What did we learn from steam assisted gravity drainage (SAGD) applications in three decades, and what is next?

Nanoparticles Technology for Improving Steam-Assisted Gravity Drainage Process Performance: A Review

“…This lack of enhancement stemmed from the inability of the gases to exhibit a mixing or diffusion effect, unlike other solvents. 19 As Butler 123 and other researchers evidenced, 124−126 the primary mechanisms of NCG involve reducing heat loss and creating a push effect due to the lower density of NCG, positioning it in the upper zone of the reservoir. Bagci et al 127 indicated that NCG at the top of the reservoir enables heat to reach the producing well sooner than steam alone, enhancing oil recovery, and reducing steam consumption.…”

“…Additionally, over time, SAGD operations tend to plateau in terms of production, and even with increased pressure and steam injection, further production enhancements become unattainable. 19 Against this background, recent research has explored potential methodologies to simultaneously enhance operational efficiency, as well as minimize the cumulative steam-oil ratio (cSOR), greenhouse gas emissions, and water disposal. 19 One of the possibly applicable methodologies involves noncondensable gas (NCG) solvent injection, of which 80% of SAGD operations in Canada have implemented this technology.…”

“…19 Against this background, recent research has explored potential methodologies to simultaneously enhance operational efficiency, as well as minimize the cumulative steam-oil ratio (cSOR), greenhouse gas emissions, and water disposal. 19 One of the possibly applicable methodologies involves noncondensable gas (NCG) solvent injection, of which 80% of SAGD operations in Canada have implemented this technology. However, its percentage of success still ranges between 5 and 10%, considering that NCG could produce a pushing mechanism instead of a mixing dissolution effect.…”

“…Among these, SAGD stands out as one of the most widely employed thermal EOR techniques, primarily, due to its high ultimate recovery factor (RF) ranging between 25% and 60% of the OOIP, even reaching levels up to 75% in some special cases, which simultaneously implies a significant reduction of unit costs for field operating labor . In Canada, for instance, SAGD projects play a fundamental role in the oil production and supply, contributing up to 25% of the total oil output, with a production of nearly 1.3 million barrels per day …”

“…In brief, SAGD involves the continuous injection of high-pressure steam into a horizontal well to supply thermal energy, which in turn lowers the oil viscosity. The now-heated well is subsequently drained into a lower well (separated by 5 to 10 m), from which the oil is pumped out. , Thus, SAGD is primarily applied in reservoirs with high vertical permeability and thick pay zones (>15 m) and without thief zones. ,, Nevertheless, some researchers align on the challenges associated with SAGD, ,− which include high operational costs, excessive steam wastage, elevated water-cut production, expensive postproduction water treatment and heat losses, among others. Additionally, over time, SAGD operations tend to plateau in terms of production, and even with increased pressure and steam injection, further production enhancements become unattainable .…”