bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative Log Evaluation in the Devonian Shales of the Northeast United States
Authors: Hashmy Kahled Husain , Hefter Todd , Chicko Robert 
Published: December 2007

ABSTRACT
The organic-rich Devonian shales underlying the Appalachian, Illinois and Michigan basins are potentially the most productive underdeveloped source of natural gas in the northeast United States. Though considerable quantities of natural gas are produced from these unconventional shale "reservoirs", standard well log evaluation techniques developed for sandstones and limestones are not suitable for the Devonian shales.
This work represents an attempt to quantify well log evaluation techniques in these shale reservoirs. The response equations for the Density and Neutron logs are used to establish the density and neutron log porosities appropriate for shale matrix. The Simandaux equation has been modified and adapted for the shale reservoir. With these modifications, the total porosity (intrinsic plus fractured), hydrocarbon density and the water saturation can be computed in these Devonian shales. Results have been consistent in four air drilled wells located in Ohio and West Virginia. Intervals in the shales which are characterized by development of porosity and where a gas saturation has been computed correspond invariably to "hot" zones on the Gamma-ray log. The organic content of these zones is also high when analyzed by the method proposed by Schmoker1. A pattern of high organic content corresponding to the development of porosity and the presence of increasing amounts of gas is discernable. Production tests indicate that large quantities of gas have been produced from intervals identified as porous and gas bearing according to the proposed technique.
Computed logs and listings of results from several wells are presented. Although this technique has been developed for the Devonian shales of the northeast United States, it could extend to other fractured shale reservoirs.
Volumes, Types, and Distribution of Clay Minerals in Reservoir Rocks Based on Well Logs
Authors: Ruhovets N. , Fertl Walter H. 
Published: December 2007

Abstract
Reliable evaluation of hydrocarbon resources encountered in shaly clastic reservoirs of low porosity and low permeability is an important although difficult task.
Log-derived estimates of the volume, type and distribution modes of various clay minerals, determination of cation exchange capacity (CEC) and Qv (CEC per unit of total pore volume), and properly selected water saturation calculation models assist formation evaluation.
Since shaly clastic reservoir rocks require extensive core sampling for CEC and Qv analysis, which is tedious, time consuming, and expensive, attempts have been made to correlate such CEC and Qv data with one specific or a combination of several well logging measurements. The latter include the spontaneous potential, gamma ray, natural gamma ray spectral data, dielectric constant and acoustic-, density-and/or neutron-derived porosity, etc. Constraints associated with these concepts will be reviewed. Discussed in this paper, is an innovative digital shaly sand evaluation approach (CLASS), which provides information on total and effective reservoir porosity, total and effective fluid distribution based on the Waxman-Smits equation, reservoir productivity, silt volume, and volumes, types and distribution modes of clay minerals present in subsurface formations.
Influence of the San Juan Mountain Geothermal Anomaly and Other Tertiary Igneous Events on the Coalbed Methane Potential in the Piceance, San Juan, and Raton Basins, Colorado and New Mexico
Authors: Choate Raoul , Rightmire Craig T. 
Published: December 2007

ABSTRACT
The San Juan Mountain igneous extrusive complex in southwestern Colorado is approximately equidistant from the southeastern Piceance, northern San Juan, and western Raton Basins. These areas are known to contain high-rank coals and to have high methane contents in those coals. Recent studies have shown that this area is the center of an anomalously high geothermal gradient, which may strongly influence the increased coal rank and therefore the gas content in those areas. Other, less extensive Tertiary igneous events locally influencing coal rank and methane content include the intrusives along the margin of southeastern Piceance Basin, northeastern San Juan Basin, and the volcanic extrusives associated with the Spanish Peaks of the Raton Mesa.
Coal samples collected in the Piceance Basin increase in gas content from west to east from approximately 200 cubic feet per ton (cf/t) (6.3 cubic centimeters per gram--cc/g) along the Colorado River in the vicinity of Cameo to greater than 1,000 cf/t (31.3 cc/g) in the vicinity of Coal Basin in the southeastern part of the basin near the Elk Mountain intrusives. Coal samples from the Fruitland Coal in northern New Mexico and southern Colorado in the San Juan Basin have been shown to contain in excess of 500 cf/t (15.6 cc/g). Samples collected by the USGS in the Raton Basin from the Vermejo Formation contain in excess of 500 cf/t (15.6 cc/g).
It is suggested here that the anomalously high geothermal gradients induced by the intrusion of the San Juan Mountain complex and aided locally by other Tertiary events is substantially responsible for the high-rank coals observed in these areas, and therefore is principally responsible for the anomalously high methane content and the high potential for coalbed methane production from these areas.
Methane Drainage: Identification and Evaluation of the Parameters Controlling Induced Fracture Geometry
Authors: Trevits Michael A. , Hanson Merle E. , Ward Victor L. 
Published: December 2007

ABSTRACT
During the conduct of the Bureau of Mines vertical borehole methane drainage research program, questions have been raised pertaining to the containment of fractures induced or extended during hydraulic stimulation operations. As a result of these inquiries, a project was initiated in September 1980, to identify the basic parameters controlling induced fracture geometry. Under this effort, 12 vertical boreholes will be completed and subsequently intercepted by mining operations. The boreholes are located at four separate mine sites, with three boreholes planned per mine site. Prior to hydraulic stimulation operations, the in situ stresses will be measured for the coalbed and the rock units immediately above and below it. This information, along with the results of mechanical and frictional properties tests, will be incorporated into the stimulation treatment design. The treatments scheduled for each borehole will allow for variability of injection rate and sand proppant concentration while strictly controlling fluid quality and treatment pressure. Current project plans call for 113m3 (30,000 gal) nitrogen-generated foam treatments and a maximum of 9,000 kg (20,000 lb) of 20-to 40-mesh-size sand proppant. Upon completion of the stimulation treatments, the boreholes will be produced or abandoned depending upon the needs of the mine operators. As borehole interception takes place, underground studies will be performed to delineate the magnitude and orientation of all induced fractures, effects on mining operations, and structural or depositional anomalies in the coalbed and adjacent rock units. These data will be correlated with the treatment design so that adjustments in the design parameters can be made for future treatments. This paper identifies project plans and provides a summary of the activities performed to date.
The GRI/lndustry Eastern Gas Shale Data Base
Authors: Zielinski Ronald E. , Sharer John C. , Ciramella Anthony F. 
Published: December 2007

ABSTRACT
The Gas Research Institute (GRI) has established, as part of its research program, the Gas Resource Information System (GRIS). GRIS is a computerized data base that contains historical data on eastern gas shale wells. GRIS was established at the request of industry and contains all those elements which industry feels are important for the evaluation of drilling, completion, stimulation and production techniques for eastern gas shale wells. While GRI will be researching the data on the base to optimize production from the eastern gas shales, it will make GRIS available to industry as a mutually beneficial tool. GRI intends to cooperate with industry in updating and maintaining the data base.
Through industry's cooperation in providing input into the data base, it is felt that sufficient data will be available so that the data base can be effectively utilized to optimize techniques for attacking the eastern gas shales as a vaiable production tarqet and as a consequence both the producer and rate payer can benefit from the availability of more gas into the pipeline.
While the data base will not answer all problems, its use as demonstrated in the study case can be of prime importance in sorting out those factors that can be used to develop optimum techniques to maximize gas production from the eastern gas shales.
Foam Fracturing of Upper Devonian Benson Formation in Central West Virginia
Authors: Shea Christopher , Bucher Dean Herbert 
Published: December 2007

ABSTRACT
Stimulation of the Upper Devonian Benson Formation of Central West Virginia has lead to the use of various types of treatments. The following is an investigation of one of the more recent techniques, Foam/Nitrogen Fracturing, as it compares to the conventional Water Frac methods.
The Benson is a shallow water turbodite deposit with thicknesses variable up to 30 feet. It is a brown siltstone which characteristically becomes commercially productive only after stimulation. Over the past three years stimulation of Union Drilling Benson wells in Upshur and Barbour Counties has been exclusively Foam Frac or Water Frac, with few exceptions. Foam Fracs were used initially for three reasons: (1) to keep large volumes of water out of the formation in order to prevent clay swelling, (2) to aid in well clean-up, (3) to allow better sand placement through increased carrying quality of foamed Nitrogen. The ultimate goal of the Foam treatment is to increase gas flow from the wells.
Methods of investigation include records kept of (1) volumes of water used for treatments, (2) cleanup and service rig time and efficiency (3) open flows from foam frac and water frac treated wells, an indication of the sand placement abilities. Conclusions based on open flow results indicate that lower volumes of water, quicker well clean-up, and improved sand placement are desirable for the Benson Formation.
Selection of a Fracture Proppant in a Tight Gas Field, Bauxite vs. Sand, Wamsutter Area, Wyoming
Authors: Seccombe James C. , Anderson Gary E. 
Published: December 2007

ABSTRACT
This paper discusses the results of a study made to evaluate the effectiveness of sintered bauxite as a propping agent for Mesaverde fracture stimulations in Wyoming's Wamsutter Tight Formation Gas Area. It is generally accepted that bauxite should be used when closure pressure exceeds 8000 psi (55 MPa). Above this pressure, sand undergoes significant crushing resulting in very large reductions in permeability. However, in areas similar to Wamsutter, where the closure pressure ranges from 6000 to 8000 psi (41 to 55 MPa), it is not clear whether sand or bauxite should be used.
A reservoir simulator and an economic model were used to optimize fracture length and to determine if bauxite should be used in Wamsutter. It was found that well performance can be accurately predicted with the simulator when a 0.1 in situ fracture flow capacity correction is made to laboratory measured fracture flow capacities.
Over the range of permeabilities studied, (0.01 to 0.4 md) it was determined that bauxite should be used as the propping agent rather than sand. The economic benefits of using bauxite are greatest at the higher reservoir permeabilities. At a reservoir permeability of 0.4 md the optimum fracture length is 2000 feet (610 m) when using bauxite, while at a reservoir permeability of 0.01 md the optimum fracture length is 5000 feet (1,524 m).
Multiple Fracturing Experiments — Propellant and Borehole Considerations
Authors: Cuderman Jerry F. 
Published: December 2007

ABSTRACT
The technology for multiple fracturing of a wellbore, using progressively burning propellants, is being developed to enhance natural gas recovery. Multiple fracturing appears especially attractive for stimulating naturally fractured reservoirs such as Devonian shales where it is expected to effectively intersect existing fractures and connect them to a wellbore.
Previous experiments and modeling efforts1–5 defined pressure risetimes required for multiple fracturing as a function of borehole diameter, but identified only a weak dependence on peak pressure attained. Typically, from four to eight equally spaced major fractures occur as a function of pressure risetime and in situ stress orientation.
The present experiments address propellant and rock response considerations required to achieve the desired pressure risetimes for reliable multiple fracturing.
Comparative Economics of Gas Production From Conventional, Tight, and Deep Reservoirs
Authors: Morra Frank , Brashear J. P. , Haas Mark R. 
Published: December 2007

ABSTRACT
In the near future, the majority of America's natural gas supply will be produced from three principal resources: conventional, deep (more than 15,000 feet), and tight (less than 0.1 md) gas reservoirs. These differ from one another in terms of: Exploration costs due to finding rates and field sizes;Extraction costs — especially drilling and stimulation;Risks -- especially in technologies for diagnosing and stimulating deep and tight reservoirs; andGas prices -- under NGPA, deep gas is deregulated and tight gas receives an incentive price, but is not deregulated.
This paper compares the overall present value economics of the three resources in light of these above factors. The analysis shows that, while extraction costs are lower for conventional gas, larger new field discoveries for "frontier" deep and tight gas may make them competitive when full-field economics is considered. This conclusion is even stronger if either differential incentive prices are continued or the technological risks affecting the deep and tight resources are reduced. To the extent this competition between conventional, deep, and tight gas can be fostered, the productivity of exploration (reserves added per foot) and overall gas reserves will be improved.
Foamed Cement — A New Technique to Solve Old Problems
Authors: Root R. L. , Barrett N. D. , Spangle L. B. 
Published: December 2007

ABSTRACT
The process of foaming cement to make lightweight slurries is well known and documented in the literature. However, the technology for applying this process to oil and gas-well cementing has been lacking. New techniques and treatment designs have now been developed which show that the use of lightweight foamed cements in oil field operations can solve many problems. Treatments can be performed with the current equipment and personnel operating in the field. When compared to other processes for making ultra-lightweight slurries, foamed cements are very economical.
There are many reasons for using lightweight slurries in oil-well cementing. Probably, the foremost of these are problems of lost circulation or where long lifts of cement are required. The use of lightweight foamed cement slurries for these problems offers several advantages over the more common lightweight slurries. Some of the advantages are given below. Lower density slurries, which will develop adequate strengths for filler-type cements, can be obtained. A density as low as eight pounds per gallon can be achieved with foamed cement while approximately 10.5 lb/gal is the lowest which can be achieved when using materials such as bentonite, perlite or sodium silicates.Hollow spheres have been used to achieve slurry densities in the eight pounds per gallon range. Foamed cements are considerably more economical and are not subject to the pressure limitations of ceramic spheres.
A series of field trials using foamed cement has been performed in the Rocky Mountain area. Descriptions of these field trials, including the techniques being used, are presented along with supporting laboratory data showing typical compressive strengths and permeabilities for foamed cement systems.
Predicting Possibility of Oil Production from Tar Sand Deposits Based on Geologic, Logging, and Chemical Composition
Authors: Vogel Albert W. , Amirijafari Bahram 
Published: December 2007

ABSTRACT
In this paper, the question, "What are tar sands?" is addressed. In an effort to categorize the tar sand deposit at Raven Ridge near Vernal, Utah, the coordinated and combined activities with corresponding disciplines such as the following were considered: recognizing the potential of the heavy oil impregnated rock,characterizing the deposit based on the composition of the oil,developing reserves,characterizing the material,establishing possible reservoir characteristics,defining conventional oil production potential.
Some fourteen shallow holes were drilled and cored. Tar sand samples were taken from the lean, medium, and rich bitumen content rock. These samples were analyzed chemically.
The results of the coring, logging and chemical analysis are as follows: There is a definite correlation between the results that were computed from electric logs and with those obtained from chemical analysis of some 268 tar sand samples.Asphaltene, polar molecule and hydrocarbon content of the bitumen from Raven Ridge was compared to similar analyses of other tar sand deposits of the world using SARA (Saturates, Aromatics, Resins, and Asphal-tenes) analyses. The results indicate that the petroleum (oil sand) deposit is a thermally mature oil.A reservoir engineering analysis was carried out to determine the potential rate of oil production, from a well drilled at a suitable location downdip based on the available geologic data from the near outcrop core data. The results indicate a good possibility of conventional oil production.
Conclusions are that chemical analysis (SARA) of tar sand samples obtained from various depths, near surface up to 50 feet deep, could provide a positive indication of oil production from a well drilled down-dip from the outcrop.
Analysis of Pressure Buildups Taken From Fluid Level Data — Tyler Sands, Central Montana
Authors: Bishop David F. 
Published: December 2007

ABSTRACT
Pressure buildups taken by fluid level recording prove to be quite usable for formation evaluation in the "Tyler" sands of Central Montana. This method provides low cost information with surprising accuracy. The procedures followed in obtaining the data, and the precautions taken in assuring the validity of the data are discussed in the paper. The data proved sufficiently accurate to perform engineering calculations in two separate "Tyler" fields. The calculations aided in determination of reservoir parameters, and in one field provided justification for additional development drilling. In another field, the data substantiated the limited reservoir, and development drilling plans were cancelled. The buildup curves illustrated well bore damage in some of the wells and subsequent stimulation of two wells resulted in sustained six-fold and nine-fold increases in producing rates of these wells.
This paper illustrates the value of the engineering calculations when applied to carefully gathered field data. The method should have application in other areas with similar producing properties to the "Tyler" sands in Central Montana.
Planning a Bit Selection for a Deep Overthrust Well
Authors: Lyon Richard C. 
Published: December 2007

ABSTRACT
Bit selection planning for a deep Overthrust well in the tri-state area of Idaho, Wyoming and Utah presents a unique challenge to the drilling engineer. Most bit selection techniques were mainly done by the trial and error method with varying degrees of success. Analysis of bit records from this area, in conjunction with electric log interpretation to locate geological formation tops, has resulted in a technique to correlate bit types to specific formations. This technique has been used with some success in bit selection planning. One particular well using this method is compared with actual performance.
Mergers And Acquisitions Of Oil And Gas Producing Companies
Authors: Collins William E. 
Published: December 2007

Introduction
In most aspects the problems arising in connection with acquisition of oil and gas producing companies, by whatever method, are essentially the same as those arising in connection with mergers and other acquisitions or other types of commercial organizations. The differences result primarily from the nature of the assets, particularly the depletable assets of oil and gas companies.
The primary difference is that the form of the transaction is usually dictated by the substantial advantages, both to buyer and seller, from the ABC transaction. It is almost universally true that from both points of view, production to the buyer is obvious. From the stand-point of the seller, even if the tax basis is almost nil, the price obtainable in a production payment transaction quite often is greater after taxes than the value obtainable in a tax free transaction.
The second difference is that in a transaction involving producing oil and gas properties the legal work involved in conveyancing and title examination is usually substantially greater than is involved in most other commercial transactions.
Basically, there are two types of corporate acquisitions - tax free reorganizations and taxable transactions.
The Deep Propagation Tool (A New Electromagnetic Logging Tool)
Authors: Huchital G. S. , Hutin R. , Thoraval Y. , Clark B. 
Published: December 2007

ABSTRACT
This paper will discuss a new well logging tool, the Deep Propagation Tool (DPT*). The device radiates electromagnetic energy into the formation surrounding the well bore. Measurements of the attenuation and velocity (wavelength) of this electromagnetic wave will yield the resistivity and dielectric constant of the formation.
The use of an accurate measurement of formation resistivity is well known. The measurement of formation dielectric constant has recently been shown to be of use in formation evaluation for cases of variable formation water resistivity.(1)
Previous devices used to measure the dielectric constant of the formation have had relatively shallow depths of investigation. The Deep Propagation Tool uses a unique antenna array in order to return formation electrical parameters characteristic of the uninvaded formation.
The device operates at a frequency in the tens of megahertz range and performs accurate measurements of signal level and relative phase at four receivers locations. These eight measurements can then be used to return a value for the formation resistivity and dielectric constant.
The theoretical basis for the design of the tool will be presented. This will be applied to predict the environment effects on the response of the device. Attention will be paid to the effect of the borehole on the measurement, the depth of investigation of the device, and its vertical resolution.
Measurements have been made in wells in both Europe and South America. Results of these measurements are quite interesting and show that the measurement of formation dielectric constant can be used to determine the presence of hydrocarbons in zones of variable connate water resistivities where traditional resistivity measurements are not easily applied.
Effect of Fluid Flow Rates on Geochemical Processes
Authors: Dibble Walter E. , Potter Jared M. 
Published: December 2007

ABSTRACT
A promising research avenue is determining the influence of fluid flow rate on mineral growth and dissolution reactions. Using flow-through hydro-thermal apparatus, we have explored experimentally the relationship between flow rate, alteration mineralogy, and reaction rates under a variety of conditions. At high flow rates, reactions occur that favor the formation of stable minerals. At low flow rates, under the same conditions, less stable phases can be produced.