bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison of Cementation Logging Tools in a Full-Scale Simulator
Authors: Hayman A. J. , Gai H. , Toma I. 
Published: December 2007

Abstract
Acoustic cementation logging tools have been run in a full-scale cement flow loop and the logs compared to a physical examination of the cement in the annulus. In the flow loop the complete cycle of cementing operations — mud and spacer circulation, and cement placement — was carried out. The flow loop included artificial formation and double string sections.
Three tools were used in the flow loop: a sonic tool and two ultrasonic pulse-echo tools. The sonic tool measures the attenuation of sonic waves along the casing and is sensitive to shear coupling between casing and cement. The ultrasonic tools measure the damping of a thickness-mode resonance and the acoustic impedance. One ultrasonic tool samples every 45 degrees in azimuth; the other provides complete coverage using a rotating probe.
Conditions such as channeling, good and contaminated cement, mud and water were created in the flow loop. The logs were consistent with the subsequent physical examination, within the resolution limits of each tool. Very thin annulus and highly contaminated cement posed interpretation problems. Of the tools investigated, the rotating ultrasonic tool provided the most accurate predictions of cement distribution and quality.
The results illustrate the advantages and limitations of the different types of tools, and will be a useful aid in the interpretation of cementation logs.
Computers And The Petroleum Engineer
Authors: Gillette J.M. 
Published: December 2007

What are some of the uses a petroleum engineer can make of electronic computers? How can he learn to use them? This paper answers these questions in terms to be understood by the reader who is not a computer expert. The computer expert may find here one or two ideas of how he may extend the use of computers in his company.
How many times have you had to estimate an answer because there was neither time nor manpower to develop a more exact answer? If the answer is, "Too many times," then you can use a computer. For example, you, as petroleum engineers can use computers for calculation of design factors for process units, prediction of water flooding in a reservoir, or optimization and control of process units.
What is a computer? A computer is a device capable of accepting data, performing prescribed operations on these data, and supplying the results. A computer is shown schematically in Fig. 1. Four sections [central processor, input, output and auxiliary memory] make up the total computer system. Data are moved between the section and within the central processor under control of the central processor control unit. In a stored program computer, the control unit interprets and executes a program stored in the internal memory.
The input, output and auxiliary memory sections may consist of any one or all of the device listed in Fig. 1. The size and cost of a compute will depend upon the number and type of devices in the three sections and upon the speed with which operations are performed. There are many commercial computers available today. They range in size from the IBM 7090 to the Monrobot XI. For example, the Computer Characteristics Chart published by Adams Associates lists 61 computers.
Comparison of computers is not within the scope of this paper; however, a few facts to illustrate the range of sizes should be of interest. [See Table 1.]
Somewhere in the wide range of available computers, there is one, or perhaps several, to fit your needs. A word of caution — seek the advice of an expert before taking a selection.
How do you make a computer perform a given job? Computers operate by executing a program. A program is a series of instructions detailing each step the computer is to perform. An instruction for a computer consists of a series of code digits which the control unit interprets and executes. For example, the instruction 60 1423 1527 would be interpreted by the IBM 650 to mean RESET and ADD to the accumulator [60], the number stored in the memory location with the address of 1423, and go to the memory location with the address of 1527 to find the next instruction. A series of such instructions is a machine language program.
Testing of Subsea Gate Valves in Sand Slurry
Authors: Norland S. O. 
Published: December 2007

Abstract
Three gate valves from different manufacturers have been performance tested in a test loop. Anticipated production rates on the Statfjord Satellite Fields (SSF) have been simulated. The testing was part of the pre-qualification of the Christmas tree valves for this project. The tests were performed in order to determine the expected cycle life and failure mode while operating in a sand slurry environment. The valve’s ability to hold gas liquid pressure was monitored throughout the test.
On completion of the tests, the valves were disassembled and inspected for wear and tear, and the gates subjected to a material analysis.
Information gained from the tests has proved to be very useful for the development of SSF.
Four main discoveries were made during the testing: (i)- Grease in the valve cavity traps and accumulates sand.(ii)- The ability to operate in a sand slurry is dependent on the geometry of the valve internals.(iii)- Valves designed for API class II sandy service do not necessarily perform satisfactorily when test conditions are changed from those specified in API spec 14D.(iv)- Gates with tungsten carbide coating on high alloy steel performed better than those on low alloy steel.
Prediction of In-Situ Shaped-Charge Penetration Using Acoustic and Density Logs
Authors: Halleck P. M. , Wesson D. S. , Snider P. M. , Navarette M. 
Published: December 2007

Abstract
This paper presents the findings of a joint research project studying the relationships between rock acoustic properties and shaped charge penetration. The project was based on results from API project 89-36 in which a relationship between compressional wave velocity and penetration depth was found to be valid regardless of overburden stress. Two new charges were used in this study and the scope was expanded to include testing in three sandstones (dominantly quartz), three limestones (dominantly calcite), and a quartzite. The target properties studies were also expanded by measuring shear velocity (Vs) as well as compressional velocity (Vp). Penetration was correlated with a range of calculated parameters available from sonic and density logs such as bulk modulus, compressional impedance, and shear impedance. Well logs from a number of actual wells were reviewed to determine the values of these parameters for typical reservoir rocks.
Shaped charge penetration can be correlated and predicted in situ using certain acoustic rock properties. The effects of the target stress can be accounted for by the corresponding change in the rock’s acoustic properties. Penetration decreases with increasing values of all parameters studied, but on to a plateau level. Further increases in the acoustic parameters above these critical values, due either to using different target materials or to increasing stress, cause little further penetration decrease. The best correlation appears to be with bulk modulus. Many of the actual wells studied have values of bulk modulus above this critical level, and thus penetration depths for the studied charges should be equal to the plateau value in many reservoirs. It is speculated that this minimum penetration corresponds to the hydrodynamic penetration by the supersonic portion of the jet.
These findings will allow more accurate estimates of the downhole performance by using the acoustic and density logs from the well. Downhole penetrations can be estimated without regard for rock compressive strength, stress, or overburden. Given only a curve for penetration of the specified charge vs. an acoustic parameter, in situ penetration can be estimated in the actual formation. It is anticipated that the theoretical models of shaped charge penetration can be improved using these observations.
Improved System Test for Perforators
Authors: Wesson D. S. , Gill B. C. , Navarette M. 
Published: December 2007

Abstract
The current API RP-43 procedures for deep penetrating shaped charges require that they be tested to Section 1 (Evaluation of Perforating Systems Under Surface Conditions, Concrete Targets) and Section 2 (Evaluation of Perforators Under Stress Conditions, Berea Targets).1 The Section 2 procedures compare charges and estimate penetration in natural rock under simulated downhole conditions. This test is conducted on a single charge.
The objectives of the Section 1 (Concrete Target) procedures are to estimate the hole size in the perforated casingto test the system.
The primary objective of a system test is to determine if the single charge performance on the Section 2, test will be representative of the shots in actual field hardware. Many variables of the system can effect actual field performance.2 This paper discusses one factor that can adversely effect shaped charge performance in a perforator system: explosive interference.
For the purposes of this paper, explosive interference is defined as the reduction of shape charge performance under single shot performance as a result of geometric and explosive factors in a gun system. Many factors can contribute to explosive interference in a perforating system. These factors are not the subject matter of this paper; rather, this paper focuses on detecting explosive interference with modified API RP-43 Section 1 procedures.
Explosive interference in a gun system can range from very severe to very slight. Severe interference may be obvious by the condition of the gun carrier and the casing hole size. Penetration reductions of 50% or more have been observed with this type of explosive interference. However, observations made on modified API Section 1 tests have shown "slight interference" can reduce overall penetration by as much as 35%. This interference can not be detected by observation of the gun, casing, or standard Section 1 concrete penetration data.
After performing many API RP-43 Section 1 tests with high shot density perforators (over 4 spf), an improved API RP-43 Section 1 test procedure has been used successfully to determine whether significant explosive interference exists in a perforating gun system. This modified procedure assures that field perforator systems do not have an explosive interference problem that reduces perforator performance significantly below published Section 2 data.
Environmental Protection and Regulatory Compliance at the Elk Hills Field
Authors: Chappelle H. H. , Donahoe R. L. , Kato T. T. , Ordway H. E. 
Published: December 2007

Abstract
Environmental protection has played an integral role in the development and operation of the Elk Hills field since production at the maximum efficient rate was authorized in 1976. The field is located in a non-attainment area for California and National Ambient Air Quality Standards for two criteria pollutants and their associated precursors, is home to four endangered species, and operates within the California regulatory framework. Environmental protection and regulatory compliance is a multi-faceted program carried out through a substantial commitment of resources and workforce involvement. This paper describes the actions taken and resources employed to protect the environment, specific technologies and projects implemented, and the ongoing nature of these efforts at Elk Hills.
Coiled-Tubing-Life Modeling
Authors: Newman K. R. , Newburn D. A. 
Published: December 2007

Abstract
The use of coiled tubing (CT) is increasing rapidly in the oilfield service industry. Large CT sizes are being developed to meet new service requirements. The CT is being pushed closer to its performance limits for many of these services. To avoid CT failures in the field, it is important that these limits are well understood.
There are three major types of CT limits: Life limits due to low cycle fatigue and corrosion of the CT.Pressure and tension limits of the CT [1].Diameter and ovality limits.
These limits are interrelated in some ways but can be analyzed separately. The corrosion effect on the CT must be considered for the first two limits; but, the fatigue life of the CT does not significantly affect the pressure and tension limits.
New Plate Pack Design Leads to Increased Separation Efficiency of a Centrifuge
Authors: Plat R. , van den Broek W. M. G. T. 
Published: December 2007

ABSTRACT
Centrifugation is a very efficient technique for the de-oiling of production water. The high efficiency is the result of the large acceleration inside the centrifuge in combination with the effect of the built-in plate pack, usually a conical disc stack. To study possibilities for the improvement of centrifuge performance a new plate pack type is developed.
In this paper the working principle of both the disc stack centrifuge and the centrifuge with the new plate pack is described. A design of the new plate pack, with vertical plates parallel to the centrifuge axis, is presented. Results of a computer simulation program indicate that this design will lead to an increased efficiency of the centrifuge. Use of the plate pack instead of the disc stack will cause a decrease of the oil concentration of the centrifuge effluent of about 25%. Experiments with the new plate pack confirmed this. Further improvement of the plate pack may lead to a decrease of the oil concentration of more than 40%.
A Thermodynamic Study of Borate Complexation With Guar and Guar Derivatives
Authors: Dawson J. C. 
Published: December 2007

ABSTRACT
Borate–crosslinked galactomannan gels are commonly used as fracturing fluids. These fluids are reversible gels having crosslink junctions that easily dissociate causing the gels to be both thermal and shear thinning. Rheological measurements and 11B NMR analysis were used to examine the nature of these crosslink junctions. The NMR data suggests that a 1:1 borate polymer complex forms in abundant quantities. The primary structure of the crosslink junction may be an ionic association between the complex and adsorbed cations on the second polymer chain. Steady and oscillatory shear measurements were also made to examine the properties of the crosslink junction.
The Fractal Nature of Geological Data Sets: Power Law Processes Everywhere!
Authors: Garrison J. R. , Pearn W. C. , von Rosenberg D. U. 
Published: December 2007

Abstract
Geological features such as lithologie beds, fractures, folds, sedimentary structures, and pore networks are evident at a variety of scales and require that a length scale be specified in order to establish a frame of reference. Recently, it has been demonstrated that such apparently self-similar, scaling objects and features could be described as stochastic natural fractals. These natural fractals exhibit structures and features whose distributions are exponential (i.e., they exhibit power-law behavior) and can be described in terms of apparent or effective fractal dimensions. This paper presents a sampling of geological data sets whose distributions can be described as natural fractals: reservoir rock/pore systems, sand layers in mixed-lithology sequences, sandstone grain-size, and fault systems. The Arun Limestone, San Andres Dolomite, Norphlet Sandstone, Lobo Sandstone, and Spraberry Sandstone all exhibit fractal rock/pore networks with fractal pore size-frequency distributions. An example of a Tertiary deep-water sand/shale sequence from off-shore Gulf of Mexico exhibits a fractal sand thickness, and both the sand and shale thickness-frequency distributions are fractal, as well. A carbonate sand/carbonate mud sequence from Saudi Arabia also exhibits a fractal sand thickness-frequency distribution. Samples of a Tertiary Gulf of Mexico deep-water sandstone and a West African deltaic sandstone exhibit fractal grain size-frequency distributions. The amplitude and residue thickness of styolites from a Limestone from Abu Dhabi illustrate an example of fractal data sets from structural geology. Most geological objects and features, common to petroleum and mineral exploration and production, can probably be described statistically in terms of fractal geometry, and their fragmentation and irregularity can be characterized by fractal dimensions.
Key Gas Well Blowout Due to Waterhammer Phenomenon
Authors: Blick E. F. , Saleem S. 
Published: December 2007

ABSTRACT
A theory based upon the "waterhammer effect" is developed to explain the cause of the blowout of the Key 1–11 well on October 4,1981, operated by Apache Corporation in Wheeler County, Texas. The real cause of the accident was not known. The operating pressures before blowout were not sufficient to stretch 778′​′″ casing 80 feet and to cause this accident. However, this analysis shows that high pressures generated due to waterhammer appear to be the probable cause. It was assumed that the tubing suddenly ruptured (possibly from corrosion), causing a pressure wave to develop in the KCl water in the annulus between the 278′​′″ tubing and 758′​′″ casing. The upward moving wave reflected off the wellhead and moved downward. Depending upon the amount of gas on top of the water in the annulus, pressures up to 30,000 psi were computed. Pressures of these magnitudes were shown to stretch the 758′​′″ casing in excess of 80 feet which correlates with the evidence at the blow-out site.
Heat Transfer During Two-Phase Flow in Wellbores: Part I—Formation Temperature
Authors: Hasan A. R. , Kabir C. S. 
Published: December 2007

ABSTRACT
Heat loss from the wellbore fluid depends on the temperature distribution in the formation. Formation temperature distribution around a well was modeled by Ramey (1962) by assuming a vanishingly small wellbore radius. The assumption, while robust for some cases, could lead to unrealistic predictions of early-time behavior. This paper uses a rigorous model of heat transfer developed with consideration for the appropriate boundary conditions; that is, the heat transfer at the formation/wellbore interface is represented by the Fourier law of heat conduction. The superposition principle is used to account for the gradual change in heat transfer rate between the wellbore and the the formation.
The results of the new analysis are in agreement with the classical work of Ramey for large times (dimensionless time, tD &gt; 10). However, significant differences are noted between the proposed solution and that of Ramey’s log-linear approximation at small (tD &lt; 1.0) times. These differences may have considerable effect on certain applications, such as static earth temperature estimation from temperature logs, and bottomhole temperature estimation for cyclic steam injection.
We also present an approximate algebraic expression for the rigorous integral solution of dimensionless formation temperature, TD. This simplified expression is accurate for most engineering calculations. Use of this solution is shown in the second part of the paper where the wellbore fluid temperature distribution is computed during two-phase flow.
The Character of Coal Fracture Treatments in Oak Grove Field, Black Warrior Basin
Authors: Palmer I. D. , King N. S. , Sparks D. P. 
Published: December 2007

Abstract
Forty-three gel fracture treatments are analyzed in this report - in both Mary Lee/Blue Creek seams and in Black Creek seams. Although 12/20 sand concentrations were added to 10 ppg, there were virtually no screen-outs, presumably because pad volumes were so high (almost 50%). The Black Creek fractures are vertical, with substantial height growth, and are characterized by high treating pressures but relatively low fracture propagation pressures. There is conspicuous erosion by 12/20 sand of the fracture "entry region": perforations, perforation/fracture junction, or near-wellbore fracture constriction. It is postulated that erosion is conspicuous because (a) not all perforated zones are taking fluid, (b) the overall perforation/fracture junction may be more complex when subfractures from Black Creek seams join up to form the main fracture, or (c) the fluid, sand, and products of erosion are not confined to the coal seams. There are relatively few proppant-induced pressure increases, again possibly due to the fact that the 12/20 sand and products of erosion are not confined to the coal seams. The constant behavior of shut-in pressure with time in the majority of cases is consistent with an absence of any poroelastic effect (although about 25% of cases are consistent with a poroelastic effect). Approximately half of the Mary Lee/Blue Creek fractures are just like the Black Creek fractures and are interpreted similarly. The other half are different and exhibit high fracture propagation pressures. They are probably T-shaped fractures. A T-fracture is confined to a coal seam (there might be a T-fracture in more than one seam). Shut-in pressures measured throughout such fracture treatments are greater than 1 psi/ft, but generally decrease with time. In general the high pressure T-fractures are shallower than the low pressure vertical fractures. They do not show any correlation with a prominent fault block, which contradicts a previous finding. There are more proppant-induced pressure increases. In the high pressure Mary Lee/Blue Creek cases, the pressure drops at final shut-in range from small ( ~ 100 psi) to large ( ~ 750 psi). The former appear to be consistent with an elevated fracture tip resistance (or apparent fracture toughness). The latter are consistent with a near-wellbore flow constriction (discrete offsets/obstructions, or multistrands, or tortuous fluid flow path due to T-fracture geometry). The pressure decline after shut-in is not any faster in the high pressure Mary Lee/Blue Creek cases than in the low pressure cases. The most likely explanation is a reduction in coal permeability due to (a) high ambient in-situ stress, (b) damage by the high fracturing pressures. Gas production appears better, by more than 50%, in low pressure Mary Lee/Blue Creek cases than in high pressure cases. This is consistent with the notion that a vertical fracture is a more effective stimulation than a T-fracture.
Fractured Reservoir Simulation and Field Development, Natih Field, Oman
Authors: Dijkum C. E. van , Walker T. 
Published: December 2007

SUMMARY
Further development of the fractured Natih field requires a good understanding of the historical contributions from gas/oil gravity drainage and water/oil displacement. A history match of the field has been made using a fractured reservoir simulator, which apart from dual porosity, can model dual permeability and block-block interaction. Several studies aimed at describing the reservoir in detail were required before simulation could start. The history match shows that gas/oil gravity drainage has been about twice as effective as water/oil displacement. This figure is in good agreement with the gas and water sweep data derived from recent gas saturation and water saturation measurements in the field. Prediction runs show that promoting gas/oil gravity drainage by lowering the fracture oil rim is an attractive way to further develop the Natih field.