bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rock Failure During Tooth Impact and Dynamic Filtration
Authors: Myers G.M. , Gray K.E. 
Published: December 2007

Abstract
In previous publications, results of single-blow bit tooth impacts on saturated rocks at various stress states were reported. This paper extends these earlier works to include study of bit impact tests on salt water-saturated Berea and Bandera sandstone samples under conditions of elevated confining and pore pressure. During the tests dynamic filtration and deposition of a mud cake were occurring due to the presence of drilling mud in the borehole and a borehole-to-formation pressure differential.
Results indicate that saturation of these sandstones with salt water tends to make them weaker than when saturated with nonreactive fluids. Plastic failure often occurs even when extremely high fluid-loss muds are present in the borehole. The failure mode tends toward plasticity with decreasing fluid loss. Brittle failure of sandstones in mud-filled holes is apparently relatively rare. Depending on the stress level, and the associated failure mode, withdrawal of the bit tooth induces a tensile force that seems rather important relative to the quantity of rock removed by vertical tooth impact.

Introduction
A vast majority of the oil wells drilled today involve the use of colloidal muds having a measurable mud filtrate loss. It is known from field experience that reduction of the water loss of a mud generally results in a reduction of the penetration rate. This paper describes an investigation of crater formation at simulated bottom-hole pressure conditions for drilling fluids having different water losses.
The literature on single bit tooth impact (cratering) at atmospheric conditions is extensive, but only a limited amount of work has been performed at the stress conditions similar to that found in oil wells. Spherical penetrator cratering tests on rocks at hydrostatic pressure were performed by Payne and Chippendale. Chisel impact studies on limestone with independently varying overburden and borehole pressure and atmospheric pore pressure were reported by Garner, et al. Gnirk and Cheatham performed "static" penetrator tests on dry rocks at equal overburden and borehole pressures. Podio and Gray studied the effect of pore fluid viscosity at atmospheric pore and borehole pressures and varying overburden pressures. Their results illustrated the importance of fluid saturation of the rock. Yang and Gray reported single tooth impact tests on saturated rocks at elevated borehole, pore and confining pressures, but with equal pore and borehole pressures. For the work reported in Refs. 4 and 5, filtration across the hole bottom purposely was avoided. Maurer has investigated the effect of independently varying pore and borehole pressures at elevated overburden pressures by using a zero water-loss mud in the borehole. His tests were carried out under conditions that allowed independent control of overburden, pore and borehole pressures, but without control of filtration at the hole bottom.
Case History: PC Analysis of Bit Records Enhances Drilling Operations in Southern Alabama
Authors: Thomas J. M. 
Published: December 2007

Summary
Kelly No. 1 was drilled on a footage basis in Escambia County, AL. Computer bit-record analysis provided summarized information in a format easily read and understood by field personneL With a PC used to compare surrounding bit records on a cost-per-foot basis, the best bit type, weight on bit (WOB), and bit speed for a given section of hole were identified. From the analysis, field personnel were able to improve bit selection, resulting in three bit runs having the lowest cost per foot in a given section of hole and an overall lower-cost-per-foot drilling operation.
Inhibition of Gas Hydrates in Deepwater Drilling
Authors: Hale Arthur H. , Dewan Ashok K. R. 
Published: December 2007

Summary
With the movement of offshore rigs into deep water, the problem of gas hydrates has become an important issue in drilling. If a kick is taken, gas hydrates can form in the blowout preventer (BOP) or chokelines while the kick is circulated out. The water-based pill presented here significantly improves gas-hydrate inhibition. This pill, which can be spotted in the BOP and weighted up, is environmentally safe and easily adaptable to offshore operations. Compatible with commonly used drilling fluids, the pill can be mixed directly into the mud system without any adverse effects after the danger of hydrate formation diminishes. This technology is an important safety consideration for deepwater drilling well control and hydrate-free operations above the mudline.
Saturation From Logs Laboratory Measurements of Logging Parameters
Authors: Walther H.C. 
Published: December 2007

Abstract
While logs provide the only in situ measurement of water saturation, the measurement is not direct. Calculated saturation depends upon the value assumed for the saturation exponent n. The literature furnishes evidence that n varies and that it depends upon the type of rock and fluids, wettability, confining pressure, etc. Hence, a laboratory technique was developed for measuring m and n under a confining pressure and at formation temperature. The technique involves mounting a sample in a Hassler-type sleeve, using an oil-brine flow system and making two- and four-electrode measurements. Results of measurements on Frio, Miocene and Berea sandstones and Cretaceous limestones are presented with applications to log analysis.
Introduction
Decisions of whether or not to complete and how to complete, as well as reservoir engineering calculations, all require accurate water saturation data. Narrowing profit margins and development of marginal fields place strong demands on accuracy of data.
Logs provide the only in situ technique for determining water saturation. However, the measurement is not direct since the logs only measure formation resistivities. While equations relating resistivities to saturations were developed more than 20 years ago, these equations are too general for accurate application to all fields or formations. Also, the equations contain constants which are known to vary with rock type, stress, water resistivity, wettability, etc. Until more is known about these basic relationships, the recent advances in log quality and application of computers to log analysis cannot be fully utilized. The basic equations for resistivity log analysis are
(1)
where phi = fractional porosityF = formation factor (the ratio of the resistivity ofa brine-filled core, Ro, to the resistivity ofthe brine, Rw)m = m factor or cementation factora = an empirical constant
(2)
where Ro = resistivity of brine-filled coreRt = resistivity of core at saturation, Swn = saturation exponent.
Constants a, m and n ideally should be determined for every reservoir. Currently, if no laboratory-measured values are available, the values a = 1.0 and m 2 are commonly used for limestone reservoirs, and a 0.62 and m = 2.15 are used for sandstone reservoirs. A value of 2.0 is assumed for n.
Values for n ranging from 1.0 to 4.3 for natural core, and up to 54 for synthetic cores, are reported in the literature (Table 1). Also, several references show that the measuring technique is very important and that many of the problems associated with relative permeability measurements might be expected. Even allowing for measurement problems, there is ample evidence to show that n does vary.
JPT
P. 251ˆ
Needed: Greater Teamwork Between Disciplines
Authors: Halbouty Michel T. 
Published: December 2007

Abstract
Petroleum industry management, as well as individuals, must realize that greater teamwork between disciplines is needed to meet the challenges of the future. In the area of exploration this teamwork is indispensable. Future successful exploration will depend an the coordinated efforts of the geologist, geophysicist and the petroleum engineer. Ways by which this coordination can be achieved are discussed.

Introduction
There is no question that greater teamwork among the disciplines of geology, geophysics and petroleum engineering is needed today more than ever before. There was a time, during the so-called golden years of the industry, when little attention was paid to combining the resources of these three powerful technical segments.
In order to understand what is needed today and what will be required in the future from these three disciplines, it is important to reflect on the status of world petroleum production on Jan. 1, 1901. The world's annual production was about 138 million bbl. Russia was the leading oil-producing nation with 68 million bbl. Of the 58 million bbl produced in the U. S., 92 percent, or 53 million bbl, was from the so-called "oil region" of Ohio, West Virginia, Pennsylvania, Indiana and New York. Four million bbl, or 6 percent, was from California, and the remaining 1 million bbl, or 2 percent, was produced from the Corsicana field in Texas.
The average production for the so-called large producers in the U. S. was 75 B/D. The entire world production was consumed in lubrication and illumination. Civilization was still in the lubrication age. There was not enough petroleum produced to justify its use as a liquid fuel. But Spindletop changed all of this.
On Jan. 10, 1901, in the dawn of a new century, the Spindletop discovery fired the imagination of the entire world. The potential from the discovery well, if estimated on a per-year basis, was more than the combined production of the entire world. Spindletop brought on the liquid fuel age and was the beginning not only of the world's industrial revolution, but also, certainly, of the oil industry.
Prior to the Spindletop discovery and for a decade after, the status of the petroleum geologist was that of a college professor who was retained occasionally by oil companies to do consulting work. On the other hand, the early engineer was merely a roughneck or a roustabout or a driller who had no formal engineering education. But these men who did the work in the field with countless improvisions and inventions brought about the know-how that is recognized throughout the world as distinctly American.
Numerical Methods of Higher-Order Accuracy for Diffusion- Convection Equations
Authors: Price H.S. , Cavendish J.C. , Varga R.S. 
Published: December 2007

Abstract
A numerical formulation of high order accuracy, based on variational methods, is proposed for the solution of multidimensional diffusion-convection-type equations. Accurate solutions are obtained without the difficulties that standard finite difference approximations present. In addition, tests show that accurate solutions of a one-dimensional problem can be obtained in the neighborhood of a sharp front without the need for a large number of calculations for the entire region of interest.
Results using these variational methods are compared with several standard finite difference approximations and with a technique based on the method of characteristics. The variational methods are shown to yield higher accuracies in less computer time.
Finally, it is indicated how one can use these attractive features of the variational methods for solving miscible displacement problems in two dimensions.

Introduction
The problem of finding suitable numerical approximations for equations describing the transport of heat or mass by diffusion and convection simultaneously has been of interest for some time. Equations of this type, which will be called diffusion-convection equations, arise in describing many diverse physical processes. Of particular interest here is the equation describing the process by which one miscible liquid displaces another liquid in a one-dimensional porous medium.
Predicting Gravity-Drainage Performance Using a Three-Dimensional Model
Authors: Hall H.N. 
Published: December 2007

Abstract
Reservoir and producing characteristics can govern the decision to use either a one-, two- or three-dimensional model for making predictions for gravity-drainage reservoirs. Examples of conditions requiring one-, two- and three-dimensional calculations are given. In 1961 the author presented a method for predicting one-dimensional gravity-drainage performance. This work has been extended to obtain a three-dimensional model, which is described and for which a sample problem is presented.

Introduction
Many papers on gravity drainage or gas-cap drive have been presented for conditions where the reservoir is treated as a single areal segment so that, in effect, only one-dimensional flow is considered. Other authors have given evidence showing that the one-dimensional concept would be unsatisfactory to predict reservoir performance for certain types of reservoirs. Experience has indicated that specific reservoir and producing conditions govern whether one-, two- or three-dimensional concepts must be used as a basis for reliable reservoir performance predictions.
Previously the author presented a paper outlining a method for predicting the performance of gravity-drainage reservoirs. That paper treated the reservoir as a single areal segment so that it was applicable for only one-dimensional flow. The work has been extended to obtain a three-dimensional model that can be used to predict performance of gravity-drainage reservoirs. Although capable of being three-dimensional, it can be used equally well for one- and two-dimensional predictions.
This paper discusses those reservoir and producing conditions governing the choice of model, and also describes a three-dimensional model suitable for predicting reservoir performance in the more complex situations.
Effects of Pipe Roughness on Friction Pressures of Fracturing Fluids
Authors: Shah Subhash N. 
Published: December 2007

Summary
In this study, the effects of pipe roughness on friction pressures of uncrosslinked and crosslinked fracturing gels are reported from flow data gathered in smooth and rough pipes. Pipe-roughness effects are found to be very significant in the estimation of friction pressures of fracturing fluids. These effects are more pronounced with less viscous fluids than with more viscous fluids and at higher rates with both fluids. From the data gathered with fluids tested in this study, correlations to estimate friction pressures of fracturing gels in turbulent flow in rough pipes are also presented. Though not ideal, these correlations allow better estimates of friction pressures in rough tubular conductors than existing methods do.
Performance of Seeligson Zone 20B-07 Enriched-Gas-Drive Project
Authors: Walker J.W. , Turner J.L. 
Published: December 2007

Abstract
In 1957 Humble Oil and Refining Co. initiated a program in the Seeligson (Zone 20B-07) field, Kleberg County, Tex., that involved displacement of oil by enriched gas. Early evaluation showed that nearly 100 percent oil recovery was being obtained in the volume of reservoir swept by enriched gas. Subsequently, it was observed that the enriched gas way breaking through at producing wells earlier than expected, and that volumetric sweep efficiency was lower than anticipated. Simultaneous injection of water and enriched gas was begun in 1963 in an attempt to improve sweep efficiency. In 1965 it was determined that sufficient enriched gas had been injected into the reservoir, and the injection substance was converted to water and dry gas.
The experiment program in Zone 20B-07 is largely complete. Cumulative production froth the reservoir has been 3.7 million bbl of oil, and oil recovery froth the Zone 20B-07 enriched-gas project has been 50 percent of the original ail in place. Production to date has greatly exceeded the native dissolved-gas-drive recovery that was predicted to be 22.3 percent of in-place oil. As another comparison, current recovery also exceeds expected waterflood recoveries in the range of 42 to 48 percent- estimates based on experiences in similar reservoirs in this area.
This paper covers field results, particularly those regarding displacement and sweep efficiency and the effects of changes in injected fluids. Reasons for observed performance are discussed with regard to future application of miscible displacement.

Introduction
The Seeligson Zone 20B-07 enriched-gas-drive project is completed. The theory of miscible displacement, reasons for experimenting in the zone, and early performance data are well documented by earlier reports. This paper presents final results of the project and discusses factors that will assist future evaluations of enriched-gas-drive applications.
Performance Review of Shoats Creek Unit Vaporizing Gas-Drive Project
Authors: Dorsey J.B. 
Published: December 2007

Abstract
Performance of a high-pressure, vaporizing gas-drive project in a volatile oil reservoir is discussed. The project has been in operation for over 8 years. Present recovery from the over-all displaced portion of the reservoir is 40 percent, and an ultimate recovery of 60 percent is indicated. Calculations reflect an over-all displacement volume of 50 percent for the entire reservoir; therefore, ultimate oil recovery will be 30 percent of the entire reservoir oil originally in place. Laboratory vaporization tests conducted prior to project initiation also are presented and discussed, along with an analytical method of determining stock-tank oil production and gas injection requirements related to over-all volumetric displacement efficiency from these data.

Introduction
The Shoats Creek field is located in Beauregard Parish, La., in the extreme western part of the state (Fig. 1 ). Discovered in 1956, the field is productive in three Cockfield sand zones, ranging in depth from 8,000 to 9,000 ft. The upper two zones, 1st and 2nd Cockfield, are condensate-bearing gas reservoirs. The lowest zone, the 5th Cockfield, is a volatile-oil reservoir. Laboratory work conducted on crude oil from the 5th Cockfield zone shortly after field discovery demonstrated that, when contacted with dry gas, significant volumes of the oil could be vaporized at reservoir temperature and at an appropriately high reservoir pressure. Further study led to the conclusion that early initiation of a crude vaporization project in the 5th Cockfield zone would be superior economically to other methods of reservoir depletion. Consequently, the zone was unitized and gas injection operations started late in 1958. This paper discusses laboratory work performed in conjunction with the project, and project performance to the present.
Gas Turbines -Application and Experience
Authors: Porter John A. 
Published: December 2007

Abstract
Gas turbine engines, which convert chemical energy to mechanical energy, have become increasingly popular for industrial uses during the past few years. Oil and gas are used as fuel for the turbine. As the demand for turbine engines grows, new markets for oil and gas products will be created. A description of the basic theory, construction and performance of the gas turbine engine, with emphasis on oil and gas field applications, is presented.

Introduction
In recent years, the gas turbine engine has captured a significant portion of the industrial prime mover market. The "1967 Annual Gas Turbine Catalog" lists a total of over 35 million industrial gas turbine horsepower now in use. The total was only 24 million hp in 1966. The population of industrial gas turbine horsepower increased 50 percent in 1 year - proof of the increasing acceptance of the industrial gas turbine engine.
Gas turbines convert chemical energy to mechanical energy. Natural gas and petroleum products are the source of chemical energy for gas turbines. In a larger sense, the oil and gas industry is interested in every turbine sold. As turbine technology improves, new markets will be created for oil and gas products. More directly, the oil and gas industry itself provides a great part of the existing turbine market.
Basic theory, construction, performance and application of the modern gas turbine is reviewed. Oil and gas field applications are emphasized.
Vertical Fracture Height-Its Effect on Steady-State Production Increase
Authors: Tinsley John M. , Williams J.R. , Tiner Robert L. , Malone W.T. 
Published: December 2007

Data taken from a steady-state electrolytic model have been used to developcurves showing production increase as a f unction of fracture height, fracture length, reservoir height, drainage radius, fracture flow capacity, formation permeability and wellbore radius. The work allows a fullerevaluation of the effect of fracturing parameters on productivityincrease.

Introduction
Hydraulic fracturing methods for productionstimulation have become a common procedure in the oiland gas industry. Fracturing treatments areperformed on wells of various potentials to help increasethe production rate. In addition to the desire forincreased production is the need to predict whatincrease might be expected. This knowledge is usefulin economical treatment planning to accomplish thedesired production goals for the well.
Theoretical production increases due to horizontalradial fractures may be calculated using equationsdeveloped from mathematical analyses and electricalmodels. It also is possible to predict theoreticalproduction increases due to vertical fractures usingcurves developed from electrical and mathematicalmodels." However, these studies assumed that thevertical fracture height and the formation height wereequal, which may not be true." In addition, the finalfracture height through which fluid is produced maynot be equal to the created height.
The development of vertical fracture proppanttransport relationships has made unrealistic theassumption that propped fracture height is equal tocreated fracture height. Through the use of publishedproppant transport equations, it is possible tocalculate the height of a bed of propping agent depositedin a fracture of a given height. Assuming that thefluid flowing in the fracture moves through only thepropped portion of that fracture (i.e., that theunpropped part of the fracture heals) it becomesessential to know how production increase varies with theratio of propped fracture height to formation height.
It should be recognized that future investigationmay determine that the fracture does not healcompletely and that a highly permeable channel existsover the deposited bed of proppant. The effect of thischannel was not considered for the present study.
The following analysis of experimental dataallowed development of curves to determinetheoretical production increases considering fracture heightas a variable.

Discussion
In designing a fracturing stimulation treatment anumber of variables must be considered. The size ofthe treatment, type of proppant used, proppantconcentration, treatment fluid properties and wellconditions are all factors affecting the dimensions andpermeability of the fracture.
Production increase due to a vertical fracture isaffected by propped length, height, width andpermeability of the fracture for a given set of formationconditions. Production increase may be defined asthe ratio of production rate after fracturing to theproduction rate before fracturing at the samepressure differential, pe - pw.
JPT
P. 633ˆ