Mapping Reservoir Volume Changes During Cyclic Steam Stimulation Using Tiltmeter-Based Surface Deformation Measurements

Subsidence in the Dutch Wadden Sea

“…Some early attempts to use inverse modelling to relate surface movement data to reservoir properties employed linear forward models and no prior knowledge of the reservoir pressure distribution (Mossop & Segall, 1999;Du & Olson, 2001;Dusseault & Rothenburg, 2002;Fokker, 2002;Du et al, 2008). In these studies, the investigators typically reverted to regularisation methods such as smoothness constraints to handle the ill-conditioning that results from compaction having a large radius of influence on surface movement.…”

Carbon Dioxide Geological Storage: Monitoring Technologies Review

“…Surface deformation monitoring technologies are based on measuring this displacement (swelling and shrinkage) for the purpose of monitoring (Davis & Marsic, 2010a;Sweatman & McColpin, 2009 synthetic aperture radar (InSAR), surface tiltmeters, and differential global positioning system (DGPS). InSAR is used to provide periodic updates of the ground deformation within a typical coverage area about 10,000 km 2 by imaging large swaths of the earth's surface (Davis & Marsic, 2010a;Davis et al, 2008;Du et al, 2005;Kherroubi et al, 2009;Lewicki et al, 2009;Sweatman & McColpin, 2009). Tiltmeter is built with a highly sensitive electrolytic bubble level to measure tilt movements in a one nanoradian of radian level.…”

Numerical Modeling and Field Monitoring of Overburden Response during Geologic Sequestration

“…Tiltmeters are the most sensitive available technology to map any surface or sub-surface elevation changes. A tiltmeter is very sensitive tool designed to record any changes in surface or subsurface tilts with abilities to measure tilts up to one nanoradian Du et al, 2008). A tilt changes of up to one nanoradian could be equivalent to measuring a quarter inch between New York and San Francisco as reported elsewhere (www.Pinntech.com).…”

“…represents a part of the total volumetric strain proposed by Segall (1985). The volumetric strain is proportional to the mean stress and change in mass of the pore fluid as expressed in Equation (4.5) (Segall, 1985): (4 Moreover, inversion models are needed to estimate volumetric changes in the reservoir (Vasco, 1998;Du et al, 2007;Du et al, 2008;Walser, 2008;Walser et al, 2009). The first step is to discretize the reservoir into a number of blocks.…”

“…and Equation 4.4) are numerically integrated over each discretized block to compute surface displacements and surface tilts (Vasco, 1998;Du et al, 2007;Du et al, 2008;Walser, 2008;Walser et al, 2009). Surface displacements are then computed based on the inversion process and superimposed on the surface deformations caused due to changes in the pore fluid volume.…”