Page 34: of Offshore Engineer Magazine (Sep/Oct 2015)

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FPSO

Fig. 2: Summary of early life operating conditions

Normal Sensitivity

Parameter SummerWinterSummerWinter

RVP [psia] 8.69.68.6 9.6

Cooler operationg temp [°F] 120120100 100

Advised reboiler operating temp [°F] 315250315 260

Freewater knockout feed ratio [BBL/1000 BBL crude] (Note 1) 323933.544.5

NGL production ratio [BBL NGL/1000 BBL crude] 10 1.5 18 8.5

Stabilized condensate production ratio [BBL stab cond/1000 cond/BBL crude] 10 16.5 10 17.5

Note 1: Ratio re? ects total liquids (water and hydrocarbons) feeding the freewater knockout.

the overhead product. After receiving condensate from a freewater knockout and coalescing ? lters, bottoms product from the stabilizer would feed into the low-pressure separator. This design would ultimately improve compression capabili-

STOP TREADING ties and increase the volume of sales oil that could be recovered. A ? ow diagram of the condensate stabilization system used at Delta House is outlined in Figure 1.

Meeting seasonal RVP speci? cations

WATER

Due to the seasonal changes in oil pipe- line RVP speci? cations, the stabilization system design had to be ? exible enough to meet requirements under various

OUR operating conditions. In the winter (April to September), the system would have to

SOLUTIONS meet an RVP speci? cation of 9.6psi abso- lute (psia). During these months, a higher concentration of C3, C4, and C5 could be present in the sales oil and the tem- perature setpoint for the reboiler could

RUN DEEP be relatively low (250°F) – resulting in higher oil production rates and a lower volume of natural gas liquids (NGL). It was estimated that approximately 16.5

From robust subsea structures to high-precision inspection bbl of stabilized condensate would be systems, Seanic Ocean Systems goes the extra mile to provide produced per every 1000 bbl of crude oil. leading-edge engineered solutions and intervention tooling for

In the summer months (April to your toughest deep water challenges.

September), a crude oil RVP speci? ca- tion of 8.6psia would have to be met. The stabilizer reboiler would operate at 315°F, which would allow for the maximum volume of stabilized condensate to be recombined with the crude before enter- ing the sales line. In these conditions, the system would produce approximately 10 bbl of stabilized condensate per every 1000 bbl of crude oil.

Additional design considerations

Ambient temperatures also had to be considered when implementing the condensate stabilization system on Delta

SEANIC OCEAN SYSTEMS

House. Outside temperature has a direct

INTERVENTION TOOLING • ENGINEERED SOLUTIONS impact on aerial cooler outlet tempera- 8860 Fallbrook Drive 713-934-3100 ture, which in turn has an impact on

Houston, TX 77064 www.seanicusa.com oedigital.com 034_OE0915_Feat3_Audubon.indd 36 8/19/15 8:02 PM