bluuebunny/crossref_metadata_2025_split huggingface dataset:
3D Analytical Model for Hydraulic Fracturing: Theory and Field Test
Authors: Bouteca M. J. 
Published: December 2007

ABSTRACT
A fully 3-D analytical model of hydraulic fracture propagation is proposed which can be used to determine both the least in situ stress and the fracture height if the pressure is recorded as a function of time. A field test is presented where the values of in situ least principal stress and height calculated by the model could be compared with in situ stress measured by shut-in pressure test and with fracture height estimated by acoustic emission analysis.
It is also shown that stress variation with depth and any pressure drop law in the fracture can be simulated by modifying boundary conditions on the fracture surface.
Engineering Manpower Supply and Demand in the Petroleum Industry as Affected by Engineering Salary Trends
Authors: Brown D. C. 
Published: December 2007

Abstract
Prepared for presentation as part of a panel discussion on Petroleum Industry Engineering Manpower Supply and Demand, at the Annual Conference of SPE at Houston September 17, 1984.
To understand the. changes that occur periodically in engineering manpower supply/demand trends in the petroleum industry, it is desirable to have an awareness of some of the major activity factors affecting such trends, of starting Petroleum Engineering salaries relating to that background, of the on-going engineering salary status which developed from these activities, and of the large effect that high starting and on-going salaries do have in attracting and retaining engineers within the petroleum industry.
There is no single entity or group, which by itself sets the climate for engineering manpower trends in the petroleum industry: rather it is set by the interactions of a very large number of companies and individuals, from the diverse and multiple parts of the industry, in creating demand for engineers of the various types and levels needed by their organizations.
Forecasting P.I. and kg/ko Behavior
Authors: Sheldon W.C. 
Published: December 2007

Abstract
Reservoir behavior is usually calculated or predicted on the basis of average values of reservoir characteristics. For reservoirs having wide variations, values calculated from field behavior often are widely different from those determined from laboratory data. Regardless of how data are treated to arrive at average values, the average cannot be used in many cases.
This paper presents a method for forecasting changes in P.I. and calculating kg/ko performance from laboratory data for fields showing wide variations in permeabilities. The resultant kg/ko relations are much more correlative with actual field performance than those where laboratory data are used with simple average reservoir characteristics. Instead of considering the reservoir as homogeneous and taking average values, this method considers the effect of the reservoir heterogeneity. The effect of size of gas cap and rate of gas return (rate of injection) on future P.I. and kg/ko behavior can then be evaluated. Also, a material balance on segments of the reservoir permits evaluation of pressure behavior as a function of rate of depletion with this form of calculation. In order to make comparison of this method with previous efforts, the results have been expressed in terms of the average gas saturation within the reservoir.

Introduction
Two parameters frequently used in reservoir studies are productivity index (P.I.) and kg/ko relationships. They are particularly important when calculating or predicting future reservoir behavior of oil producing reservoirs. Equations have been developed which permit easy calculation of the effect future pressure changes will have upon the P-V-T factors of the future P.I., but these tacitly assume that the relative permeability to oil within the reservoir will remain constant. Actually, these equations are incomplete unless they include terms which will take into account the effect of changing oil saturations. In the past, no adequate way of forecasting relative permeability to oil within the reservoir was available, hence no reliable method had been developed for forecasting P.I. where reservoir saturations would change.
Before permeability to any phase may be developed within a reservoir, the saturation of that phase must be sufficient to establish continuous flow channels. This is the minimum or threshold saturation which must exist before flow can take place. Calculated relative permeabilities or kg/ko ratios for free gas produced from an oil producing reservoir, based upon field performance, result in threshold values which frequently are much below those indicated from laboratory results. This leads to the fact that the second parameter, kg/ko, is also dependent upon relative permeability to oil within the reservoir. Many times, laboratory results fail to agree with kg/ko figures calculated from production data. The relationship between kg/ko and either oil or gas saturation is not linear, but exponential. Therefore, it is difficult, if not impossible, for a single laboratory datum to represent a whole field or a whole reservoir.
VOLAN Interpretation and Application in the Bone Spring Formation (Leonard Series) in Southeastern New Mexico
Authors: Howard A. D. , Fraga J. A. 
Published: December 2007

ABSTRACT
The VOLAN computation, whose name is derived from the words "volumetric analysis," is a new log interpretation technique that uses advanced computer analysis for the evaluation of complex formations. This technique has had successful application in the Bone Spring formation (Leonard series) of southeastern New Mexico.
In complex carbonate deposits where the porosity types include vugs and fractures, conventional log analysis generally has been questionable if only the Sonic log was used. The Sonic measurement tends to overlook the variable degree of secondary porosity inclusive of natural vugs and fractures. The neutron-density tools, on the other hand, measure the total porosity. Thus, to accurately determine values of effective porosity, water saturation, and lithology, the VOLAN program uses the unrefined data from three porosity tools (CNL* compensated neutron, Litho-Density* (LDT), and Sonic) and the resistivity measurements from the Dual Laterolog (DLL*) and Microspherically Focused (MSFL) tools. Positive results with this type of computer analysis have been obtained in the Bone Spring formation where the lithology is complex.
Applications derived from this type of computer analysis are: Identification of potential pay zones by determining the volume of dolomite and degree of secondary porosity.An in-situ formation description using the LDT three-mineral model enhanced by the Sonic measurement.Calculation of an effective water saturation value which has been corrected for the influence of bound water.Correlation with existing logs for mapping.
Rig Preparation for Drilling with Oil-Based Muds
Authors: Carter T. S. 
Published: December 2007

ABSTRACT
Operator requirements for cost effective technical solutions to borehole stability problems have historically been the impetus for new product and mud system development by the industry. Oil-based drilling fluids have long been recognized as a sound technical answer to problems encountered in deep-hot holes and, more recently, to stabilize boreholes with thick intervals of reactive clay formations. However, oil-based mud product development was slowing down until the introduction of low toxicity base oils in the late seventies created a need for new investigations. This innovation sparked a resurgence of oil mud research and development which has resulted in oil-based mud (OBM) systems being used routinely in many active drilling areas worldwide.
Concerns for conservation, both economic and environmental, persist even after low toxicity oils have been accepted, based on field performance, as a suitable diesel replacement. These concerns are important to both the operator and contractor alike. Control of intangible costs related to mud expenditures is important to the operator, but rig modification and installation of auxiliary equipment to process the oil-based drilling fluid are equally important to both companies.
This paper discusses a variety of equipment that is currently available for both onshore and offshore locations to improve oil-based drilling fluid conditioning, to aid oil recovery, to reduce pollution, and to maintain a safe working environment. Minor modification of most of these techniques will allow their utilization on land, inland barge, platform, jack-up, semi or floating drilling units.
A New Approach for Simulating Complex Fractured Reservoirs
Authors: Hill A. C. , Thomas G. W. 
Published: December 2007

ABSTRACT
This paper treats a dual porosity and dual permeability system in which two grids – one each for the fractures and matrix occupy the same volume. We employ 5 pseudo components in the formulation which extends the capability beyond normal blackoil applications. The formulation also permits inert gas injection (i.e. nonhydrocarbon – N2, CO2, etc.) which can diffuse into the liquid phases. Moreover, the oil properties can be optionally treated as functions of pressure and API gravity.
We briefly review the mathematical description of the system. We also describe a memory management scheme whereby one can study large reservoir problems (in excess of 20,000 cells) on computers offering modest core capability. Finally, we present example applications for an isolated fracture system, the effect of cyclic water injection, and the effect of variable API gravity.
Synthesis, Characterization, and Testing of Lignin Graft Copolymers for Use in Drilling Mud Applications
Authors: Meister J. J. , Patil D. R. , Channell H. 
Published: December 2007

ABSTRACT
Partially hydrolyzed poly(lignin-g-(1-amidoethylene)) lowers yield point, lowers gel strength, lowers API filtrate volume, and, after the mud has been hot-rolled at 250°F for 16 hours, functions more effectively as a thinner and agent to control filtration loss than does an equal concentration of chrome lignosulfonate in a water-base mud containing 28 ppb Wyoming bentonite. Poly(lignin-g-(1-amidoethylene)) is formed along with poly(1-amidoethylene) in a graft copolymerization reaction of 2-propenamide on Kraft pine lignin contained in 1, 4-dioxacyclohexane. Formation of graft copolymer was proved by attachment of a derivitized, 1-amidoethylene sidechain to lignin and demonstration by U.V. spectroscopy that sidechain and backbone migrate together in a size exclusion column.
The dried, two-part reaction product is treated with aqueous base to form anionic polymers which produce the changes in mud rheology noted above. Both components of the reaction product are active in controlling mud properties.
Foaming of Anhydrous Methanol for Well Stimulation
Authors: Crema S. C. , Alm R. R. 
Published: December 2007

ABSTRACT
Use of foamed anhydrous methanol for stimulation of formations sensitive to water damage is a tested technology whose wider application is limited by the relatively high cost of the additive systems needed to obtain foams of a satisfactory quality and half-life.
The additive cost has now been sharply reduced by the introduction of new foaming systems which comprise a mixture of fluorosurfactant and a foam extender. While the foam extenders by themselves do not produce stable foams in anhydrous methanol, they dramatically decrease the amount of fluorosurfactant needed to produce satisfactory anhydrous methanol foams. Several compounds have been found to perform well when used in conjunction with fluorosurfactants. Of these, nonionic surfactants based on oxyalkylated fatty alcohols and amines or polyethers containing ethylene and propylene oxide units seem to be the most efficient foam extenders. The amount of fluorosurfactant needed to obtain satisfactory anhydrous methanol foams can be decreased by as much as two-thirds when 2% of these materials are added to the methanol solution. These results give a 50 to 60% decrease in the cost of the additive package without any decrease in the foam quality and half-life.
Effect of Various Alkaline Chemicals on Phase Behavior of Surfactant/Brine/Oil Mixtures
Authors: Martin F. D. , Oxley J. C. 
Published: December 2007

ABSTRACT
Recovery of crude oils which are low in naturally occurring organic acids may be enhanced by supplementing an alkaline flood with surfactant. Much of the work concerning surfactant addition to alkaline slugs reported to date has been directed toward crude oils with sufficient organic acids to produce natural surfactants. The present work considers the addition of surfactants to midcontinent-type crude oils that alone do not produce low interfacial tensions against high pH aqueous phases. This paper presents the effects of various alkaline agents on the phase behavior of brine, oil and petroleum sulfonate mixtures. Specifically, we have investigated the effect of alkaline chemicals (sodium carbonate, sodium hydroxide, potassium hydroxide, ammonium hydroxide, and sodium silicate) on the optimal salinity of a synthetic petroleum sulfonate system.
In the first phase of the work, a normal alkane with an oil molar volume approximating that of a "J" Sand crude oil was used. Tests were performed with a simulated fresh injection water at a reservoir temperature of 160°F. This portion of the work defined the effect of the alkali and alkali counterion on phase behavior. While the presence of alkaline chemicals lowered optimal salinity, the effect was ascribed to their role as salts rather than their role in pH adjustment. Phase behavior of the system studied was sensitive to the type of alkaline cation added: potassium had a greater effect than sodium, and ammonium had the least effect. However, phase behavior appeared to be insensitive to the alkaline anion.
The second phase of the work utilized various volumes of "J" Sand crude oil with formulations of the petroleum sulfonate and alkaline solutions. Since this type of crude oil does not contain large amounts of organic acids, the alkaline/surfactant systems were not very sensitive to crude oil volumes.
The Effects of Chemical Degradation on Polymer Flooding
Authors: Clifford P. J. , Sorbie K. S. 
Published: December 2007

ABSTRACT
Polymers are known to degrade chemically under reservoir conditions. In this paper we simulate the effect of chemical degradation on polymer flooding, using a modified chemical flooding code. We particularly investigate layered reservoirs, in which vertical crossflow is shown to be the leading oil recovery mechanism. The calculated effects of degradation are explained in terms of the effects of polymer on fluid flow patterns. Results are presented for different polymer and reservoir types, and the effect of non-uniform reservoir temperature on degradation rates is also studied. It is shown that there are a number of types of polymer flood in which the effects of chemical degradation are less severe than might initially be expected.
Characterization of Tracer Retention Processes and Their Effect on Tracer Transport in Fractured Geothermal Reservoirs
Authors: Walkup G. W. , Horne R. N. 
Published: December 2007

Abstract
Retention processes such as adsorption and diffusion into an immobile region can effect tracer movement through a fractured reservoir. In this study, retention processes have been characterized in experimental work and by the development of a two-dimensional mathematical model. A method to directly determine some important reservoir parameters, such as the fracture aperture, from the analysis of tracer tests has been developed and applied to field data.
Cal Canal Field, California: Case History of a Tight and Abnormally Pressured Gas Condensate Reservoir
Authors: Engineer R. 
Published: December 2007

Summary
The Cal Canal Field, situated in the San Joaquin Valley near Bakersfield, California, produces, a rich (280 bbl/MMSCF) gas condensate from an average depth of 11,500 feet. The upper Miocene Stevens Sand, the producing formation in the field, is a very tight, abnormally pressured gas condensate reservoir. The average reservoir parameters are 12 percent porosity, .01 to .1 md permeability and a connate water saturation of 59%. The dew point pressure of 5835 psi is 1508 psi below the initial reservoir pressure. The material balance method, corrected for abnormal pressure, indicates an original wet gas-in-place of 103.3 BSCF. Production performance history suggests that the ultimate recovery from the field will be approximately ±10% of the original wet GIP. Such a poor recovery could be attributed to retrograde fallout and increasin; water saturation in the vicinity of the wellbores.
This paper presents an analysis of the reservoir characteristics and a review of its performance to date. The purpose of the study was to investigate the feasibility of improving hydrocarbon recovery from the field.
An Evaluation of the Prudhoe Bay Gravity Drainage Mechanism by Complementary Techniques
Authors: Haldorsen H. H. , Rego C. A. , Chang D. M. , Mayson H. J. , Creveling D. M. 
Published: December 2007

Abstract
The gravity drainage mechanism in the Prudhoe Bay Field has been evaluated by means of repeat Compensated Neutron Log (CNL) data, centrifugal gas/oil displacements in small preserved cores, and by an analytical stochastic approach.
From the repeat CNL data, in-situ displacement efficiencies as observed above the advancing gas-oil contact in 50 gravity drainage wells have been estimated. A Monte Carlo-type error analysis is presented to give the range of uncertainty associated with the results.
Gas/oil centrifuge displacements in small preserved cores were performed in order to validate the CNL results, and to investigate the time dependency of recovery in gassed out zones which is otherwise beyond CNL resolution. Conventional scaling theory was subsequently used to find homologous times for the reservoir and laboratory models, thus making comparisons (between CNL and centrifuge data) possible. In addition, relative permeability to oil (to be used in the analytical study) was computed from the centrifuge data.
Finally, an approximate analytical description of the gravity drainage process was formulated and a Monte Carlo analysis performed to cover the wide range of values the input parameters in the equations may take on. This analysis yields a statistical distribution in displacement efficiencies at each point in time. The "average" behavior may be compared to the CNL and centrifuge data.
The results demonstrate that the gravity drainage mechanism in Prudhoe Bay is very time-effective and yields high quantifiable displacement efficiencies. The consistency obtained among the various evaluation techniques gives confidence in the results.
Development of the Khuff Gas Reservoir, Bahrain Field
Authors: Janahi I. A. , Dakessian B. A. 
Published: December 2007

Abstract
The Khuff gas reservoir in Bahrain was discovered in 1948 when a shallow crestal Well No.52 was deepened to a depth of 10,078'. The reservoir was not developed until late 60's when the country planned to embark on an industrialization. scheme that would rely on Khuff gas as the main source of energy. Two commercial development Wells 254 and 255, were drilled in 1969 to meet the demand for a newly constructed alumimum smelter. Nine more wells were drilled during the 70's as the relatively lean Khuff gas replaced the richer Arab Zone gas for injection and artificial lift in the oil field, for municipal power generation and for use as feed stock and fuel in the local refinery. With the continued industrial expansion in Bahrain the need for Khuff gas was greatly increased and as a result a 10-well development drilling program was undertaken in 1982.
Khuff gas consumption has increased 50 MMSCFD in 1969 to around 400 MMSCFD in 1984 at an annual growth rate of 15%. Excessive growth will not only create the need for huge investments but will also rapidly deplete this vital resource. Future demand should be forecasted and controlled at this early stage of depletion to properly manage the reserovoir and, if necessary, to seek an alternative source of supply.
The objective of this paper is to outline a development/production strategy for the Khuff Reservoir based on deliverabilities and estimated reserves.
Oil Pollution Control Equipment and Facilities
Authors: Scott G. A. 
Published: December 2007

Abstract
Development of a pollution response capability to match offshore exploration and development often goes unnoticed until a major incident occurs. At that time one hopes that like the fire extinguisher on the wall it may be unnoticed but it is available when needed. During the 1980 Hasbah spill Aramco found that the in-house spill response capability had not kept pace with offshore development. There were more than 300 offshore production wells and five production platforms each of which had a potential for large scale oil releases. The spill response effort had been focused on terminal operations and needed upgrading to meet the needs of offshore development. Therefore a major study was initiated to determine overall spill response needs for the entire offshore activity.
In order to focus the study on exploration and production needs the study team was given the following criteria to follow in developing the response needs:
To accurately evaluate Aramco's current offshore spill response capabilities. Develop containment and recovery systems and also dispersant application systems capable of dealing with a spill of up to 70,000 barrels in the Gulf under favorable conditions. To recommend an organization with trained manpower to effectively handle in-house offshore spills. To provide an estimate of the costs involved in purchasing the recommended equipment.
Rock Bits Equipped With Extended Nozzles Lower Drilling Cost in the Middle East Region
Authors: Selby B. A. , Sauvageot W. A. 
Published: December 2007

ABSTRACT
An analysis of three-cone rock bit runs using extended jet nozzles (EN) in the Middle East Region is presented.
These runs were made from 1982 to 1984 in several Middle East countries. They represent wells drilled onshore and offshore, vertical and deviated, using oil and water based mud systems.
The improvements in performance gained by enhanced hole cleaning with extended nozzles are well documented.
This feature has been widely used in the South East Asia – Far East region and in certain areas of the continental U.S.A. and Alaska since the mid – 1970's.
The result of the EN runs in the Middle East correlate well with results in the proven areas elsewhere in the world. Penetration rate increases over regular jet bits of 7-80% have been recorded.
The high daily rig costs characteristic of Mideast drilling operations make it fairly easy to show a cost per foot decrease with only slight increases in performance.
The increased bit cost due to the EN feature is found to be virtually negligible.