Paul Schettler

Juniata College · Department of Chemistry

In order to fully realize the separation power of comprehensive two-dimensional gas chromatography (GC x GC), a means of predicting and optimizing separations based on operating variables was developed. This approach initially calculates the enthalpy (DeltaH) and entropy (DeltaS) for the target compounds from experimental input data, and then uses...

A computer modeling technique has been developed which allows for the prediction of chromatographic separation and stationary-phase selectivity. This technique enables development of application-specific gas chromatographic columns by allowing for the simultaneous optimization of physical dimensions, flow and temperature programs, and stationary-ph...

"Column Watch" guest authors describe methods to predict optimal stationary phases, which enable more rapid and improved gas chromatography column development. By calculating optimal stationary-phase composition and physical parameters, column developers can construct columns that provide the exact separation requirements desired by analysis or cur...

This second volume of the two-volume set contains the experimental measurements data for the wells discussed in volume I, where the research in gas adsorption by organic rich shales is reported. Adsorption within the shale matrix effectively doubles the gas capacity of these reservoir materials as compared with the effect of porosity alone. The fun...

Three laboratory methods were developed to measure matrix gas permeability (Km) of Devonian shale cores and drill cuttings at native water saturations. The first method uses pulse pressure testing of core plugs with helium. The second, new method uses pulse pressure testing of core chips or drill cuttings with helium. These methods gave comparable...

The report briefly summarizes the work done on natural gas storage and transport on Eastern Devonian Shale in Appalachia. The laboratory data indicates that gas is not only stored within the mesoporous structure of the reservoir rock, but also adsorbed onto pore surfaces, and perhaps dissolved in oil or bitumen. Transport parameters, including diff...

The low-temperature chemistry of isobutylene in zeolites HY and HZSM-5 was probed by in situ variable-temperature C-13 NMR spectroscopy with magic-angle spinning (MAS). Isobutylene interacts with Bronsted acid sites of the zeolites at a temperature of ca. 123 K to form a hydrogen-bonded species, as indicated by a 2-C-13 DELTA-delta value (relative...

Sorption properties of individual constituents of Devonian shale were compared with similar properties of a wide variety of shales of different lithologies. Major components examined included illite, quartz, chlorite, kerogen, and oil. Kerogen was isolated from a core sample retrieved from a producing gas well, while the oil used was taken from a g...

A novel design for a downhole flowmeter that can locate and quantify gas-entry points in a well is presented. The instrument has a gas-tracer injector at its lower end and a tracer detector at its upper end. We determine gas flow in the well by injecting tracer gas at a precisely measured rate into the natural gas flow and measuring the concentrati...

The mechanisms by which butadiene oligomerizes in acidic zeolite catalysts leading to deactivation by pore blockage are elucidated.

The mechanisms by which butadiene oligomerizes in acidic zeolite catalysts leading to deactivation by pore blockage have been elucidated by using in situ {sup 13}C solid-state NMR spectroscopy with magic-angle spinning (MAS). Butadiene is found to oligomerize primarily by the 1,4-addition reaction upon adsorption at its melting point (164 K). Secon...

Selecting specific zones to stimulate in wells is a major problem in designing stimulation treatments for low permeability reservoirs, such as the Devonian shale. Treatments should be concentrated over small intervals of a well, so the selection of the most productive intervals is critical. The Dye Leachback technique helps to locate these zones by...

Natural gas storage in Devonian shales occurs in part because of the adsorption of methane onto internal pore surfaces. Methane is released during production and is a significant fraction of the total gas produced. Thus, porosity, as a measure of gas storage capacity, must be supplemented with a term that will account for the condensed-phase methan...

Dye leachback is a simple, inexpensive technique for locating formations with gas production potential using rotary or cable-tool cuttings obtained at the well site during drilling. The process itself is field adaptable and can produce a permeability profile while the drilling is proceedings. Dye leachback is not only quicker than standard logging...

Summary The effects of mixed solvent systems and anions on the rate of reaction of the title compounds were investigated. The results were shown to be best interpreted in terms of ion-pair formation and solvation-desolvation effects, in addition to the factors included in the outer-sphere electron transfer rate theory expounded by Marcus.

Data and interpretations relating the physical chemistry of Devonian shale to the productivity of natural gas wells are presented in this report. Specifically, methane isotherms, helium porosity, BET, and permeability and diffusion data are presented along with a dual porosity model that takes specific account both of Poiseuille flow through a frac...

Eighty-four measurements (diffusion constants, BET's, or ice temperature isotherm) were performed on 17 core samples of the Lincoln County number 20403 well. Outgassing analyses were made on 129 samples for CH/sub 4/, C/sub 2/H/sub 6/, C/sub 3/H/sub 8/, O/sub 2/, N/sub 2/, and CO/sub 2/. The first step toward the construction of an automated diffus...

The binary interaction between two electrons solvated in ammonia is considered by treating the electrons in the valence bond approximation with dispersion forces added. Solvent-solvent and solvent-electron interactions vary as a function of distance between the salvated electrons. These changes are considered within the continuum approximation alon...

Large fluctuations of concentration occur in the vicinity of the critical point in metal-ammonia solutions. Their existence is indicated by a plateau in the activity-concentration curve. If there is no pressure work associated with fluctuations, the probability of finding a concentration X2 different from the average concentration X̄2 is given by P...

A computer can be a powerful teaching tool because statistical thermodynamic results can be "derived" in what a student perceives as a more direct manner as opposed to derivations involving mathematical techniques of which she or he is at best only dimly familiar.

The following data are presented for shales from wells in Ohio and New York: density, isotherm slope (volume of gas sorbed), BET area, specific degasibility, and porosity. (DLC)

An apparatus is described for measuring the mass flow rate of gas in a well comprising, an instrument mounted in the well, the instrument having a tracer gas dispensing means near one end and a tracer gas concentration measuring means near the other end, a source of tracer gas in the instrument, means connecting the source of tracer gas to the gas...

This report deals with the determination of how natural gas is stored in Devonian shales and what the theoretical implications of the storage mechanisms are. Isotherm measurements show that approximately 50% of the methane present in shale is either dissolved in other fluids or is adsorbed; the remainder exists as gas in the pore spaces of the shal...

Work on Hydrocarbon-Shale Interaction at Juniata College from June 1, 1976 through September 30, 1976 is summarized. Work was accomplished in the following areas: constrictive and geometric effects associated with gas production from shale wells, diffusion constants, hydrocarbon gas analysis, adsorption isotherms and powder x-ray diffraction. A bib...

The report details the flow parameters and behavior of methane and helium gas flow in Vycor glass, berea sandstone, and Devonian shale samples. Over 100 degassing runs were made, however, fewer are reported here due to poor data sampling rate and other experimental difficulties in the initial stages of the study. In a second area, a gas well compos...

Data and interpretations relating the physical chemistry of Devonian shale to the productivity of natural gas wells are presented in this report. Specifically, methane isotherms, helium porosity, BET, and permeability and diffusion data are presented at pressures ranging up to 1000 psi. Use of the data in productivity calculations and resource esti...

Shale consists of several component responsible for adsorbing gas. Kerogen, insoluble organic material commonly present in shale, has been identified as one of the primary gas-adsorbing components. Kerogen has been successfully isolated from shale by a chloroform extractions to remove the soluble organic material, a series of acid treatments to eli...

This report deals with gas adsorption by organic rich shales. Adsorption within the shale matrix effectively doubles the gas capacity of these reservoir materials as compared with the effect of porosity alone. Gas is adsorbed primarily onto the organic (kerogen) components. Isotherms made on kerogen isolates from shale showed that the kerogen adsor...

Work during the report period was directed at obtaining data at the maximum design equipment rate (1-2 samples/day). Procedures were streamlined so as to be able to approach the equipmental design rate during the academic year. Work on the high pressure apparatus was delayed because of delays in delivery of component parts. Data on diffusion, degas...

The report deals with the determination of how natural gas is stored in Devonian shales. One hundred seventy-five helium and methane isotherms on 38 shale cores are presented. An additional 27 isotherms were determined from the constituents of Devonian shale: illite, chlorite, corrensite, quartz, kerogen, and oil. Using the isotherms for all sample...

During the period the DOE computer became operational except for plotting capability. Work devoted to the calibration and performance testing of the isothermal diffusion apparatus and related software is reported. Data gathering was initiated on CHâ and He isotherms and CHâ degasibilities on particles. Data on diffusion and isotherm parameters for...

The major conclusion reached by the contracted work is that, although fracturing is necessary in order to obtain Devonian shale production, the nature of the shale-hydrocarbon interaction remains a major contributing (but often neglected) factor in determining the degree of success of the well. Although natural fractures serve as conduits to the we...

A mathematical model describing production of gas from wells in Devonian shales is introduced, and the extent of agreement with existing productivity data is discussed. Parameters needed for this model include the diffusion constant of gas through the rock and the sorption isotherms of gas within the rock. Methods and results of measurements of the...

The nonequilibrium theory of chromatography is developed in general terms for complex laminar flow involving local fluctuations in the direction and magnitude of the velocity vector. This theory leads to an effective diffusion coefficient which describes zone dispersion. It is shown that flow complexities are responsible for the phenomenon of coupl...

The nonequilibrium theory of chromatography, in the general form recently developed for complex flow transport, is applied to a two-channel flow model having a steplike velocity exchange between channels. Equations are obtained for an arbitrary degree of velocity correlation from cell to cell within the system. This model of complex flow is the fir...

Computer methods make possible the detailed analysis of Chromatographic peak shape, and can be used to obtain the various moments of experimental peaks. The importance of the statistical moments and related properties is discussed here. The moments characterize a peak completely and are related to parameters such as theoretical plate height and for...

An ionic-lattice model with long-range forces is proposed for alkali metal-ammonia solutions to allow calculation of the chemical potentials of both components in both phases as functions of a rationalized concentration scale in which ammonia molecules are presumed strongly to solvate the metal. From the chemical potentials both phase diagrams and...

A theoretical analysis of the several ways in which nonideal gases affect chromatographic characteristics is presented. Of primary concern is the effect of nonideal and thus nonconstant compressibilities, viscosities, and retention ratios. The theoretical formalism accounts quite generally for these nonideal factors for any degree of nonideality, t...

An easily applied method for predicting binary gas-phase diffusivities is based on the use of special diffusion volumes coupled with extensive experiment and nonlinear least squares analysis of the data. Comparison with eight other correlations demonstrates the relative reliability and simplicity of the new method.

Fluctuations in column pressure, due to inadequate pressure regulation, flow startup, or other flow changes, hinder the use of gas chromatography for qualitative and quantitative analysis and research purposes. The time-dependent pressure profiles resulting from these fluctuations have been studied. These profiles should be used whenever there is a...

Phase diagrams are presented for the liquid-liquid phase separation of lithium and potassium solutions in liquid ammonia. Solutions of lithium separate into two phases at temperatures below -63.5° in the range of concentration between approximately 0.02 and 0.09 g.-atom of lithium/mole of ammonia. Separation of potassium solutions is observed below...

Results are presented for the effect on the phase separation of solutions of sodium in liquid ammonia of adding varying amounts of sodium iodide. The measurements were performed at -33.35, -56.50, and -75.00°. Apparatus is described which makes possible the convenient preparation and separation of these solutions under conditions guaranteeing their...

This work deals with the significance of the nonequilibrium or C terms in gas chromatography. It is shown, first, that the C terms have an important role in column resolution. Two new methods are then proposed for the experimental isolation of liquid and gas contributions, Cl and Cv. These methods are applied to a conventional GLC column, a glass b...