Page 30 - Formation Damage during Improved Oil Recovery Fundamentals and Applications

Overview of Formation Damage During Improved and Enhanced Oil Recovery 13

1.10 GEOTHERMAL RESERVOIRS

Geothermal energy provides a direct source of heat energy from
within the Earth that can also be exploited for power generation with
potential benefits associated with its reliability, sustainability, abundant
reserve, and low environmental impacts (Glassley, 2010). In recent dec-
ades, the exploitation of geothermal energy has been extensively investi-
gated and exploited in areas with high geothermal gradients, such as
Geysers in California, USA, Rhine Graben in Soultz-sous-Fore ˆts, France,
Landau and Insheim, Germany, and Reykjavı ´k, Iceland (Moore and
Simmons, 2013).
The incompatibility among drilling fluids and formation minerals can
lead to the shrinkage of wellbore due to clay swelling, and also, the reac-
tions of invasion fluids with in-situ reservoir minerals can lead to severe
scaling problems. Also, transporting particles along with leak-off fluids
can result in permeability damage in geothermal reservoirs (Finger and
Blankenship, 2010). The application of enhanced geothermal systems
(EGS) is to improve the efficiency of extracting heat energy by pumping
out injection water after it has become heated in deep high-temperature
reservoirs (Markus et al., 2008). However, EGS has been reported to trig-
ger earthquakes associated with some intensive applications of hydraulic
fracturing (Deichmann et al., 2007). In addition, the migration of fines
and clay swelling in rocks during water injection and recycling can lead
to severe damage to reservoir permeability and consequential decline of
well injectivity and productivity (You et al., 2016).

1.11 DEEPWATER RESERVOIRS

Deepwater and offshore oilfields contribute about 30% of total oil
production over the past decade. In 2015, offshore production reached
29% of total global production, with a moderate decrease from 32% in
2005 (Manning, 2016). Deepwater oilfields under high-rates of depletion
typically demonstrate rapid decline of reservoir pressure as production con-
tinues, leading to significant damage issues including: (1) severe reduction
of permeability and well productivity (Yuan et al., 2016a; Wang et al.,
2018); (2) sands production caused by excessive reservoir compaction due