A seismic and gravity study of the McGregor geothermal system, southern New Mexico

Geophysics ◽  
2001 ◽  
Vol 66 (4) ◽  
pp. 1002-1014 ◽  
Author(s):  
T. M. O’Donnell ◽  
K. C. Miller ◽  
J. C. Witcher
Keyword(s):  
New Mexico ◽  
Heat Flow ◽  
Water Table ◽  
Alluvial Fan ◽  
Hot Water ◽  
Thermal Waters ◽  
Small Scale ◽  
Geothermal System ◽  
Velocity Models ◽  
Basin Fill

Seismic and gravity studies have proven to be valuable tools in evaluating the geologic setting and economic potential of the McGregor geothermal system of southern New Mexico. An initial gravity study of the system demonstrated that a gravity high coincides with the heat‐flow high. A subsequent seismic reflection survey images a strong reflector, interpreted to be associated with a bedrock high that underlies the gravity and heat‐flow highs. A single reflection, which coincides with the water table, occurs within the Tertiary basin fill above bedrock. This reflector is subhorizontal except above structurally high bedrock, where it dips downward. This observation is consistent with well data that indicate a bedrock water table 30 m lower than water in the basin‐fill aquifer. Velocity models derived from seismic tomography show that the basin fill has velocities in the range of 800 to 4000 m/s and that the bedrock reflector coincides with high velocities of 5000 to 6000 m/s. Low‐velocity zones within the bedrock high are interpreted as karsted bedrock with solution‐collapse breccias and cavities filled with hot water. Higher velocity material that flanks the bedrock high may represent an earlier stage of basin fill or older alluvial‐fan deposits. The heat‐flow anomaly appears to be constrained to the region of shallowest bedrock that lacks these deposits, suggesting that they may act as an aquitard to cap underlying bedrock aquifers or geothermal reservoirs. Taken together, these observations suggest that the geothermal system is associated with karsted and fractured structurally high bedrock that serves as a window for upwelling and outflow of thermal waters. Thermal waters with a temperature as high as 89°C have the potential for space heating, geothermal desalinization, and small‐scale electrical production at McGregor Range.

RESISTIVITY, SELF‐POTENTIAL, AND INDUCED‐POLARIZATION SURVEYS OF A VAPOR‐DOMINATED GEOTHERMAL SYSTEM

Geophysics ◽  
1973 ◽  
Vol 38 (6) ◽  
pp. 1130-1144 ◽  
Author(s):  
A. A. R. Zohdy ◽  
L. A. Anderson ◽  
L. J. P. Muffler
Keyword(s):  
Geothermal Field ◽  
Induced Polarization ◽  
Hot Water ◽  
Thermal Waters ◽  
Geothermal System ◽  
Electrical Soundings ◽  
Lateral Extent ◽  
High Concentrations ◽  
Lake Deposits ◽  
Self Potential

The Mud Volcano area in Yellowstone National Park provides an example of a vapor‐dominated geothermal system. A test well drilled to a depth of about 347 ft penetrated the vapor‐dominated reservoir at a depth of less than 300 ft. Subsequently, 16 vertical electrical soundings (VES) of the Schlumberger type were made along a 3.7‐mile traverse to evaluate the electrical resistivity distribution within this geothermal field. Interpretation of the VES curves by computer modeling indicates that the vapor‐dominated layer has a resistivity of about 75–130 ohm‐m and that its lateral extent is about 1 mile. It is characteristically overlain by a low‐resistivity layer of about 2–6.5 ohm‐m, and it is laterally confined by a layer of about 30 ohm‐m. This 30‐ohm‐m layer, which probably represents hot water circulating in low‐porosity rocks, also underlies most of the survey at an average depth of about 1000 ft. Horizontal resistivity profiles, measured with two electrode spacings of an AMN array, qualitatively corroborate the sounding interpretation. The profiling data delineate the southeast boundary of the geothermal field as a distinct transition from low to high apparent resistivities. The northwest boundary is less distinctly defined because of the presence of thick lake deposits of low resistivities. A broad positive self‐potential anomaly is observed over the geothermal field, and it is interpretable in terms of the circulation of the thermal waters. Induced‐polarization anomalies were obtained at the northwest boundary and near the southeast boundary of the vapor‐dominated field. These anomalies probably are caused by relatively high concentrations of pyrite.

Two-Phase, Two-Dimensional Simulation of a Geothermal Reservoir

1977 ◽  
Vol 17 (03) ◽  
pp. 171-183 ◽  
Author(s):  
R.M. Toronyi ◽  
S.M. Farouq Ali
Keyword(s):  
Heat Flow ◽  
Physical State ◽  
Water Systems ◽  
Hot Water ◽  
Geothermal Reservoir ◽  
Geothermal System ◽  
Heat Flow Rate ◽  
Two Dimensional ◽  
Two Phase ◽  
One Dimensional

Abstract A numerical mathematical model for simulating production from a two-phase geothermal reservoir production from a two-phase geothermal reservoir was developed and tested. The model was a two-dimensional areal or cross-sectional unsteadystate description of the flow of mass and heat within an anisotropic, heterogeneous, porous medium containing a single-component, two-phase fluid. Flow in the production well was. taken to be one dimensional and steady state, using an approximate representation of a two-phase mixture. A totally implicit solution scheme was used. The simulator was used to investigate the effects of various levels of porosity, permeability, and initial pressure and liquid-phase saturation distributions on production. The numerical simulator was tested for a wide variety of conditions and was found to be stable for large time steps. Based on the numerical results, the behavior of a two-phase geothermal reservoir was classified into three types, depending on the initial liquid saturation. It was found that superheated regions formed more readily in reservoirs of low porosity and permeability. Introduction A geothermal system occurs as a heat anomaly that can be explained as follows. The earth's interior is hotter than its surface. This difference produces a temperature gradient that, in turn, produces a temperature gradient that, in turn, provides a measure of the heat flow rate. The provides a measure of the heat flow rate. The average heat flux for the earth is 1.5 mu cal/sq cm-sec. A geothermal system involves a flux that is 1 1/2 to 5 times higher than the average. Consequently, a geothermal system occurs as an anomaly in terms of heat flow. A high heat flux, along with surface seeps, is indicative of a geothermal system. Since the main mode of heat transfer within a geothermal fluid reservoir is convection, the reservoir itself is called a hydrothermal convention system. Hydrothermal convection systems have been classified into two types based on the physical state of the dominant pressure-controlling physical state of the dominant pressure-controlling phase: hot-water systems and vapor-dominated phase: hot-water systems and vapor-dominated system. In hot-water systems, fluids exist within the reservoir mostly in the liquid state and generally produce from 70 to 90 percent of their total mass as water at the surface. Vapor-dominated systems generally produce dry to superheated steam, and fluids exist within the reservoir mostly in the vapor state, Surface manifestations will usually take the form of fumaroles, mud pots, mud volcanoes, turbid pools, and acid-leached ground. Only three known areas exist as this type of system. These are the Geysers field in California, the Larderello field in Italy, and the Matsukawa field in Japan. The pressures of vapor-dominated systems are below hydrostatic. Also, the initial pressures and temperatures in vapor-dominated systems are very close to the temperature and pressure relating to the maximum enthalpy of saturated steam - 236 degrees C and 31.8 kg/sq cm. An explanation for this behavior has been given by James and by White et al. Reservoir engineering principles have been used to study production aspects of geothermal systems only during the last decade. In that time, relatively few models have been developed that simulate the production from a geothermal reservoir containing production from a geothermal reservoir containing both a liquid and a vapor phase. In fact, only three models have assumed the presence of a two-phase Hudd within a geothermal presence of a two-phase Hudd within a geothermal reservoir. One of these models, developed by Donaldson, was a steady-state, one-dimensional description of two-phase flow within porous media, but did not simulate production. The other two models, those of Whiting and Ramey and of Brigham and Morrow, were lumped-parameter formulations. Thus, objective of this paper is to develop a model that simulates production from a two-phase geothermal reservoir in greater detail than has been done previously. SPEJ P. 171

Subsurface stratigraphy and basin-fill architecture of the late Paleozoic eastern Taos trough, northern New Mexico, U.S.A.

2020 ◽  
Vol 57 (3) ◽  
pp. 149-176
Author(s):  
Nur Uddin Md Khaled Chowdhury ◽  
Dustin E. Sweet
Keyword(s):  
New Mexico ◽  
Sediment Accumulation ◽  
Late Paleozoic ◽  
North Central ◽  
The North ◽  
Basement Rocks ◽  
Basin Geometry ◽  
Deformation Event ◽  
Thrust System ◽  
Basin Fill

The greater Taos trough located in north-central New Mexico represents one of numerous late Paleozoic basins that formed during the Ancestral Rocky Mountains deformation event. The late Paleozoic stratigraphy and basin geometry of the eastern portion of the greater Taos trough, also called the Rainsville trough, is little known because the strata are all in the subsurface. Numerous wells drilled through the late Paleozoic strata provide a scope for investigating subsurface stratigraphy and basin-fill architecture of the Rainsville trough. Lithologic data obtained predominantly from petrophysical well logs combined with available biostratigraphic data from the greater Taos trough allows construction of a chronostratigraphic framework of the basin fill. Isopach- and structure-maps indicate that the sediment depocenter was just east of the El Oro-Rincon uplift and a westerly thickening wedge-shaped basin-fill geometry existed during the Pennsylvanian. These relationships imply that the thrust system on the east side of the Precambrian-cored El Oro-Rincon uplift was active during the Pennsylvanian and segmented the greater Taos trough into the eastern Rainsville trough and the western Taos trough. During the Permian, sediment depocenter(s) shifted more southerly and easterly and strata onlap Precambrian basement rocks of the Sierra Grande uplift to the east and Cimarron arch to the north of the Rainsville trough. Permian strata appear to demonstrate minimal influence by faults that were active during the Pennsylvanian and sediment accumulation occurred both in the basinal area as well as on previous positive-relief highlands. A general Permian decrease in eustatic sea level and cessation of local-fault-controlled subsidence indicates that regional subsidence must have affected the region in the early Permian.

scholarly journals Velocity structure and radial anisotropy of the lithosphere in southern Madagascar from surface wave dispersion

2020 ◽  
Vol 224 (3) ◽  
pp. 1930-1944 ◽  
Author(s):  
E J Rindraharisaona ◽  
F Tilmann ◽  
X Yuan ◽  
J Dreiling ◽  
J Giese ◽  
...  
Keyword(s):  
Receiver Functions ◽  
Dispersion Curves ◽  
Eastern Coast ◽  
Small Scale ◽  
Seismic Structure ◽  
Lithospheric Thickness ◽  
Velocity Models ◽  
Phase Velocities ◽  
Maximum Value ◽  
Radial Anisotropy

SUMMARY We investigate the upper mantle seismic structure beneath southern Madagascar and infer the imprint of geodynamic events since Madagascar’s break-up from Africa and India and earlier rifting episodes. Rayleigh and Love wave phase velocities along a profile across southern Madagascar were determined by application of the two-station method to teleseismic earthquake data. For shorter periods (<20 s), these data were supplemented by previously published dispersion curves determined from ambient noise correlation. First, tomographic models of the phase velocities were determined. In a second step, 1-D models of SV and SH wave velocities were inverted based on the dispersion curves extracted from the tomographic models. As the lithospheric mantle is represented by high velocities we identify the lithosphere–asthenosphere boundary by the strongest negative velocity gradient. Finally, the radial anisotropy (RA) is derived from the difference between the SV and SH velocity models. An additional constraint on the lithospheric thickness is provided by the presence of a negative conversion seen in S receiver functions, which results in comparable estimates under most of Madagascar. We infer a lithospheric thickness of 110−150 km beneath southern Madagascar, significantly thinner than beneath the mobile belts in East Africa (150−200 km), where the crust is of comparable age and which were located close to Madagascar in Gondwanaland. The lithospheric thickness is correlated with the geological domains. The thinnest lithosphere (∼110 km) is found beneath the Morondava basin. The pre-breakup Karoo failed rifting, the rifting and breakup of Gondwanaland have likely thinned the lithosphere there. The thickness of the lithosphere in the Proterozoic terranes (Androyen and Anosyen domains) ranges from 125 to 140 km, which is still ∼30 km thinner than in the Mozambique belt in Tanzania. The lithosphere is the thickest beneath Ikalamavony domain (Proterozoic) and the west part of the Antananarivo domain (Archean) with a thickness of ∼150 km. Below the eastern part of Archean domain the lithosphere thickness reduces to ∼130 km. The lithosphere below the entire profile is characterized by positive RA. The strongest RA is observed in the uppermost mantle beneath the Morondava basin (maximum value of ∼9 per cent), which is understandable from the strong stretching that the basin was exposed to during the Karoo and subsequent rifting episode. Anisotropy is still significantly positive below the Proterozoic (maximum value of ∼5 per cent) and Archean (maximum value of ∼6 per cent) domains, which may result from lithospheric extension during the Mesozoic and/or thereafter. In the asthenosphere, a positive RA is observed beneath the eastern part Morondava sedimentary basin and the Proterozoic domain, indicating a horizontal asthenospheric flow pattern. Negative RA is found beneath the Archean in the east, suggesting a small-scale asthenospheric upwelling, consistent with previous studies. Alternatively, the relatively high shear wave velocity in the asthenosphere in this region indicate that the negative RA could be associated to the Réunion mantle plume, at least beneath the volcanic formation, along the eastern coast.

Interferometric imaging condition for wave-equation migration

Geophysics ◽  
2008 ◽  
Vol 73 (2) ◽  
pp. S47-S61 ◽  
Author(s):  
Paul Sava ◽  
Oleg Poliannikov
Keyword(s):  
Large Scale ◽  
Wigner Distribution ◽  
Random Noise ◽  
Velocity Model ◽  
Distribution Functions ◽  
Small Scale ◽  
Interferometric Imaging ◽  
Imaging Data ◽  
Imaging Condition ◽  
Velocity Models

The fidelity of depth seismic imaging depends on the accuracy of the velocity models used for wavefield reconstruction. Models can be decomposed in two components, corresponding to large-scale and small-scale variations. In practice, the large-scale velocity model component can be estimated with high accuracy using repeated migration/tomography cycles, but the small-scale component cannot. When the earth has significant small-scale velocity components, wavefield reconstruction does not completely describe the recorded data, and migrated images are perturbed by artifacts. There are two possible ways to address this problem: (1) improve wavefield reconstruction by estimating more accurate velocity models and image using conventional techniques (e.g., wavefield crosscorrelation) or (2) reconstruct wavefields with conventional methods using the known background velocity model but improve the imaging condition to alleviate the artifacts caused by the imprecise reconstruction. Wedescribe the unknown component of the velocity model as a random function with local spatial correlations. Imaging data perturbed by such random variations is characterized by statistical instability, i.e., various wavefield components image at wrong locations that depend on the actual realization of the random model. Statistical stability can be achieved by preprocessing the reconstructed wavefields prior to the imaging condition. We use Wigner distribution functions to attenuate the random noise present in the reconstructed wavefields, parameterized as a function of image coordinates. Wavefield filtering using Wigner distribution functions and conventional imaging can be lumped together into a new form of imaging condition that we call an interferometric imaging condition because of its similarity to concepts from recent work on interferometry. The interferometric imaging condition can be formulated both for zero-offset and for multioffset data, leading to robust, efficient imaging procedures that effectively attenuate imaging artifacts caused by unknown velocity models.

Terrestrial heat flow and crustal radioactivity in northeastern New Mexico and southeastern Colorado

1978 ◽  
Vol 89 (9) ◽  
pp. 1341 ◽  
Author(s):  
C. L. EDWARDS ◽  
MARSHALL REITER ◽  
CHARLES SHEARER ◽  
WESLEY YOUNG
Keyword(s):  
New Mexico ◽  
Heat Flow ◽  
Terrestrial Heat Flow

Investigation of the Internal Blowout Accident Involving Overpressured Reservoirs: Case of CI-11 Well, Southern Tunisia

2021 ◽  
pp. 1-14
Author(s):  
Chaouki Khalfi ◽  
Riadh Ahmadi
Keyword(s):  
Water Flow ◽  
Water Table ◽  
Action Plan ◽  
Oil Field ◽  
Hot Water ◽  
Shallow Water Table ◽  
Ecological Consequences ◽  
Southern Tunisia ◽  
Drilling Operations ◽  
Recovery Program

Summary This study consists of an assessment of the ecological accident implicating the Continental Intercalaire-11 (CI-11) water well located in Jemna oasis, southern Tunisia. The CI-11 ecological accident manifested in 2014 with a local increase of the complex terminal (CT) shallow water table salinity and temperature. Then, this phenomenon started to spread over the region of Jemna, progressively implicating farther wells. The first investigation task consisted of logging the CI-11 well. The results revealed an impairment of the casing and cement of a huge part of the 9⅝ in. production casing. Historical production records show that the problems seem to have started in 1996 when a sudden production loss rate occurred. These deficiencies led to the CI mass-water flowing behind the casing from the CI to the CT aquifers. This ecological accident is technically called internal blowout, where water flows from the overpressurized CI groundwater to the shallower CT groundwater. Indeed, the upward CI hot-water flow dissolved salts from the encountered evaporite-rich formations of the Lower Senonian series, which complicated the ecological consequences of the accident. From the first signs of serious water degradation in 2014 through the end of 2018, several attempts have been made to regain control of annular upward water flow. However, the final CT groundwater parameters indicate that the problem is not properly fixed and communication between the two involved aquifers still persists. This accident is similar to the OKN-32 case that occurred in the Berkaoui oil field, southern Algeria, in 1986, and included the same CI and CT aquifers. Furthermore, many witnesses claim that other accidental communications are probably occurring in numerous deep-drilled wells in this region. Concludingly, Jemna CI-11, Berkaoui OKN-32, and probably many other similar accident cases could be developing regional ecological disasters by massive water resource losses. The actual situation is far from being under control and the water contamination risk remains very high. In both accidents, the cement bond failure and the choice of the casing point are the main causes of the internal blowout. Therefore, we recommend (1) a regional investigation and risk assessment plan that might offer better tools to predict and detect earlier wellbore isolation issues and (2) special attention to the cement bond settlement, evaluation, and preventative logging for existing wells to ensure effective sealing between the two vulnerable water table resources. Besides, in the CI-11 well accident, the recovery program was not efficient and there was no clear action plan. This increased the risk of action failure or time waste to regain control of the well. Consequently, we suggest preparing a clear and efficient action plan for such accidents to reduce the ecological consequences. This requires further technical detailed study of drilling operations and establishment of a suitable equipment/action plan to handle blowout and annular production accidents.

Revised hydrogeological model of the hydrothermal system Waiwera (New Zealand)

2021 ◽  
Author(s):  
Andreas Grafe ◽  
Thomas Kempka ◽  
Michael Schneider ◽  
Michael Kühn
Keyword(s):  
Water Management ◽  
New Zealand ◽  
Water Level ◽  
Hot Water ◽  
Hydrogeology Journal ◽  
Natural State ◽  
Geothermal System ◽  
Geological Model ◽  
Species Transport ◽  
Study Region

<p>The geothermal hot water reservoir underlying the coastal township of Waiwera, northern Auckland Region, New Zealand, has been commercially utilized since 1863. The reservoir is complex in nature, as it is controlled by several coupled processes, namely flow, heat transfer and species transport. At the base of the aquifer, geothermal water of around 50°C enters. Meanwhile, freshwater percolates from the west and saltwater penetrates from the sea in the east. Understanding of the system’s dynamics is vital, as decades of unregulated, excessive abstraction resulted in the loss of previously artesian conditions. To protect the reservoir and secure the livelihoods of businesses, a Water Management Plan by The Auckland Regional Council was declared in the 1980s [1]. In attempts to describe the complex dynamics of the reservoir system with the goal of supplementing sustainable decision-making, studies in the past decades have brought forth several predictive models [2]. These models ranged from being purely data driven statistical [3] to fully coupled process simulations [1].<br><br>Our objective was to improve upon previous numerical models by introducing an updated geological model, in which the findings of a recently undertaken field campaign were integrated [4]. A static 2D Model was firstly reconstructed and verified to earlier multivariate regression model results. Furthermore, the model was expanded spatially into the third dimension. In difference to previous models, the influence of basic geologic structures and the sea water level onto the geothermal system are accounted for. Notably, the orientation of dipped horizontal layers as well as major regional faults are implemented from updated field data [4]. Additionally, the model now includes the regional topography extracted from a digital elevation model and further combined with the coastal bathymetry. Parameters relating to the hydrogeological properties of the strata along with the thermophysical properties of water with respect to depth were applied. Lastly, the catchment area and water balance of the study region are considered.<br><br>The simulation results provide new insights on the geothermal reservoir’s natural state. Numerical simulations considering coupled fluid flow as well as heat and species transport have been carried out using the in-house TRANSport Simulation Environment [5], which has been previously verified against different density-driven flow benchmarks [1]. The revised geological model improves the agreement between observations and simulations in view of the timely and spatial development of water level, temperature and species concentrations, and thus enables more reliable predictions required for water management planning.<br><br>[1] Kühn M., Stöfen H. (2005):<br>      Hydrogeology Journal, 13, 606–626,<br>      https://doi.org/10.1007/s10040-004-0377-6<br><br>[2] Kühn M., Altmannsberger C. (2016):<br>      Energy Procedia, 97, 403-410,<br>      https://doi.org/10.1016/j.egypro.2016.10.034<br><br>[3] Kühn M., Schöne T. (2017):<br>      Energy Procedia, 125, 571-579,<br>      https://doi.org/10.1016/j.egypro.2017.08.196<br><br>[4] Präg M., Becker I., Hilgers C., Walter T.R., Kühn M. (2020):<br>      Advances in Geosciences, 54, 165-171,<br>      https://doi.org/10.5194/adgeo-54-165-2020<br><br>[5] Kempka T. (2020):<br>      Adv. Geosci., 54, 67–77,<br>      https://doi.org/10.5194/adgeo-54-67-2020</p>

scholarly journals Geothermal System Study Case near Bucharest

2019 ◽  
Vol 111 ◽  
pp. 06058
Author(s):  
Galina Prică ◽  
Lohengrin Onuțu ◽  
Grațiela Țârlea
Keyword(s):  
Thermal Response ◽  
Hot Water ◽  
Geothermal System ◽  
System Study ◽  
Accurate Calculation ◽  
Good Efficiency ◽  
Efficient System ◽  
One Step ◽  
Study Case ◽  
Geological Formations

The article shows a study case of a geothermal system near Bucharest. In the paper it is shown that for a good efficiency of a geothermal system for heating and air conditioning, it is important to follow a few steps. One step is a very accurate calculation of the heat and cold load. In the next step it is important to use a specific equipment to obtain the Thermal Response Test (TRT) of geological formations crossed by the borehole. TRT is helpful in providing information related to the evolution of the soil temperature while introducing a thermal load. All information that can be obtained or calculated from the TRT will provide how the climate system will function in time and its efficiency. Furthermore, the effective thermal conductivity and thermal resistance of the well will be determined, extremely important parameters in designing the correct length of the geoheat exchanger. The article used specific software to simulate the evolution of parameters in time, for soil and heat pump. Earth Energy Design offer information for the number of needed boreholes, the depth and the yearly evolution of the soil’s temperature in time for the system etc. Following all these main steps, finally a very efficient system can be designed, that can ensure the heating and produce hot water for the consumption of a house, office building or of other destination buildings.

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