scholarly journals Gravity monitoring of C O2 movement during sequestration: Model studies

Geophysics ◽  
2008 ◽  
Vol 73 (6) ◽  
pp. WA105-WA112 ◽  
Author(s):  
E. Gasperikova ◽  
G. M. Hoversten
Keyword(s):  
Oil Recovery ◽  
Vertical Section ◽  
Vertical Component ◽  
Time Lapse ◽  
Surface Gravity ◽  
Coal Bed ◽  
Change Analysis ◽  
Model Studies ◽  
Gravity Response ◽  
Gravity Measurements

Sequestration/enhanced oil recovery (EOR) petroleum reservoirs have relatively thin injection intervals with multiple fluid components (oil, hydrocarbon gas, brine, and carbon dioxide, or [Formula: see text]), whereas brine formations usually have much thicker injection intervals and only two components (brine and [Formula: see text]). Coal formations undergoing methane extraction tend to be thin [Formula: see text] but shallow compared to either EOR or brine formations. Injecting [Formula: see text] into an oil reservoir decreases the bulk density in the reservoir. The spatial pattern of the change in the vertical component of gravity [Formula: see text] is correlated directly with the net change in reservoir density. Furthermore, time-lapse changes in the borehole [Formula: see text] clearly identify the vertical section of the reservoir where fluid saturations are changing. The [Formula: see text]-brine front, on the order of [Formula: see text] within a [Formula: see text]-thick brine formation at [Formula: see text] depth with 30% [Formula: see text] and 70% brine saturations, respectively, produced a [Formula: see text] surface gravity anomaly. Such an anomaly would be detectable in the field. The amount of [Formula: see text] in a coal-bed methane scenario did not produce a large enough surface gravity response; however, we would expect that for an industrial-size injection, the surface gravity response would be measurable. Gravity inversions in all three scenarios illustrate that the general position of density changes caused by [Formula: see text] can be recovered but not the absolute value of the change. Analysis of the spatial resolution and detectability limits shows that gravity measurements could, under certain circumstances, be used as a lower-cost alternative to seismic measurements.

The State of the Art in Monitoring and Surveillance Technologies for IOR, EOR and CCUS Projects

2021 ◽  
Author(s):  
Abdulaziz S. Al-Qasim ◽  
Sunil L. Kokal ◽  
Muataz S. Al-Ghamdi
Keyword(s):  
Best Practices ◽  
Oil Recovery ◽  
Time Lapse ◽  
Migration Flow ◽  
Improved Oil Recovery ◽  
Novel Technologies ◽  
Gravity Measurements ◽  
Gas Flooding ◽  
Monitoring And Surveillance ◽  
Project Objectives

Abstract Monitoring and surveillance (M&S) is one of the key requisites for assessing the effectiveness and success of any Improved Oil Recovery (IOR) or Enhanced Oil Recovery (EOR) project. These projects can include waterflooding, gas flooding, chemical injection, or any other types. It will help understand, track, monitor and predict the injectant plume migration, flow paths, and breakthrough times. The M&S helps in quantifying the performance of the IOR/EOR project objectives. It provides a good understanding of the remaining oil saturation (ROS) and its distribution in the reservoir during and after the flood. A comprehensive and advanced monitoring and surveillance (M&S) program has to be developed for any given IOR/EOR project. The best practices of any such M&S program should include conventional, advanced and emerging novel technologies for wellbore and inter-well measurements. These include advanced time-lapse pulsed neutron, resistivity, diffusion logs, and bore-hole gravity measurements, cross-well geophysical measurements, water and gas tracers, geochemical, compositional and soil gas analyses, and 4D seismic and surface gravity measurements. The data obtained from the M&S program provide a better understanding of the reservoir dynamics and can be used to refine the reservoir simulation model and fine tune its parameters. This presentation reviews some proven best practices and draw examples from on-going projects and related novel technologies being deployed. We will then look at the new horizon for advanced M&S technologies.

Advanced Reservoir Monitoring Technologies for IOR/EOR: An Overview

2021 ◽  
Author(s):  
Abdulaziz S. Al-Qasim ◽  
Sunil Kokal
Keyword(s):  
Best Practices ◽  
Oil Recovery ◽  
Time Lapse ◽  
Migration Flow ◽  
Improved Oil Recovery ◽  
Novel Technologies ◽  
Gravity Measurements ◽  
Monitoring And Surveillance ◽  
Monitoring Technologies ◽  
Project Objectives

Abstract Monitoring and surveillance (M&S) is one of the key requisites for assessing the effectiveness and success of any Improved Oil Recovery (IOR) or Enhanced Oil Recovery (EOR) project. These projects can include waterflooding, gas flooding, chemical injection, or any other types. It will help understand, track, monitor and predict the injectant plume migration, flow paths, and breakthrough times. The M&S helps in quantifying the performance of the IOR/EOR project objectives. It provides a good understanding of the remaining oil saturation (ROS) and its distribution in the reservoir during and after the flood. A comprehensive and advanced monitoring and surveillance (M&S) program has to be developed for any given IOR/EOR project. The best practices of any such M&S program should include conventional, advanced and emerging novel technologies for wellbore and inter-well measurements. These include advanced time-lapse pulsed neutron, resistivity, diffusion logs, and bore-hole gravity measurements, cross-well geophysical measurements, water and gas tracers, geochemical, compositional and soil gas analyses, and 4D seismic and surface gravity measurements. The data obtained from the M&S program provide a better understanding of the reservoir dynamics and can be used to refine the reservoir simulation model and fine tune its parameters. This presentation reviews some proven best practices and draw examples from on-going projects and related novel technologies being deployed. We will then look at the new horizon for advanced M&S technologies.

Estimating saturation and density changes caused by CO2 injection at Sleipner — Using time-lapse seismic amplitude-variation-with-offset and time-lapse gravity

2017 ◽  
Vol 5 (2) ◽  
pp. T243-T257 ◽  
Author(s):  
Martin Landrø ◽  
Mark Zumberge
Keyword(s):  
Gravity Data ◽  
Time Lapse ◽  
Co2 Injection ◽  
Injection Point ◽  
Amplitude Variation With Offset ◽  
Seismic Method ◽  
Seismic Amplitude ◽  
Gravity Measurements ◽  
Measured Time ◽  
Best Fit

We have developed a calibrated, simple time-lapse seismic method for estimating saturation changes from the [Formula: see text]-storage project at Sleipner offshore Norway. This seismic method works well to map changes when [Formula: see text] is migrating laterally away from the injection point. However, it is challenging to detect changes occurring below [Formula: see text] layers that have already been charged by some [Formula: see text]. Not only is this partly caused by the seismic shadow effects, but also by the fact that the velocity sensitivity for [Formula: see text] change in saturation from 0.3 to 1.0 is significantly less than saturation changes from zero to 0.3. To circumvent the seismic shadow zone problem, we combine the time-lapse seismic method with time-lapse gravity measurements. This is done by a simple forward modeling of gravity changes based on the seismically derived saturation changes, letting these saturation changes be scaled by an arbitrary constant and then by minimizing the least-squares error to obtain the best fit between the scaled saturation changes and the measured time-lapse gravity data. In this way, we are able to exploit the complementary properties of time-lapse seismic and gravity data.

scholarly journals Analysis of geomagnetic measurements prior the Maule (2010), Iquique (2014) and Illapel (2015) earthquakes, in the Pacific Ocean sector of the Southern Hemisphere

2019 ◽  
Author(s):  
Enrique G. Cordaro ◽  
Patricio Venegas-Aravena ◽  
David Laroze
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Field ◽  
Seismic Event ◽  
Vertical Component ◽  
Time Lapse ◽  
Radial Component ◽  
Cumulative Number ◽  
Research Groups ◽  
Low Frequencies ◽  
Ocean Sector

Abstract. It has been possible to detect variations in the vertical component of the geomagnetic field (Bz) through its first and second derivate in a range of frequencies (microHz); these seem to be roughly related with some major seismic subduction events. We studied the period 2010–2015, analysing the daily values of magnetic records over periods close to the last three significant events that occurred through the Chilean margin, i. e., along a boundary between convergent plates that is characterized by the occurrence of seismic events of magnitude greater than Mw8. These are the events of Iquique 2014, Illapel 2015 and Maule 2010, all at different latitudes, on different dates and characterized by different types of margin (erosive or accretionary). Certain similarities were found in the associated magnetic field variations: 1) Variation in the radial or z component of the geomagnetic field and its first and second temporal derivative, modelled as a small jump, and small oscillations in the second derivative, generating a frequency band between 1c / 48.9 hours and 1c / 79.13 Hrs. 2) A variable time lapse of between 30 and 120 days; and 3) The seismic event. Furthermore, when analysing spectrograms for the second temporal derivate of the radial component, different behaviour is found related to its spectral density. This takes the form of an increase in ultra-low frequencies (0.01–0.4 mHz) between the start of the magnetic jump and the seismic event. These frequencies are lower than those found during the last years by research groups that related magnetic field and earthquakes, furthermore the concept of time lapse close to 30 days is in agreement with those research groups. The previous analyses may not be so robust, this is why additionally a new method is used with stations closer to the events and time periods of two years. We analysed the daily cumulative number of anomalous behaviour in z component of magnetic field on ground based magnetometers. The results show an increase in the number of magnetic anomalies prior to the occurrence of the three earthquakes. The behavior of the anomalies is similar to those presented by other authors for other earthquakes with similar methods in ionosphere. All this magnetic features might recover seismic information of the events and could be related with Lithosphere-Atmosphere-Ionosphere Coupling.

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