bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soviets Relying on Turbodrill to Help Meet Future Production Quota
Authors: Salnikov I.S. 
Published: December 2007

Abstract
The Soviet Government has given its petroleum industry a 1965 production target of 4,800,000 B/D. The target centers on progress of Russian drilling technology and application of new developments and production techniques.
Performance of Soviet development rigs is estimated to increase from 3,180 ft/rig/month in 1956 to 5,800 ft/rig/ month in 1960. By far the greater part of Russian wells are drilled by turbodrill. Electrodrills and small turbodrills are being tested to improve drilling efficiency at depths below 7,000 ft where turbines have difficulty in making hole.
In production technology emphasis is being placed on supplementing natural reservoir energy by water injection. The current injection ratio is 1 bbl of water for each barrel of oil produced. Automation of crude oil production from wells to refineries is under study by technical groups. A concerted effort to reduce cost and improve efficiency of operations is now in progress.

Introduction
The Soviet Government recently announced a plan to boost crude oil production by 1965 to 4,800,000 B/D. During the same period natural gas output is scheduled to rise to 14.5 billion cu ft/ day. These targets in crude production amount to an average increase of slightly over 14 per cent per year for the seven-year period (1959–1965). In the light of their recent annual increases in production, 18.0 and 17.8 per cent for 1955 and 1956, respectively, the rates do not appear to be unreasonable targets. By implication these plans reflect the confidence of the Soviet Government in the ability of their petroleum technology to double current output and to reach a rate which is approximately half of U. S. production at this time.
Since World War II information on Russian technology has been scarce but in the past few years export of some 250 technical and scientific publications has been permitted. Among these are such journals on petroleum industry as Oil Worker, Oil Economy, Geology of Petroleum, Geophysics, etc. These publications are giving us a clear picture of Russian industry and its accomplishments and a better understanding of their petroleum technology. Much of the Soviet's ability to attain the targets set for 1960 and beyond will depend on their technical accomplishments. Therefore, a review of Russian petroleum technology should certainly give us a better understanding of their aims and efforts.
Discounted Cash Flow as a Measure of Market Value
Authors: Reynolds Fred S. 
Published: December 2007

Abstract
The discounted-cash-flow method has been used for years in the field of finance and banking. It has been gaining stature for several years in the money management for certain industries, and the oil and gas industry is rapidly recognizing its merit for choosing investment alternatives.
The method is suggested as a measure of market value because it is conceptually realistic and suffers from none of the limitations that the other yardsticks do.
Data are presented that are indicative of profitable levels of return. Comparisons of various measures of value for five actual sales or valuations are given, and the effects of using any one of the parameters of value have been calculated to show the superiority of the discounted-cash-flow method.
An oil and gas investor must place a time value on his money; hence, the discounted-cash-flow method is gaining its acceptance in directing management toward new capital expenditures. It is hoped the method will be utilized and accepted for determining fair market values.

Introduction
Most engineers whose profession involves evaluating oil, gas, or other mineral interests must sooner or later create hypothetical sales to ascertain the fair market values of mineral reserves. The principal causes for these perplexing situations are the necessities of providing bases for settling estate, gift and ad valorem taxes.
If an engineer were pursuing a valuation so that he could advise management or a client concerning the worth of an investment, his requirement would be extremely similar and should be treated no differently. Any profit-conscious investor must either determine if a desirable level of return is realized for a quoted price or the maximum price that can be paid to yield a desirable level of return. In essence then, this problem leans heavily on the basic requirements of engineering valuations; however, the engineer is often faced with defending his basis for determining worth in the ground in addition to the calculated reserves for the interest. The experienced engineer or investor can often determine the approximate value of an oil and gas interest by prudent examination of the engineering computations; however, many officials are reluctant to ascribe to the experience and prestige the valuator has attained in his profession. It then behooves appraisers to utilize a definitive concept for determining fair market values. There have been many concepts formulated and utilized, and each is characterized by varying intrinsic weaknesses. it is the purpose of this paper to propose a method that eliminates most of the conjectural features.
Methods for Field Monitoring of Oil-Based Drilling Fluids for Hydrogen Sulfide and Water Intrusions
Authors: Garrett R. L. , Carlton L. A. , Denekas M. O. 
Published: December 2007

Summary
Analytical methods are presented for rig-site monitoring of oil muds for H2S and "active" sulfides (such as the neutralization products of lime and H2S) and for small changes in water content. Applications of the two methods are discussed. The sulfide method is a modification of the water-mud API Garrett Gas Train (GGT) procedure adapted to test a sample of whole oil mud. The water-content method is a modification of the conventional retort method that uses a necked-down, precision-calibrated (Kolmer) centrifuge tube as the retort liquid receiver. Additionally, an effective, high-zinc-content, sulfide-scavenging chemical, ZnO, is discussed for use in oil muds as an additive for converting the active sulfides into a more inert form, ZnS.
Experimental Study of Cuttings Transport in Directional Wells
Authors: Tomren P. H. , lyoho A. W. , Azar J. J. 
Published: December 2007

Summary
A large-scale study of cuttings transport in directional wells is discussed in this paper. Previous investigators used unrealistically high fluid velocities and/or short test sections where steady-state conditions had not been established. This study used a 40-ft [12.2-m] test section. Pipe rotation and eccentricity, as well as several types of drilling muds and flow regimes, were studied. Annulus angles varied from 0 to 90°, and actual drilled cuttings were used.
The major factors affecting cuttings transport are drilling fluid velocity, hole inclination, and fluid rheological properties. Much higher annular velocities are required for effective hole cleaning in directional wells than in vertical wells. An increase in hole angle and/or drilling rate reduces the transport performance of drilling fluids. Hole angles of 40 to 50° are critical because of cuttings buildup and downward sliding of the bed of cuttings. High-viscosity muds were observed to provide better transport than low-viscosity muds.
Mechanisms of Foam Flow in Porous Media: Apparent Viscosity in Smooth Capillaries
Authors: Hirasaki G. J. , Lawson J. B. 
Published: December 2007

Abstract
The apparent viscosity of foam flowing through smooth capillaries was measured experimentally, and a mathematical model was developed. Foam texture (a measure of bubble volume) is a key parameter in determining the following properties of foam flowing through a capillary: (1) whether the foam exists as bulk foam or as a chain of bubbles where each pair of bubbles is separated by an individual lamella, (2) the number of lamellae per unit length of the capillary, and (3) the radius of curvature of the gas-liquid interface. The apparent viscosity is the sum of three contributions: (1) that from slugs of liquid between bubbles, (2) the resistance to deformation of the interface of a bubble passing through a capillary, and (3) the surface tension gradient that results when surface active material is swept from the front of a bubble and accumulates at the back of it. The sensitivity of both measured and calculated apparent viscosity is presented as a function of bubble size, capillary radius, ratio of bubble radius to capillary radius, velocity, quality, and surface tension gradient.
An Improved Acid for Calcium Sulfate-Bearing Formations
Authors: Dunlap Peggy M. , Hegwer John S. 
Published: December 2007

Abstract
An improved acid for the treatment of sulfate-containing limestones and dolomites is described. The acid is designed to reduce the reprecipitation of dissolved calcium sulfate and the possibility of plugging permeable flow channels. In addition, this improved acid has a much lower reaction rate than that of regular acid; the advantages of a "retarded" acid are obtainable.
Field testing of the acid has shown it suitable for use in sulfate-containing formations. Substantial improvements in productivity generally resulted.

Introduction
Acid treatments of limestones, dolomites and other formations bearing carbonate deposits are frequently unsuccessful when the calcareous formation contains sulfate, either as anhydrite (CaSO4) or gypsum (CaSO4 2H2O). Preliminary dissolution in acid followed by redeposition of calcium sulfate appears to be a major factor contributing to poor well performance after acidizing. The precipitate is usually the gypsum form of calcium sulfate, but in higher temperature formations it may be anhydrite. The freshly precipitated crystals are nearly always very small and needlelike. They may occupy a gross volume many times that of the original anhydrite crystals and will obviously constitute an impediment to flow through newly enlarged flow channels.
It is believed that the redeposition problem is most severe when anhydrite lines the fracture systems and large pores which supply the effective permeability of a formation. Microscopic inclusions of calcium sulfate also present large sulfate surface areas for dissolution in acid. In either case, great amounts of calcium sulfate may dissolve before the acid can be spent on formation carbonates. For regular spent acid (originally 15 per cent hydrochloric acid) the precipitate could be as much as 270 lb gypsum/1000 gal acid.
Two techniques have been applied by the industry for reducing sulfate plugging during acidizing. The method commonly employed in the field is the attempted removal of a quantity of regular treating acid before it has reacted completely with the formation. This is practiced because the solubility of calcium sulfate is greater in a solution that is still acidic than in one which has been largely spent on the formation rock. The chance of precipitative plugging is therefore reduced if the withdrawal is successful. However, it is often impossible to get the acid out of the formation before precipitation occurs.
A Compositional Formulation of the Pressure and Saturation Equations
Authors: Watts J. W. 
Published: December 2007

Summary
This paper describes a sequential implicit formulation of the compositional reservoir flow equations. This procedure offers improved stability over implicit pressure, explicit saturation (IMPES) methods but, in general, is not as expensive computationally as fully implicit methods. It also possesses several other attractive features. It permits an efficient combination of compositional and black-oil capabilities in a single program. Important to this is the fact that it lends itself to a modular program design. Finally, it has a natural physical interpretation that can be very helpful in the understanding of model behavior.
Curvilinear Coordinate Systems for Reservoir Simulation
Authors: Leventhal S. H. , Klein M. H. , Culham W. E. 
Published: December 2007

Abstract
This paper presents a set of curvilinear coordinate transformations that lead to no mixed derivative terms in transformed flow equations. The transformations are created by examining the transformed flow equations and by showing that the mixed derivative terms are zero if the transformation satisfies a system of differential equations that depend on the geometry and rock property distribution within the reservoir. Numerical examples with a black-oil simulator are presented to show the increased accuracy resulting from the use of the curvilinear coordinate system and the importance of eliminating the mixed derivative terms.
A Fast Convolution Method for Implementing Single-Porosity Finite/Infinite Aquifer Models for Water-Influx Calculations
Authors: Leung W. F. 
Published: December 2007

Summary
Existing aquifer models are either computationally inefficient or inaccurate for reservoir water-influx calculations. A new fast convolution method (FCM) that does not require lengthy data manipulation is used to implement four different single-porosity finite and infinite aquifer modeis for unsteady-state water-influx calculations. Numerical examples on circular and linear aquifers, together with a step-by-step calculation, are used to demonstrate the accuracy and efficiency of the models. These numerical studies show that the FCM approach is as much as 20% more accurate than the widely used methods for both finite and infinite aquifers. The models can be implemented readily in numerical reservoir simulators, as well as in hand computations.
Severe Slugging in Offshore Pipeline Riser-Pipe Systems
Authors: Schmidt Želimir , Doty Dale R. , Dutta-Roy Kunal 
Published: December 2007

Abstract
Severe slug flow (i.e., terrain-dominated slug flow) was studied in a simulated offshore pipeline riser-pipe system. Severe slug flow is characterized by extremely long liquid slugs generated at the base of the vertical riser. This phenomenon occurs at low gas and liquid flow rates and for negative pipeline inclinations. Slugging in some offshore platforms has required the use of operating procedures that drastically curtail production. Losses in flow capacity up to 50% have been reported.
A hydrodynamic model has been developed for severeslug flow. The model's predictions agree with experimental data. The model can be used to design new pipeline riser-pipe systems or to adjust the operation of existing systems to prevent the occurrence of severe slug flow. Also, a flow-regime map is presented for predicting the severe slug flow regime, where the boundaries are determined analytically. Finally, additional methods are proposed to prevent the flooding of separation facilities by riser-pipe generated slugs. This study is an extension of Ref. 1, in which severe slug flow was introduced and was only partially modeled.
Recording Downhole Formation Data While Drilling
Authors: Elliott L.R. , Barolak J.G. , Coope D.F. 
Published: December 2007

Abstract
An understanding of the formation is essential for effective drilling, casing and completion of oil and gas wells. Several methods and many tools are available to obtain information about the formation. Some of these tools collect or provide downhole data during the drilling process and are, therefore, termed measurement-while-drilling (MWD) tools. This paper describes a new MWD tool which records formation data during the drilling process. process. System hardware is described and its operation and rig impact outlined. A discussion of the theoretical implications of measuring formation data during the drilling process is presented. Field data are presented and compared with wireline data. From these data, excellent MWD log quality is demonstrated. MWD gamma ray logs are shown to have a superior bed resolution to those produced by wireline, for most cases, and the resistivity sensor, contained in the recording system, is demonstrated to be the most versatile MWD resistivity tool commercially available. It is seen from field history that recording formation data while drilling is a cost-effective and reliable method of obtaining formation information when compared to other available methods.

Introduction
A variety of MWD tools is commercially available which provide services ranging from only directional through multi-sensor packages which include various combinations of hole angle and direction, formation gamma and resistivity, and downhole temperature and pressure and weight and torque on bit. Except for the recording system discussed in this article, all commercial MWD systems depend on some form of mud-pulse telemetry for communication of the data from downhole to the surface. There are many cases when real time transfer of data is required. Tool face measurement during steering and WOB, for instance, would be of little use if not provided in real time. However, information obtained during drilling can provided in real time. However, information obtained during drilling can be of value when available at the completion of each bit run. Using this approach, a complex and costly portion of the MWD system can be eliminated, with concomitant advantages in cost, reliability and rig impact.
Many applications do exist for recording formation characteristics (lithology) during the drilling process. A recording MWD service can be used when drilling surface hole to identify shallow hydrocarbons and eliminate a wireline log. High-angle and difficult holes are easily logged with a recording MWD tool when wireline logging is difficult, costly or impossible.
Pressure Maintenance and Model Studies
Authors: Eckles W.W. 
Published: December 2007

Abstract
Pressure maintenance programs play an important role in the efficient and economical recovery of oil and gas. For this reason, it is advantageous to consider carefully all of the factors involved in the design of an efficient pressure maintenance program.
The purpose of this article is to
- review the methods of evaluating past reservoir performance and predicting future performance for various proposed plans of pressure maintenance operations, and
- discuss the use of potentiometric model studies in designing pressure maintenance programs.
The following aspects of model studies are discussed at length:
- purpose of model studies,
- how model studies are carried out,
- technique employed in the construction of potentiometric models,
- sweep patterns and how they are obtained from a potentiometric model, and
- model data and how it is used in evaluating a pressure maintenance waterflood program.
Since the ultimate recovery of hydrocarbons under certain pressure maintenance programs will depend on how the injected water, gas or other types of fluid will sweep the reservoir, it is concluded that model studies can play a very important part in evaluating various proposed plans of operation, in determining the best locations for injection wells, in determining the proper distribution of injection between wells and in picking locations of producing wells which would increase ultimate recovery and profit.

How Are the Injection Requirements for Pressure Maintenance Programs Determined?
The first signs of reservoir trouble generally are detected from a study of the reservoir behavior after the field has been developed and produced. Rapidly falling reservoir pressures, increasing gas-oil ratios and increasing water production may be the first indicators of trouble. One of the best recognized and most important tools for studying the past performance of a reservoir is the material balance which is discussed abundantly in the literature. Digital computers and electronic reservoir simulation are used for the prediction of future performance of the reservoir under various operating conditions. From these studies, the future needs for the pressure maintenance program can be determined. In other words, how much injection is needed to maintain the pressure at the desired level, or to stop shrinkage or expansion of the gas cap, and how much natural water influx, if any, may be experienced in the future for the different plans of operation?
The Sonic Log and The Delaware Sand
Authors: Millican Marcus L. 
Published: December 2007

Abstract
The objective of this study has been to develop a method of log interpretation in the Delaware sand whereby the effects of the shale contained within the sand can be recognized and accounted for in a quantitative solution for porosity and water saturation.
Both theoretical and empirical considerations are discussed. A simplified interpretation chart is presented which provides a means of amending the conventional porosity resolution of the Sonic log to compensate for the presence of shale. The amount of shale within the sand and its degree of lamination may be inferred from a calibrated gamma ray log. The resulting porosity value may then be used in conjunction with a knowledge of the formation resistivity to determine water saturation.
Of added interest, particularly in the Delaware sand, is an approximation of permeability which may be derived empirically from the simplified chart.
The discussion is illustrated by field examples.

Introduction
The performance of the Sonic log in defining the porosity fraction in clean, consolidated formations is well known, particularly in sandstones that are well compacted and free of shale. An approach to Sonic log porosity determination in shaly sands has been recently developed. This method involves correcting the Sonic log readings by means of an a factor, where a is the ratio of the pseudo-static SP to the static SP, and is a function of the amount of shale present.
This method is dependent upon a contrast between the salinities of the drilling fluid and the connate water in the formation, inasmuch as this contrast produces the SP effect. In wells drilled with salt mud, the contrast, and with it the means of obtaining the a correction, disappear.
In the Delaware basin, the large majority of rotary wells drilled to the uppermost sands of the Bell Canyon group employ salt mud as the drilling fluid. These sands have been the objective of most of the drilling exploration in the basin to date. A comparison of porosity values in these sands, as determined by core analysis, to Sonic log readings has indicated that a correction for the shaliness of the sand is needed. In the absence of an SP curve to determine the correction factor, the porosity resolution of the Sonic log in these sands has been questionable.
Reservoir Engineering in Coal Seams: Part 1—The Physical Process of Gas Storage and Movement in Coal Seams
Authors: Gray Ian 
Published: December 2007

Summary
This is the first of two papers concerning the movement of gas in coal seams. It deals directly with the physical behavior of the coal seam as a reservoir. Coal seams show considerable differences in behavior from normal porous gas reservoirs in both the mode of gas storage and permeability characteristics. Most of the storage of gas in coal is by sorption into the coal structure, while the coal permeability is cleat-(fracture-) or joint-controlled and may vary over a wide range during production. This permeability fluctuation is not solely a phase relative permeability effect, but is rather a result of the opposing effects of effective stress increase with fluid pressure reduction and shrinkage of the coal. Reducing fluid pressure tends to close the cleats, reducing permeability, while shrinkage tends to open them.