Reduction of Contaminants in Soil and Water By Direct Electric Current - Electrokinetics for Petroleum and Environmental Engineers - page 89

3000 300

Oil Parain

2500

250

2000

200

1500

150

1000

100

500 50

0 0

0 50 100 150

Time (days)

Figure 2.43 Oil and paraffin production (Pennsylvania field)(Ghazanfari, 2013)

with Pennsylvania oil where white -colored foam like material was formed
in the catholyte, identified as paraffin.
Examining the daily production data, it was determined that when the
applied current was reversed, the production of paraffin decreased. This
is attributable to the counter current flow resulting in decreased oil pro-
duction and lowering of the pH at the well. Lower pH and less oil avail-
able at the location would potentially reverse the paraffin production. The
increase in paraffin production corresponded to the periods of elevated
temperature due to sustained power over long term (~ at 100 days), or
when the maximum power of 29 kW was applied (~ at 150 days). As
observed from Figure 2.43, at times of increased paraffin production, the
oil production decreased or completely ceased. Among some of the plau-
sible reasons for this exchange are: the easier transport of existing paraffin
in the pore space at elevated temperatures, and the increased availability
of oil and mineral components to form paraffin under elevated tempera-
ture and power.

2.4.3 Laboratory Evidence of Oil Transformation

The electrochemical reactions result in reduction of the interfacial ten-
sion between the formation water and crude oil, as well as reduction in
the viscosity of the crude oil. It is postulated that both phenomena eventu-
ally lead to increased oil mobility and serve to enhance the oil recovery