bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Measurement of Drilling Fluid Rheology at Elevated Temperature and Pressure
Authors: Moussa M. M. , Al-Marhoun M. A. 
Published: December 2007

ABSTRACT
Due to instability and degradation of the conventional drilling fluids specially under high shear rate, elevated temperatures and chemically complex environments of deep and geothermal wells, it is essential to modify and develop stable batches of clay suspensions that can perform adequately under these conditions. To obtain batches, a reliable set-up should be designed and constructed to examine and measure all the properties that may possibly change under the prevailing conditions. A scaled dynamic flow loop is designed and built in the Department of Petroleum Engineering at the University of Petroleum & Minerals, Dhahran.
This set-up can simulate efficiently the bottomhole condition e.g. high temperature up to 450°F, high shear rate up to 50,000 sec−1. The system pressure is maintained above the saturation pressure of water at the test temperature. Dynamic filteration rate and the corrosion rate is monitored instantaneously at wide range of bottomhole conditions. The flow parameters N&K,τ, γ etc., are obtained by measuring AP across the 3-tube viscometer using the DP 15-150 pressure differential transducers. The ambient properties are measured by Baroid multi-speed viscometer and compared with data obtained from the loop.
Two batches composed of sepiolite and polymer were tested. Effective viscosity is increased significantly at high temperature for the first and second batches. The consistency and thermal stability of these fluids may be attributed to the transfer of sepiolite to smectite at high temperature and high shear.
Deliverability Projection Model for Overpressured Gas-Condensate Reservoirs
Authors: Aziz R. M. 
Published: December 2007

ABSTRACT
During the depletion history of an abnormally pressured reservoir, pressure is initially maintained by a decrease in the pore volume. The P/Z vs cumulative gas produced graph in such reservoirs shows two distinct slopes and the initial gas in place can be estimated by extrapolation of P/Z straight line after the reservoir gradient has been reduced to normal. This decrease in pore volume also results in a reduction in the effective permeability of the rock thus affecting the formation in-flow performance.
In the gas-condensate reservoirs, hydrocarbon liquids drop out of the gas phase below the dewpoint pressures increasing the total liquids saturation. An increase in the liquid saturation decreases the relative permeability to gas.
The paper develops a high pressure gas-condensate reservoir deliverability calculation incorporating the effect of gas permeability reduction due to a decrease in pore volume and increase in oil saturation.
The Formation of Salt Balls in a Deep Exploratory Well
Authors: Samhouri F. A. , Al-Chalabi A. 
Published: December 2007

ABSTRACT
A high pressure salt water influx was encountered while drilling a Deep Exploration well at 20,363 ft. Attempts were carried out to control this influx but the well killed itself. The fishing operations revealed the drill pipe to be plugged with salt balls. The paper describes and analyses the phenomenon that resulted in the formation of the salt balls which subsequently plugged the drill pipe and led to the killing of the well.
A Compositional Simulator for Performing Large Field Studies in a Vector Computing Environment
Authors: Harper J. L. , Heinemann R. F. , Ray M. B. , Stephenson P. E. 
Published: December 2007

ABSTRACT
This paper describes COSMOS, a new equation-of-state, compositional simulator. COSMOS is designed for full-field studies of hydrocarbon gas and carbon dioxide injection for miscible flooding, gas condensate reservoirs and volatile oil reservoirs. The numerical procedures in this simulator are based on Newton's method and couple together the phase equilibrium constraints and species continuity equations. The transport flux terms in the flow equations may depend on pressure alone, or may be treated as implicit functions of both pressure and saturation. With this latter option, COSMOS contains the coupling terms which give fully-implicit, black-oil simulators their stability. The well management package is flexible and provides for platform and field limits as well as individual well controls. The coupling of the well flow equations with the continuity equations parallels the implicit treatment of the transport terms. This implicit option also affects our linear algebra routines which are capable of solving matrices with one or three unknowns per grid block.
COSMOS was constructed as an efficient vector code which can be easily modified as simulation needs or capabilities arise. Structured design methodologies were employed to achieve as high a degree of modularity as is consistent with extensive vectorization. COSMOS contains a resource manager to efficiently run large and small problems within a limited central memory. Additional resource management software determines a critical path to optimally schedule computations and data traffic. We have also developed a flexible, hierarchical data base package for the storage and retrieval of data which provides printing and restarting capabilities. Although the COSMOS code and these software packages were targeted for the CRAY-1, the simulator is designed to run on other machines with a minimal number of changes.
Reservoir Management of the Yibal Field in North Oman: A Simulation Approach
Authors: Blaskovich F. T. , Thurber S. S. , Echols D. P. , Al-Hinai K. B. M. 
Published: December 2007

ABSTRACT
This paper describes the techniques used and results derived during a reservoir simulation study of the Shuaiba Reservoir in the Yibal Field in North Oman. This was the final portion of a comprehensive study of the Shuaiba Reservoir that was begun in 1981. An extensive geological, petrophysical and reservoir engineering analysis was performed and described in a previous paper1. Reservoir simulation studies were then conducted to understand past performance and to determine the best operating plan for the future.
The reservoir simulation was conducted in three phases. In the first phase, a full field coarse grid model was used to determine the predominant drive mechanism and direction of fluid movement in the reservoir. Based on the results, very detailed single well (mini-sector) studies were performed to investigate fault plane water movement in the highly faulted crestal portions of the field. Finally, sector models were used to study areal and vertical sweep efficiencies and to determine an operating strategy that would maximize oil productivity and recovery in the future. The results of this work defined a coherent development plan for the major oil producing regions of the reservoir that was then extrapolated to the entire field.
Interference Testing: A New Analysis Approach
Authors: Al-Marhoun M. A. 
Published: December 2007

ABSTRACT
A new mathematical and graphical approach to analyze the interference tests is presented. This is based on a mathematical manipulation of the line source solution to the diffusivity equation. This approach yields the exact exponential integral function solution in a straight line form if pressure versus the inverse of time is plotted on a specially devised exponential integral graph paper. Obtaining a straight line on such a graph paper makes the analysis of inter ference tests very simple.
EPT Applications in the Middle East
Authors: Chardac J. L. M. 
Published: December 2007

ABSTRACT
The Electromagnetic Propagation Tool was originally intended to be run only in fresh-water environment. However, in Middle East its range of applications have been expanded as much as possible. It has been used as a formation-water salinity estimator on one test well. Another unusual application is oil-base mud logging, which is becoming more and more frequent. A field example is presented.
Daily Monitoring and Control of Well Performance: A Novel Approach Applied in the Upper Zakum Field
Authors: Al-Tamimi Y. K. 
Published: December 2007

ABSTRACT
This paper presents a review of the unique field monitoring & control system already installed on the Upper Zakum field, offshore Abu-Dhabi in the United Arab Emirates. This system may be considered as a pioneer project of its kind in the Middle Eastern Oil Industry.
The size and scope of this project is given in the proceeding general description of the field and its development philosophy. Followed by description of the Telesystem and its use as a hierarchical distributed control and data acquisition system.
The paper is then concluded with an appraisal of the system by highlighting its merits and demands.
State-of-the-Art of Water Coning Modelling and Operation
Authors: Alikhan Abbas A. , Ali S. M. Farouq 
Published: December 2007

ABSTRACT
Water-coning is often a serious operational problem in oil formations with underlying water. In the Middle East, some of the largest oil reservoirs have water-coning problems. The operation of a field under water-coning can employ a number of strategies, ranging from production limitation to production at maximum rate, possibly with interval control. This paper reviews the state-of-the-art of water-coning from the point of view of field operation, experimental modelling and numerical simulation. Selected field examples are cited.
It is shown that water-coning control measures are of limited efficacy at best, under practical conditions. Other techniques, such as barriers, are of academic interest only. Production at very high rates – with concomitant high water production rates – can be problematic in the Middle East reservoirs, with very highly saline connate water.
Simulation of water-coning and/or gas coning is possible on a single well basis. However, it is still not practical to simulate water-coning on a fieldwide basis. The numerical difficulties involved and some of the solutions proposed are discussed.
Experimental modelling of water-coning has been fairly successful, again on a single well basis. Occasionally, numerical simulation has provided useful backup to physical modelling. Types of experimental models used are reviewed.
On the whole, the paper provides a useful view of all aspects of water-coning, and should be of value to large segment of petroleum engineers and researchers.
Temperature Distribution Around Water Injectors: Effects on Injection Performance
Authors: Platenkamp R. J. 
Published: December 2007

ABSTRACT
When cold water is injected into a reservoir at initial temperature conditions, the sands around the water injector into which injection occurs will be cooled down to virtually the temperature of the injected water. The resulting temperature distribution can be described by simple expressions even in the case of a multi-layered reservoir. The presence of such a cold water bank has a strong bearing on injection performance. In order to arrive at a correct interpretation of pressure fall-off surveys conducted in water injectors it is essential to take the temperature distribution into account. Some field examples will be discussed.
Impact of Investment Criteria, and Reservoir Characteristics, Taxes, Royalty, and Price on Optimal Field Development Plans
Authors: Dougherty E. L. , Lombardino E. , Hutchison P. 
Published: December 2007

ABSTRACT
A system which combines a gas reservoir simulation model with optimal development and production scheduling models has been used succssfully for some time to develop long range plans for an oil and gas/NGL producing complex. The system determines how to integrate gas production from more than 40 reservoirs over a 25-year horizon to maximize net present value (NPV) while meeting sales requirements.
The timing of drilling wells and installing compressors, as well as the number of each such facility, is affected by economic factors (taxes, royalty, price of products, cost of development and production), reservoir characteristics (permeability of producing layers, heterogeneity, conductivity of induced fractures, gas composition, gas in place) and investment criteria. The criterion determining investments to add to the development schedule is PWPI; the incremental PWPI of each facility added to the optimal schedule must exceed a cutoff value of PWPI. The sensitivity of the optimal development schedule and desired depletion rate to various parameter changes are presented for (a) a single reservoir with an unlimited market, (b) a single reservoir with a limited market, and (3) two reservoirs with a shared market.
For (a) the results reveal considerable variation in the sensitivity to the parameters considered. For (b) the results illustrate the danger of oversaturating investment in a producing reservoir. For (c) the findings show that in some instances the complex interactions between economic and reservoir parameters and market specifications give rise to an optimal strategy which does not agree with intuitive expectations; sometimes, using negative cutoff values of PWPI results in larger values of PWPI.
Government Regulatory Practices in Transition
Authors: Kutchins G. L. 
Published: December 2007

ABSTRACT
The exploration for new energy and the resultant economics of new finds is in transition, especially as it applies to exploration on government lands where there are constantly new regulations for most exploration development and production activities. Politics, not science, is the main force behind the transition and change. Surface land "experts", called "range specialists", rather than sub-surface experts regulate most exploration and development activity.
When the three E's -- Energy, Economics, and Exploration -- are in transition, as they are today, it is all the more important that we in the business of exploring for and developing more economical energy practice the three C's -- Communication, Cooperation, and Coordination -- with the people who regulate our industry.
Drilling, Production, Deregulation, and Pricing in the Wellhead Natural Gas Market Under the Natural Gas Policy Act
Authors: O'Neill R. P. 
Published: December 2007

ABSTRACT
Since 1978 the natural gas market has changed radically in response to NGPA pricing policies, changes in world oil prices, and changes in energy markers. These changes have affected new drilling as much as any other part of the industry. In 1981 drilling activity reached all-time highs. This paper examines the course of natural gas drilling since the NGPA, examines the effects of post-NGPA drilling on production, and provides estimates of the quantities of gas deregulated.
Comparison of Methods for Determining Fair Market Values
Authors: Gustavson J. B. 
Published: December 2007

ABSTRACT
When an operator seeks financing of a venture, he generally provides information relating to his oil and gas reserves, as well as to his company's financial status. It is often left up to a bank, to a new venture partner or to a potential buyer to form his own opinion about the actual value of the reserves and the operator's ability to recover these. This paper will show how to bridge the gap between a conventional reserve estimate and the Fair Market Value of a property.
The paper first discusses the necessary reserve report as well as the often overlooked review of the operator's capabilities. The paper then discusses four different methods of determining the Fair Market Value of a property, and specifically point out sensitivities of the various assumptions used in the valuation methods. These appraisal methods include the following: Value per BOE. Gross recoverable barrels in the ground of both oil and oil-equivalent gas are determined through conventional reserve estimating. The barrels in the ground are multiplied by a dollar amount which reflects the risk and time period required to recover the oil (usually $7.00 per barrel). Non-producing reserves and proven, undeveloped reserves can be further discounted.Risked Present Worth. Present worth is first determined by an escalated future cash flow discounted back to present worth. Sources of risk include any lack of history of the producing formation, the operator's inexperience, and the time span over which the reserves will have to be recovered. A percentage in the 30 to 75% range is applied to the present worth of the property to account for these various risk factors.Three-year Cumulative Cash. The Fair Market Value can be determined by establishing a time criteria for payback of the acquisition price. The net cash flow is summed up from the present to the end of the selected time period (usually two-and-a-half to four years).Present Worth at 25%. A desired internal rate of return is targeted. The future net cash flow is discounted by this amount to establish a Fair Market Value. This method can also be adjusted to consider risk.
Cases are used to illustrate where the various methods are applicable and generally agree, as well as cases where pitfalls exist.
Guidelines for Proper Application of Four Commonly Used Investment Criteria
Authors: Dougherty E. L. 
Published: December 2007

ABSTRACT
Two aspects of the most favored investment criterion; discounted-cash-flow rate of return (DCFROR), continue to confound evaluation engineers. These are how to interpret the value obtained, and what to do when dual values arise. Using continuous discounting formulas, it is demonstrated mathematically that when a single value is obtained, DCFROR is the rate of return realized on the unamortized investment.
Three alternative investment criteria used to cover the breach caused by the occurence of dual values of DCFROR are a modified DCFROR, growth rate of return (GROR) and ratio of net present value to present worth of invesment (PWPI). It is shown that the modified procedure for computing DCFROR must be applied to all projects to obtain a consistent measure of investment performance; because a standard modification cannot be defined far all projects, modified DCFROR is unsatisfactory as an economic evaluation yardstick. PWPI always provides desired consistency. GROR, which is analytically related to PWPI, provides a consistent measure if the same year is used to compute the future value for all projects. As is demonstrated, with these latter two criteria care must be exercised to specify the investment properly.
Rapid increases in oil and gas prices, followed by similar runups in costs, followed in turn by a price decrease, have caused analysts to more commonly escalate prices and costs in evaluations. These escalated numbers may then; (1) be used directly, or (2) be deflated and the resulting values used, to calculate economic yardsticks. In the second case depreciation deductions are also deflated. The rates of return obtained via these two procedures differ by the inflation rate, but, if followed properly, both procedures yield the same value of PWPI.
An Improved Computation Procedure for Risk Analysis Problems With Unusual Probability Functions
Authors: Startzman R. A. , Wattenbarger R. A. 
Published: December 2007

Abstract
A computational method called Latin Hypercube Sampling (LHS) has been developed. LHS is superior to Monte Carlo simulation for risk analysis problems which involve discrete probability distributions containing events having very small probabilities but drastically large effects on the final solution.
The LHS method is applied with evenly spaced probability intervals for a random variable. Each interval is then sampled without replacement, thus avoiding clustering of values.
Monte Carlo simulation has the disadvantage that random samples may become clustered in an apparent biased fashion until a large number have been selected. LHS, in effect, forces samples to correspond more closely to a given probability distribution earlier in the selection process. Examples are shown comparing the number of computations with Monte Carlo simulation, which has a very slow convergence in the example cases, to a relatively accurate and rapid computation by the LHS method.
We were able to show that the LHS method can be used to advantage in problems having smooth probability functions as well as abnormal probability functions.
Reservoir Economic Optimization
Authors: Nystad A. N. 
Published: December 2007

Abstract
This paper outlines a reservoir-economic approach and quantifies the microeconomic adjustment of the exploitation of different types of petroleum reservoirs by means of a numerical optimization model.
The numerical reservoir-economic optimization will be presented here. In this model the microeconomic adjustment is viewed in relation to reservoir engineering. The model optimizes the exploitation of an oil or gas reservoir in terms of: 1) Total depletion rate (production capacity, including the aspects of Maximum Efficient Rate) and, 2) Geographical distribution of total production capacity (well density, number of platforms, etc).
The model can be adjusted (calibrated) to the reservoir simulations of a specific oil or gas reservoir. The generation of production profiles is based on a limited number of reservoir simulations. This information is used to generate a fine network of production profiles in the reservoir module. The income side is coupled with a reservoir cost module and the optimal solution is sought in the net present value surface. The model is used for further economic analysis in different economic, financial and taxation modules.
It may serve to improve the general understanding of the effects of reservoir economics on the engineering decision-making process, and as such is a tool for communication between economists and reservoir engineers.
Relative Economics of Domestic Oil and Gas Exploration and Development, 1978 to 1983
Authors: Glanville T. S. 
Published: December 2007

ABSTRACT
This paper analyzes the relative economics of domestic oil and gas exploration and development for the period 1978–1983 by constructing annual ratios of oil and gas prices to their finding cost. This analysis is done in the context of the economic theory of depletable natural resources and the causal factors that determine the domestic net prices and finding cost for oil and gas. The paper concludes that industry economics improved in 1983 from the peak levels of industry activity in 1981 and 1982 due to oil price stabilization, a fall in Windfall Profits Tax (WPT) liability and operating costs, increases in gas prices, and a large drop in finding cost.
Risk Assessment in Project Financing
Authors: Campbell J. M. , Hubbard R. A. 
Published: December 2007

ABSTRACT
Project financing has grown in popularity and monetary volume over the last five years, partly because of the budget cut backs in major oil companies, and partly because of the attractive terms offered by the, lending institutions. Many companies mistakenly view project financing as a lower cost source of funds, making previously marginal prospects justifiable using standard evaluation procedures. The costs and risks to the borrower are illustrated in this paper, and shown to be much larger than typically incorporated into most evaluations. A methodology is developed and illustrated to incorporate cost/risk consequences into the project financing decision.