Search

Process designers often find that available data are insufficient in number, precision and/or range of independent variables(s) for the design task at hand. This occurs because the experiments were not designed with the end use of data in mind. This paper presents a method for designing an experiment based on criteria related to the end use of the data. Probability for success of a given experimental design can be judged by this method prior to actually taking any experimental data. This means that laboratory effort is utilized more efficiently and the likelihood of acquiring data which would be of insufficient quality for process design is minimized.

Governing equations for layered Timoshenko beam theory for the general case of unsymmetrically stacked laminated beams are presented. A computer program is developed to use the theory to investigate layered beam problems with any kind of end conditions and any transverse loading. Capability is also demonstrated for varying properties such as modulus of elasticity along the length of the beam. The method is applied to the study of laminated wooden beams. Variations of deflection, shear stress, and normal stress with percentage of strong wood along the outer fibers is shown. The program is not meant to be a design tool. The main purpose of the program is to furnish an analytical tool to use in correlating experimental data with theoretical results so that assumptions regarding physical properties can be altered if need be. A study of the effect of changing the properties of a wooden laminated beam is presented.

Total pressure, vapor—liquid equilibrium data for the binary system 2-methyl-1,3-butadiene and 2-methylbutene-2 are reported at 310.93, 316.48 and 322.04 K. The experimental uncertainties in measured variables, expressed as standard deviations, are 0.0005 mole fraction, 0.01 K and 0.2% of measured pressure. The coefficients for a modified Wilson solution model are also reported. These coefficients were determined from the experimental data using a general non-linear least-squares technique which accounts for experimental uncertainties in independent and dependent variables. The standard deviations of prediction for temperature-independent coefficients are 0.17% for pressure, 0.001 K for temperature and 0.00001 for mole fraction.

Total pressure, vapor-liquid equilibrium data for the binary system composed of 2-methylbutene-1 and 2-methyl-1,3-butadiene are reported at 310.93, 316.48 and 322.03 K. The uncertainties in the measured variables, expressed as standard deviations, are 0.001 mole fraction, 0.02 K, and 0.1% of measured pressure. The coefficients for a modified form of the Wilson solution model are also reported. These coefficients were determined from the data using a general non-linear least squares technique which takes into account uncertainties in both the independent and dependent variables. The standard deviation of prediction, for temperature independent coefficients, is 0.24% for pressure, 0.0001 for mole fraction, and 0.02 K for temperature.

Bubble point pressure data were acquired at 344 K and about 9600 kPa on ternary mixtures of carbon dioxide and n-butane with paraffinic (n-decane), naphthenic (n-butylcyclohexane), and aromatic (n-butylbenzene) compounds to determine what effect differences in compound type might have on carbon dioxide-hydrocarbon miscibility of such systems. The data on carbon dioxide-n-butane-n-decane, when compared with those from the literature, showed good agreement. This suggests that the remaining data reported here are reliable. The data were regressed by using the Soave-Redlich-Kwong equation of state to determine interaction coefficient sets for phase behavior prediction. These sets of interaction coefficients were used to calculate carbon dioxide-hydrocarbon miscibility. No significant difference in miscibility was found as the heavy hydrocarbon compound was changed from paraffinic to naphthenic to aromatic type.

This article presents new, total pressure data for the isoprene—n-pentane binary system over the temperature range 300–330 K. The experimental design procedure of Howat and Swift was used as a guide for the selection of data points and for the analysis of the impact of random and potential systematic errors on the data. Regression analysis procedures used are those presented by Shanker et al. Quatitative data are presented which show the effect of mercury—hydrocarbon interaction on the measured vapor pressures of C5 hydrocarbons. The new data surpass the precision of any previously published literature data for this binary pair. The uncertainty in the measurements are 0.02 K, 0.08 kPa and 0.002 mole fraction. The predicted azeotrope composition is 0.743±0.003 mole fraction isoprene with no significant change with temperature.

Abstract Proper scaling of unsteady-state flow in laboratory gas reservoir models can be achieved in the permeability/fractional porosity ratio is less than 0.5 md. Porous media meeting this specification can be obtained from mixtures of sand and Portland cement providedthe water/cement ratio is in the range of 0.35 to 0.40,the sand/cement ratio is in the range of 1/1 to 2/1,the sand grain size is in the range of 48–100 to 18–28 mesh,the mortar curing time is 7 days or more andthe cured mortar is dried under vacuum to reduce the temperature level employed during the drying process. The areal homogeneity of the mortars tested is reasonably good, although significant trends in vertical permeability were noted. The Klinkenberg and non-Darcy coefficients of mortar are such that proper scaling of these effects in the laboratory model could be expected. Introduction A long term deliverability prediction for a gas well is generally based on data determined from flow tests that are of short duration relative to the producing life of the well. These data, together with an estimate of gas reserves in place, form the basis for establishing the parameters of the mathematical model used to predict performance at future times. Results obtained from a mathematical model represent only an interpretation of the physical process being modeled. Experimental verification of the production process from discovery to abandonment is needed where production occurs under carefully controlled conditions. Ideally, one might consider such an experiment to be conducted in the field. Even if the cost of such an experiment could be justified, the time required would make it impractical to consider. However, if the time scaling problem could be handled properly, an experimental model of the gas reservoir production process could provide the necessary data to study the mechanisms of the production process in a reasonable time period. An experimental model has been designed and constructed using the data of this study as a basis. The model reservoir system consists of one producing well located at the center of a right-circular cylinder of porous material. Ten to 15 observation wells are located at strategic offset positions from the producing well. These wells, and the producing well, are fitted with pressure transducers so that the pressure-time history can be recorded at various radial and azimuthal positions in the drainage area during the entire production life of the system. Time is scaled in the model so that the time required to produce gas from discovery pressure to abandonment pressure is about 2 hours. This compares with a 20-year producing life in the model's field counterpart and gives a time scale factor of approximately 1:100,000. DESIGN CRITERIA To establish design criteria for the experimental model, the reservoir is considered to be a finite right-circular cylinder of radius r, and height h with a producing well of radius r, located at the center and completed through the producing formation. This reservoir consists of a porous medium which has a uniform permeability k and gas porosity and the gas contained in the reservoir has density, viscosity and molecular weight. Initially, the pressure at all points within the reservoir is uniform at, and the reservoir temperature is . SPEJ P. 189ˆ

A variational method has been used to study the entrance and exit effects in a falling cylinder viscometer for creeping and noncreeping flow. The computed result indicate solution convergence for NRe less than 100 and agree with experiment within ± 0.5% for NRe less than 25.

Since Turk in 1853 called attention to retinal congestion and hemorrhages in all tumors of the brain, and von Graefe in 1860 described "choked disk" and attributed the condition to pressure, either direct or indirect, against the cavernous sinuses, both opththalmologists and neurologists have tried to explain, through various theories and many experiments, the actual mechanism whereby the disk becomes congested, edematous and, finally, choked. In a previous paper 1 attention was called to the various theories and a return to the mechanical theory was suggested as the probable, or at least a reasonable, solution to the problem. In that paper no effort was made to explain the absence of choked disk in certain cases of tumor of the brain in which normally one would expect to find a marked choking, for instance, in tumors of the cerebellopontile angle, but I believe that a reasonable explanation can be found

Viscosities, obtained with a falling-cylinder viscometer, are presented for liquid methane, ethane, and propane from their normal boiling points to their critical points and for n-butane from its normal boiling point to 100°C. The data of this study are compared with those of other investigators. The experimental viscosities of this study are correlated within ± 5% over the reduced-temperature range from 0.65 to 0.95 by means of a modified Smith-Brown correlation. The Grunberg-Nissan equation for estimating the critical viscosity was tested with the experimentally determined critical viscosities of this study and was found satisfactory.

The theory and calibration procedure for a cylindrical falling body viscometer is presented. Experimental viscosity data are given for liquid methane from −150°C. to the critical point and for liquid propane from −185° to +90°C. The maximum experimental error for methane data is ±8% and for propane data ±5%.

The viscosities and densities of methane-propane mixtures were determined at pressures to 5,000 lb./sq.in.abs. for 22.1 and 50.0 mole % methane over a temperature range from −120 to 37.78°C. and for 75.3 mole % methane over a temperature range from −150° to 37.78°C. Reproducibility of the viscosity data was ± 2%, and the agreement with literature values was, on the average, within ± 2%. The reproducibility of the density data was ± 0.8%, and the agreement with literature values was ± 1.2%.

A generalized differentiation method for analyzing rheological data of time-independent fluids is presented. The method is demonstrated to be valid and useful in analyzing rheological data and comparing such data obtained on the same time-independent fluid in rheometers of the capillary, annular, coaxial cylinder rotational, and falling cylinder types.

Summary of Post-Traumatic Treatment The following are the problems which demand consideration in posttraumatic treatment: 1. Classification of cases as those of (a) simple concussion, (h) concussion with skull fractures, fe) concussion with brain tissue damage, (d) concussion with skull fracture and brain tissue damage. 2. Operative interference. 3. Dehydration. 4. Spinal drainage. 5. Post-traumatic neurosis. 6. Traumatic psychosis.

The theoretical equations for the flow of Newtonian fluids in a falling cylinder viscometer with eccentricity are developed. The error in fall velocity of the cylinder caused by eccentricity is determined and presented in tabular form. An approximate method to determine the error in fall velocity caused by eccentricity for non-Newtonian fluids of the power law type is also presented. For the Newtonian case, n=1, the approximate method is shown to give excellent agreement with the exact method.

A theoretical analysis was made for laminar fluid flow in the annulus of a falling cylinder viscometer. A viscometer calibration constant was defined from the results of this analysis. This constant was expressed in terms of only the physical dimensions of the viscometer. The volues lidity of the theory was demonstrated by the agreement between predicted and experimental values of the viscometer constant. Methods of representing calibration data were compared. Temperature and pressure effects on the viscometer constants were related to the mechanical properties of the viscometer materials. The results of this investigation showed that the practical design of falling cyclinder viscometers is possible.

Total pressure and PVT data are reported on n-butane, butene-1, and butadiene-1,3 and their mixtures over the temperature range 100/sup 0/ to 150/sup 0/F and the pressure range 20 to 500 psia. The data have an estimated precision of 0.1%. The experimental data are correlated, and the vapor-liquid equilibrium behavior of the binary systems is computed by integration of the general coexistence equation by the method Manley and Swift. Wilson parameters for the binary systems are computed from the experimental data and used to predict the ternary system bubble-point pressures. The predicted pressures are compared with experimental results to test the validity of the predictions, and satisfactory agreement is achieved. No ternary azeotrope is observed over the range of conditions investigated. (19 refs.)

Raynaud's Disease: Twenty-three operations were performed on 10 patients; 11 for the lower extremity and 12 for the upper. Three of the cases were primarily scleroderma with secondary vasospasm and 2 were primarily Raynaud's disease with secondary scleroderma. The rest of the cases were typical Raynaud's disease. In all of the cases of Raynaud's disease the results were excellent. In the cases where scleroderma was primary the results were very good but not as good as in the other cases. Thromboangiitis Obliterans: There were 13 operations on 11 patients; 9 for the lower extremity and 4 for the upper. The immediate results were excellent in every case. Only one case has since come to major amputation. There was one death in this series following transabdominal sympathectomy. Chronic Arthritis: There were 23 operations on 10 patients; 15 for the upper extremity and 8 for the lower. There was one death following the transabdominal operation. This death, together with the one before reported, constitute the entire operative mortality from the lumbar operation. Both of these deaths occurred following transabdominal sympathectomy. Since we have adopted the extraperitoneal approach there have been no deaths. Seven of the patients have been distinctly improved. There have been 3 failures. Spastic Paraplegia: There have been 17 operations on 9 patients; 10 for the lower extremity and 7 for the upper. Of the 10 operations for the lower extremity, the results were classified as good in 6, fair in 2, and failures in 2. Of the 7 operations for the upper extremity, 2 were classed as fair and the other 5 as failures. Three cases of megacolon are reported in which left lumbar ganglionectomy was done. The results in all cases were entirely satisfactory. There were 5 cases of chronic constipation treated by left lumbar ganglionectomy; all of these have been entirely relieved. Traumatic Sympathalgia: There have been 6 cases; 3 male and 3 female. The operation has been performed 5 times for the upper extremity and once for the lower extremity. The results were classified as excellent in 4 cases, good in one case, fair in one case, the last 2 being cases in which the element of compensation was strong. Painful Amputation Stump: There have been 4 patients operated upon, all for the upper extremity. Three of these cases have been failures and one has had a fair result. Among the group of miscellaneous cases reported were 2 of atypical facial pain, one of epilepsy, one of varicose ulcer and one of angina pectoris. The cases of atypical pain in the face were very successful. The rest of the cases were unsuccessful. Anomalies of the lumbar sympathetic chain occur in about 20 per cent of cases. There may be multiple trunks or multiple ganglia, and at times fewer ganglia than normal are found. These anomalies may be overlooked and thus lead to incomplete denervation. Anomalies of the dorsal trunk are infrequent, but when they do occur may lead to technical difficulties in their removal. The trunk may lie quite anteriorly on the bodies of the vertebrae. These anomalies should always be borne in mind.

Abstract The purpose of this investigation was to measure PVT behavior of various types and combinations of PVT behavior of various types and combinations of heavy hydrocarbon components from the paraffinic, naphthenic and aromatic classes where the relative proportions of the various components were selected proportions of the various components were selected to approximate those of natural gas or gas condensate systems. Synthetic mixtures were used so that the compositions of the various components could be measured accurately. n-Heptane, methylcyclohexane and methylhenzene were used to represent the paraffinic, naphthenic and aromatic components of paraffinic, naphthenic and aromatic components of the heavy fraction. In the mixtures studied, the heavy fraction composition was held constant at 0.05-mole fraction, the balance being methane except for one mixture where 0.10-mole fraction of an intermediate component, propane, was added. The PVT data for the mixtures were determined in a variable-volume, constant-mass apparatus at psuedo-reduced temperatures from 1.84 to 2.00, over psuedo-reduced temperatures from 1.84 to 2.00, over a pseudo-reduced pressure range from 2.3 to 12.0. The experimental results showed that, regardless of the type of heavy material (paraffinic, naphthenic, aromatic, or combinations thereof) mixed with methane or methane and propane, the compressibility factors at equal values of pseudo-reduced temperature and pressure varied by less than 2.2 percent. pressure varied by less than 2.2 percent Introduction PVT data is used for natural gas and gas condensate fluids in determining reserves of reservoirs and performance of wells, in metering produced fluids, performance of wells, in metering produced fluids, and in recombining samples for laboratory studies. While there are vast amounts of PVT data reported for natural gas and gas condensate systems from which useful correlations have been developed, the compositional analyses for these systems and the resultant correlations typically were made with components analyzed through some arbitrary carbon number, usually C6, with the residue reported as a lumped "heavy" fraction. The heavy fraction was stoichiometrically recombined on the basis of an apparent molecular weight to give the final compositional analysis. It is virtually impossible to make a systematic analysis of the effect that variation of the relative amounts of paraffinic, naphthenic and aromatic constituents of the heavy fraction of natural systems might have on PVT behavior. Because there is considerable latitude in the relative amounts of these constituents, one speaks of crudes or condensate liquids as being "paraffin base", etc. It is of interest to determine if changes in the relative amounts of these three types of hydrocarbons in the heavy fraction cause significant changes in PVT behavior. If so, steps should be Taken to PVT behavior. If so, steps should be Taken to describe better the nature of the heavy fraction in PVT correlations. If not, more confidence can be PVT correlations. If not, more confidence can be placed in the correlations presently employed. placed in the correlations presently employed. DESIGN OF THE EXPERIMENTAL INVESTIGATION We attempted to determine if changes in the base of the heavy fraction would cause significant changes in the PVT behavior of gas or gas condensate fluids. Synthetic mixtures were used to enable us to systematically vary the base of the heavy fraction and to analyze accurately the fluids. We found that the heavy fraction of naturally occurring condensate systems seldom exceeds 0.05-mole fraction. Thus, the mole fraction of the heavy fraction in the synthetic systems studied was set arbitrarily at 0.05, to maximize whatever deviations in PVT behavior that might occur. Further, we judged that since the C7 hydrocarbons normally are present in greater quantities than higher carbon number hydrocarbons in naturally occurring systems, the use of n-heptane, methylcyclohexane, and methylbenzene to represent the paraffinic, naphthenic, and aromatic species in the heavy fraction would be most appropriate. SPEJ P. 338

The viscosities of methane and propane were determined at pressures to 5,000 lb./sq. in. abs. over a temperature range from −170° to 0°C. and −100° to 0°C., respectively, and the densities of propane were measured at pressures to 5,000 lb./sq. in. abs. over the temperature range from −100° to 0°C. Reproducibility of the viscosity data was about ± 1.2% and for the most part agreement with literature values was within ± 2%. the estimated accuracy of the density measurement was ± 0.5%. The data reported were well correlated in terms of residual viscosity vs. density.

In the conservative treatment of head injuries we have found need for certain immediate measures for the control of shock, hemorrhage, edema, and brain damage. These measures may be continued for a short time or in cases of prolonged unconsciousness must be continued for a longer period. Shock is the first and most important factor to control. After shock symptoms have subsided and hemorrhage and edema are under control one must make a careful survey to ascertain what damage has been done to (1) the brain, meninges and spinal cord, and (2) other organs and viscera. This survey requires complete physical, neurologic, and ophthalmologic examinations, including the use of roentgenograms and spinal puncture. The results of these examinations plus observation of changes in symptoms will indicate the proper procedure. Later treatment includes the prevention of post-traumatic neurosis. This depends upon the constant supervision of all personal contacts the patient may have during his convalescent period. Neurosis should never be allowed to develop. Psychoses associated with cerebrocranial injuries are the direct result of brain damage. They cannot be prevented; their presence is revealed as soon as the conscious period begins to appear. Treatment requires special and prolonged care and restraint. While it is embarrassing at autopsy to find that a case should have been operated on, it is more embarrassing to find that an operation was unjustified. Experience has convinced us that about 90 per cent of the cerebrocranial injuries may be safely treated under these conservative rules.

Theoretical equations and their solutions for the falling cylinder viscometer are presented for the Bingham plastic and power law models.

Evers, John F., Student Member AIME, U. of Kansas, Lawrence, Kansas Dempsy, John R., Member AIME, U. of Texas, Austin, Texas Preston, Floyd W., Member AIME, U. of Preston, Floyd W., Member AIME, U. of Kansas, Lawrence, Kansas Swift, George W., Member AIME, U. of Kansas, Lawrence, Kansas Abstract This paper reports on the development of an experimental model which simulates the production of gas from a reservoir. The model is comprised of a cylinder of reinforced Portland cement which is two feet in diameter and six inches in height. It is fitted with a production well at the center and 32 observation wells—eight logarithmically spaced on each of four mutually perpendicular azimuths. All wells are 0.014 inches in diameter and are completed (open hole) through the thickness of the cylinder. The measured porosity of the model is 0.146 and the apparent permeability is in the range of 25–100 microdarcies. These properties are such that a 20 year production history properties are such that a 20 year production history of a field reservoir drilled on 640 acre spacing can be simulated in approximately 9 hours, giving a time scaling factor between the model and its field counterpart of 1:20,000. Data are presented showing a drawdown and a buildup test, presented showing a drawdown and a buildup test, the variation of permeability with distance from the producing well, and the effect of incomplete pressure buildup on the estimation of gas pressure buildup on the estimation of gas reserves. Since the model only recently become operational, data analysis on the runs made to date has not yet been completed. However, the data presented in this paper demonstrate the feasibility presented in this paper demonstrate the feasibility of experimentally modelling gas flow in porous media. This type of experimentation will allow fuller understanding of the mechanisms of gas flow in reservoir geometries. The described modelling technique opens broad vistas for experimentally studying conventional, interference, and pulse testing method, multiple well production phenomena, retrograde effects on permeabilities phenomena, retrograde effects on permeabilities near the producing well, etc. Introduction A long term deliverability prediction for a gas well is generally based on data determined from flow tests that are of short duration relative to the producing life of the well. These data form the basis for establishing the parameters of a mathematical model used to predict performance at future times. Since the results obtained from such a model represent only a theoretical interpretation of the physical process occurring, experimental verification under carefully controlled conditions from discovery to abandonment is needed. Ideally, one might consider such an experiment to be conducted in the field. Even if the cost could be justified, the time required would be prohibitive. Thus an experimental model would be desirable if the scaling of pertinent parameters, e.g., time, is properly treated. parameters, e.g., time, is properly treated.

This paper was prepared for presentation at the 47th Annual Fall Meeting of the Society of Petroleum Engineers held in San Antonio, Tex., Oct. 8–11, 1972. 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 who the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. 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 The Least Squares Differential Algorithm (LSDA) automatically determining reservoir description parameters in an optimal manner is described. in contrast to current reservoir history matching schemes, LSDA provides for: Pseudo-linearization of the relationships between Pseudo-linearization of the relationships between performance data and reservoir description performance data and reservoir description parameters; Description of the system transfer parameters; Description of the system transfer function as a second order polynomial trend; and Least squares reduction as the criterion for optimizing the description parameters. These provisions eliminate the problems associated with provisions eliminate the problems associated with applying linear approximations to non-linear systems and analyzing error-corrupted data. LSDA is tested using a mathematical model of a single well, radial, gas reservoir which provides for the inclusion of nondarcy and provides for the inclusion of nondarcy and Klinkenberg effects as well as the properties of real gases. The results of LSDA are compared with those obtained by the Least Squares Linear Programing (LSLP) method. Programing (LSLP) method Introduction Estimation of future reservoir performance from past reservoir history is usually accomplished by employing an appropriate mathematical model to match past history and, having done so within acceptable limits, to compute future performance. The matching procedure is the critical performance. The matching procedure is the critical phase of this process and requires the phase of this process and requires the determination of an optimal (and hopefully unique) set of reservoir parameters which enables the mathematical model to successfully describe the reservoir performance data during the match period. The performance data during the match period. The quest for a better procedure for automatically determining this optimal set of reservoir description parameters is the basis for this paper. Green, et al., present a good discussion of the various methods for using computer modeling to predict reservoir performance. Coats, et al., have developed a method for automatically determining the optimal reservoir description parameters using Least Squares Linear Programming parameters using Least Squares Linear Programming (LSLP). LSLP assumes that the performance data and the description parameters are linearly related (although the authors of LSLP pointed out that transforming performance data and description parameters to more nearly assure this assumption parameters to more nearly assure this assumption would probably improve the method's ability to determine optimal description parameters). LSLP also uses a first order trend to describe the system transfer function and makes no claim as to its abilities to handle error-corrupted data.

At the time of the epidemic of influenza1 and influenzal pneumonia, the military population of the United States Reservation at Fort Riley was 63,374, distributed as in Table 1. The total number of cases of influenza were divided as shown in Table 2. The influenza incidence for the population of the military reservation was 23.9 per cent. As will be observed in Table 3, 2,624 instances of pneumonia occurred during the epidemic, of which 2,496 were definitely traceable to influenza. The largest number of influenza and pneumonia patients admitted to the base hospital was on September 30, when 785 were received. The largest total number of patients in the hospital was 5,666, October 8, of whom 2,951 had influenza and 719 influenzal pneumonia. The largest number of pneumonia patients at one time under treatment in the base hospital was 1,338, October 15, as shown in the accompanying chart. The incidence