bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Integrated 3D Model for Underground Coal Gasification
Authors: Biezen E. N. J. , Bruining J. , Molenaar J. 
Published: December 2007

Abstract
Underground coal gasification has received renewed interest in both Western and Eastern Europe because of the vast amounts of otherwise unminable coal deposits that occur on the European continent. A field test is currently being held in Spain, and other countries have also shown interest in this method of utilizing coal resources.
In this study we have developed a model to combine reactive heat and mass transport together with thermo-mechanical failure behavior. In the model, we use multigrid methods to solve the flow equations in the entire domain. This is combined with thermo-mechanical failure properties of both coal and rock overlying the coal formation. With this approach, a 3D picture of the development of an underground coal gasifier is obtained, and the influence of well-layout and the sensitivity of the process to other model parameters can be investigated in detail, with high computational efficiency.
The model consists of two modules: The first module solves the flow equations in the entire flow domain. The second module selects a block of coal for gasification and a block of coal and/or rock for thermo-mechanically induced spalling. Other features such as ash content, the possibility of including heterogeneities, and natural convection-driven cavity gasification are also incorporated in the model.
A Comprehensive Study of the Analysis and Economic Benefits of Radioactive Tracer Engineered Stimulation Procedures
Authors: Fisher K. , Robinson B. M. , Voneiff G. W. 
Published: December 2007

Abstract
Hydraulic Fracturing is an important technology to enhance production from tight gas reservoirs. Several techniques have been utilized to attempt to evaluate the effectiveness of hydraulic fracturing treatments. One technique, radioactive tracers, is currently used on over 15% of the stimulation treatments performed in the U.S. With proper materials, design, and execution, tracers can be used to locate the presence and concentration of proppant at the wellbore in order to evaluate vertical and radial proppant distribution. A comprehensive study of over 100 fracture treatments has been completed in which radioactive tracers were used along with production logs, stress logs, post-fracturing completion reports, and production history to analyze completion effectiveness in four different reservoirs. Additionally, an economic benefit model was constructed to evaluate the benefit/cost ratio of applying the technology.
Catalyzed Silicate Process Replaces Cement on Well-Deepening Operations
Authors: Shelley Robert F. , Sciullo Felix C. 
Published: December 2007

Abstract
The deepening and recompletion of existing wells has proven to be a good economic investment for many operators in eastern Kentucky. The deepening process involves squeezing the zone of initial completion, deepening the well, running casing, and recompleting in the Devonian shale. In many cases, problems occur after initial completions are squeezed. For example, fluids leaking into the drilled hole can compromise efficiencies if the well is drilled with air. If another cement squeeze is required to seal the zone, the operator incurs lost time and additional expense.
To produce an effective seal within the producing zone, operators may choose to use catalyzed silicates. This paper describes the catalyzed silicate process and explains why catalyzed silicates may often be more effective than cement. Case histories will show that catalyzed silicates are economically and operationally successful elements of the well-deepening process.
Down Hole Corrosion: Problems & Possible Solutions
Authors: Morrison William K. 
Published: December 2007

Abstract
Over the past several years the industry has encountered many production problems in the Antrim play. Among these are calcium carbonate scale, NORM and C02 removal. One problem, the oorrosion of steel within the production system, has developed due to the chemical nature of the Antrim gas and water. This corrosion has become a major problem for NOMECO and other operators. This paper will discuss the problem, its source and effects and some possible solutions.
Satellites and the Oilpatch or, Resolving the Heckarewe Problem
Authors: Walbe Kim A. 
Published: December 2007

Abstract
The Global Positioning System (GPS) is a navigation system consisting of a constellation of 24 satellites in 6 orbital planes that provide accurate 3-dimensional position and velocity as well as precise time to users anywhere in the world 24 hours a day.
User receivers measure their apparent range to the satellites by processing the received signals to determine transit time and correcting for atmospheric delay using stored and broadcast models. Since the location of the satellites, at the time of signal transmission, is known from the broadcast ephemeris, the location of the receiver can be triangulated from the range measurements.
Similarly, the user receiver’s velocity can be solved by comparing the measured Doppler shift of the received signals to the expected Doppler shift based on the satellites velocity vector, calculated from the ephemeris, projected on the line of sight to the satellite. After the receiver’s clock error is eliminated, by over determination, the residual Doppler is attributed to the user velocity.
The viable utilization of the GPS in the Appalachian Oilpatch comes from the ability to take small handheld units, the size of a pocket calculator, to the field to quickly position by latitude and longitude or by UTM the location of fixtures or facilities for which there is no surveyed data (examples would include older non-platted wells, the location of old pipeline systems and the location of new well roads that are not yet shown on topographic or company maps). This data can be obtained and stored in the field and later downloaded to mapping software such as AutoCad.
The system can be used in reverse with surveyed positions uploaded into the GPS system in the office before leaving for the field and then using the navigation capabilities of the GPS unit to lead you to the surveyed location or site.
The simplicity of use together with the low cost and pocket size makes a GPS unit one more viable tool for the field engineer or geologist.
Effects of Wall Slip and Shear-Induced Transition on the Viscosity Measurements of Crosslinked Fracturing Fluids
Authors: Fan Yong , Holditch S. A. 
Published: December 2007

Abstract
This paper presents a method to correct results of laboratory measurements where we investigated the effects of wall slip, wall roughness and shear-induced slip on the viscous properties of crosslinked fracturing fluids. Our research indicates that crosslinked gels exhibit wall slip. The measurement of viscosity is dependent upon the surface roughness of the bob used in the tests. Unless an appropriate correction is made, the measured viscosity will be less than the true viscosity because of wall slip. Our study also demonstrates the occurrence of a rheological transition of polymer gel induced by shear forces. The critical shear rate, which we define as the beginning of stress transition from one state to another, may vary between 10-90 sec-1, depending upon the fluid nature, test procedure and temperature. Viscosities calculated using data from the different stress states at the same nominal shear rate can be different by a factor of 3 to 5. The gel with the higher critical shear rate exhibits more stable viscous properties when subjected to the thermal and shear degradation.
Completion Methods and Results Comparison of Devonian Shale in the Big Sandy Field
Authors: Friend Michael L. , Keenan Robert L. , Huck Donald R. 
Published: December 2007

Abstract
Considerable effort has been made by various research groups and exploration companies to improve completion techniques in the Devonian Shale. Completions in the Devonian Shale in the Big Sandy Field run the gamut from natural completions, shot-hole completions, Nitrogen fracturing, Nitrogen foam fracturing, C02 foam fracturing, and gelled water fracturing, to the latest technique promoted by the DOE, sand-laden C02 fracturing. Production rates from wells using the different completion techniques in this field vary widely. Of these techniques, Nitrogen foam fractured wells have been observed to have by far the lowest production rates.
This paper compares production rates and well test results of the various completion techniques and attempts to quantify the problem with the Nitrogen foam fractured wells in terms of reservoir parameters. This will establish a base from which any improvement can be measured.
The conclusions will be drawn from the case histories of approximately 105 wells located within the Big Sandy Field. A summary comparison of production data will allow a fair analysis of the techniques investigated. Well test data from a sampling of these wells will help define reservoir parameters and fracture geometry.
Putting Technology to Work: The Petroleum Technology Transfer Council
Authors: Rowell D. , Benton J. H. 
Published: December 2007

Abstract
As the domestic oil and natural gas industry strives to become more competitive, technology has been presented as one answer to reduce instability in oil and gas markets and escalating regulatory compliance costs. To exploit the remaining resources of the eastern US, operators need access to new technologies that reduce the costs of finding, drilling for and producing hydrocarbons from mature reservoirs. The problem is that new and emerging technologies are often beyond the reach of domestic producers, both large and small.
The Petroleum Technology Transfer Council (PTTC) is a new national, producer-driven organization designed to make technology work for independent and major producers. Formed by the Independent Petroleum Association of America (IPAA) in cooperation with state and regional industry associations, and the Gas Research Institute (GRI), the PTTC's mission is to enhance and accelerate the transfer of upstream petroleum technologies to and among producers. The US Department of Energy (DOE) has provided start-up funds to help this important project become a reality.
The PTTC technology transfer program has several components: problem identification workshops, focused technology workshops, regional resource centers with electronic information systems, and producer outreach. Through these steps, the PTTC will make the latest advancements in exploration, reservoir characterization, drilling, production, offshore and environmental technologies accessible to the producer in the field. The PTTC is interdisciplinary, involving petroleum geology, engineering and geophysics. Many state geological surveys and universities are involved in implementing the PTTC regional activities.
As a grassroots organization, the PTTC has nearly finished holding problem identification workshops around the country. This process is helping producers to assess current technology and communicate their technological needs to the government, universities, GRI, national labs, service companies and others in the research and development (R&D) community.
Field Tests of the Water/Liquid Oxygen Injection Process
Authors: Andersen Len 
Published: December 2007

Abstract
Two field tests were done injecting a mixture of water and liquid oxygen near Graham, Texas. On the first test the results were on initial decrease in injection pressure and a 20% increase in production for 40 days. The oil field was an irregular six spot water flooded, Gun Sight Sand unconsolidated channel sand formation at a depth of 520 ft. (158 m.). In the second field test oil production increased 20% for 300 days, water injection pressure done on a batch basis increased from 0 to 230 psi (0 to 1590 kPa) to a range of 300 to 550 psi (2068 to 3790 kPa), and oil production from a deeper formation doubled. The oil field was an irregular, five spot, water flooded, Strawn Sand (consolidated sand with limestone formation at a depth of 1900 ft. (579 m.). These tests indicated the water/liquid oxygen process would be an economic success done on an going basis in similar oil formations.
The Value of Wellhead Electronic Flow Measurement in Gas Storage Fields
Authors: Brown K. G. , Meikle D. E. 
Published: December 2007

Abstract
The design, operation, and value derived from a wellhead electronic flow measurement (EFM) system recently installed in the Belle River Mills (BRM) gas storage field in southeastern Michigan are discussed. The automated process of corporate data integration to identify problem wells on a daily basis is presented. Four specific examples are cited which demonstrate the value of such a system: immediate identification of operational problems occurring during routine operations which rendered several 35 MMSCFD wells inoperable; empirical assessment of the impact of subsurface safety valves on well deliverability; pressure transient analysis using wellhead data collected at 10-second intervals during routine operations; automated daily assessment of individual well performance to alert operators of deteriorating well performance. The potential to monitor inventory using EFM data and pressure transient analysis techniques is discussed, including the difficulties encountered when using wellhead data for such analyses.
Using Geologic Modeling and Reservoir Simulation to Increase Gas Storage Efficiency: A Case Study
Authors: Ammer James R. , Mercer James C. , Mroz Thomas H. , Koperna George J. , Harris Ramon P. 
Published: December 2007

Abstract
The U.S. Department of Energy/Morgantown Energy Technology Center (METC), through partnerships with industry, is demonstrating the importance of geologic modeling and reservoir simulation for optimizing the development and operation of gas storage fields. METC entered into a Cooperative Research and Development Agreement with National Fuel Gas Supply Corporation (NFGSC) to investigate the expansion of an existing gas storage field in western New York.
A geologic model of the reservoir was developed using data from 14 existing vertical wells, mainly concentrated in the center of the field. A good history match of simulator predicted and field measured flowing wellhead pressure was achieved through 2.5 injection and withdrawal cycles. Biannual inventory shut-in pressures were matched within 5 percent.
Forecasts of reservoir performance were made for various field development strategies that included the operation of 11 existing vertical wells plus (1) 14 additional vertical wells, (2) four, 2000-foot horizontal wells, and (3) a combination of horizontal and vertical wells.
Although there has been no field verification of the modeling results, the results of the study have shown that geologic modeling and reservoir simulation can be very important to the efficient development of a storage reservoir. The modeling results have shown the possible advantages of using horizontal wells and have also focused efforts to gather additional data necessary to make the final decision on a field development strategy. While cost savings opportunities have been identified through this modeling effort with NFGSC, the need for additional reservoir description will require three to four vertical step-out wells before proceeding with full field development, especially with horizontal wells.
Case Study: Hydraulic Fracturing with Cross-Linked Gels in the Oriskany Formation to Improve Gas Storage Deliverability
Authors: Stiles Edward K. , Reese Rhys R. 
Published: December 2007

Abstract
During the summer and fall of 1994, CNG Transmission Corporation fracture-stimulated thirty (30) gas storage wells with a cross-linked gel fluid system. The work was done to increase late-season field deliverability. Individual well tests taken to date have shown that, on average, per-well deliverability has increased by a factor of five. The text that follows will detail the engineering and geologic aspects, procedures, results, and analysis of the project.
A discussion of the strategic placement of the storage fields involved will be presented, along with a review of FERC Order 636 and it's impact on the current gas storage business mechanics.
Overviews are presented on the geology, reservoir properties, and characteristics of the storage fields involved in the project. General well design and well completion configuration are discussed. Fracturing/refracturing candidate selection criteria are presented. Basic fracturing design criteria are discussed including: fluid parameters, geometry, proppant selection, and concentration. Discussions of observations and minor changes in treatment designs which occurred between the different fields are discussed.
The treatments are summarized and compared on a pre and post fracturing deliverability test analysis. Explanations are offered for wells with exceptional results, as well as marginally successful treatments.
Pore and Throat Network Model and Its Application to the Optimal Selection of Temporary Plugging Particles
Authors: Wenrong Mei , Shihong Shu , Tianhua Lai , Wenzhong Liu , Guoheng Hu 
Published: December 2007

Abstract
To a great extent, experiment selection of temporary plugging particles(TPP) in the temporary plugging techniques (TFT) is blind at present. Based on the investigation of particle migration, deposition and plugging mechanism in the porous media, network model, the inter-connected pore and throat network on the basis of reservoir pore structure, is applied to the optimization of TPP in the TPT. It is shown that the result of simulation has a good agreement with that of core flooding experiment and can be used to guide the study of core flooding experiments. The main advantages of this method are: 1. the model can be repeatedly used many times and can be used in the simulations of various purposes and aspects; 2. the results are highly comparable by the simulation while much less by the core flooding experiments.
Comparison of Numerical and Analytical Inflow Performance Modelling of Gravelpacked and Frac-Packed Wells
Authors: Burton Robert C. , Rester Stephen , Davis Eric R. 
Published: December 2007

Abstract
Estimation of completion pressure losses in gravelpacked and frac-packed wells is generally performed through use of empirical or semi-empirical analytical relations. This paper reports on work conducted by Conoco to compare numerical simulation results with analytical inflow performance relations. The work shows how and where completion pressure losses occur in flow to gravelpacked and frac-packed wells.
A fine gridded finite difference model has been developed to simulate flow and pressure loss behavior in the reservoir/well system. The grid system employs elements as small as 1 cm5 to model complex near well and intra-well flow effects including near-wellbore flow convergence to perforations, flow distribution between perforations and flow through gravel-filled perforations. These near-wellbore effects are reviewed for both symmetrical gravelpacked well flow cases and asymmetrical flow cases associated with frac-packed wells. Intra-well flow through gravel-filled perforation tunnels and the casing/screen annulus is also modelled for both cases.
Pressure losses and skin effects due to damage, fracturing and wellbore geometry are calculated through the flow system and compared to predictions from analytical relations. Results of these comparisons lead to an improved understanding of the effects of damage and flow asymmetry on gravelpacked and frac-packed well performance. Further, they show how current analytical skin relations can be enhanced to provide more effective completion pressure loss predictions.
Effect of Acids and Stimulation Additives on the Cloud Point of Nonionic Surfactants
Authors: Nasr-El-Din H. A. , Al-Ghamdi A. M. 
Published: December 2007

Abstract
Nonionic surfactants are commonly used during well stimulation for several reasons. They reduce interfacial tension between the acid and oil phases, thus improving acid/rock interaction. They are also used to form a stable foam which improves the sweep efficiency during acidizing. However, these surfactants should be employed at temperatures below their cloud point (defined as the temperature at which the surfactant solution becomes cloudy). This temperature signifies the onset of the surfactant salting out, which will reduce the efficiency of the stimulation and may damage the formation.
An experimental study was conducted to assess the effect of various acids and stimulation additives on the cloud point of nonionic surfactants. The influences of acids (inorganic and organic), mutual solvents, friction reducers, hydrogen sulfide scavengers, sequestering agents, short chain alcohols, simple salts, scale inhibitors, anionic surfactants on the cloud point of several nonionic surfactants were examined over a wide range of parameters.
The results indicated that the cloud point monotonically increased with the acid concentration. However, the rate of increase depended on the acid type and the number of ethylene oxide groups of the surfactant. Salts depressed the cloud point of nonionic surfactants at all hydrochloric acid concentrations examined. Alcohols, methanol and isopropanol enhanced the cloud point of nonionic surfactants. The effect of mutual solvents was found to be a function of the number of ethylene oxide groups of the surfactant, acid and mutual solvent concentrations. Anionic surfactants depressed the cloud point of nonionic surfactants at all sodium chloride concentrations examined. Clay stabilizers (cationic polymers) and hydrogen sulfide scavengers depressed the cloud point whereas scale inhibitor and phosphonic acid did not affect the cloud point significantly.
It is extremely important to measure the cloud point of nonionic surfactants before performing a stimulation job. It is also recommended to use the acid formulation and mixing waters that will be used in the field
Effects of Completion Fluid Loss On Well Productivity
Authors: Foxenberg William E. , Ali Syed A. , Ke Mingjie 
Published: December 2007

Abstract
Laboratory studies and field case histories are presented that demonstrate enhanced well productivity when selection and formulation of solids-free, high density completion fluids are optimized prior to field use. Results of return permeability studies and compatibility tests between completion fluids and formation fluids are presented. These results illustrate the tendency for high density completion fluids to form stable emulsions with certain crude oils. Studies supporting the treatment of these fluids with non-emulsifiers, surface tension reducing surfactants or mutual solvents to reduce formation damage are discussed. Preliminary data describing unique chemistry of calcium chloride, calcium bromide and zinc bromide solutions are provided. These properties influence recovery of high density fluids from oil or gas formations.