducted drill stem tests have provided the well owner an ever increasing amount of useful data in regard to formation evaluation. The distance to a discontinuity is a significant formation parameter that can be calculated from drill stem test data. This study investigates the various methods available for calculating the approximate distance to a discontinuity. The transient response curves obtained during a drill stem test exhibit more than one slope if the flow periods and shut-in periods are sufficiently large. The distance to the discontinuity can be calculated by picking the point of deviation from the straight line portionT +0 of a well bore pressure vs. log ------ plot.0
Calculations are shown for a theoretical example of a build-up curve and two field examples of drill stem tests.

Introduction
A need has existed for an accurate method of determining the distance from a well bore to a discontinuity. Many advantages will be afforded the well owner if he can determine the distance to a discontinuity. For, example, a much higher permeability section may be indicated at some distance from permeability section may be indicated at some distance from the well bore as shown in Figure 1. Calculating the distance to the higher permeability section will provide the answer as to whether or not the section can be reached with a stimulation treatment such as hydraulic fracturing. Also, assume a test of a water bearing section indicates a gas-water contact as shown in Figure 2. The distance to the contact will determine whether a new well must be drilled higher on the structure or whether a side track from the original hole is feasible for penetrating the formation above the gas-water contact. Additional examples of common discontinuities are shown in Figures 3 and 4.
One of the prime objectives of a drill stem test is to determine the flow capacity of the zone being tested. The flow capacity is directly related to the transmissibility of the formation which is directly related to the effective reservoir permeability and effective formation thickness, and inversely permeability and effective formation thickness, and inversely proportional to the viscosity of the flowing fluids. The flow proportional to the viscosity of the flowing fluids. The flow capacity is further affected by the amount of well bore damage present. present. Drill stem tests are usually comprised of a sequence of flow periods followed by shut-in periods. The shut-in periods (build-up curves) provide the basic data which is utilized in calculating values for transmissibility and well bore damage.
Data Analysis For High Influx Wells
Authors: van Poollen H.K. , Weber J.B. 
Published: December 2007

Abstract
During drillstem tests, fluid influx into the drillstem is measured as flowing pressure increases. On moderate liquid producers, the influx is essentially constant and the final flowing pressure is in the order of 10 to 30 percent of the reservoir pressure. In good oil percent of the reservoir pressure. In good oil wells, flow will reach the surface and the final flowing pressure will be up to 80 percent of the reservoir pressure. In both instances cited, a subsequent pressure buildup will allow transmissibility and wellbore damage calculations.
Good producers of high density fluids, such as water, will show an initially high influx rate which slowly decreases to essentially zero and the final flowing pressure is about equal to the reservoir pressure. The same is true for a high permeability oil well with low reservoir pressure. The resultant test data cannot be interpreted with conventional methods.
Presently a method is given which makes use of type curves to interpret tests where the well kills itself during the flowing period of a drillstem test.

Introduction
Drillstem tests are often the only source of information available for reservoir data, especially early in the life of the field or when the test is in the aquifer portion. In the case of wells in the aquifer, subsequent data are not usually obtained, even in later stages of development when the aquifer properties are needed for performance studies. properties are needed for performance studies. In testing good producers of high density fluids, such as water, the fluid influx into the drillstem will be at an initially high rate, but will decrease to almost zero. In this case, the final flowing pressure will be nearly equal to the reservoir pressure. When this happens, the subsequent buildup portion of the test does not lend itself to conventional interpretation to determine transmissibility. The same situation is true for high permeability oil wells with low reservoir pressure.
Because drillstem test data on wells that kill themselves are available, but not easily solved, an investigation was made to find a way to use this source of information. A method of analyzing DST's for this type of well is presented. The method uses type curves as presented. The method uses type curves as developed by ground water hydrologists and provides for determination of both provides for determination of both transmissibility and storage.
Creating Field Management Information Systems Using Microsoft ® Software
Authors: Handsel-Johnson P. L. , Schroeder C. Y. 
Published: December 2007

Summary
A field management information system (FMIS) was created for the Trinidad Resource Development teams in Amoco's International Operations Group. This application uses Microsoft Access ® 2.0 and the other Microsoft Office 4.2 software products. The purpose of this information system is to assist these teams in the management of their producing oil and gas fields. This is accomplished by providing: centralized data storage◊for a variety of data, such as well, production, engineering and geologic◊in various forms, including raw, interpreted and derived,customized analysis, planning and reporting tools, such as reservoir performance summaries and dynamic field management plans, andthe capability to easily exchange data with a variety of engineering and geoscience analytical software.
Additional benefits provided to the Resource Development teams by this approach are: improved data accuracy and accessibility from a centralized, relational database,enhanced efficiency as a result of the application being tailored to the teams’ operating environment and work processes, andaccess to an expanded knowledge base by consolidating information from several fields into one database.
In short, this product was developed in response to the Trinidad Resource Development teams’ need to improve their data integrity, efficiency and analysis and planning capability. The resultant application is not just a database, but rather, a field management information system.