Geothermal reservoir engineering computer code comparison and validation using the GEONZ simulator program

This paper describes the main steps and results of preparing WWER-440/213 model for TRACE system thermohydraulic code to be used in further deterministic analysis calculations. As the basis for developing the model, the previously developed RELAP5/Mod.3.2 input deck was used. As a first step, the thermohydraulic components of input deck were automatically converted to TRACE format using SNAP utility. Then, necessary manual adjustments and additions were implemented to incorporate the safeguards actuation logic and operation of various plant controllers into the model. A set of validation calculations was performed for various transients (abnormal operation events) that had actually occurred at Rivne NPP Unit 1 to confirm that the TRACE model is capable of reproducing adequately the response of nuclear power plant with WWER-440/213 reactor. The results for one of validation calculations (Loss of normal power supply with reactor scram and additional failures) are provided as an example. Comparison of calculation results with plant measured data demonstrate acceptable agreement for the main plant parameters. To extend the scope of model validation, the cross-code comparison between TRACE and RELAP5 results is planned to be performed for a number of representative design-basis accident scenarios.

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Characterization Methodology for Analysis in Neighboring Productive and Nonproductive Zones of Los Humeros Geothermal Field

Current Journal of Applied Science and Technology ◽

10.9734/cjast/2020/v39i630566 ◽

2020 ◽

pp. 114-129

Author(s):

Alfonso Aragon-Aguilar ◽

Abel Hernandez-Ochoa ◽

Alejandro Arriola-Medellin

Keyword(s):

High Temperatures ◽

Geothermal Field ◽

Geothermal Reservoir ◽

Reservoir Engineering ◽

Low Permeability ◽

Temperature Profiles ◽

Fluid Circulation ◽

Transient Pressure ◽

Eastern Zone ◽

Pressure Tests

The study focused on the analysis of two neighboring zones in the Los Humeros geothermal field (LHGF), each one with different characteristic behaviors. A characterization methodology which can be used in geothermal reservoir engineering was designed and applied to study the zones. The static temperature profiles determined in wells located at the studied zone of the field ranged between 300°C and 360°C. From these temperatures, isotherms in the studied area were calculated and these trend to be deeper toward eastern zone of the field. Similarly the thicknesses tend to reduce in this direction. By analyzing the profiles of fluid circulation losses were determined during drilling of wells in this zone, the existence of low permeability in the rock formation was inferred. From the results of transient pressure tests, low permeability was confirmed. A marked difference in the productive characteristics between the wells, in the close neighborhood was also observed. Behavior of wells also shows tendency to increase in their steam fractions, with the exploitation time. The characterization methodology applied to the studied zones, allows identify that there is a reservoir section with low permeability, but with high temperatures the depth increases.

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