bluuebunny/crossref_metadata_2025_split huggingface dataset:
Examination of Field Data from a New Gas Sweetening Process
Authors: Bhatia Kishan , Brown Timothy M. 
Published: December 2007

ABSTRACT
A new patented sour gas sweetening process was introduced to the gas processing industry in September 1984. This process consists of bubbling sour gas through a tower filled with a proprietary formulation, an alkaline aqueous solution of an anionic oxidizing agent. The toxic hydrogen sulfide is selectively removed from the sour gas and dissolved sulfides are converted to nonhazardous sulfur by the sweetening solution in the tower. The process is generally operated at ambient temperatures. The spent slurry from this batch process has been classified as a nonhazardous waste by the U.S. Environmental Protection Agency, fourteen state agencies, and the U.K. Department of Energy. The process was initially field tested at various locations in California in cooperation with major gas producers. More than 100 units are now operating in the United States and Canada. The hydrogen sulfide concentrations of sour gases treated with this process range from as low as 10 ppm to more than 20 percent; the operating pressures range between near atmospheric to greater than 1000 psig. The largest unit processes 16 MMscf/d sour gas using one tower at 1035 psig and the smallest unit handles 8 to 10 Mscf/d gas containing greater than 20 percent hydrogen sulfide. This paper presents: Detailed field data for over 100 operating unitsA description of the chemistry of the processComparative kinetic data on several hydrogen sulfide scavengers used in other batch processesDefines factors utilized in the design of improved towers used for this gas sweetening process based on the experience gained in the field.
Analysis of Pressure Tests Through the Use of Instantaneous Source Response Concepts
Authors: Cinco-Ley H. , Kuchuk F. , Ayoub J. , Samaniego-V. F. , Ayestaran L. 
Published: December 2007

ABSTRACT
A general method of analysis for pressure transient tests is presented. This technique is based on the pressure response of an instantaneous source and it provides a mean to compute the first and second derivatives of the influence function (unit flow rate response) of the well-reservoir system. This information is basic in identifying the flow regimes occurring during the test. This method eliminates the effect of producing time on pressure buildup data.
An explicit and stable procedure is discussed to compute both the derivatives of the influence function and the initial reservoir pressure. This technique is suitable for DST and Repeat Formation Tests as well as for pressure buildup and fall off tests with long shut in period; variable flow rate before shut in can be taken into account. Examples of application are presented.
Microscopic Aspects of Capillary Imbibition
Authors: Rose Walter , Channapragada Rao 
Published: December 2007

Abstract
As a general rule, the action of capillary forces cannot be ignored in treating capillary imbibition (where one fluid is displaced by another replacing fluid). This circumstance requires that the capillary driving force term be identified and cast in a form which will serve the needs of analysis and throw some light on the details of the displacement process.
Given a saturation gradient defining the flood-front profile at a particular instant, the corresponding capillary pressure gradient is found to have only qualitative meaning as a measure of the capillary driving force acting to project flood-front forward. This viewpoint is contrary to common opinion; hence, it is necessary to re-examine the microscopic aspects of capillary imbibition so that a quantitatively meaningful capillary driving force term can be derived which has a macroscopic importance.
The microscopic analysis leads to some interesting conclusions. Of major importance is the idea that a Darcy Law analog cannot be written as the macroscopic law of force descriptive of the unsteady states of multiphase-flow systems. This means, for example, that published solutions of the Buckley-Leverett problem are in error, as are other analyses which depend on use of the conventional relative permeability concept. A second conclusion which can be drawn is that the capillary forces are the major factor determining microscopic displacement efficiency, even for cases when the injection rates are high (e.g., there is a large imposed gradient in pressure energy). It is found, moreover, that the capillary driving force and, hence, the displacement efficiency are rate-dependent in ways usually overlooked.
In this paper, the Buckley-Leverett problem is discussed at length as a device to show the importance of taking the microscopic viewpoint before attempting to deduce how capillary imbibition and displacement can be characterized in the macroscopic sense. Attention is thus focused on the need to derive a valid law of force for the unsteady states of multiphase flow, if valid equations of motion are to be written. Although this paper does not suggest a law of force to replace the rejected Darcy Law analog, at least the capillary driving force term is given in unambigious form.
It is concluded that, for a while at least, capillary imbibition of a wetting fluid into and through porous media cannot be cast in an analytically or numerically integrable form; hence, experimental procedures (scaled-model experiments) are proposed as an appropriate way to investigate fluid-fluid displacement. To be noted is the fact that these experimental procedures are no more difficult to undertake than the relative permeability and capillary pressure experiments required to give the basic data needed for conventional Buckley-Leverett calculations.
Hydraulic Fracturing of a Moderate Permeability Reservoir, Kuparuk River Unit
Authors: Niemeyer B. L. , Reinart M. R. 
Published: December 2007

ABSTRACT
Sixty-five percent of the proven reserves in one of the United States' largest oil fields, the Kuparuk River Unit, are contained in the lower of two producing horizons. This zone, commonly referred to as the "A" sand, has a permeability of between 30 and 100 md. Unfortunately this interval is easily damaged during drilling and completion operations. Low initial flow efficiencies have been confirmed by numerous pressure transient tests. A program of hydraulic fracturing was initiated in March 1984 to overcome near wellbore damage and provide stimulation to more efficiently tap "A" sand reserves.
More than 300 fracture stimulations have been completed to date in the arctic setting of the Kuparuk River Unit. These jobs have used a variety of fluids, proppants, and pumping schedules. The current hydraulic fracture design was evolved by continual interpretation of field results and related data from these previous stimulations. Success of the overall program has been impressive. Average post-fracture flow efficiency has been in excess of 100%. Post-fracture rate increase has averaged approximately 300%, accounting for a total rate increase of over 125,000 BOPD (19,900 m3/d). Based on these results, fracturing will continue to play an important part in future field development.
This paper is the first review of the Kuparuk River Unit fracture program. It provides a case history of the development of a standard fracture design. In addition, the findings of this study would be applicable to reservoirs elsewhere with similar characteristics.
A Post-Audit of Fracture Stimulations in the Vicksburg Formation of South Texas
Authors: Brim H. B. 
Published: December 2007

ABSTRACT
Many South Texas low permeability Vicksburg gas completions have been made economical through hydraulic fracturing. Between 1981 and 1984, 36 Vicksburg completions by Sun Exploration and Production Company were evaluated and subsequently fraced based on the results of pre-frac testing and frac optimization studies. These completions are located in 14 gas fields in Jim Wells, Brooks, Starr, and Hidalgo Counties of South Texas at depths ranging from 4,500' to 12,200' (1,372 m to 3,719 m).
This paper details a post-audit of well performance for these 36 Vicksburg completions, introduced by a review of Vicksburg reservoir characteristics and Sun's pre-frac evaluation methods. An example of the frac optimization and selection process is presented. The post-audit reviews predicted/actual initial deliverability, ultimate gas recovery, and frac length. An economic post-audit is also presented to illustrate the profitability of Sun's Vicksburg fracturing program. Finally, the conclusions of the post-audit as they relate to future Vicksburg frac candidates are presented and discussed.
The results of the post-audit generally indicate that the accuracy of post-frac initial deliverability projections provides a good correlation to the accuracy of projected ultimate recovery and the accuracy of frac length calculations. Also, the average ratio of predicted/actual initial deliverability provides a good overall indicator of a confidence factor that can be applied to Sun's reservoir simulator's projections of fractured well performance. Finally, statistical data infers that there is an evolution of skill in projections of post-frac well performance.
Offshore Safety - Drilling Operations
Authors: Dawson James A. 
Published: December 2007

This paper was prepared for the 41st Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Dallas, Tex., Oct. 2–5, 1966. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
This paper presents the safety practices as applied by Gulf Oil Corporation to simultaneous drilling and producing operations in the Gulf of Mexico.
Safety rules and regulations, both company and Coast Guard, are set forth and some detailed instructions are given as to the procedures to follow in particular situations.
Personnel safety equipment and training, safety devices, safety practices and Hurricane Action Plans are explained.
The use of special systems for control of small fires and the procedures for cheeking and maintaining this equipment has increased the confidence of the personnel engaged in offshore operations. Routine testing of equipment and daily practice drills have reduced the time to close a drilling well in from the 5 to 10 minutes required 10 years ago to an average of less than 1-1/2 minutes today.
Another result of the safety practices employed has been the maintenance of near normal production rates while a drilling rig is in the process of drilling and completing a particular platform.
The over-all result of the application of these safety practices has been the establishment and maintenance of high morale among all personnel involved in the exploitation of petroleum resources in the Gulf of Mexico.

Introduction
The application of good safety practices has been recognized for many years by operators and drilling contractors. The benefits derived from an effective safety program are large in terms of tangibles and intangible. The greatest intangible reward is better morale which is the most important single incentive that will keep a man returning to his job and performing to the best of his ability.
Since the advent of large scale offshore operations in the late 1950's, one of the basic problems confronting a major company operating in the Gulf of Mexico has been the development of proper habits and training of men to safely drill wells while producing from the same platform.
An Integrated Approach to Refining Reservoir Description Through Monitoring Fluid Movements in the Prudhoe Bay Reservoir
Authors: Bradley M. E. , Mayson H. J. , Wilkins K. L. 
Published: December 2007

ABSTRACT
Accurate reservoir description significantly enhances the ability to assess reservoir performance and to predict future performance from simulation and analytical techniques. These predictions impact infill drilling, waterflood area selection and operation, production offtake strategies, well completions, and workover philosophy. An integrated approach that uses available production and surveillance data has been employed to refine reservoir description. The available data includes: open and cased hole log data, reservoir pressure and transient analysis interpretations, RFT pressure data, and individual well production histories.
Downdip production from beneath continuous shale complexes has resulted in lateral movement of gas from the original gas cap at Prudhoe Bay. This and other physical evidence of barriers to vertical flow have been used to calibrate and enhance confidence in geologic shale maps based on well to well correlations. In areas where vertical gas cap expansion has occurred, tracking reservoir fluid movements has provided a method to identify the occurrence and observe the drainage of oil lenses from discontinuous shales. In addition, the data has allowed the computation of volumetric sweep efficiencies to improve reserve estimates, and delineate areas where recoveries can be increased by adjustments to offtake strategy, or application of future improved oil recovery techniques.
Evaluation of Oil-Soluble Resin as an Acid-Diverting Agent
Authors: Houchin L. R. , Dunlap D. D. , Hudson L. M. , Begnaud P. C. 
Published: December 2007

ABSTRACT
Laboratory tests were conducted to study the effects of using finely ground oil soluble resin as a diverting agent in hydrochloric-hydrofluoric acid treatments. The evaluation was conducted using a wellbore model which simulates varying permeability. These test results indicate that even though an even vertical distribution of fluids occurred when oil soluble resin was added continuously to all fluids, an inadequate ratio of HCl to HCl-HF acid was evident in the high permeability sections. This problem limits the effectiveness of a mixed acid system and may create acid induced inorganic precipitates. Based on results of the continuous diverting tests, a series of staged diverting evaluations were conducted. These results indicate that oil soluble resin may be effectively used in stages between acid stages to divert injected fluids.
Obtaining and Verifying Quality Cement Blends
Authors: Kunze K. R. 
Published: December 2007

ABSTRACT
A blending study showed that air agitation and transfer methods perform best when cement solids volume is kept below 30% of blend bottle volume. Above this volume the blend quality markedly declines. In the air agitation method, additional agitation longer than the customary ten minutes provides no benefit. In the transfer method, additional transfers beyond three do not improve blend uniformity. There is evidence that the admix bottle blending method is less adversely affected by blend size. However, the consistent uniformity of small blends suggests that the 30% maximum volume guidelines should be applied without exception.
Huntsman and West Engelland Fields, Cheyenne County, Nebraska: A Case History of Technical Lessons from a Legal Conflict
Authors: Tek M. R. , Coleman D. D. , Parker J. M. 
Published: December 2007

ABSTRACT
During the years 1982-85, a lengthy litigation took place between KN Energy and Marathon Oil Corp. The case involved performance of two fields on structures adjacent to a common saddle and suspected migration of storage gas into the gas cap of a producing oil field. After some 3 years of extensive study, discovery proceedings and preparations, the case came to trial in U.S. District Court in Lincoln, Nebraska, 8 Duly 1985. After nearly a month in court, agreement was reached between the parties to settle the case on 6 August 1985. The purpose of this paper is not to redress and reargue the legal controversy. Rather, it is to share in the technical forum of gas technology, the lessons learned from the synergistic study leading to a forensic conclusion.
The case history is unique and significant because it relates to extensive data from 2 fields and provides insight helpful to understanding major geological and operational factors affecting migration, exchange and mixing of mobile fluids underground.
The paper, written from the perspectives of applied reservoir engineering, geology and geochemistry, includes methodologies applicable to other similar situations – often suspected but not sufficiently investigated.
Application and calculations involving inventory verification methods, production-pressure trends, study of well records, gas-water, gas-oil contacts, computer simulation by finite element method, and identification of resident gas by isotope chemistry are among areas highlighted by specific examples.
Simultaneous Determination of Residual Saturation and Capillary Pressure Curves Utilizing the Ultracentrifuge
Authors: King M. J. , Falzone A. J. , Cook W. R. , Jennings J. W. , Mills W. H. 
Published: December 2007

ABSTRACT
Residual saturation and capillary pressure curves are important for modelling reservoir and laboratory processes. Knowledge of the residual saturation curve is necessary to determine the ultimate production from a tertiary recovery process Capillary pressure is required to interpret laboratory core floods and to describe multi-phase reservoir fluid flow.
The ultracentrifuge provides a rapid means of determining capillary pressure and residual saturation relationships. It is non-destructive, uses small samples, and is capable of attaining both high capillary pressures and extremely low residual saturations.
The effects of variation in residual saturation with Bond number are not included in the traditional Hassler-Brunner analysis for capillary pressure. Such desaturation effects can explain the anomalous experimental saturation distributions reported at high rotation rates [1,2]. The current work generalizes the Hassler-Brunner analysis to include desaturation and also to include the variation in centripetal acceleration through the core. The analysis also provides for the determination of residual saturation as a function of Bond number (kΔρg/σ).
Laboratory ultracentrifuge data is analyzed and both capillary pressure and Bond number residual saturation curves are obtained. The conversion of Bond number residual saturation curves to capillary number (µv/σ) curves may be performed by comparison with residual saturation curves obtained from core floods. In general, the ultracentrifuge residual saturation curves greatly extend those measured during conventional, non-destructive core floods; close to 100% oil recovery has been observed with the ultracentrifuge.
Mechanisms of Oil Displacement by Microorganisms
Authors: Kianipey S. A. , Donaldson E. C. 
Published: December 2007

ABSTRACT
Mechanisms of oil displacement at the oil-brine-sand interfaces by bacteria were investigated by microscopic observations and capillary pressure changes using unconsolidated, thin, reservoir flow cells. Three genera of bacteria, Bacillus, Pseudomonas. and Clostridium. were injected into water-wet and oil-wet cells of unconsolidated sand, saturated with brine and crude oil. The flow cells were placed under a microscope for visual and photographic observations. The flow cells were connected to a manometer to examine the complete capillary pressure hysteresis loop before and after introduction of bacteria.
The thin reservoir flow cells were first saturated with brine, and then displaced to irreducible water saturation with crude oil. Oil and brine displacements were then made to determine the complete capillary pressure relationship. Next, the bacteria and nutrients were introduced and incubated in the flow cell for 24-48 hours. Microscopic observations were recorded photographically. After incubation, oil and brine displacements were again made to determine the capillary pressure hysteresis loop.
During incubation, some emulsification of the oil at the oil-brine-sand interfaces were observed. Biogenic gas production caused pressure increases in the flow cells. Final measurements of the capillary pressure hysteresis loop showed decreases in residual oil saturation of 9-24% and changes in wettability to more water-wet systems.
This work shows the potential of microbial enhanced oil recovery, and investigates some of the mechanisms of oil displacement by three genera of bacteria. These considerations are important with regard to the technical feasibility of microbial enhancement of oil recovery.
A Fully-Implicit Model for Electrically Enhanced Oil Recovery
Authors: Killough J. E. , Gonzalez J. A. 
Published: December 2007

Abstract
A fully-implicit, three-dimensional reservoir simulator has been developed to model the electrically-enhanced oil recovery process (EEOR). The EEOR process is based orí the concept that by passing an electrical current through a conductive oil bearing formation, resistive heating of the oil will occur with corresponding reduction in oil viscosity. Over the past decade several attempts have been made to model this process with limited success because of simplifying assumptions in either the numerical formulation or the physics of the process. The formulation presented here rigorously models the physical phenomena important to the process with the additional feature of a fully-implicit treatment for added stability. Features of the model include the following: Rigorous treatment of formation resistivity as a function of temperature, water resistivity, and salinityAbility to simulate DC or multiphase AC electrical powerCapability of handling vaporization of connate water with resultant effects on resistance and power levelsCurvilinear, radial, or cartesian grid systemsCapability for horizontal electrodes and conductive fractures
Solution of the multiphase alternating current
case is accomplished by solving for both the real and imaginary portions of the complex electrical potential field. Through the use of the complex field it is necessary to solve only two equations for the electrical potential regardless of the number of phase differences in the power source. Since the model is based on the combustion formulation of Coats9, it includes many of the general features of that formulation.
Examples include a validation of the simulator using both laboratory data available in the literature and an analytical model. Grid orientation effects for the EEOR process are shown to be somewhat less than those for a conventional waterflood of a viscous oil. The importance of detailed modeling of nearwell phenomena is demonstrated. A unique feature of the model is demonstrated with a simulation involving the vaporization of connate water. Application of the EEOR process to a forty acre five spot waterflood shows the rate acceleration effect that is available with the process. Hypothetical simulations of novel electrode configurations involving horizontal electrodes and conductive well fractures show the advantages of these completion/electrode schemes. Finally, a comparison of direct current and three phase alternating current indicates an advantage for three phase power in a nine-spot pattern.