Feasibility of time-lapse gravity and gravity gradiometry monitoring for steam-assisted gravity drainage reservoirs

Abstract

There is presently an increased need to monitor production efficiency as heavy oil reservoirs become more economically viable. We present a feasibility study of monitoring steam-assisted gravity drainage (SAGD) reservoirs using time-lapse gravimetry and gravity gradiometry. Even though time-lapse seismic has historically shown great success for SAGD monitoring, the gravimetry and gravity gradiometry methods offer a low-cost interseismic alternative that can complement the seismic method, increase the survey frequency, and decrease the cost of monitoring. In addition, both gravity-based methods are directly sensitive to the density changes that occur as a result of the replacement of heavy oil by steam. Advances in technologies have made both methods viable candidates for consideration in time-lapse reservoir monitoring, and we have numerically evaluated their potential application in monitoring SAGD production. The results indicate that SAGD production should produce a strong anomaly for both methods at typical SAGD reservoir depths. However, the level of detail for steam-chamber geometries and separations that can be recovered from the gravimetry and gravity gradiometry data is site dependent. Gravity gradiometry shows improved monitoring ability, such as better recovery of nonuniform steam movement due to reservoir heterogeneity, at shallower production reservoirs. Gravimetry has the ability to detect SAGD steam-chamber growth to greater depths than does gravity gradiometry, although with decreasing resolution of the expanding steam chambers.

Identification of Natural and Technogenic Decompacted Zones in the Worked-Out Massif Based on High-Precision Gravimetric Observations

“…Весьма эффективно применение гравиметрических данных для изучения карстовых явлений (Пугин и др., 2014;Eppelbaum et al, 2008;Jacob et al, 2009: Rybakov et al, 2001. Большой объем повторных наблюдений проводится на месторождениях нефти и газа, где гравиметрические данные используются для определения изменений пластового давления и оценки подъема нефте-и газо-водяного контакта (Андреев и др., 2012;Каленицкий, Ким, 2012;Паровышный и др., 2005;Gelderen et al, 1999;Glegola et al, 2015;Reitz et al, 2015;Gasperikova, Hoversten, 2008). Исследования оседаний земной поверхности и развития подземных полостей по гравиметрическим данным над соляными шахтами осуществляется в Великобритании (Branston, Styles, 2002;Styles et al, 2006Styles et al, ) и Украине (Багрій и др., 2016Дубовенко, Черная, 2011;Tsiupiak et al, 2019).…”

Feasibility of 4D Gravity Monitoring in Deep-Water Turbidites Reservoirs

“…Several studies performed all over the world in the last two decades show the efficiency of the seafloor 4D gravity technique. These include feasibility studies, survey improvements, time-lapse gravity processing, application of inversion methods, use of borehole and gravity gradiometry information, and real data interpretation [7,[10][11][12]16,17,[19][20][21][22][23][24][25][26][27].…”

Feasibility of electromagnetic methods to detect and image steam-assisted gravity drainage steam chambers

“…Other methods to monitor steam flooding include temperature measurements (Krawchuk et al, 2006), pressure logging, and resistivity logging (Ranganayaki et al, 1992). Gravity has been used for waterflood monitoring in a reservoir (Ferguson et al, 2008) and investigated for SAGD use by Reitz et al (2015). Electrical and electromagnetic (EM) methods have a large presence in fluid monitoring (e.g., LaBrecque et al, 1996;Oldenborger et al, 2007).…”