bluuebunny/crossref_metadata_2025_split huggingface dataset:
Results of an Optimization Study on a Major Gas Field Complex
Authors: Miller R.T. , Gattis J.R. , Talbert J.M. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Abstract
This paper describes the results of recent optimization study of the Sheridan-Provident City gas field complex. A total of 34 reservoirs and 132 wells were studied in order to develop a plan which would optimize the recovery of the remaining gas-in-place. Production was initiated from these fields in Production was initiated from these fields in the middle 1940's, and they are presently about 75 percent depleted. Sheridan and Provident City are currently characterized Provident City are currently characterized by low pressure reservoirs and complex gathering systems. The gathering systems include:a high pressure, branched flow-line network;a low pressure flowline network with multiple loops;remote field compressors; andlarge central compressor stations.
The problem involved modeling the performance of the reservoirs, wells, gathering systems and compressors in order to predict the field response to several predict the field response to several alternative plans of operation.
The study was carried out by use of a digital computer program which can simulate the conditions existing during production of one or more gas reservoirs connected through a common surface gathering system. The program is capable of simulating both pure program is capable of simulating both pure depletion drive reservoirs and reservoirs having some degree of pressure support either from the expansion of rock and connote water, or from the influx of water from a communicating aquifer, or both. The surface gathering system can be looped and/or branched. Compressors can be simulated at any point in the gathering system and can be added or removed at any preset time. Two-phase flow is modeled in the gathering system and the production tubing, while semisteady state, single-phase flow is modeled in the reservoirs.
This paper demonstrates that, even in the case of complex, mature fields, the use of sophisticated engineering techniques can increase the remaining recoverable gas reserves.
PURPOSE AND SCOPE PURPOSE AND SCOPE The primary objective of this study was to formulate a plan which would optimize the recovery of the remaining Sheridan and Provident City gas reserves. Provident City gas reserves.
A Two-Dimensional Mathematical Model of the Underground Coal Gasification Process
Authors: Magnani Charles F. , Ali S.M. Farouq 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Abstract
A two-dimensional mathematical model of the underground coal gasification process is developed, and is used to study the effect of the process variables on the total heat recovery by the gasification process.
The model simulates the stream method of underground coal gasification, using the producer gas stoichiometry. Specifically, producer gas stoichiometry. Specifically, reaction kinetics and heat and mass transfer are considered in a horizontal circular channel in a coal seam. Air is injected at one end, where the coal seam is ignited. The carbon dioxide formed is reduced to carbon monoxide farther downstream. The mathematical equations describe the conduction and generation of the heat at the surface of the coal, convective heat transport by the gas stream, and gas phase mass transfer of the chemcial species. The equations were solved analytically, obtaining a closed form solution, which was employed for studying the process, for a variety of operating options.
The model is unique in that it considers heterogeneous, intermediate combustion, i.e. the reaction zone temperature is not high enough so that diffusion controls the process, nor is it low enough that reaction kinetics dominate.
It was found that the use of oxygen or enriched air is superior to air as the gasification agent, i.e. the total heat content of the produced gas increases with an increase in the oxygen concentration. An increase in the mean axial velocity leads to an increase in the total heat content of the produced gas up to a certain point, beyond which a decrease is observed. The gasification process is more effective in small diameter channels. Results obtained show that the production of carbon monoxide is critically dependent on the gasification agent, the reduction zone temperature, the average gas velocity, the contact time for the reduction reaction, and the channel diameter for a given reactivity of coal.

Introduction
Underground gasification of coal has received a great deal of attention in the past, as the numerous publications and field tests indicate. Currently, there is renewed interest in the process, first on account of its environmental advantages, and secondly, because the economics of the process are likely to be more favorable now than was the case in the earlier field tests. The process has not been analyzed and modeled mathematically to any great extent. In a previous publication, the authors presented the development of a mathematical model of the process, assuming producer gas stoichiometry, homogeneous reaction producer gas stoichiometry, homogeneous reaction kinetics, and one-dimensional heat and mass transport. This paper extends the previous model to consider two-dimensional mass transport, and heterogeneous reaction kinetics.
Erosion of Perforation Tunnels in Gas Wells
Authors: Vriezen P.B. , Spijker A. , van der Vlis A. C. 
Published: December 2007

Vriezen, P.B., Member SPE-AIME, Koninklijke/Shell Exploratie en Produktie Laboratorium, Spijker, A., Koninklijke/Shell Exploratie en Produktie Laboratorium and van der Vlis, A.C., Member SPE-AIME, Koninklijke/Shell Exploratie en Produktie Laboratorium
American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Abstract
The stability of a perforation depends on its geometry, and on both the mechanical strength and the effective-stress distribution in the vicinity of the perforation.
Erosive action of the gas flow into and through a perforation may gradually increase the perforation diameter. This effect could considerably reduce the mechanical stability of such a perforation.
This paper presents an experimental evaluation of the relative importance of erosion on perforation stability. It describes a special triaxial cell, which permits axial and radial flow through a thick-walled cylinder of the core material being tested. The other components of the closed-loop gas-flow system used including gas-humidifying equipment and a sand-particle detector, are outlined. With this unique set-up, experiments have been performed under simulated downhole conditions on samples selected from the Rotliegendes sandstone formation of the Groningen gas field.
It appeared that, for a given hardness of the sandstone being investigated, perforation stability is mainly determined by the effective stress level. Erosion was found to have only a minor influence on perforation stability.

Introduction
A substantial amount of the world's oil and gas production is from reservoirs requiring some type of sand control. The decision whether a sand-exclusion technique should be incorporated in the design of a well completion, is generally based on core description and/or the outcome of production tests. If the formation is a completely unconsolidated sand, this decision is evident. More difficult to decide on are the formations of friable nature, in particular when production facilities limit proper simulation of future production rates and production conditions, production rates and production conditions, such as depletion of reservoir pressure and the onset of water production. Efficient development and management of these types of reservoirs would certainly benefit from more quantitative techniques to appraise the necessity of sand-exclusion methods.
Well Test Characterization of Wedge-Shaped, Faulted Reservoirs
Authors: Charles D. D. , Rieke H. H. , Purushothaman R. 
Published: December 2007

Abstract
Two south Louisiana offshore, wedge-shaped reservoirs were interpreted using pressure-buildup responses by comparing the results from simulated finite-element model studies. The importance of knowing the correct reservoir shape is briefly discussed and how it is used to interpret the generated boundary pressure responses. Two different 3-D computer models incorporating different wedge-shaped geometries simulated the test pressure-buildup response patterns. Variations in the two configurations are topologically expressed as a constant thickness and a non-constant thickness, smooth surface, wedged-shaped reservoir models. The variable thickness models were pinched-out up-dip at one end and are faulted at the other end. Numerical well test results demonstrated changes in the relationships between the pressure derivative profile, wellbore location, and the extent of partial penetration in the reservoir models. The wells were placed along the perpendicular bisector (top view) at distances starting from the apex at 5, 10, 20, 40, 50, 60, 80, and 90 percent of the reservoir length. Results demonstrate that boundary distance identification (such as distance, number and type) solely on the basis of the log-log derivative profile in rectangular and triangular wedge- shaped reservoirs should be strongly discouraged. Partial penetration effects in wedge reservoirs are highly dependent on the wellbore location relative to the wedge and adds to the complexity of well test data analysis.
Lateral Proppant Distribution: The Good, the Bad, and the Ugly of Putting Frac Jobs Away
Authors: Aud W. W. , Poulson T. D. , Burns R. A. , Rushing T. R. , Orr W. D. 
Published: December 2007

Abstract
This paper shows proppant induced pressure increase (i.e., "tip screenout", "pack", "body pack", etc.) can relate to restricted vertical and lateral proppant distribution in hydraulic fractures. We discuss a way of interpreting the character of the pressure response during the proppant stages of a fracture stimulation. The pressure response during the proppant stages will determine the quality of the production response and the level of success that is achieved. The technology presented has been found to apply to all rock types and most formations.
This area of study is based upon common sense observations and extensive engineering. It fits the reservoir engineering of the producing character and advanced fracture treatment pressure interpretation on over 1,000 wells. When early proppant bridging occurs in the fracture, the lateral and vertical proppant distribution adjacent to the pay interval can be negatively affected. This results in less effective stimulation because the pay interval, both vertically and laterally, is not effectively propped. The fracture stimulation may have been "put away"; but the negative aspects of how the stimulation was designed and implemented may have a significant affect on the resultant production response.
To lay the basis for additional thought and investigation, there is discussion about deficiencies in overly simplified pretreatment mini-fracture analysis procedures. These analysis methods are not focused on the proppant induced friction character, and therefore can not optimize fracture length. An evolved approach is presented, that addresses leakoff, fracture geometry, and proppant induced friction, to optimize the proppant distribution, and overall stimulation of the pay interval.
Description and Modeling of a Complex Fluid Column in the Santa Barbara and Bosque Fields, North Monagas State, Venezuela
Authors: Smith Richard W. , Trias Olimpia , Yemez Ivan , Bard Wade A. , Corredor Jairo 
Published: December 2007

Abstract
The Santa Barbara and Bosque (SB/BSQ) fields, located in northern Monagas State of Venezuela, are in an area of the largest and most prolific oil fields in Venezuela and currently produce nearly 1 million BOPD. The fields are operated by Petroleos de Venezuela, S.A. (PDVSA). The proven SB/BSQ hydrocarbon column is more than 6,000 feet thick. The vertical compositional variation creates a complex system where relatively low yield condensate gas changes to high yield condensate, near critical fluid, volatile oil, and finally, highly under saturated oils. The fluid system is complex and area differences exist because of structural compartmental-ization. Original field management strategies identified the high potential of increasing reserves by high-pressure injection of produced gas. Modeling of the complex interactions of injected gas is important, thus a full and detailed study of the PVT samples, evaluation of area fluid distributions, and the definition of an equation of state to allow reservoir modeling were performed. This paper documents the effort of 1998 and the ongoing process to define an Equation-of-State (EoS) to meet reservoir modeling and management objectives.
Advanced Fractured Well Diagnostics For Production Data Analysis
Authors: Poe B. D. , Conger J. G. , Farkas R. , Jones B. , Lee K. K. , Boney C. L. 
Published: December 2007

Abstract
New analysis procedures are presented for analyzing the production data of fractured wells in low permeability reservoirs to quantify estimates of the reservoir effective permeability, effective fracture half-length, and average fracture conductivity. The rate-transient based analyses reported in this paper have been used to analyze the production performance of over 200 wells in low permeability reservoirs in North America.
Direct comparisons of the fracture properties resulting from conventional crosslinked fluid fractures and low viscosity base fluid ("Water-Frac") treatments in direct offset wells clearly demonstrates that more effective fractures are created in low-permeability reservoirs using the higher viscosity fracturing fluids and large proppant volumes to achieve higher conductivity fractures with greater effective half-lengths than are achieved with "Water-Fracs" with little or no proppant.
New Concentric Annular Packing System Limits Bridging in Horizontal Gravel Packs
Authors: LaFontaine Jackie , Sanders Mike , Hailey Travis , Mickelburgh Ian , Lord David 
Published: December 2007

Abstract
Although horizontal completions in unconsolidated sands have become common, challenges associated with the inflow of formation sand during production still exist. The industry has responded to the challenge of controlling formation sand flow in horizontal wells by advancing the technology currently used in vertical wells. Wells with record-breaking production have been successfully completed with this technology, but failures have also occurred because of problems associated with imperfect gravel placement. If excessive leakoff is encountered during gravel placement, or sand concentrations fluctuate excessively during the treatment, bridges can form, resulting in incomplete packing. As the current technology is increasingly challenged with longer horizontal intervals and/or lower bottomhole pressures, further development will be required for complete, effective gravel placement. This paper discusses the concept and initial experimental results of a project designed to further develop the technology of horizontal gravel-packing.
A Comparison of Jet Perforating Services Kern River Field
Authors: Keese J.A. , Oden A.L. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Abstract
In 1974 and 1975 the authors supervised the perforation of 184 steamflood production and perforation of 184 steamflood production and injection wells. The large number of completions plus the combination of shallow depth (less than plus the combination of shallow depth (less than 2,000 feet) and low reservoir pressure (less than sixty psia) provided an opportunity to compare quantitatively the performance of different perforating companies. perforating companies. All perforating guns were inspected immediately after firing. The numbers of misfires, blown port plugs, and misaligned charges are tabulated. Significant variations in performance are noted between perforators. As a followup, inflatable impression packers were run in a number of the wells. The variation in perforation diameter is presented statistically.
The four companies perforated wells on the same lease during the years 1970 to 1972. The subsequent productions of these wells are compared. Two of the perforators shot six adjacent steamflood wells in 1974. The production characteristics of these wells are also compared.

Introduction
During recent years, there has been a recurring controversy about the practice of bidding large perforating jobs. The perforation of a well is perhaps the most critical phase of completion. Consequently, operators experience misgivings in automatically awarding jobs to perforating companies offering the least perforating companies offering the least expensive price. Two alternatives are:Restrict the bid to only those perforators giving superior performance.Award jobs only to the best perforator no matter what the cost.
A requirement of either possibility is the existence of some method to evaluate quantitatively perforating company performance. The procedure must be simple to employ as well as relatively inexpensive or the purpose of the endeavor is lost. This paper explains such a comparison program and describes it and the results. It should be noted that the procedures discussed here are applicable to a specific region and type well completion.

COMPLETION PROCEDURES
The Kern River Field consists of unconsolidated Pleistocene deposits located at depths above 2,000 feet. These channels and delta sands have thicknesses ranging from five to fifty feet.
A Practical and Efficient Uplayering Method for Scale-Up of Multimillion-Cell Geologic Models
Authors: Li D. , Beckner B. 
Published: December 2007

Abstract
Geophysicists, geologists, and reservoir engineers can now routinely build reservoir geologic models with ten million geologic cells and more than one thousand geologic layers. This explosion in reservoir detail capability presents new challenges for existing upscaling methods. Uplayering (the first step of upscaling) is a technique that provides reservoir engineers with optimal geologic layer-grouping schemes for simulation model construction. Much uplayering is still done by hand by reservoir engineers. Even though some advanced methods can provide automatic tools for uplayering, they are limited in the applicable model size and are also computationally expensive. This paper presents a practical and efficient method for uplayering of multimillion-cell geologic models. The proposed method defines a displacing front conductivity, a combination of porosity, permeability, and facies (in terms of relative permeability, endpoint saturation, and various facies rules), as the uplayering property. Use of the new property ensures that the most important geologic features for fluid flow simulation can be preserved after uplayering. The new method utilizes a residual optimization technique to determine the optimal geologic layer-grouping scenario for a given number of simulation layers. The method is so efficient that multiple optimal grouping scenarios, from the one simulation layer model to the model consisting of all geologic layers, can be generated in a short time, allowing the inspection of all possible combinations of layer-grouping scenarios. A residual curve (the difference of the defined property between the fine-layer and coarse-layer models) is produced from exhaustive analysis of all possible layering combinations. Using the residual curve, engineers are able to determine the number of simulation layers needed based on their tolerance of possible loss of fine-layer geologic features. The uplayering method has been successfully employed in most of major reservoir study projects in Mobil and results from three of these studies will be included in this paper.
Enhancing Production in Multizone Wells Utilizing Fracturing Through Coiled Tubing
Authors: Spady D. W. , Udick T. H. , Zemlak W. M. 
Published: December 2007

Abstract
Zonal stimulation using hydraulic Fracturing, which typically was performed through jointed pipe, has recently been performed with Coiled Tubing. In the last two years, over one thousand fracturing treatments in North America have been executed using this method. Coiled Tubing allows a method of stimulating individual, bypassed or marginal zones, using positive zonal placement of proppant. Coiled tubing also gives the advantage of treating a well under pressure without introducing a kill fluid to the formation. In the Appalachians, where multiple small zones exist in one wellbore, this technology can provide significant cost savings by reducing trips to the well, equipment on location, and rig time to move downhole hardware. Coiled tubing fracturing eliminates the need for bridge plugs and allows stimulation of multiple zones in a single trip to the well. Ultimately the size of a stimulation treatment can be re-engineered because of the positive isolation for each specific zone in the wellbore. The overall effect to the producer is greater production at a lower total cost.
Effect of Abnormal Pore Pressure on Deep Water Drilling
Authors: Andriesse D. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
This paper was prepared for the SPE-European Spring Meeting 1976 of the Society of Petroleum Engineers of AIME, held in Amsterdam, The Netherlands, April 8–9, 1976. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal, provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
Drilling operations in deep water are more constrained than on land. Apart from sophistications concerning control systems, hardware, etc. this is caused by the convergence of mud and formation strength gradients, the weakness of shallow formations, the possible small margins between formation strength and pore pressure and the mud weight pore pressure and the mud weight capacity of the riser system.
As a result of these constraints, the ultimate well depth would be severely limited when encountering abnormal pressures. In order to investigate this pressures. In order to investigate this problem a survey was carried out on problem a survey was carried out on formation strength and abnormal pore pressure occurrence. The outcome of it pressure occurrence. The outcome of it suggests that the majority of deep water wells can be drilled with conventional casing systems.
Mud weights required to control abnormal pore pressures will cause fracturing of the formation more readily in deep water than in land operations. A solution to this problem has not yet been found.
Consequently prediction and early detection of abnormal pore pressures is of greatest importance for deep sea operations.

Introduction
Formation strength, expressed as fracture pressure, is lower at any given depth below derrick floor in deep water than in shallow water or land drilling operations. This is caused by the fact that in wells located offshore a part of the overburden consists of water rather than of sediments.
As a result there is an interval above the intersection of the formation strength and mud gradients in which the mud pressure exceeds the formation strength.
In order to avoid fracturing, casing will have to be set prior to raising the mud weight.