Clean disposal of well effluent
Heavy oil production is linked with frontier exploration risks, lower
gas costs, and low pricing differentials, but its high viscosity poses a
challenge to efficient completion. One contractor with a heavy oil well in
Saudi Arabia was facing this challenge but was unable to find a way to process
and measure flow data with accuracy and burn the oil effluent properly. The
well’s environment had an extremely low gas rate, a low contrast of
liquid density, and the instability of the well led to carryover and
carryunder, contaminating the different effluents after separation. Without an
efficient alternative to traditional heavy oil burners, the operator risked
inefficient burning, fallouts, and large plumes of black smoke.
Minimize smoke and risk of fallout
After consulting with the operator, Schlumberger proposed the use of the
EverGreen effluent burner, which was specifically designed to minimize
environmental damage while efficiently burning effluents. Due to the high
viscosity of the oil, Schlumberger modified the operator’s original well
test workflow to bring the viscosity within a range suitable to process, burn,
and measure the effluent with efficiency.
In the operator’s environment, recirculating the heavy oil in
tanks prefilled with diesel while heating the mixture at strategic points can
significantly enhance final results by reducing viscosity. Following the
workflow proposed by Schlumberger, the operator recirculated its heavy oil with
diesel and slowly aligned the flow to a burner, returned the rest to the tank,
and alternated between the left and right sides of the skimmer. This was
repeated until the trial concluded.
Lower viscosity and environmental impact
The trial test was completed successfully, and the operator noted the benefits of the recirculating procedure used in conjunction with the EverGreen burner. The operator was able to burn effluent with high efficiency while preserving environmental awareness in their heavy oil test. Viscosity levels of the heavy oil were successfully lowered to fit the burner envelope, the effluent was burned with higher efficiency, and both environmental damage and the risk of heavy oil cooldown was minimized.