Preliminary heat flow estimates for Wyoming and Montana

A table is presented containing basic thermal data for preliminary heat flow estimates in Wyoming and Montana. The thermal data include thermal conductivities of rock samples from drill holes, temperature gradients, depth ranges for the least-squares calculation of the temperature gradients, and the computed heat flow values. Other data listed the country code, the locality, and the elevation of each drill hole

Improved Computational Schemes for the Numerical Modeling of Hydrothermal Resources in Wyoming

A new method, the Conjugate Gradient Squared (CGS) solution technique, is shown to be extremely effective when applied to the finite-difference solution of conductive and convective heat transfer in geologic systems. The CGS method is compared to the Successive Over/Under Relaxation schemes, a version of the Gaussian elimination method, and the Generalized Minimum Residual (GMRES) approach. The CGS procedure converges at least ten times faster than the nearest competitor. The model is applied to the Thermopolis hydrothermal system, located in northwestern Wyoming. Modeled results are compared with measured temperature-depth profiles and results from other studies. The temperature decrease from 72{degree}C to 54{degrees}C along the crest of the Thermopolis anticline is shown to result from cooling of the geothermal fluid as it moves to the southeast. Modeled results show correct general trends, however, a time-varying three-dimensional model will be needed to fully explain the effects of mixing within the aquifers along the crest of the anticline and thermal affects of surface surface topography. 29 refs., 18 figs., 2 tabs

Thermopolis hydrothermal system, with an analysis of Hot Springs State Park. Preliminary report No. 20

Thermopolis is the site of Hot Springs State Park, where numerous hot springs produce nearly 3000 gallons per minute (gpm) of 130/sup 0/F (54/sup 0/C) water. The University of Wyoming Geothermal Resource Assessment Group has studied a 1700-square-mile area centered roughly on the State Park. Available literature, bottom-hole temperatures from over 400 oil well logs, 62 oil field drill stem tests, the Wyoming State Engineer\u27s water well files, 60 formation water analyses, thermal logs of 19 holes, and field investigations of geology and hydrology form the basis of this report. Analysis of thermal data reveals that temperatures of up to 161/sup 0/F (72/sup 0/C) occur along the crest of the Thermopolis Anticline within 500 feet of the surface. The hydrology and heat flow of these geothermal anomalies was studied

Thermopolis hydrothermal system, with an analysis of Hot Springs State Park. Preliminary report No. 20

Thermopolis is the site of Hot Springs State Park, where numerous hot springs produce nearly 3000 gallons per minute (gpm) of 130/sup 0/F (54/sup 0/C) water. The University of Wyoming Geothermal Resource Assessment Group has studied a 1700-square-mile area centered roughly on the State Park. Available literature, bottom-hole temperatures from over 400 oil well logs, 62 oil field drill stem tests, the Wyoming State Engineer\u27s water well files, 60 formation water analyses, thermal logs of 19 holes, and field investigations of geology and hydrology form the basis of this report. Analysis of thermal data reveals that temperatures of up to 161/sup 0/F (72/sup 0/C) occur along the crest of the Thermopolis Anticline within 500 feet of the surface. The hydrology and heat flow of these geothermal anomalies was studied

Estimating uncertainties on net erosion from well‐log porosity data

International audienceEstimating the amount of erosion experienced by a sedimentary basin during its geo-logical history plays a key role in basin modelling. In this paper, we present a novel probabilistic approach to estimate net erosion from porosity–depth data from a single well. Our approach uses a Markov chain Monte Carlo algorithm which readily al-lows us to deal with imprecise knowledge of the lithology‐dependent compaction parameters in a joint inversion scheme using multiple lithologies. The results using synthetic data highlight the advantages of our approach over conventional techniques for net erosion estimation: (a) uncertainties on compaction parameters can be effec-tively mapped into a probabilistic solution for net erosion; (b) posterior uncertain-ties are easy to quantify; (c) the joint inversion scheme can automatically reconcile porosity data from different lithologies. Our results also underscore the critical role of prior assumptions on controlling the retrieved estimates for net erosion. Using real data from a well in the Barents Sea, we simulate three possible scenarios of variable prior assumptions on compaction parameters to demonstrate the general applicabil-ity of our approach. Strong prior assumptions on the compaction parameters led to unrealistic estimates of net erosion for the target well, indicating the assumptions are probably inappropriate. Our preferred strategy for this dataset is to include additional data to constrain the normal compaction trend of the sediments. This provides a net erosion estimate for the target well of about 2300 m with a standard deviation of 140 m which is in line with previous studies. Finally, we discuss potential guidelines to deal with real applications in which data from normally compacted sediments are not available. One is to use our algorithm as a hypothesis‐testing tool to evaluate the results under a large set of assumed compaction parameters. A second is to infer compaction parameters and net erosion simultaneously from the target well porosity data. Although appealing and successful with synthetic data, this strategy provides results which are strongly dependent on the calibration data and the geological his-tory of the sediments sampled by the target well

Infrared Imaging Fourier Transform Spectrometer as the Stand-Off Gas Detection System

The article presents the detection of gases using an infrared imaging Fourier-transform spectrometer (IFTS). The Telops company has developed the IFTS instrument HyperCam, which is offered as a short- or long-wave infrared device. The principle of HyperCam operation and methodology of gas detection has been shown in the paper, as well as theoretical evaluation of gas detection possibility. Calculations of the optical path between the IFTS device, cloud of gases and background have been also discussed. The variation of a signal reaching the IFTS caused by the presence of a gas has been calculated and compared with the reference signal obtained without the presence of a gas in IFTS's field of view. Verification of the theoretical result has been made by laboratory measurements. Some results of the detection of various types of gases has been also included in the paper