Igor V. Haljasmaa

Dynamic morphology of gas hydrate on a methane bubble in water: Observations and new insights for hydrate film models

Predicting the fate of subsea hydrocarbon gases escaping into seawater is complicated by potential formation of hydrate on rising bubbles that can enhance their survival in the water column, allowing gas to reach shallower depths and the atmosphere. The precise nature and influence of hydrate coatings on bubble hydrodynamics and dissolution is largely unknown. Here we present high-definition, experimental observations of complex surficial mechanisms governing methane bubble hydrate formation and dissociation during transit of a simulated oceanic water column that reveal a temporal progression of deep-sea controlling mechanisms. Synergistic feedbacks between bubble hydrodynamics, hydrate morphology, and coverage characteristics were discovered. Morphological changes on the bubble surface appear analogous to macroscale, sea ice processes, presenting new mechanistic insights. An inverse linear relationship between hydrate coverage and bubble dissolution rate is indicated. Understanding and incorporating these phenomena into bubble and bubble plume models will be necessary to accurately predict global greenhouse gas budgets for warming ocean scenarios and hydrocarbon transport from anthropogenic or natural deep-sea eruptions.

Integrating velocity measurements in a reservoir rock sample from the SACROC unit with an AVO proxy for subsurface supercritical CO2

One of the most promising methods proposed to mitigate global CO2 and one that is useful in enhanced oil recovery is carbon sequestration, a process in which CO2 is pressurized and injected into geologic formations. A technical challenge surrounding the geologic sequestration of CO2 is tracking the movement of the fluids pumped underground. Monitoring, verification, and accounting activities related to CO2 storage are important for assuring that any sequestered CO2 does not escape to the surface and can be considerably aided by reflection seismic-based detection methods. Through the use of lab-scale velocity measurements under in-situ conditions, combined with multiple 3D reflection seismic surveys, we hope to effectively track the movements of CO2 after injection.

Control of a fluid particle under simulated deep-ocean conditions in a high-pressure water tunnel

An apparatus that permits the observation of liquid CO2 particles in a simulated deep-ocean environment was designed, modeled, constructed, and tested. Analysis concerning the vertical stability and control of the fluid particle in a countercurrent flow loop is presented. The vertical position of the particle was found to vary due to the gradual dissolution of the CO2 into the water and various other random effects. Using linearized equations for spherical particle motion in the fluid flow, a second-order dynamic equation is derived and analyzed. The servocontrol system consists of a video system that digitizes particle position in a viewing window and a centrifugal pump that can control the speed of the countercurrent flow in order to maintain the particle within the observation window of a charge-coupled device camera. Currently, the system is being used to obtain information on the dissolution behavior of CO2 in seawater at various conditions of pressure and temperature that simulate ocean depths down ...