Michael Wilt - Profile on Academia.edu (original) (raw)

Papers by Michael Wilt

Sixteen s h a l l ow and deep c o n t r o l 1 ed source e l ectromagnetic soundings were performe... more Sixteen s h a l l ow and deep c o n t r o l 1 ed source e l ectromagnetic soundings were performed i n Buena V i s t a Valley, near Winnemucca, Nevada, t o investigate an intra-basement conductor previously detected w i t h magnetotell urics. The survey was c a r r i e d o u t with t h e LBL EM-60 system using a remote magnetic reference f o r 1 ow-f requency geomagnetic noise cancel 1 ation, 100-m-and 2.8-km-diameter t r a n s m i t t e r 1 oops, and a minicomputer for i n -f i e l d processing. EM soundings were made a t distances from 0.5 t o 30 km from three loops over t h e frequency range 0.02 t o 500 Hz. Data were i n t e r p r e t e d by means o f 1-D inversions and the r e s u l t i n g layered models were pieced together t o y i e l d an approximate 2-0 geoelectric model along the N-S a x i s o f the valley. The EM soundings and one MT sounding show a 3 t o 7 oh-m zone a t a depth o f four t o seven km. The conductor appears t o be deepest a t the northern end o f the v a l l e y and shallowest beneath a basement r i d g e t h a t seems t o d i v i d e Buena V i s t a Valley i n t o two basinal structures. Similar intra-basement conductors are a1 so reported 50-75 m i l e s south i n the Carson Sink-Fa1 l o n areas, suggesting a comnon source, probably r e l a t e d t o an anomalously hot, t h i n crust.

OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), May 29, 2002

Geo-BILT (Geothermal Borehole Induction Logging Tool) is an extended induction logging tool desig... more Geo-BILT (Geothermal Borehole Induction Logging Tool) is an extended induction logging tool designed for 3D resistivity imaging around a single borehole. The tool was developed for deployment in high temperature geothermal wells under a joint program funded by the California Energy Commission, Electromagnetic Instruments (EMI) and the U.S. Department of Energy. EM1 was responsible for tool design and manufacture, and numerical modeling efforts were being addressed at Lawrence Livermore Laboratory (LLNL) and other contractors. The field deployment was done by EM1 and LLNL. The tool operates at fiequencies from 2 to 42 kHz, and its design features a series of threecomponent magnetic sensors offset at 2 and 5 meters from a three-component magnetic source. Valley site offered an environment where the tool could locate near-well fractures associated with steam development. The Lost Hills field measurements yielded a data set suitable for 3D imaging. The Geo-BLT data corresponded to existing conventional logging data and showed clear indications, in several depth intervals, of near-well 3D structure. Subsequent 3D inversion of these data produced a model consistent with non-planar water flow in specific layers. The Dixie Valley measurements identified structures associated with dike intrusions and water inflow at particular depths. Preliminary analysis suggests these structures are steeply dipping, which is consistent with the geology.

Second International Meeting for Applied Geoscience & Energy

Electromagnetic (EM) geophysical techniques offer the possibility of monitoring subsurface CO2 in... more Electromagnetic (EM) geophysical techniques offer the possibility of monitoring subsurface CO2 in saline reservoirs due to the fact that CO2 has high electrical resistivity compared to the surrounding geologic materials. In this paper we first discuss the underlying physics of two different borehole-based EM monitoring techniques; electrical resistivity tomography (ERT) and crosswell EM. This discussion is followed by the description of an experiment at the Carbon Management Canada CaMI FRS test site where time-lapse single well ERT and crosswell EM data have been acquired to image CO2 injection into a shallow aquifer. Resistivity imaging results from inversion of the two data types separately and jointly will be compared and contrasted, and interpretation of the extent of the injected CO2 provided.

OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), Nov 7, 2021

Wellbore integrity is of paramount importance to subsurface resource extraction, energy storage 1... more Wellbore integrity is of paramount importance to subsurface resource extraction, energy storage 1 and waste disposal. After installation, well casing and cement are subject to mechanical stress due to near-well pressure changes and fluid induced corrosion. This is exacerbated for geothermal wells where produced fluid is at high temperature and corrosive. The current state-of-the-art technologies for wellbore integrity assessments are an array of cased hole logging tools. Wireline deployed acoustic, electromagnetic and mechanical tools are all available to inspect steel casing corrosion and casing-cement bond and these tools can provide high-resolution assessment of borehole conditions. They are intrusive, however, in terms of borehole preparation and interruption to the normal operation of the wells, and not suitable for high temperature or highly deviated well deployments. In addition, these measurements are performed infrequently due to high cost, and are therefore incapable of providing frequent data to better predict borehole degradation trajectory, which can help provide early warning of potential borehole failures. For this project we are developing a suite of novel, non-invasive, casing based tools for wellbore integrity assessment, combining fast/low cost screening with higher-precision investigation. Our approach is based on monitoring the response of the casing when energized at the wellhead, thereby interrogating the casing without well intervention. Lab, field and numerical approaches are used in our study. During the early stage of the research, we focus on numerical simulations, which have shown the sensitivity of the low frequency electromagnetic (EM) signals to changes in borehole depths and have successfully tested the concept at a field site with different length well casings. Initial seismic modeling efforts have also demonstrated our capability to simulate seismic tube wave and seismic field alterations due to borehole breakage and associated fluid leakage. Further numerical, laboratory and field experiments are underway for additional technology sensitivity analysis, particularly the transient EM/Seismic reflectometry methods, data acquisition optimization, and numerical simulation improvements.

SEG Technical Program Expanded Abstracts 2018, 2018

Imaging hydraulically-active fracture zones (HAFZ) is of paramount importance to subsurface resou... more Imaging hydraulically-active fracture zones (HAFZ) is of paramount importance to subsurface resource extraction, geological storage and hazardous waste disposal. We present advanced 3D finite-element (FE) electrical imaging algorithms for HAFZ in the presence of a steel-cased well. The algorithms employ tetrahedral FE meshes in the simulation domain and coarse rectangular finite-difference (FD) meshes in the imaging domain. This heterogeneous dual-mesh approach is well suited to modeling multi-scale earth model due to steel-cased wells. We show that the algorithms accurately and efficiently simulate surface electric field measurements over a 3D HAFZ at depth when one end point of a surface electric source is connected to a wellhead. For brevity, this configuration is called the top-casing electric source method. By replacing a hollow cased well with a solid prism, we improve our computational efficiency without affecting the solution accuracy. The sensitivity of the top-casing source method to HAFZ highly depends on the continuity of a steel-cased well, because it makes currents preferentially flow to HAFZ. The sensitivity also depends on conductivity structures around the well because they control current leaking from the steel-cased well. We show that the method can image a localized HAFZ and detect changes in its width and height. The imaging results are improved when a volume of the imaging domain is constrained from geomechanical perspectives. A primary advantage of the method is the fact that both sources and receivers are placed on the surface, thus not interrupting well operation.

Casing-integrity mapping using top-casing electrodes and surface based EM fields

SEG Technical Program Expanded Abstracts 2018, 2018

Crosswell Electromagnetic Imaging for Subsurface Fluid Monitoring

AGUFM, Dec 1, 2005

Crosswell electromagnetic imaging is an emerging oilfield technology for mapping the resistivity ... more Crosswell electromagnetic imaging is an emerging oilfield technology for mapping the resistivity structure between two wells located tens to hundreds of meters apart. The method employs an electromagnetic dipole source in one well oscillating at 10Hz to 1kHz, and makes measurements of the axial component of the electric or magnetic field in the second well. The use of multiple source

The EM-60 system, a large-moment frequency-domain electromagnetic loop p r o s p e c t i n g syst... more The EM-60 system, a large-moment frequency-domain electromagnetic loop p r o s p e c t i n g system, w a s o p e r a t e d i n t h e Soda Lakes geothermal a r e a , Nevada.

WISE-CASING: Cymric Field, CA Frequency Domain EM Data

Cymric oil field frequency domain electromagnetic (FEM) data with two parts of data labeled Part ... more Cymric oil field frequency domain electromagnetic (FEM) data with two parts of data labeled Part 1 and Part 2. Part 1 utilizes an electrical source line parallel to the receiver line, while Part 2 utilizes an electrical source line at a 75 deg angle to the receiver line. Data are plotted and compared to numerically modeled data to observe electric field response to well structure. In two configuration files are diagrams of the experiment layout.

The depth to surface resistivity (DSR) method transmits current from a source located in a cased ... more The depth to surface resistivity (DSR) method transmits current from a source located in a cased or openhole well to a distant surface return electrode while electric field measurements are made at the surface over the target of interest. This paper presents both numerical modelling results and measured data from a hydraulic fracturing field test where conductive water was injected into a resistive shale reservoir during a hydraulic fracturing operation. Modelling experiments show that anomalies due to hydraulic fracturing are small but measureable with highly sensitive sensor technology. The field measurements confirm the model results, showing that measured differences in the surface fields due to hydraulic fracturing have been detected above the noise floor. Our results show that the DSR method is sensitive to the injection of frac fluids; they are detectable above the noise floor in a commercially active hydraulic fracturing operation, and therfore this method can be used for mo...

The effects of well damage and completion designs on geoelectrical responses in mature wellbore environments

GEOPHYSICS, 2021

Well integrity is one of the major concerns in long-term geologic storage sites due to the potent... more Well integrity is one of the major concerns in long-term geologic storage sites due to the potential risk of well leakage and groundwater contamination. Evaluating changes in electrical responses due to energized steel-cased wells has the potential to quantify and predict possible wellbore failures because any kind of breakage or corrosion along highly conductive well casings will have an impact on the distribution of the subsurface electrical potential. However, realistic wellbore-geoelectrical models that can fully capture fine-scale details of well completion design and the state of well damage at the field scale require extensive computational effort, or they can even be intractable to simulate. To overcome this computational burden while still keeping the model realistic, we have used the hierarchical finite-element method that represents electrical conductivity at each dimensional component (1D edges, 2D planes, and 3D cells) of a tetrahedral mesh. This allows well completion ...

Effects of completion design on electrically stimulated casing and its 3D response

SEG Technical Program Expanded Abstracts 2018, 2018

Improved reservoir characterization and monitoring using electromagnetic geophysical techniques

Subsurface Sensing Technologies and Applications II, 2000

This paper presents recent advances and case histories of two non-traditional electromagnetic geo... more This paper presents recent advances and case histories of two non-traditional electromagnetic geophysical techniques for oil reservoir characterization, and production/process monitoring. The crosswell electromagnetic induction method has seen rapid advancement since its inception in the early 1990's, and to this date numerous surveys have been completed in active oil fields as well as other sites. Here one example is given where a 2D electrical conductivity image derived from crosswell data is employed for reservoir characterization, and two other examples presented where the method provided valuable insight into the 2- and 3-D progress of water flood operations. The second, less mature method discussed involves 3-D imaging from multi-component induction log data. Here all three components of the magnetic field generated by a single or multiple sources are inverted to produce estimates of the electrical conductivity distribution surrounding the borehole. For this technology an example is given of three component data acquisition in an active oil field, as well as a proof of the 3-D imaging concept on a synthetic data set.

sponsored by an-agency of the United States Government. Neither the United States Government mor ... more sponsored by an-agency of the United States Government. Neither the United States Government mor any agency thereof, nor any of their employeessiakes any warranty, express or implied, i x sssumes any legal liability or responsibility for the accuracy. completeness. or usefulness of any hfonnation, apparatus, product. or process &dosed, or represenk that its use would not infringe privately owned rights. Reference herein to any specific-commerdal product, process, or service by trade &me, trademark, manufacturer, or &erwise, doa not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency tbereof. The vimp and opinions of authors exnecessarily state or reflect tates Government or any GEOTHERMAL EXPLORATION ASSESSMENT AND INTERPRETATION, UPPER KLAMATH LAKE AREA, KLAMATH BASIN, OREGON

Journal of Zhejiang University-SCIENCE A, 2005

In this paper, we describe some recent imaging technologies developed by Schlumberger for oilfiel... more In this paper, we describe some recent imaging technologies developed by Schlumberger for oilfield downhole multiphase flow production logging (PL) and cross-well electromagnetic (EM) survey applications. FloScan Imager (FSI TM) has been introduced as a 3-phase oil/gas/water flow PL tool for deviated and horizontal wells. FSI sensors can map fluid velocity and holdup profiles along a vertical diameter of the wellbore at every survey depth, enabling a robust estimate of the individual phase flow rates in complex flow regimes. The cross-well EM survey is based on cross-borehole induction logging technique and provides resistivity distribution at a reservoir scale. It is a useful tool for reservoir management and is most effective in dynamic fields where fluid saturations are variable in time and space. The tool can be used to identify (water or steam) flooded and bypassed regions. By monitoring changes in the resistivity spatial distribution with time, cross-well EM survey is very effective at mapping inter-well temperature and structure. Some field examples are shown for both FloScan Imager PL tool and cross-well resistivity imaging survey.

The following two letters used as part of the number designating technical reports of research pu... more The following two letters used as part of the number designating technical reports of research published under the Repair. E 'aluation Maintenance, and Rehabilitation (REMR) Research Program identify the problem area under which the report was prepared Problem Area Problem Area CS Concrete and Steel Structures EM Electrical and Mechanical GT Geoiut',iiic'd El Environmental Impacts HY Hydraulics OM Operations Management CO Coastal Destroy this report when no longer needed. Do not return it to the originator The findings in this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. This program is furnished by the Government and is accepted and used by the recipient with the express understanding that the United States Government makes no warranties, expressed or implied, concerning the accuracy, completeness, reliability, usability, or suitability for any particular purpose of the information and data contained in this program or furnished in connection therewith, and the United States shall be under no liability whatsoever to any person by reason of any use made thereof The program belongs to the Government. Therefore, the recipient further agrees not to assert any proprietary rights therein or to represent this program to anyone as other than a Government program. The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products CC>ER PHOTOS TOP I ,nw (of a portion of Beaver Dam. Arkansas MiFJFLE. Concept of mapping anomalous subsurface flow paths P r, 1'O CorT'0ept of self potential generation by fluid flow Unclassified SECURITY CLASSIFICATION OF TH.S PAGE Form Approved REPORT DOCUMENTATION PAGE 0M8No. 0704-0188 la REPORT SECURITY CLASSiFICATION 1b RESTRICTIVE MARKINGS Unclassified 2a SECURITY CLASSIFICATION AUTHORITY 3 DISTRIBUTION /AVAILABILITY OF REPORT Approved for public release; distribution 2b DECLASSIFICATION / DOWNGRADING SCHEDULE unlimited. 4 PERORMING ORGANIZATION REPORT NUMBER(S) S. MONITORING ORGANIZATION REPORT NUMBER(S) Technical Report REMR-GT-6 6a. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7&. NAME OF MONITORING ORGANIZATION See reverse j (If applicable) 6c. ADDRESS (City, State, and ZIP Code) 7b. ADDRESS (City, State, and ZIP Code) See reverse Ba. NAME OF FUNDING,SPONSOR NG 8b OFFICE SYMBOL 9 PROCUREMENT .NSTRuVENT IDENTIFICATION NUMBER ORGANiZATION (If applicable) LS Army Corps of Engi eIrs Bc. ADDRESS (City, State, and ZIP Code, 10 SOURCE OF FUNDING NUMBERS PROGRAM PROJECT TASK WORK UNIT ELEMENT NO. NO. NO.

A Numerical Sensitivity Study Of Three Dimensional Imaging From A Single Borehole

Petrophysics, 2001

Wellbore integrity is of paramount importance to subsurface resource extraction, energy storage a... more Wellbore integrity is of paramount importance to subsurface resource extraction, energy storage and waste disposal. After installation, well casing and cement are subject to mechanical stress due to near-well pressure changes and fluid induced corrosion. This is exacerbated for geothermal wells where produced fluid is at high temperature and corrosive. The current state-of-the-art technologies for wellbore integrity assessments are an array of cased hole logging tools. Wireline deployed acoustic, electromagnetic and mechanical tools are all available to inspect steel casing corrosion and casing-cement bond and these tools can provide high-resolution assessment of borehole conditions. They are intrusive, however, in terms of borehole preparation and interruption to the normal operation of the wells, and not suitable for high temperature or highly deviated well deployments. In addition, these measurements are performed infrequently due to high cost, and are therefore incapable of prov...

Injection of CO2 into the subsurface at industrial-scale can result in significant fluid pressure... more Injection of CO2 into the subsurface at industrial-scale can result in significant fluid pressure increases in the reservoir that if not properly controlled, can lead to potential environmental impacts such as fault activation, leakage through abandoned wells, or caprock fracturing. Brine extraction is one approach for managing formation pressure, effective stress, and plume movement in response to CO2 injection. The management of the extracted brine has a cost that is added to carbon capture and sequestration operations, and therefore minimizing the extraction volume of brine is of great importance. This work presents an integrated adaptive management approach involving monitoring, model calibration, and optimization of brine extraction for pressure control. Knowledge of the subsurface properties is always incomplete, and especially during the planning stages of CO2 projects, very little is known because of often quite limited site characterization data and related uncertainties. T...

Adaptive Pressure Management and Plume Control in Geological Co2 Storage: Designing a Brine Extraction Field Experiment

SSRN Electronic Journal, 2019

Sixteen s h a l l ow and deep c o n t r o l 1 ed source e l ectromagnetic soundings were performe... more Sixteen s h a l l ow and deep c o n t r o l 1 ed source e l ectromagnetic soundings were performed i n Buena V i s t a Valley, near Winnemucca, Nevada, t o investigate an intra-basement conductor previously detected w i t h magnetotell urics. The survey was c a r r i e d o u t with t h e LBL EM-60 system using a remote magnetic reference f o r 1 ow-f requency geomagnetic noise cancel 1 ation, 100-m-and 2.8-km-diameter t r a n s m i t t e r 1 oops, and a minicomputer for i n -f i e l d processing. EM soundings were made a t distances from 0.5 t o 30 km from three loops over t h e frequency range 0.02 t o 500 Hz. Data were i n t e r p r e t e d by means o f 1-D inversions and the r e s u l t i n g layered models were pieced together t o y i e l d an approximate 2-0 geoelectric model along the N-S a x i s o f the valley. The EM soundings and one MT sounding show a 3 t o 7 oh-m zone a t a depth o f four t o seven km. The conductor appears t o be deepest a t the northern end o f the v a l l e y and shallowest beneath a basement r i d g e t h a t seems t o d i v i d e Buena V i s t a Valley i n t o two basinal structures. Similar intra-basement conductors are a1 so reported 50-75 m i l e s south i n the Carson Sink-Fa1 l o n areas, suggesting a comnon source, probably r e l a t e d t o an anomalously hot, t h i n crust.

OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), May 29, 2002

Geo-BILT (Geothermal Borehole Induction Logging Tool) is an extended induction logging tool desig... more Geo-BILT (Geothermal Borehole Induction Logging Tool) is an extended induction logging tool designed for 3D resistivity imaging around a single borehole. The tool was developed for deployment in high temperature geothermal wells under a joint program funded by the California Energy Commission, Electromagnetic Instruments (EMI) and the U.S. Department of Energy. EM1 was responsible for tool design and manufacture, and numerical modeling efforts were being addressed at Lawrence Livermore Laboratory (LLNL) and other contractors. The field deployment was done by EM1 and LLNL. The tool operates at fiequencies from 2 to 42 kHz, and its design features a series of threecomponent magnetic sensors offset at 2 and 5 meters from a three-component magnetic source. Valley site offered an environment where the tool could locate near-well fractures associated with steam development. The Lost Hills field measurements yielded a data set suitable for 3D imaging. The Geo-BLT data corresponded to existing conventional logging data and showed clear indications, in several depth intervals, of near-well 3D structure. Subsequent 3D inversion of these data produced a model consistent with non-planar water flow in specific layers. The Dixie Valley measurements identified structures associated with dike intrusions and water inflow at particular depths. Preliminary analysis suggests these structures are steeply dipping, which is consistent with the geology.

Second International Meeting for Applied Geoscience & Energy

Electromagnetic (EM) geophysical techniques offer the possibility of monitoring subsurface CO2 in... more Electromagnetic (EM) geophysical techniques offer the possibility of monitoring subsurface CO2 in saline reservoirs due to the fact that CO2 has high electrical resistivity compared to the surrounding geologic materials. In this paper we first discuss the underlying physics of two different borehole-based EM monitoring techniques; electrical resistivity tomography (ERT) and crosswell EM. This discussion is followed by the description of an experiment at the Carbon Management Canada CaMI FRS test site where time-lapse single well ERT and crosswell EM data have been acquired to image CO2 injection into a shallow aquifer. Resistivity imaging results from inversion of the two data types separately and jointly will be compared and contrasted, and interpretation of the extent of the injected CO2 provided.

OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), Nov 7, 2021

Wellbore integrity is of paramount importance to subsurface resource extraction, energy storage 1... more Wellbore integrity is of paramount importance to subsurface resource extraction, energy storage 1 and waste disposal. After installation, well casing and cement are subject to mechanical stress due to near-well pressure changes and fluid induced corrosion. This is exacerbated for geothermal wells where produced fluid is at high temperature and corrosive. The current state-of-the-art technologies for wellbore integrity assessments are an array of cased hole logging tools. Wireline deployed acoustic, electromagnetic and mechanical tools are all available to inspect steel casing corrosion and casing-cement bond and these tools can provide high-resolution assessment of borehole conditions. They are intrusive, however, in terms of borehole preparation and interruption to the normal operation of the wells, and not suitable for high temperature or highly deviated well deployments. In addition, these measurements are performed infrequently due to high cost, and are therefore incapable of providing frequent data to better predict borehole degradation trajectory, which can help provide early warning of potential borehole failures. For this project we are developing a suite of novel, non-invasive, casing based tools for wellbore integrity assessment, combining fast/low cost screening with higher-precision investigation. Our approach is based on monitoring the response of the casing when energized at the wellhead, thereby interrogating the casing without well intervention. Lab, field and numerical approaches are used in our study. During the early stage of the research, we focus on numerical simulations, which have shown the sensitivity of the low frequency electromagnetic (EM) signals to changes in borehole depths and have successfully tested the concept at a field site with different length well casings. Initial seismic modeling efforts have also demonstrated our capability to simulate seismic tube wave and seismic field alterations due to borehole breakage and associated fluid leakage. Further numerical, laboratory and field experiments are underway for additional technology sensitivity analysis, particularly the transient EM/Seismic reflectometry methods, data acquisition optimization, and numerical simulation improvements.

SEG Technical Program Expanded Abstracts 2018, 2018

Imaging hydraulically-active fracture zones (HAFZ) is of paramount importance to subsurface resou... more Imaging hydraulically-active fracture zones (HAFZ) is of paramount importance to subsurface resource extraction, geological storage and hazardous waste disposal. We present advanced 3D finite-element (FE) electrical imaging algorithms for HAFZ in the presence of a steel-cased well. The algorithms employ tetrahedral FE meshes in the simulation domain and coarse rectangular finite-difference (FD) meshes in the imaging domain. This heterogeneous dual-mesh approach is well suited to modeling multi-scale earth model due to steel-cased wells. We show that the algorithms accurately and efficiently simulate surface electric field measurements over a 3D HAFZ at depth when one end point of a surface electric source is connected to a wellhead. For brevity, this configuration is called the top-casing electric source method. By replacing a hollow cased well with a solid prism, we improve our computational efficiency without affecting the solution accuracy. The sensitivity of the top-casing source method to HAFZ highly depends on the continuity of a steel-cased well, because it makes currents preferentially flow to HAFZ. The sensitivity also depends on conductivity structures around the well because they control current leaking from the steel-cased well. We show that the method can image a localized HAFZ and detect changes in its width and height. The imaging results are improved when a volume of the imaging domain is constrained from geomechanical perspectives. A primary advantage of the method is the fact that both sources and receivers are placed on the surface, thus not interrupting well operation.

Casing-integrity mapping using top-casing electrodes and surface based EM fields

SEG Technical Program Expanded Abstracts 2018, 2018

Crosswell Electromagnetic Imaging for Subsurface Fluid Monitoring

AGUFM, Dec 1, 2005

Crosswell electromagnetic imaging is an emerging oilfield technology for mapping the resistivity ... more Crosswell electromagnetic imaging is an emerging oilfield technology for mapping the resistivity structure between two wells located tens to hundreds of meters apart. The method employs an electromagnetic dipole source in one well oscillating at 10Hz to 1kHz, and makes measurements of the axial component of the electric or magnetic field in the second well. The use of multiple source

The EM-60 system, a large-moment frequency-domain electromagnetic loop p r o s p e c t i n g syst... more The EM-60 system, a large-moment frequency-domain electromagnetic loop p r o s p e c t i n g system, w a s o p e r a t e d i n t h e Soda Lakes geothermal a r e a , Nevada.

WISE-CASING: Cymric Field, CA Frequency Domain EM Data

Cymric oil field frequency domain electromagnetic (FEM) data with two parts of data labeled Part ... more Cymric oil field frequency domain electromagnetic (FEM) data with two parts of data labeled Part 1 and Part 2. Part 1 utilizes an electrical source line parallel to the receiver line, while Part 2 utilizes an electrical source line at a 75 deg angle to the receiver line. Data are plotted and compared to numerically modeled data to observe electric field response to well structure. In two configuration files are diagrams of the experiment layout.

The depth to surface resistivity (DSR) method transmits current from a source located in a cased ... more The depth to surface resistivity (DSR) method transmits current from a source located in a cased or openhole well to a distant surface return electrode while electric field measurements are made at the surface over the target of interest. This paper presents both numerical modelling results and measured data from a hydraulic fracturing field test where conductive water was injected into a resistive shale reservoir during a hydraulic fracturing operation. Modelling experiments show that anomalies due to hydraulic fracturing are small but measureable with highly sensitive sensor technology. The field measurements confirm the model results, showing that measured differences in the surface fields due to hydraulic fracturing have been detected above the noise floor. Our results show that the DSR method is sensitive to the injection of frac fluids; they are detectable above the noise floor in a commercially active hydraulic fracturing operation, and therfore this method can be used for mo...

The effects of well damage and completion designs on geoelectrical responses in mature wellbore environments

GEOPHYSICS, 2021

Well integrity is one of the major concerns in long-term geologic storage sites due to the potent... more Well integrity is one of the major concerns in long-term geologic storage sites due to the potential risk of well leakage and groundwater contamination. Evaluating changes in electrical responses due to energized steel-cased wells has the potential to quantify and predict possible wellbore failures because any kind of breakage or corrosion along highly conductive well casings will have an impact on the distribution of the subsurface electrical potential. However, realistic wellbore-geoelectrical models that can fully capture fine-scale details of well completion design and the state of well damage at the field scale require extensive computational effort, or they can even be intractable to simulate. To overcome this computational burden while still keeping the model realistic, we have used the hierarchical finite-element method that represents electrical conductivity at each dimensional component (1D edges, 2D planes, and 3D cells) of a tetrahedral mesh. This allows well completion ...

Effects of completion design on electrically stimulated casing and its 3D response

SEG Technical Program Expanded Abstracts 2018, 2018

Improved reservoir characterization and monitoring using electromagnetic geophysical techniques

Subsurface Sensing Technologies and Applications II, 2000

This paper presents recent advances and case histories of two non-traditional electromagnetic geo... more This paper presents recent advances and case histories of two non-traditional electromagnetic geophysical techniques for oil reservoir characterization, and production/process monitoring. The crosswell electromagnetic induction method has seen rapid advancement since its inception in the early 1990's, and to this date numerous surveys have been completed in active oil fields as well as other sites. Here one example is given where a 2D electrical conductivity image derived from crosswell data is employed for reservoir characterization, and two other examples presented where the method provided valuable insight into the 2- and 3-D progress of water flood operations. The second, less mature method discussed involves 3-D imaging from multi-component induction log data. Here all three components of the magnetic field generated by a single or multiple sources are inverted to produce estimates of the electrical conductivity distribution surrounding the borehole. For this technology an example is given of three component data acquisition in an active oil field, as well as a proof of the 3-D imaging concept on a synthetic data set.

sponsored by an-agency of the United States Government. Neither the United States Government mor ... more sponsored by an-agency of the United States Government. Neither the United States Government mor any agency thereof, nor any of their employeessiakes any warranty, express or implied, i x sssumes any legal liability or responsibility for the accuracy. completeness. or usefulness of any hfonnation, apparatus, product. or process &dosed, or represenk that its use would not infringe privately owned rights. Reference herein to any specific-commerdal product, process, or service by trade &me, trademark, manufacturer, or &erwise, doa not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency tbereof. The vimp and opinions of authors exnecessarily state or reflect tates Government or any GEOTHERMAL EXPLORATION ASSESSMENT AND INTERPRETATION, UPPER KLAMATH LAKE AREA, KLAMATH BASIN, OREGON

Journal of Zhejiang University-SCIENCE A, 2005

In this paper, we describe some recent imaging technologies developed by Schlumberger for oilfiel... more In this paper, we describe some recent imaging technologies developed by Schlumberger for oilfield downhole multiphase flow production logging (PL) and cross-well electromagnetic (EM) survey applications. FloScan Imager (FSI TM) has been introduced as a 3-phase oil/gas/water flow PL tool for deviated and horizontal wells. FSI sensors can map fluid velocity and holdup profiles along a vertical diameter of the wellbore at every survey depth, enabling a robust estimate of the individual phase flow rates in complex flow regimes. The cross-well EM survey is based on cross-borehole induction logging technique and provides resistivity distribution at a reservoir scale. It is a useful tool for reservoir management and is most effective in dynamic fields where fluid saturations are variable in time and space. The tool can be used to identify (water or steam) flooded and bypassed regions. By monitoring changes in the resistivity spatial distribution with time, cross-well EM survey is very effective at mapping inter-well temperature and structure. Some field examples are shown for both FloScan Imager PL tool and cross-well resistivity imaging survey.

The following two letters used as part of the number designating technical reports of research pu... more The following two letters used as part of the number designating technical reports of research published under the Repair. E 'aluation Maintenance, and Rehabilitation (REMR) Research Program identify the problem area under which the report was prepared Problem Area Problem Area CS Concrete and Steel Structures EM Electrical and Mechanical GT Geoiut',iiic'd El Environmental Impacts HY Hydraulics OM Operations Management CO Coastal Destroy this report when no longer needed. Do not return it to the originator The findings in this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. This program is furnished by the Government and is accepted and used by the recipient with the express understanding that the United States Government makes no warranties, expressed or implied, concerning the accuracy, completeness, reliability, usability, or suitability for any particular purpose of the information and data contained in this program or furnished in connection therewith, and the United States shall be under no liability whatsoever to any person by reason of any use made thereof The program belongs to the Government. Therefore, the recipient further agrees not to assert any proprietary rights therein or to represent this program to anyone as other than a Government program. The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products CC>ER PHOTOS TOP I ,nw (of a portion of Beaver Dam. Arkansas MiFJFLE. Concept of mapping anomalous subsurface flow paths P r, 1'O CorT'0ept of self potential generation by fluid flow Unclassified SECURITY CLASSIFICATION OF TH.S PAGE Form Approved REPORT DOCUMENTATION PAGE 0M8No. 0704-0188 la REPORT SECURITY CLASSiFICATION 1b RESTRICTIVE MARKINGS Unclassified 2a SECURITY CLASSIFICATION AUTHORITY 3 DISTRIBUTION /AVAILABILITY OF REPORT Approved for public release; distribution 2b DECLASSIFICATION / DOWNGRADING SCHEDULE unlimited. 4 PERORMING ORGANIZATION REPORT NUMBER(S) S. MONITORING ORGANIZATION REPORT NUMBER(S) Technical Report REMR-GT-6 6a. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7&. NAME OF MONITORING ORGANIZATION See reverse j (If applicable) 6c. ADDRESS (City, State, and ZIP Code) 7b. ADDRESS (City, State, and ZIP Code) See reverse Ba. NAME OF FUNDING,SPONSOR NG 8b OFFICE SYMBOL 9 PROCUREMENT .NSTRuVENT IDENTIFICATION NUMBER ORGANiZATION (If applicable) LS Army Corps of Engi eIrs Bc. ADDRESS (City, State, and ZIP Code, 10 SOURCE OF FUNDING NUMBERS PROGRAM PROJECT TASK WORK UNIT ELEMENT NO. NO. NO.

A Numerical Sensitivity Study Of Three Dimensional Imaging From A Single Borehole

Petrophysics, 2001

Wellbore integrity is of paramount importance to subsurface resource extraction, energy storage a... more Wellbore integrity is of paramount importance to subsurface resource extraction, energy storage and waste disposal. After installation, well casing and cement are subject to mechanical stress due to near-well pressure changes and fluid induced corrosion. This is exacerbated for geothermal wells where produced fluid is at high temperature and corrosive. The current state-of-the-art technologies for wellbore integrity assessments are an array of cased hole logging tools. Wireline deployed acoustic, electromagnetic and mechanical tools are all available to inspect steel casing corrosion and casing-cement bond and these tools can provide high-resolution assessment of borehole conditions. They are intrusive, however, in terms of borehole preparation and interruption to the normal operation of the wells, and not suitable for high temperature or highly deviated well deployments. In addition, these measurements are performed infrequently due to high cost, and are therefore incapable of prov...

Injection of CO2 into the subsurface at industrial-scale can result in significant fluid pressure... more Injection of CO2 into the subsurface at industrial-scale can result in significant fluid pressure increases in the reservoir that if not properly controlled, can lead to potential environmental impacts such as fault activation, leakage through abandoned wells, or caprock fracturing. Brine extraction is one approach for managing formation pressure, effective stress, and plume movement in response to CO2 injection. The management of the extracted brine has a cost that is added to carbon capture and sequestration operations, and therefore minimizing the extraction volume of brine is of great importance. This work presents an integrated adaptive management approach involving monitoring, model calibration, and optimization of brine extraction for pressure control. Knowledge of the subsurface properties is always incomplete, and especially during the planning stages of CO2 projects, very little is known because of often quite limited site characterization data and related uncertainties. T...

Adaptive Pressure Management and Plume Control in Geological Co2 Storage: Designing a Brine Extraction Field Experiment

SSRN Electronic Journal, 2019