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D. G. Jorgensen

Publications and source records attributed to D. G. Jorgensen.

6 recordsLinked to original sources
USGS2005

The ratio method of estimating water resistivity and TDS from resistivity logs

It is a general belief that useful estimates of total dissolved solids concentrations of ground water cannot be made from borehole geophysical logs. A case study of estimating total dissolved solids concentration of ground water in the local area using the ratio method yielded estimates with an average error of less than 25 percent. The results do not support the hypothesis that useful estimates of total dissolved solids concentration cannot be made from borehole geophysical logs. The case study included a comparison of estimates of total dissolved solids concentration utilizing a resistivity of the mud input versus using resistivity of the mud filtrate input. Estimates made using resistivity of mud had a correlation coefficient of 0.97 whereas estimates using resistivity of mud filtrate had a correlation coefficient of only 0.27. The results from the case study suggest that at least in some cases the resistivity of the mud (Rm) produce a better estimate of the resistivity of water (Rw) in the fully flushed zone than an estimate using the resistivity of the mud filtrate Rmf. The ratio method can be easily used to estimate ground-water resistivity and total dissolved solids concentration of the formation water based only on data from resistivity logs. The advantage of the method is that data on porosity, cementation exponent, temperature, and volume of clay are not required. The method, which has been used by the oil industry to crudely estimate water resistivity, is based in part on the ratio of the resistivity of a fully water-saturated formation to the resistivity of the fully flushed zone adjacent to the annulus in a mud-filled borehole. The method, which is very robust, requires only an estimate of the resistivity of a fully water-saturated formation from a deep looking induction or resistivity log, an estimate of the resistivity of the fully flushed zone from a microresistivity or short normal log, and a measurement of resistivity of the mud or mud filtrate and its temperature.

Ground Water↗
USGS1997

Geohydrology and simulation of steady-state flow conditions in regional aquifer systems in Cretaceous and older rocks underlying Kansas, Nebraska, and parts of Arkansas, Colorado, Missouri, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming

Three regional aquifers systems are the basis for describing the geohydrology of bedrock aquifers in the central United States. The Great Plains aquifer system, composed of Lower Cretaceous sandstone, generally contains brackish water (1,000 to 10,000 milligrams per liter dissolved solids); the Western Interior Plains aquifer system of lower Paleozoic rocks contains saline water and is laterally adjacent to the freshwater-bearing Ozark Plateaus aquifer system composed of rocks of the same age.

Professional Paper↗
USGS1982

A Numerical model to evaluate proposed ground-water allocations in southwest Kansas

A computer model was developed to assist the Southwest Kansas Groundwater Management District No. 3 in the evaluation of applications to appropriate ground water. The model calculated the drawdown due from a proposed well at all existing wells in the section of the proposed well and at all wells in the adjacent eight sections. The depletion expected in the 9-square-mile area due to all existing wells and the proposed well is computed and compared with allowable limits defined by the management district. An optional program permits the evaluation of allowable depletion for one or more townships. All options are designed to run interactively, thus allowing for immediate evaluation of proposed ground-water withdrawals. (USGS)

Water-Resources Investigations Report↗
USGS1973

Analog-model studies of the effects of recharge wells along the Houston Ship Channel on potentiometric surfaces of the Chicot and Evangeline aquifers, Houston, Texas

Because of increasing concern about the continuing decline of water levels in the Houston area, an electric analog model was used to determine the effects on the potentiometric surfaces resulting from recharging water through wells along the Houston Ship Channel into the two major aquifers, the Chicot and Evangeline. The model conditions simulated for this study are too complex to be described in detail. The upper model layer simulated the hydrologic conditions in the lower unit of the Chicot aquifer undifferentiated. The simulation included clay compaction and vertical leakage as well as transmissivity and storage. The lower model layer simulated the hydrologic conditions in the Evangeline aquifer which underlies the Chicot aquifer.

Texas↗